Sintering Performance of Brockman s Marillana Fines Sample

Transcription

1 Sintering Performance of Brockman s Marillana Fines Sample Wang Zhihua, Li Guangsen, Teng Fei August Xueyuan Nanlu, Haidian District, Beijing, China Sintering Performance of Brockman s Marillana Fines Sample August 2013

2 Enquiries should be addressed to: Wang Zhihua Senior Engineer Ironmaking Technology Engineering Department New Metallurgy Hi-Tech Group Co., Ltd No.76 Xueyuan Nanlu, Haidian district, Beijing, China, Tel: Fax: Mob: Sintering Performance of Brockman s Marillana Fines Sample August 2013

3 TABLE OF CONTENTS SUMMARY INTRODUCTION Background Objectives WORK PROGRAMME AND METHODOLOGY Raw Materials Preparation and Assessment Pilot-scale Sintering Test General Approach to Pot Grate Sintering Pot Grate Sintering Test Procedure Sinter Mix Preparation Firing Shatter Treatment and Sampling Sintering Parameters - Definitions (where applicable, see Appendix A for formulae) Sintering Test Conditions and Performance/Quality Targets Sintering Test Conditions Performance and Quality Targets CHARACTERISATION OF RAW MATERIALS Chemical Analysis of Raw Materials Moisture and Size Distribution of Raw Materials Summary SINTERING PERFORMANCE OF BLENDS WITH MARILLANA FINES Series 1 (Inland Mills) Substituting Marillana fines for PB fines Substituting Marillana fines for FMG Rocket fines Substituting Marillana fines for Yandi fines Substituting Marillana fines for Robe River fines Substituting Marillana fines for Yandi fines and Robe River fines Series 3 (Inland Mills) Series 2 (Coastal Mills) Substitute Marillana fines for FMG Rocket fines Substitute Marillana fines for Newman fines Substitute Marillana fines for Yandi fines Substitute Marillana fines for PB fines SINTER CHEMICAL ANALYSIS Sintering Performance of Brockman s Marillana Fines Sample August 2013

4 6. METALLURGICAL PROPERTIES Reducibility Index Low temperature reduction degradation index Softening and melting property of sinters ANALYSIS OF MINERAL COMPOSITION & MICROSTRUCTURE Mineral composition Microstructure of Sinter SUMMARY OF TEST RESULTS UNDER OPTIMUM CONDITIONS FOR ALL BLENDS CONCLUSION Characteristics of Marillana fines Sintering performance of Marillana fines LIST OF APPENDICES APPENDIX A APPENDIX B APPENDIX C Definitions of sintering parameters Summary tables for sintering test results Detailed results of RI, RDI and softening and melting properties Sintering Performance of Brockman s Marillana Fines Sample August 2013

5 LIST OF FIGURES Figure 2-1 Flow chart of pot sintering test and associated tests 10 Figure 3-1 Comparisons between the Marillana fines sample and other 16 Australian fines based on their Al 2 O 3, SiO 2, S, P and LOI at 900 Figure 3-2 The size distribution of iron ore fines used in this programme 18 Figure 3-3 Comparison of the size distribution of Marillana fines with other 18 Australian fines. Figure 4-1 Comparison of sintering results for blends 1, 2, 3 and 7 24 Figure 4-2 Comparison of sintering results for blends 1 and Figure 4-3 Comparison of sintering results for blends 1 and 4 26 Figure 4-4 Comparison of sintering results for blends 1 and 5 27 Figure 4-5 Comparison of sintering results for blends 1 and 6 28 Figure 4-6 Comparison of sintering results for blends 1 12 and Figure 4-7 Comparison of sintering results for blends 8 and 9 30 Figure 4-8 Comparison of sintering results for blends 8 & 9 with higher mix 31 moisture Figure 4-9 Comparison of sintering results for blends 8 & 9 with higher mix 32 moisture and same fixed carbon rate Figure 4-10 Comparison of sintering results for blends 8 & Figure 4-11 Comparison of sintering results for blends 8 & 10 with higher 34 mix moisture Figure 4-12 Comparison of sintering results for blends 8 and Figure 4-13 Comparison of sintering results for blends 8 and 11 with higher 36 mix moisture Figure 4-14 Comparison of sintering results for blends 8 and Figure 6-1 Reducibility of each blend 40 Figure 6-2 Low-temperature reduction degradation index of each blend 41 Photo 7-1 Microstructure of sinter (A) 46 Photo 7-2 Microstructure of sinter (B) 46 Photo 7-3 Microstructure of sinter (C) 47 Photo 7-4 Microstructure of sinter (D) 47 Figure 7-1 Sinter mineralogy of each blend 49 Sintering Performance of Brockman s Marillana Fines Sample August 2013

6 LIST OF TABLES Table 1-1 Ore blends studied 5 Table 3-1 Chemical Analysis of Raw Materials for Sinter Test 15 Table 3-2 Moisture and size distribution of dry screen (%) 17 Table 4-1 Details of mixtures for all blends under the optimum conditions 21 Table 4-2 Sinter pot test results for all blends under the optimum conditions 22 Table 4-3 Size distribution of product sinter for all blends under the optimum 23 conditions Table 5-1 Sinter chemical analysis of each blend 38 Table 6-1 Reducibility index of each blend 39 Table 6-2 Low-temperature reduction degradation index of each blend 41 Table 6-3 Softening and melting performance for each blend 42 Table 7-1 Mineral composition of each blend 48 Table 8-1 Summary of test results under optimum conditions for all Blends 50 Sintering Performance of Brockman s Marillana Fines Sample August 2013

7 SUMMARY For this testwork programme, there are three series or fifteen ore blends, which were tested at CISRI s laboratory to evaluate the sintering performance of Brockman s Marillana fines sample. Series 1 (Blends 1-7 and 14): The sinter blends for inland mills of China typically consist of several Australian fines, Brazilian fines and a high level of domestic concentrate. Based on this blend, substituting Marillana fines for other Australian fines was recommended. Series 2 (Blends 8-11 and 15): The sinter blends for coastal mills of China typically consist of several Australian fines, Brazilian fines and a low level of domestic concentrate. Based on this blend, substituting Marillana fines for other Australian fines was recommended. Series 3 (Blends 12-13): Blend 12 removes some coarse materials compared to blend 1. Blend 13 introduces 20% of Marillana fines to replace the Newman fines. Chemical characteristics Marillana fines have a low LOI content of 1.94%, a moderate Fe grade of 61.24% and relatively high SiO 2 and Al 2 O 3 contents of 5.85 and 3.25% respectively. The P and S contents of the Marillana fines were within the acceptable limits of steel mills. Size distribution Marillana fines sample was extremely coarse, consisting of 59.28% +2 mm material as potential nuclei, 39.85% mm intermediate particles and only about 0.87% mm material as potential adhering fines. Due to the high proportion of coarse +2 mm particles and the extremely low proportion of mm particles, the addition of Marillana fines has increased the mean particle size of the ore blends. Sintering performance 1) For Series 1, as PB fines were replaced by Marillana fines at substitution rates of 10, 20 and 25%, the productivity increased from to t/m 2 d and the fuel rate decreased from to kg/t. The tumble index of blend 1 and 2 are similar at 69.9 and 69.7% respectively. When the amount of Marillana fines is increased to 20% and the fuel rate decreases to kg/t, the tumble index decreases slightly to 68.6%. When the amount of Marillana fines is increased to 25%, the tumble index decreases to 67.67%. 2) When substituting 10% Marillana fines for 10% of FMG Rocket fines in base blend 1, the productivity increases from to t/m 2 d and the fuel rate decreases by approximately 5 kg/t from to kg/t. The Sintering Performance of Brockman s Marillana Fines Sample August

8 tumble index is similar to the base blend at 69.4%. 3) When substituting 15% Marillana fines for 15% of Yandi fines in base blend 1, the productivity increases from to t/m 2 d and the fuel rate decreases by approximately 4 kg/t from to kg/t. The tumble index decreases slightly to 68.47%. 4) When substituting 10% Marillana fines for 10% of Robe River fines in base blend 1, the productivity increases from to t/m 2 d and the fuel rate decreases by approximately 4 kg/t from to kg/t. The tumble index is almost the same as base blend 1 at 69.74%. 5) When substituting 25% Marillana fines for 15% Yandi fines and 10% Robe River fines in base blend 1, the productivity increases from to t/m 2 d and the fuel rate decreases by approximately 4 kg/t from to kg/t. The tumble index is similar to base blend 1 at 69.20%. 6) For Series 3, blend 12 removes some coarse materials compared to blend 1 by substituting Newman fines. Therefore blend 12 consists of 25% PB fines, 10% Yandi fines, 5% FMG Rocket fines, 20% Newman fines, 10% SSF fines and 30% domestic magnetite concentrate and is the base blend for Series 3. It was anticipated that the productivity for blend 12 may be lower than blend 1 due to the finer blend; however, this did not prove to be the case. Blend 12 and blend 1 productivities were and t/m 2 d respectively. Blend 13 introduces 20% of BIPL Marillana fines to replace Newman fines in base blend 12 and the productivity increases from to t/m 2 d, the fuel rate is similar and the tumble index decreases from 69.60% to 68.84%. 7) Series 2 includes five ore blends (Blend 8-11 and 15) which were based on the typical sinter blend for coastal mills of China. Blend 8 is the base blend. When substituting 15% Marillana fines for 15% FMG Rocket fines, the productivity increases from to t/m 2 d, the fuel rate decreases by 0.9 kg/t from to kg/t and the tumble index is almost the same as blend 8 at 67.77%. When substituting 15% Marillana fines for 15% Newman fines, the productivity increases from to t/m 2 d, the fuel rate decreases by approximately 4 kg/t from to kg/t and the tumble index decreases from 67.80% to 66.0%. When substituting 15% Marillana fines for 15% Yandi fines, the productivity increases from to t/m 2 d, the fuel rate decreases approximately 4 kg/t from to kg/t and the tumble index decreases from 67.80% to 66.50%. When substituting 15% Marillana fines for 15% PB fines, the productivity increases from to t/m 2 d, the fuel rate decreases about 4 kg/t from Sintering Performance of Brockman s Marillana Fines Sample August

9 64.98 to kg/t and the tumble index is almost the same as blend 8 at 67.90%. 8) Sinter Chemistry: Because of the higher SiO 2 and Al 2 O 3 content of Marillana fines, the Fe grade of the Marillana sinter products decreased slightly and the SiO 2 and Al 2 O 3 content increased slightly. In terms of other contaminants, such as P, the differences for the various sinter products are negligible. 9) The Reducibility Index (RI) for all blends is high (i.e. >85%), which is regarded as being very good. The Series 1 blends (inland mills) had a lower RI, ranging from % versus base blend 1 of 91.34%; Series 2 blends (coastal mills) were higher, ranging from % versus base blend 8 of 85.44%; and the Series 3 blend (inland mills) was higher at 92.64% versus base blend 12 of 84.33%. 10) The Reduction Degradation Index (RDI) for all blends was above the nominal target of 35%. The Series 1 blends were mixed, ranging from % versus base blend 1 of 38.73%; Series 2 blends were lower, ranging from % versus base blend 8 of 41.6%; and the Series 3 blend was higher at 42.43% versus base blend 12 of 35.41%. 11) The Softening and Melting properties for Series 1 blends are generally similar, and the comprehensive melting property (S value) improves slightly (i.e. is lower) when substituting Marillana fines for other Australian iron ores. The softening and melting properties for Series 2 blends are also similar, while the S value for the Series 3 blend is higher. 12) The Mineral Composition and Microstructure of the fifteen blends are very similar as a typical high basicity sinter. Magnetite is the dominant ferrous mineral of sinter followed by hematite with calcium ferrites, the main bonding phase. These ferrites appear mainly in the form of platelike CaO Fe 2 O 3, acicular SFCA, and small amounts of CaO 2Fe 2 O 3. The rest of the bonding minerals are glass, β-2cao SiO 2, and small amounts of melilite and periclase. The microstructure of the sinters is a heterogeneous structure, which includes ferrous minerals bonded by interlocking platelets and acicular calcium ferrite; and ferrous minerals bonded by glass, β-2cao SiO 2 and melilite, the relict structure of hematite. Sintering Performance of Brockman s Marillana Fines Sample August

10 1. INTRODUCTION 1.1 Background CISRI was engaged by Brockman Iron Pty Ltd (BIPL) to conduct a sintering testwork programme to evaluate the granulating and sintering performance of their Marillana fines product. 1.2 Objectives The aim of the test programme is to understand the sintering performance of Marillana fines based on the sinter blends of Chinese sinter mills. For this testwork programme, there are three series or fifteen ore blends, which were tested at CISRI s laboratory. The test blends are detailed in Table 1-1. Series 1 (Blends 1-7 and 14,): The sinter blends for inland mills of China typically consist of several Australian fines, Brazilian fines and a high level of domestic concentrate. Based on this blend, substituting Marillana fines for other Australian fines was recommended. Series 2 (Blends 8-11 and 15): The sinter blends for coastal mills of China typically consist of several Australian fines, Brazilian fines and a low level of domestic concentrate. Based on this blend, substituting Marillana fines for other Australian fines was recommended. Series 3 (Blends 12-13): Blend 12 removes some coarse materials compared to blend 1. Productivity is expected to be lower for blend 12 than blend 1. Blend 13 introduces 20% of Marillana fines to replace the Newman fines. The aim of the pot grate tests was to establish the sintering conditions required for optimal sintering performance of the ore blends. This was achieved by targeting a balanced return fines outcome, maximising productivity and yield, minimising fuel rate and achieving specified sinter quality, which is measured by sinter size and strength, reduction degradation, reducibility and softening and melting properties. Sintering Performance of Brockman s Marillana Fines Sample August

11 Table 1-1 Ore blends studied Series 1 (Inland Mills) 2 (Coastal Mills) Blend Marillana Fines PB Fines (Rio) Yandi Fines Robe River Fines Newman Fines FMG Fines SSF Fines Carajas Fines Domestic concentrate Total Notes: 1. Blend 1 is the base blend for Series 1 and contains a high level of domestic concentrate (i.e. 30%). 2. Based on blend 1, blend 2, 3 and 7 are tested by substituting Marillana fines for PB fines at rates of 10%, 20% and 25% respectively. 3. Based on blend 1, blend 14 is tested by substituting Marillana fines for FMG Rocket fines at the rate of 10%. 4. Based on blend 1, blend 4 is tested by substituting Marillana fines for Yandi fines at the rate of 15%. 5. Based on blend 1, blend 5 is tested by substituting Marillana fines for Robe river fines at the rate of 10%. 6. Based on blend 1, blend 6 is tested by substituting Marillana fines for Yandi fines and Robe river fines at the rate of 25%. 7. Blend 12 is the new base blend for Series 3 and was created by removing coarse material (i.e. reduce Yandi Fines by 5%, reduce RR Fines by 10%, reduce FMG Fines by 5% and increase Newman Fines by 20%). 8. Based on blend 12, blend 13 is tested by substituting Marillana fines for Newman fines at the rate of 20%. 9. Blend 8 is the base blend for Series 2 and contains a low level of domestic concentrate (i.e. 10%). 10. Based on blend 8, blends 9, 10, 11 and 15 are tested by substituting 15% Marillana fines for FMG Rocket fines, Newman fines, Yandi fines and PB fines respectively. Sintering Performance of Brockman s Marillana Fines Sample August

12 2. WORK PROGRAMME AND METHODOLOGY 2.1 Raw Materials Preparation and Assessment Each raw material sample was homogenised and enclosed in plastic bags. The chemical analyses were carried out by National Analysis Center for Iron and Steel, the proximate analysis and ash chemical analysis of fuel was carried out by Beijing Research Institute of Coal Chemistry, CCRI, while the sizing and moisture saturation were determined in accordance with CISRI procedures. 2.2 Pilot-scale Sintering Test General Approach to Pot Grate Sintering Sintering is a high temperature agglomeration process in which iron ore fines are partially melted and bonded together using fluxes and a relatively cheap source of fuel, usually coke breeze. The agglomerated product, sinter, has improved metallurgical properties making it an ideal ferrous burden for feed into the iron-making blast furnace. In modern day operations sinter can make up to % of the total ferrous burden. The sintering process is normally carried out over three basic stages: granulation, ignition/sintering, and product sizing. In the granulation stage, iron ore fines (usually a blend of selected ores), sinter return fines, fluxes and fuel, are mixed with water and granulated in a rotating drum to form appropriate granules and improve the green bed permeability. The granulated mixture is then laid down on a grate to a bed depth ranging from 500 mm to 700 mm. The top of the bed is ignited using burners and hot gases generated ( C) is drawn down into the bed underneath with suction fans. The ignition process usually lasts 90 seconds, during which the fuel contained at the top of the bed is ignited. Upon ignition of the top layer, additional air is preheated by the hot upper layer and drawn into the bed by sucking fans to ignite the fuel in subsequent lower layers. The combustion zone moves down through the bed at a speed of, typically mm/min, this speed being the main factor influencing sinter productivity. The rate of movement of the heat front depends on the permeability of the sinter bed and for a fixed set of processing conditions is largely dependent on the nature of the ore blend being sintered. The sintering process is completed when the heat front has travelled down through the bed. The sinter plug is then processed and sized in accordance with specific procedures. The fraction between 5 and 50 mm is referred to as the product sinter which usually accounts for about 75-80% of the output of the sinter strand. The undersized material (-5.0 mm) is recycled as "return sinter fines". Product sinter must satisfy certain quality criteria in terms of its chemical and physical properties for feeding into the blast furnace. The chemical Sintering Performance of Brockman s Marillana Fines Sample August

13 composition of sinter is dictated by the blast furnace requirements. Sinter must be mechanically strong to support the furnace burden yet reactive and relatively stable in the blast furnace environment of reducing atmospheres at high temperatures Pot Grate Sintering Test Procedure The solid components used in making up a sinter mix consist of the ore blend, fluxes, return fines and fuel. ie. [ores + fluxes + fuel] = 100 (wt.%) The amount of fluxes (in this case dolomite, limestone and burnt lime, rate of burnt lime in the mixture was controlled at 3.0%) needed is calculated by the required sinter chemistry, which depends on the operation of the blast furnace. In accordance with industry practice CaO and SiO 2 levels are measured in terms of "basicity ", i.e. the ratio of CaO/SiO 2 in the product sinter. For this programme a typical target value of 2.0 was selected for basicity, at a float SiO 2 level. The MgO level in the sinter was controlled at 2.2%. The amount of return fines and fuel required is usually not prescribed and depends on the results of the pot grate tests. The amount of returns used in the mix has to be estimated so that it matches the amount of returns generated in the shatter treatment after the sinter plug has been fired. This match is termed the "return fines balance" (RFB). Return fines (-5.0 mm) were pre-fired from the same ore before the sinter pot tests could be carried out. Specific hearth layer material ( mm) was also prepared at this stage. The amount of fuel required is determined as the minimum amount that gives an acceptable RFB, sinter strength, as measured by the ISO Tumble Index. The fuel rate is defined as the amount of coke required (in kg) to produce one tonne of product sinter, i.e., kg-coke/ tonne-product-sinter. Water is added to the sinter mix to granulate the components. The water addition required is estimated and fine-tuned during the pot grate tests Sinter Mix Preparation Sampling and analysis Upon receipt, all raw materials were homogenised and bagged. Representative sub-samples were taken and prepared for chemical analysis of head samples. Representative samples of the fired sinter produced from each blend under the optimal pot-grate test were taken, prepared and submitted for chemical analysis and the analysis was further compared with predicted sinter chemistries. Mineralogical analysis of the fired sinter was conducted. Sintering Performance of Brockman s Marillana Fines Sample August

14 Mixing For each test, the requisite sinter mix components (ores, return fines, fluxes and fuel) were calculated using a computer programme and weighed out. The solid components were dry mixed four times by the moving cone method prior to water addition. The amount of water required to achieve the target moisture level was weighed out and poured into the dry mixture, then mixed another four times by the moving cone method. The moisture of the mix was checked by using a rapid moisture measure meter and adjusted prior to being loaded into a granulating drum (700 mm diameter. by 1470 mm long) for granulation. Granulation The granulation stage was carried out for five minutes at a rotary speed of 17 rpm. At this speed the material in the drum moves with a cascade motion, the wet particles rolling over one another and growing to form granules or "quasi-particles". For this test series a standard dry charge of 80 kg (~90 kg wet) was used. Sampling and Testing After granulation, each mix was sampled for moisture, bulk density and size distribution determination. A representative sample of about 1kg of moist granulated sinter feed is frozen in a refrigerator for 15 minutes and the granules (quasi-particles) are then screened without degradation using a laboratory sieve shaker to obtain their size distribution Firing Pot Loading The wet granulated sinter feed was carefully loaded into a 300 mm diameter sinter pot that had been pre-loaded with a ~20 mm deep layer (or 2 kg) of mm hearth layer material, to give a total bed height of 600 mm. As previously stated, both the return fines and hearth layer were prepared from fired sinter made from each of the fifteen ore blends so that the chemical analysis and mineralogy were compatible with the blend being tested. Ignition The ignition conditions used were as follows: Temperature C ± 50 C Time 90 - seconds Suction mm H 2 O Sintering Performance of Brockman s Marillana Fines Sample August

15 Sintering and cooling After the ignition, the burners were turned off and the pressure drop across the bed was increased to 1400 mm H 2 O. During the test, suction and waste gas temperature are monitored continuously. After burn-through, indicated by the peak in the waste gas temperature profile, the sinter plug is cooled for two minutes. The sintering time was measured from the commencement of the ignition cycle to the time when the waste gas temperature reached a maximum Shatter Treatment and Sampling Following cooling, the plug of fired sinter was removed from the pot, crushed to smaller pieces and subjected to the shatter test by dropping four times from two meters. The sinter was screened at 40, 25, 16, 10 and 5 mm using a set of trommel screens. The +5 mm fraction was weighed and termed 'product sinter' while the -5 mm fraction was weighed and recorded as 'return sinter'. In all these tests, sintering performance is quantified by sintering time, vertical flame speed, productivity (tonnes per square meter of grate per day), fuel rate (kg coke required to produce a tonne of sinter), sinter yield, sinter tumble index and return fines balance. After the shatter treatment, a 15 kg sample of the -40~+10mm fraction was collected for Tumble testing and tested in accordance with ISO Tumble tests were carried out on each run. For the optimum runs, samples were also taken for chemistry, Reducibility testing (ISO 7215 or GB/T 13241), low temperature Reduction Degradation testing (ISO 4696 or GB/T 13242), Softening and melting test, Mineralogy and microstructure analysis. A flow chart for the sintering pot test is illustrated in Figure 2-1. Sintering Performance of Brockman s Marillana Fines Sample August

16 Iron Ore Fluxes Fuels Return fines Proportioning First mixing and moisture adjustment Second mixing and granulation Pot loading, Igniting and Sintering Measuring the moisture, size distribution and bulk density. Crushing Drop test Screening Product Sinter Return fines (-5mm) Tumble Index Chemical analysis RDI & RI Softening/Melting Mineralogy/microstructure. Figure 2-1 Flow chart of pot sintering test and associated tests Sintering Parameters - Definitions (where applicable, see Appendix A for formulae) Sintering Time The sintering time is defined as the time elapsed from the commencement of the ignition cycle to the time when the waste gas temperature reaches a maximum. Yield The yield is the ratio of the mass of product sinter (i.e. +5 mm sinter) to the total mass of sinter produced less the mass of the hearth layer. Sintering Performance of Brockman s Marillana Fines Sample August

17 Return Fines Balance (RFB) The return fines balance is defined as the ratio of the weight of return fines (-5 mm) generated after the shatter treatment to the weight of return fines charged to the pot: RFB = Wt of return fines generated Wt of return fines charged The targeted RFB is 1.0 ± Productivity The productivity result, expressed as tonnes per square metre of grate area of sintering machine per day, is calculated from the sintering time, the cross-sectional area of the pot grate, and the weight of product sinter recovered from the test less the weight of hearth layer added to the pot. Fuel Rate The fuel rate, defined as the weight (in kilograms) of dry coke required to produce one tonne of product sinter, is calculated from the weight of coke in the sinter mix charged to the pot and the weight of product sinter generated. The "balanced" productivity and fuel rates have been calculated on a RFB = 1 basis (see Appendix A). Sinter Strength (Tumble Index, TI) The sinter strength is measured using ISO 3271 to determine the TI of the sinter. The TI is quoted as the weight % +6.3 mm material remaining after the tumble treatment in which 15 kg of mm sinter is tumbled in a 1 m diameter drum for 200 revolutions at a speed of 25 rpm. The target TI for the sinter product was 65% minimum. Reducibility Index (RI) GB/T The reducibility test is carried out to evaluate the reduction behaviour of various iron oxide burden materials in the middle zone of the blast furnace shaft and is a measure of the amount of oxygen removed from the sample. A 500 g sample of mm sinter is reduced isothermally at 900 C for 180 minutes in a fixed bed with a 30% CO + 70% N 2 gas mixture flowing at 15 L/min. An RI value of 80% or more is regarded as being very good while a reducibility index below 60% for sinter would be regarded as being poor. Sintering Performance of Brockman s Marillana Fines Sample August

18 Reduction Degradation Index (RDI) GB/T The RDI is a measure of the breakdown of the blast furnace burden materials under conditions chosen to resemble those in the upper part (low temperature zone) of the blast furnace shaft. In the test, a 500 g sample of mm sinter is reduced isothermally at 500 C for 60 minutes in a fixed bed with a 20% CO, 20% CO 2 and 60% N 2 gas mixture flowing at 15 L/min. After cooling under N 2, the sample is tumbled for 10 minutes at a speed of 30 rpm and then screened at 6.3mm, 3.15mm and 0.5mm. As a result, the reduction disintegration degree is indicated by the weight percentage of fractions plus 6.3 mm, plus 3.15 mm and minus 0.5 mm. The RDI is the weight % of tumbled product passing 3.15 mm and a higher RDI value corresponds to a greater amount of degradation and therefore lower quality. The target RDI value for the sinter product was <35%. Softening and Melting performance The softening and melting test is designed to simulate the high temperature reduction process of iron ores in the blast furnace to examine the influence on the running condition of the blast furnace, the softening/melting zone forming and the forming position. There is neither an ISO standard or GB standard for the softening and melting test, so the aim of this programme is to study material behaviour during a softening and melting test in the same facility under the same conditions, rather than just determine the standard test parameters. The ferrous material is enclosed in a graphite reactor, and above and below the test sample are two layers of coke particles. The sample is reduced by a flowing gas stream composed of 30% CO + 70% N 2 gas mixture flowing at 12 L min -1. The normal load acting on the sample is kept constant at 9.8 Ncm -2 (or 1 kg cm -2 ). Sintering Performance of Brockman s Marillana Fines Sample August

19 The softening and melting performance of the sinter is determined by the following parameters: T 10% : T 40% : Commence softening temperature (ie. temp at which the bed has contracted by 10%). Finish softening temperature (ie. temp at which the bed has contracted by 40%). ΔT 1 : Softening temperature interval, ΔT 1 = T 40% -T 10%. Ts : Commence melting temperature (ie. temp at which the pressure difference reaches 490 Pa). Td : ΔT 2 : ΔP m : S : Commence dripping temperature (ie. temp at which blast furnace burden starts to drip). Melting temperature interval, ΔT 2 = Td-Ts. Maximum pressure difference in melting. Characteristic number of softening/melting: S=(ΔPm-ΔPs) ΔT 2, (ΔPs = 490 Pa) Sintering Performance of Brockman s Marillana Fines Sample August

20 2.3 Sintering Test Conditions and Performance/Quality Targets Sintering Test Conditions The optimal sintering performance for simulated sinter blends is normally determined by CISRI under the following test conditions: Bed height (total) = 600 mm Hearth layer depth = 20 mm Hearth layer size = mm Size of return sinter fines = 5 mm Return fines (tdmb) = 20% and adjustable if necessary Ignition flame temperature = 1100 C ± 50 Ignition time = 90 secs Ignition suction = 6 kpa Sintering suction = 14 kpa Basicity (CaO/SiO 2 ) = 2.0 Sinter SiO 2 = float, (i.e. minimum achievable) Sinter MgO level = 2.2% Burnt lime rate = 3% Performance and Quality Targets The following performance and quality targets were used in this test programme and are generally acceptable in pot grate sintering test for these types of ores/blends: Productivity = Maximum Fuel rate = Minimum Return fines balance = 1.00 ± 0.05 Sinter strength (ISO 3271) 65% of mm However, in some cases it may not be possible to achieve some of the above targets because they are dependent on the sintering performance of the ores/blends. Sintering Performance of Brockman s Marillana Fines Sample August

21 3. CHARACTERISATION OF RAW MATERIALS 3.1 Chemical Analysis of Raw Materials Table 3-1 summarises the chemical composition of raw materials which were used in this sintering test programme. Figure 3-1 compares the chemistry of Marillana fines against other Australian fines samples (e.g. PB fines, Yandi fines, Newman fines, Robe River fines and FMG fines). Table 3-1 Chemical Analysis of Raw Materials for Sinter Test Ore TFe SiO 2 CaO Al 2 O 3 MgO Cu Mn TiO 2 Ni K 2 O S P LOI (%) (%) (%) (%) (%) (%) (%) (%) (%) (%) (%) (%) (%) Marillana fines Carajas fines PB fines Yandi fines BHP SSF fines Newman fines Domestic concentrate Robe River fines FMG Rocket fines Dolomite Limestone Burnt Lime Coke Ash Coke breeze Fixed Carbon: 86.13%, Volatile: 1.11%, Ash: 12.76% Sintering Performance of Brockman s Marillana Fines Sample August

22 BIPL Marillana fines PB fines Yandi fines Robe river fines Newman fines FMG Rocket fines Wt% SiO2 Al2O3 S P LOI900 Figure 3-1 Comparisons between the Marillana fines sample and other Australian fines based on their Al 2 O 3, SiO 2, S, P and LOI at 900 Marillana fines have a low LOI content of 1.94%, a moderate Fe grade of 61.24% and relatively high SiO 2 and Al 2 O 3 contents of 5.85 and 3.25% respectively. Substitution of the Marillana fines for other Australian fines in the base blend has increased the SiO 2 and Al 2 O 3 and reduced the LOI in the ore blends. The P and S contents of the Marillana fines were within the acceptable limits of steel mills, but the TiO 2 content was slightly higher compared with the other Australian fines. Sintering Performance of Brockman s Marillana Fines Sample August

23 3.2 Moisture and Size Distribution of Raw Materials The moisture and size distribution of the raw materials used in the sinter test programme are detailed in Table 3-2 and Figures 3-2 & 3-3. Table 3-2 Moisture and size distribution of dry screen (%) Size distribution (%) Ore Moisture (%) > <0.063 mm mm mm mm mm mm mm mm mm mm mm Total Marillana fines Carajas fines PB fines Yandi fines SSF fines Newman fines Robe River fines FMG fines Domestic concentrate 7.72 >0.154mm: %, mm: %, mm: 6.92 %, <0.063mm: % 100 Dolomite Limestone Burnt lime Coke breeze Sintering Performance of Brockman s Marillana Fines Sample August

24 Cumulative, % Passing BIPL Marillana fines Carajas fines PB fines Yandi fines SSF fines Newmn fines Robe River fines FMG Rocket fines Screen size, mm Figure 3-2 The size distribution of iron ore fines used in this programme -0.25mm mm -2+1mm +2mm 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% BIPL Marillana fines PB fines Yandi fines Robe river fines Neman fines FMG rocket fines Figure 3-3 Comparison of the size distribution of Marillana fines with other Australian fines. The size distribution of Marillana fines is very different from the other Australian fines, with approximately 84% of particles contained in the 1 mm to 6.3 mm fraction. Sintering Performance of Brockman s Marillana Fines Sample August

25 To achieve effective granulation, an ore or an ore blend needs an appropriate balance of the following size groups: i. Nucleus particles, typically +2 mm in size. ii. Intermediate particles, typically fines from 0.25 to 2 mm in size. These particles are either too small to act as nuclei, or too large to act as adhering fines, and iii. Adhering fines, typically mm. These particles tend to be adhered to the nuclei via liquid bridges to form a stable coating layer. Fine clays in the adhering fine particles, such as kaolinite, should help form a stable coating of fine particles (including some of the intermediates) around the coarse nucleus particles. Considerable effort has been made to quantify the granulability of an ore or an ore blend. However, given the complexity of the phenomena involved, only limited success has been achieved. Ideally, an ore or an ore blend should avoid too much material in the intermediate size group and contain appropriate proportions of coarse and fine particles. Adhering fines will not only help contribute to the granule coatings, but to matrix formation as well. Industrial practices have demonstrated that ores with relatively high proportions of coarse and fine particles and a relatively low proportion of intermediate particles tend to granulate better. However, the boundary limits between the three fractions vary with individual ores. Other ore characteristics, such as porosity, shape and surface characteristics, can also affect the granulability. The size distribution of the Marillana fines sample was determined and compared with the other Australian fines in Table 3-2 and Figures 3-2 & 3-3. The Marillana fines sample was extremely coarse, consisting of 59.28% +2 mm material as potential nuclei, 39.85% mm intermediate particles and 0.87% mm material as potential adhering fines. Due to the high proportion of coarse +2 mm particles and the extremely low proportion of mm particles, the addition of Marillana fines has increased the mean particle size of the ore blends. Sintering Performance of Brockman s Marillana Fines Sample August

26 3.3 Summary The Marillana fines sample was higher in Fe, SiO 2 and Al 2 O 3, and lower in LOI when compared to the target Australian fines (i.e. PB fines, Yandi fines, Robe River fines, Newman fines and FMG rocket fines). Therefore, substitution of Marillana fines for the target Australian fines increased the SiO 2 and Al 2 O 3, and reduced the LOI of the ore blends. The P and S levels of the Marillana fines sample were within the acceptable limits of steel mills, but the TiO 2 content was slightly higher compared with the target Australian fines. The Marillana fines sample was extremely coarse, consisting of 59.28% +2 mm material as potential nuclei, 39.85% mm intermediate particles and 0.87% mm material as potential adhering fines. Due to the high proportion of coarse +2 mm particles and the extremely low proportion of mm particles, the addition of Marillana fines has increased the mean particle size of the ore blends. Overall, the Marillana fines sample was very coarse and relatively dense. In comparison with the other Australian fines samples used, the Marillana fines sample had a very low LOI. All of these factors can affect both sinter quality and sintering performance. Sintering Performance of Brockman s Marillana Fines Sample August

27 4. SINTERING PERFORMANCE OF BLENDS WITH MARILLANA FINES The detailed sintering test results for all blends are listed in Appendix B. The average parameters for sintering performance and sinter quality from the optimum tests are summarised in Tables 4-1 to 4-3. Table 4-1 Details of mixtures for all blends under the optimum conditions Blend C % Moisture % >10 mm 10-8 mm Size distribution of mix (%) 8-5 mm 5-3 mm 3-1 mm <1 mm AMD mm Bulk density kg/m Sintering Performance of Brockman s Marillana Fines Sample August

28 Blend C % Table 4-2 Sinter pot test results for all blends under the optimum conditions Moisture % Sintering time mins Yield % Productivity t/m 2 d RFB ISO TI % Solid fuel kg/t Balanced productivity t/m 2 d Balanced Fuel rate kg/t Sintering Performance of Brockman s Marillana Fines Sample August

29 Table 4-3 Size distribution of product sinter for all blends under the optimum conditions Blend >40 mm mm Sinter product size distribution (%) mm mm 10-5 mm AMD mm Sintering Performance of Brockman s Marillana Fines Sample August

30 4.1 Series 1 (Inland Mills) Series 1 includes 8 ore blends (Blend 1-7 and 14) which were based on the typical sinter blend for inland mills of China, which consists of several Australian fines, Brazilian fines and a high level of domestic concentrate. Blend 1 is the base blend, consisting of 25% PB fines, 15% Yandi fines, 10% Robe river fines, 10% FMG fines, 10% SSF fines and 30% domestic magnetite concentrate. Based on this blend, sintering tests were conducted by substituting Marillana fines for other Australian fines Substituting Marillana fines for PB fines For blends 2, 3 and 7, the PB fines were replaced by Marillana fines at the rates of 10, 20 and 25% respectively. The average parameters for sintering performance and sinter quality from two optimum runs for these four blends are summarised and compared in Figure Balanced productivity,t/m2d TI,% Balanced fuel rate,kg/t Blend 1 Blend 2 Blend 3 Blend 7 Figure 4-1 Comparison of sintering results for blends 1, 2, 3 and 7 1) The productivity increases from to 41.56t/m 2 d when the amount of Marillana fines increased from 0 to 25%. 2) The fuel rates for blends 1 and 2 are similar at 61.5 kg/t. When the amount of Marillana fines continues to increase to 20%, the fuel rate decreases to kg/t. When the amount of Marillana fines is increased to 25%, the fuel rate decreases to kg/t. 3) The tumble index for blends 1 and 2 are similar at 69.9 and 69.7% respectively. When the amount of Marillana fines is increased to 20 and 25%, the tumble index decreases to 68.6 and 67.67% respectively. All tumble index values are higher than the nominal target of 65%. Sintering Performance of Brockman s Marillana Fines Sample August

31 4.1.2 Substituting Marillana fines for FMG Rocket fines Blend 14 was generated by substituting 10% Marillana fines for 10% of FMG Rocket fines in base blend 1. The average parameters for sintering performance and sinter quality from two optimum runs for these two blends are summarised and compared in Figure Balanced productivity,t/m2d TI,% Balanced fuel rate,kg/t Blend 1 Blend 14 Figure 4-2 Comparison of sintering results for blends 1 and 14 1) The productivity increases from to t/m 2 d. 2) The fuel rate decreases approximately 5 kg/t from to kg/t. 3) The tumble index for blends 1 and 14 are similar at and 69.40% respectively. Sintering Performance of Brockman s Marillana Fines Sample August

32 4.1.3 Substituting Marillana fines for Yandi fines Blend 4 was generated by substituting 15% Marillana fines for 15% of Yandi fines in base blend 1. The average parameters for sintering performance and sinter quality from two optimum runs for these two blends are summarised and compared in Figure Balanced productivity,t/m2d TI,% Balanced fuel rate,kg/t Blend 1 Blend 4 Figure 4-3 Comparison of sintering results for blends 1 and 4 1) The productivity increases from to t/m 2 d. 2) The fuel rate decreases approximately 4 kg/t from to kg/t. 3) The tumble index for blends 1 and 4 are and 68.47% respectively. Sintering Performance of Brockman s Marillana Fines Sample August

33 4.1.4 Substituting Marillana fines for Robe River fines Blend 5 was generated by substituting 10% Marillana fines for 10% of Robe River fines in base blend 1. The average parameters for sintering performance and sinter quality from two optimum runs for these two blends are summarised and compared in Figure Balanced productivity,t/m2d TI,% Balanced fuel rate,kg/t Blend 1 Blend 5 Figure 4-4 Comparison of sintering results for blends 1 and 5 1) The productivity increases from to t/m 2 d. 2) The fuel rate decreases approximately 4 kg/t from to kg/t. 3) The tumble index for blends 1 and 5 is similar at and 69.74% respectively. Sintering Performance of Brockman s Marillana Fines Sample August

34 4.1.5 Substituting Marillana fines for Yandi fines and Robe River fines Blend 6 was generated by substituting 25% Marillana fines for 15% Yandi fines and 10% Robe River fines in base blend 1. The average parameters for sintering performance and sinter quality from two optimum runs for these two blends are summarised and compared in Figure Balanced productivity,t/m2d TI,% Balanced fuel rate,kg/t Blend 1 Blend 6 Figure 4-5 Comparison of sintering results for blends 1 and 6 1) The productivity increases from to t/m 2 d. 2) The fuel rate decreases by approximately 4 kg/t from to kg/t. 3) The tumble index for blends 1 and 6 is similar at and 69.20% respectively. Sintering Performance of Brockman s Marillana Fines Sample August

35 4.2 Series 3 (Inland Mills) Series 3 includes two blends (blend 12 and blend 13). Blend 12 removes some coarse materials compared to blend 1 (i.e. reduce 5% Yandi fines, 10% Robe River fines and 5% FMG Rocket fines; increase Newman fines by 20%), therefore blend 12 consists of 25% PB fines, 10% Yandi fines, 5% FMG Rocket fines, 20% Newman fines, 10% SSF fines and 30% domestic magnetite concentrate as the base blend for series 3. Blend 13 introduces 20% of Marillana fines to replace the Newman fines. The average parameters for sintering performance and sinter quality from two optimum runs for these two blends and blend 1 are summarised and compared in Figure Balanced productivity,t/m2d TI,% Balanced fuel rate,kg/t Blend 1 Blend 12 Blend 13 Figure 4-6 Comparison of sintering results for blends 1 12 and 13 1) The productivity is not lower for blend 12 than blend 1 as had been anticipated and there is an increase in productivity for the finer base blend 12 (i.e vs t/m 2 d. When substituting Marillana fines for Newman fines, the productivity increases from to t/m 2 d. 2) The fuel rate is similar for blends 12 and 13 at and respectively. 3) The tumble index decreases from 69.60% to 68.84%, but both are higher than the nominal target of 65%. Sintering Performance of Brockman s Marillana Fines Sample August

36 4.3 Series 2 (Coastal Mills) Series 2 includes five ore blends (Blends 8-11 and 15) which were based on the typical sinter blend for coastal mills of China, which consists of several Australian fines, Brazilian fines and a low level of domestic concentrate. Blend 8 is the base blend for series 2, consisting of 25% PB fines, 15% Yandi fines, 15% Newman fines, 15% FMG Rocket fines, 10% SSF fines, 10% Carajas fines and 10% domestic magnetite concentrate. Based on this blend, sintering tests were conducted by substituting Marillana fines for other Australian fines Substitute Marillana fines for FMG Rocket fines Blend 9 was generated by substituting 15% Marillana fines for 15% FMG Rocket fines in base blend 8. The average parameters for sintering performance and sinter quality from two optimum runs for these two blends are summarised and compared in Figure Balanced productivity,t/m2d TI,% Balanced fuel rate,kg/t Blend 8 Blend 9 Figure 4-7 Comparison of sintering results for blends 8 and 9 1) The productivity decreases from to t/m 2 d. 2) The fuel rate decreases approximately 4 kg/t from to kg/t. 3) The tumble index for blends 8 and 9 is 67.8 and 67.74% respectively. Sintering Performance of Brockman s Marillana Fines Sample August

37 To achieve a higher productivity, the mix moisture of blend 9 was increased from 6.58 to 6.90%. For this repeat trial (1), the fixed carbon rate was maintained at 3.6% and is lower than that of base blend 8, which is 3.8%. The average parameters for sintering performance and sinter quality from two optimum runs with higher mix moisture content for blend 9 are summarised and compared with blend 8 in Figure Balanced productivity,t/m2d TI,% Balanced fuel rate,kg/t Blend 8 Blend 9/6.90% Figure 4-8 Comparison of sintering results for blends 8 & 9 with higher mix moisture 4) The productivity increases from to t/m 2 d. 5) The fuel rate decreases approximately 4 kg/t from to kg/t. 6) The tumble index decreases from to 65.77%. Sintering Performance of Brockman s Marillana Fines Sample August

38 To maintain the higher productivity from repeat trial (1) and to improve the tumble strength, the coke rate was increased for repeat trial (2) from 3.6 to 3.8% (i.e. the same as base blend 8), while maintaining the higher mix moisture (i.e. 6.87%). The average parameters for sintering performance and sinter quality from two optimum runs with higher mix moisture for blend 9 are summarised and compared with blend 8 in Figure Balanced productivity,t/m2d TI,% Balanced fuel rate,kg/t Blend 8 Blend 9/6.87%/3.8% Figure 4-9 Comparison of sintering results for blends 8 & 9 with higher mix moisture and same fixed carbon rate 7) The productivity increases from to t/m 2 d. 8) The fuel rate decreases by approximately 0.9 kg/t from to kg/t. 9) The tumble index is almost the same as blend 8 at 67.77%. Therefore, by increasing the coke rate from 3.6 to 3.8% the desired increase in sinter strength has been achieved, but at the expense of a higher fuel rate. Sintering Performance of Brockman s Marillana Fines Sample August

39 4.3.2 Substitute Marillana fines for Newman fines Blend 10 was generated by substituting 15% Marillana fines for 15% Newman fines in base blend 8. The average parameters for sintering performance and sinter quality from two optimum runs for these two blends are summarised and compared in Figure Balanced productivity,t/m2d TI,% Balanced fuel rate,kg/t Blend 8 Blend 10 Figure 4-10 Comparison of sintering results for blends 8 & 10 1) The productivity decreases from to t/m 2 d. 2) The fuel rate decreases approximately 3 kg/t from to kg/t. 3) The tumble index for blends 8 and 10 are very similar at 67.8 and 67.54% respectively. Sintering Performance of Brockman s Marillana Fines Sample August

40 To achieve a higher productivity, the mix moisture of blend 10 was increased from 6.55 to 6.98%, which will increase the sintering speed. For this repeat trial (3), the fixed carbon rate was maintained at 3.6% and is lower than that of base blend 8, which is 3.8%. The average parameters for sintering performance and sinter quality from two optimum runs with higher mix moisture content for blend 10 are summarised and compared with blend 8 in Figure Balanced productivity,t/m2d TI,% Balanced fuel rate,kg/t Blend 8 Blend 10/6.98% Figure 4-11 Comparison of sintering results for blends 8 & 10 with higher mix moisture 4) The productivity increases from to t/m 2 d. 5) The fuel rate decreases approximately 3 kg/t from to kg/t. 6) The tumble index decreases from to 66%. Sintering Performance of Brockman s Marillana Fines Sample August

41 4.3.3 Substitute Marillana fines for Yandi fines Blend 11 was generated by substituting 15% Marillana fines for 15% Yandi fines in base blend 8. The average parameters for sintering performance and sinter quality from two optimum runs for these two blends are summarised and compared in Figure Balanced productivity,t/m2d TI,% Balanced fuel rate,kg/t Blend 8 Blend 11 Figure 4-12 Comparison of sintering results for blends 8 and 11 1) The productivity increases slightly from to t/m 2 d. 2) The fuel rate decreases approximately 4 kg/t from to kg/t. 3) The tumble index decreases from 67.80% to 66.67%. Sintering Performance of Brockman s Marillana Fines Sample August

42 To achieve a higher productivity, the mix moisture of blend 11 was increased from 6.5 to 6.64%, which will increase the sintering speed. For this repeat trial (4), the fixed carbon rate was maintained at 3.6% and is lower than that of base blend 8, which is 3.8%. The average parameters for sintering performance and sinter quality from two optimum runs with higher mix moisture content for blend 11 are summarised and compared with blend 8 in Figure Balanced productivity,t/m2d TI,% Balanced fuel rate,kg/t Blend 8 Blend 11/6.68% Figure 4-13 Comparison of sintering results for blends 8 and 11 with higher mix moisture 4) The productivity increases from to t/m 2 d. 5) The fuel rate decreases approximately 4 kg/t from to kg/t. 6) The tumble index decreases from 67.80% to 66.54%. Sintering Performance of Brockman s Marillana Fines Sample August

43 4.3.4 Substitute Marillana fines for PB fines Blend 15 was generated by substituting 15% Marillana fines for 15% PB fines in base blend 8. The average parameters for sintering performance and sinter quality from two optimum runs for these two blends are summarised and compared in Figure Balanced productivity,t/m2d TI,% Balanced fuel rate,kg/t Blend 8 Blend 15 Figure 4-14 Comparison of sintering results for blends 8 and 15 1) The productivity increases from to t/m 2 d. 2) The fuel rate decreases approximately by 4 kg/t from to 60.66kg/t. 3) The tumble index for blends 8 and 15 are very similar at and 67.90% respectively. Sintering Performance of Brockman s Marillana Fines Sample August

44 5. SINTER CHEMICAL ANALYSIS Sufficient sinter from each blend made under the optimum conditions is produced and the samples of each blend are taken for chemical analysis and the analysis results are shown in Table 5-1. Table 5-1 Sinter chemical analysis of each blend Sinter TFe FeO SiO 2 CaO Al 2 O 3 MgO Cu Mn TiO 2 Ni K 2 O S P (%) (%) (%) (%) (%) (%) % % % % % (%) (%) Basicity Blend Blend Blend Blend Blend Blend Blend Blend Blend Blend Blend Blend Blend Blend Blend Because of the higher SiO 2 and Al 2 O 3 content of Marillana fines, the Fe grade of the Marillana sinter products decreased slightly and the SiO 2 and Al 2 O 3 content increased slightly. In terms of other contaminants, such as P, the differences for the various sinter products are negligible. Sintering Performance of Brockman s Marillana Fines Sample August

45 6. METALLURGICAL PROPERTIES Samples from each of the optimum tests for the 15 blends were selected for RI, RDI, and Softening and Melting testwork. 6.1 Reducibility Index The reducibility index of each blend is shown in Table 6-1 and Figure 6-1. The weight loss and variation of reduction degree with reduction time of each blend sinter are shown in Appendix C. The reducibility index (RI) for all blends is high (i.e. >85%), which is regarded as being very good. The Series 1 blends (inland mills) had a lower RI, ranging from % versus base blend 1 of 91.34%; Series 2 blends (coastal mills) were higher, ranging from % versus base blend 8 of 85.44%; and the Series 3 blend (inland mills) was higher at 92.64% versus base blend 12 of 84.33%. Table 6-1 Reducibility index of each blend Blend Reducibility (%) Blend Blend Blend Blend Blend Blend Blend Blend Blend Blend Blend Blend Blend Blend Blend Sintering Performance of Brockman s Marillana Fines Sample August

46 Reducibility, % Blend1 Blend 2 Blend 3 Blend 7 Blend 14 Blend 4 Blend 5 Blend 6 Blend 12 Blend 13 Blend 8 Blend 9 Blend 10 Blend 11 Blend 15 Figure 6-1 Reducibility of each blend 6.2 Low temperature reduction degradation index The low temperature reduction degradation index for each sinter blend is detailed in Table 6-2 and illustrated in Figure 6-2. The low temperature reduction degradation index for all blends was above the nominal target of 35%. The Series 1 blends were mixed, ranging from % versus base blend 1 of 38.73%; Series 2 blends were lower, ranging from % versus base blend 8 of 41.6%; and the Series 3 blend was higher at 42.43% versus base blend 12 of 35.41%. Comparing the results of blend 1, 12 and 13; the removal of coarse material from blend 1 and substituting with Newman fines has decreased the RI and improved the RDI of the sinter product. Substitution of Marillana fines for Newman fines improved the RI but worsened the RDI. Sintering Performance of Brockman s Marillana Fines Sample August

47 Table 6-2 Low-temperature reduction degradation index of each blend Blend RDI +6.3 mm % RDI mm % RDI -0.5 mm % RDI mm % Blend Blend Blend Blend Blend Blend Blend Blend Blend Blend Blend Blend Blend Blend Blend RDI, % Blend 1 Blend 2 Blend 3 Blend 7 Blend 14 Blend 4 Blend 5 Blend 6 Blend 12 Blend 13 Blend 8 Blend 9 Blend 10 Blend 11 Blend 15 Figure 6-2 Low-temperature reduction degradation index of each blend Sintering Performance of Brockman s Marillana Fines Sample August

48 6.3 Softening and melting property of sinters Test results for the softening and melting performance for each blend are detailed in Table 6-3. The variations of pressure and displacement with increasing temperature for each blend are illustrated in Appendix C. Table 6-3 Softening and melting performance for each blend T 10% T 40% ΔT 1 T S ΔPm T d ΔT 2 S Blend ( C) ( C) ( C) ( C) (Pa) ( C) ( C) kpa C T 10% : T 40% : Commence softening temperature (ie. temp at which the bed has contracted by 10%). Finish softening temperature (ie. temp at which the bed has contracted by 40%). ΔT 1 : Softening temperature interval, ΔT 1 = T 40% -T 10%. Ts : Td : ΔT 2 : ΔP m : S : Commence melting temperature (ie. temp at which the pressure difference reaches 490 Pa). Commence dripping temperature (ie. temp at which blast furnace burden starts to drip). Melting temperature interval, ΔT 2 = Td-Ts. Maximum pressure difference in melting. Characteristic number of softening/melting: S =(ΔPm-ΔPs) ΔT 2, (ΔPs = 490 Pa) Sintering Performance of Brockman s Marillana Fines Sample August

49 (1) For blends 2 and 3, the softening properties are similar to base blend 1. The melting property improves as the substitution of Marillana fines for PB fines increases from 0% to 20%, and the maximum pressure difference (ΔPm) decreases from 3971 to 3449 Pa. A reduced ΔPm generally means that the permeability of the material bed has improved. When the amount of Marillana fines increases to 25%, the melting temperature range increases and this has resulted in an increase in the thickness of the cohesive zone and an increase in the comprehensive melting property (the S value). (2) For Blend 14, both commence and finish softening temperatures are lower, and the softening temperature range is similar to base blend 1. Both commence and finish melting temperatures are lower, and the melting temperature range has decreased slighty. Furthermore the maximum pressure difference (ΔPm) has decreased from 3971 to 2197 Pa, so the S value has improved. (3) For blend 4, both commence and finish softening temperatures are lower, and the softening temperature range is similar to the base blend 1. The commence melting temperature is lower, and the melting temperature range has increased. The thickness of the cohesive zone has increased and the maximum pressure difference (ΔPm) has decreased from 3971 to 2145 Pa, resulting in a lower and improved S value. (4) For blend 5, both commence and finish softening temperatures are lower, and the softening temperature range is similar to base blend. Commence and finish melting temperatures, and the melting temperature range are similar to the base blend. The maximum pressure difference (ΔPm) decreased from 3971 to 2823 Pa, resulting in a lower and improved S value. (5) For blend 6, both commence and finish softening temperature are lower, and the softening temperature range is similar to base blend 1. Commence and finish melting temperatures, and the melting temperature range are similar to the base blend. The maximum pressure difference (ΔPm) decreased from 3971 to 3200 Pa and the S value has improved. (6) Comparing the test result of base blend 12 and blend 13, the softening performance is similar and the melting temperature range of blend 13 is higher than that of blend 12. The S value is higher for blend 13 than it is for blend 12, but is lower than that recorded for base blend 1. (7) For blend 9, the commence softening temperature increased and the finish softening temperature decreased. The softening temperature range decreased, an indication that softening properties impoved. Both commence and finish melting temperature decreased while the melting temperature range increased. The maximum pressure difference (ΔPm) decreased from 2980 to 2328 Pa and the S value increased (ie. deteriorated). Sintering Performance of Brockman s Marillana Fines Sample August

50 (8) For blend 10, both commence and finish softening temperatures decreased, and the softening temperature range decreased. Both commence and finish melting temperatures decreased, however, the melting temperature range increased. The maximum pressure difference (ΔPm) is similar to base blend 8 and the S value has deteriorated. (9) For blend 11, the commence softening temperature increased and the finish softening temperature decreased, resulting in a reduction in the softening temperature range; an indication that softening properties impoved. Both commence and finish melting temperature decreased while the melting temperature range increased. The maximum pressure difference (ΔPm) decreased from 2980 to 1937 Pa, which has resulted in an improved lower S value. (10) For blend 15, the commence softening temperature increased and finish softening temperature decreased, resulting in a reduction in the softening temperature range, an indication that softening properties improved. Both commence and finish melting temperatures decreased while the melting temperature range increased slightly. The maximum pressure difference (ΔPm) decreased from 2980 to 2615 Pa and the S value increased slightly. Sintering Performance of Brockman s Marillana Fines Sample August

51 7. ANALYSIS OF MINERAL COMPOSITION & MICROSTRUCTURE 7.1 Mineral composition Magnetite is the dominant ferrous mineral of sinter followed by hematite. The magnetite generally formed during sintering process, exists mostly in forms of subhedral crystal. The size of crystal is small generally around 50~100μm. There are three types of hematite in the sinters: The first is Relict hematite, which is formed from the raw limonite after calcinations, with the coarse size around 2~8 mm. The second is Hematite formed during sintering process, exists mostly in form of subhedral crystal with small size about 50μm. The third is secondary skeletal hematite, which is formed close to the interface with larger pores and voids or on the cleavage plane of magnetite crystal during cooling of sinter. Ferrite is the dominant bonding phase, followed by silicate. Calcium ferrite mainly present in forms of plate like CaO Fe 2 O 3 with coarser size of around μm, followed by acicular SFCA and CaO 2Fe 2 O 3. The silicate consists of glass, β-2cao SiO 2, a little of melilite and a very tiny periclase. The mineral composition of each blend is shown in Table 7-1 and Figure Microstructure of Sinter The microstructure of the sinters is heterogeneous structure, including relict structure of hematite as shown in Photo 7-1. Ferrous minerals are bonded by interlocking platelets and acicular calcium ferrite, as shown in Photo 7-2 and Photo 7-3; and ferrous minerals are bonded by glass, β-2cao SiO 2 and melilite, as shown in Photo 7-4. Sintering Performance of Brockman s Marillana Fines Sample August

52 Photo 7-1 Microstructure of sinter (A) Relict hematite Granular white (left) - relict hematite of raw ore, Acicular grey (right) SFCA, Black pore (Reflected light: 200 times) Photo 7-2 Microstructure of sinter (B) Rounded magnetite grains (grey white) with prismatic calcium ferrite (grey) Granular grey white - magnetite, Platelike and prismatic grey - CaO Fe 2 O 3 Dark grey (irregular shape) glass (Reflected light: 200 times) Sintering Performance of Brockman s Marillana Fines Sample August

53 Photo 7-3 Microstructure of sinter (C) Interlocking acicular calcium ferrite (grey) surrounding magnetite (grey white) Granular grey white - magnetite, Small acicular grey - SFCA (Reflected light: 200 times) Photo 7-4 Microstructure of sinter (D) Glass (dark grey) surrounding granular magnetite (grey white) Granular grey white- magnetite, Dark grey (irregular shape) glass, Small acicular grey in glass - melilite (Reflected light: 200 times) Sintering Performance of Brockman s Marillana Fines Sample August

54 Table 7-1 Mineral composition of each blend Blend Magnetite Hematite Calcium ferrite Silicate Periclase CaO Fe 2 O 3 SFCA CaO 2Fe 2 O 3 β-2cao SiO 2 Melilite Glass Sintering Performance of Brockman s Marillana Fines Sample August

55 Magnetite Hematite CaO Fe2O3 SFCA CaO 2Fe2O3 β-2cao SiO2 Melilite Glass Periclase 100% 90% % 70% % Area % 50% 40% % 20% 10% % Blend 1 Blend 2 Blend 3 Blend 7 Blend 14 Blend 4 Blend 5 Blend 6 Blend 12 Blend 13 Blend 8 Blend 9 Blend 10 Blend 11 Blend 15 Figure 7-1 Sinter mineralogy of each blend Sintering Performance of Brockman s Marillana Fines Sample August

56 8. SUMMARY OF TEST RESULTS UNDER OPTIMUM CONDITIONS FOR ALL BLENDS Table 8-1 Summary of test results under optimum conditions for all Blends Test parameter Blend 1 Blend 2 Blend 3 Blend 7 Blend 14 Blend 4 Blend 5 Blend 6 Blend 12 Blend 13 Blend 8 Blend 9 Blend 10 Blend 11 Blend 15 Moisture (% H 2 O) Fixed carbon rate (%) Bulk Density (kg/m 3 ) Sintering performance Productivity (t/m 2 d) Fuel Rate (kg/t) Balanced Productivity (t/m 2 d) Balanced Fuel Rate (kg/t) Yield (%) RFB Metallurgical Quality ISO TI (% +6.3 mm) RDI (% mm) RI (%) Chemistry FeT (%) FeO (%) SiO 2 (%) CaO (%) Al 2 O 3 (%) MgO (%) S (%) P (%) Basicity(CaO/SiO 2 ) Sintering Performance of Brockman s Marillana Fines Sample August

57 9. CONCLUSION 9.1 Characteristics of Marillana fines Marillana fines have a low LOI content of 1.94%, a moderate Fe grade of 61.24% and relatively high SiO 2 and Al 2 O 3 contents of 5.85 and 3.25% respectively. The P and S contents of the Marillana fines were within the acceptable limits of steel mills. Marillana fines sample was extremely coarse, consisting of 59.28% +2 mm material as potential nuclei, 39.85% mm intermediate particles and only about 0.87% mm material as potential adhering fines. Due to the high proportion of coarse +2 mm particles and the extremely low proportion of mm particles, the addition of Marillana fines has increased the mean particle size of the ore blends. 9.2 Sintering performance of Marillana fines 1) For Series 1, as PB fines were replaced by Marillana fines at substitution rates of 10, 20 and 25%, the productivity increased from to t/m 2 d and the fuel rate decreased from to kg/t kg/t The tumble index of blend 1 and 2 are similar at 69.9 and 69.7% respectively. When the amount of Marillana fines is increased to 20% and the fuel rate decreases to kg/t, the tumble index decreases slightly to 68.6% When the amount of Marillana fines is increased to 25%, the tumble index decreases to 67.67%. 2) When substituting 10% Marillana fines for 10% of FMG Rocket fines in base blend 1, the productivity increases from to t/m 2 d and the fuel rate decreases by approximately 5 kg/t from to kg/t. The tumble index is similar to the base blend at 69.4%. 3) When substituting 15% Marillana fines for 15% of Yandi fines in base blend 1, the productivity increases from to t/m 2 d and the fuel rate decreases by approximately 4 kg/t from to kg/t. The tumble index decreases slightly to 68.47%. 4) When substituting 10% Marillana fines for 10% of Robe River fines in base blend 1, the productivity increases from to t/m 2 d and the fuel rate decreases by approximately 4 kg/t from to kg/t. The tumble index is almost the same as base blend 1 at 69.74%. 5) When substituting 25% Marillana fines for 15% Yandi fines and 10% Robe River fines in base blend 1, the productivity increases from to t/m 2 d and the fuel rate decreases by approximately 4 kg/t from to kg/t. The tumble index is similar to base blend 1 at 69.20%. 6) For Series 3, blend 12 removes some coarse materials compared to blend 1 by substituting Newman fines. Therefore blend 12 consists of 25% PB fines, 10% Yandi fines, 5% FMG Rocket fines, 20% Newman fines, 10% SSF fines Sintering Performance of Brockman s Marillana Fines Sample August

58 and 30% domestic magnetite concentrate and is the base blend for Series 3. It was anticipated that the productivity for blend 12 may be lower than blend 1 due to the finer blend; however, this did not prove to be the case. Blend 12 and blend 1 productivities were and t/m 2 d respectively. Blend 13 introduces 20% of BIPL Marillana fines to replace Newman fines in base blend 12 and the productivity increases from to t/m 2 d, the fuel rate is similar and the tumble index decreases from 69.60% to 68.84%. 7) Series 2 includes five ore blends (Blend 8-11 and 15) which were based on the typical sinter blend for coastal mills of China. Blend 8 is the base blend. When substituting 15% Marillana fines for 15% FMG Rocket fines, the productivity increases from to t/m 2 d, the fuel rate decreases by 0.9 kg/t from to kg/t and the tumble index is almost the same as blend 8 at 67.77%. When substituting 15% Marillana fines for 15% Newman fines, the productivity increases from to t/m 2 d, the fuel rate decreases by approximately 4 kg/t from to kg/t and the tumble index decreases from 67.80% to 66.0%. When substituting 15% Marillana fines for 15% Yandi fines, the productivity increases from to t/m 2 d, the fuel rate decreases approximately 4 kg/t from to kg/t and the tumble index decreases from 67.80% to 66.50%. When substituting 15% Marillana fines for 15% PB fines, the productivity increases from to t/m 2 d, the fuel rate decreases about 4 kg/t from to kg/t and the tumble index is almost the same as blend 8 at 67.90%. 8) Sinter Chemistry: Because of the higher SiO 2 and Al 2 O 3 content of Marillana fines, the Fe grade of the Marillana sinter products decreased slightly and the SiO 2 and Al 2 O 3 content increased slightly. In terms of other contaminants, such as P, the differences for the various sinter products are negligible. 9) The Reducibility Index (RI) for all blends is high (i.e. >85%), which is regarded as being very good. The Series 1 blends (inland mills) had a lower RI, ranging from % versus base blend 1 of 91.34%; Series 2 blends (coastal mills) were higher, ranging from % versus base blend 8 of 85.44%; and the Series 3 blend (inland mills) was higher at 92.64% versus base blend 12 of 84.33%. 10) The Reduction Degradation Index (RDI) for all blends was above the nominal target of 35%. The Series 1 blends were mixed, ranging from % versus base blend 1 of 38.73%; Series 2 blends were lower, ranging from % versus base blend 8 of 41.6%; and the Series 3 blend Sintering Performance of Brockman s Marillana Fines Sample August

59 was higher at 42.43% versus base blend 12 of 35.41%. 11) The Softening and Melting properties for Series 1 blends are generally similar, and the comprehensive melting property (S value) improves slightly (ie. is lower) when substituting Marillana fines for other Australian iron ores. The softening and melting properties for Series 2 blends are also similar, while the S value for the Series 3 blend is higher. 12) The Mineral Composition and Microstructure of the fifteen blends are very similar as a typical high basicity sinter. Magnetite is the dominant ferrous mineral of sinter followed by hematite with calcium ferrites, the main bonding phase. These ferrites appear mainly in the form of platelike CaO Fe 2 O 3, acicular SFCA, and small amounts of CaO 2Fe 2 O 3. The rest of the bonding minerals are glass, β-2cao SiO 2, and small amounts of melilite and periclase. The microstructure of the sinters is a heterogeneous structure, which includes ferrous minerals bonded by interlocking platelets and acicular calcium ferrite; and ferrous minerals bonded by glass, β-2cao SiO 2 and melilite, the relict structure of hematite. Sintering Performance of Brockman s Marillana Fines Sample August

60 APPENDIX A Definitions of Sintering Parameters Sintering Performance of Brockman s Marillana Fines Sample August

61 All calculations below are performed based on the dry weights of raw materials. Raw Materials Used in the Sinter Mix 1 Fine ores and concentrates, M1 2 Fluxes limestone, dolomite and burnt lime, M2 3 Fuel coke breezes, M3 4 Return fines, M4 Total Dry Mix Basis [tdmb] Fuel and Return Fines are expressed as a percentage of the total dry mix including the return fines Coke [%tdmb] = [M3/(M1+M2+M3+M4)] * 100 Return Fines [%tdmb] = [M4/(M1+M2+M3+M4)] * 100 Return Fines Balance [RFB] = Mass of Returns Out / Mass of Returns In = R out / M4 M (1,2,3,4) in Sinter Pot M p (+5 mm) R out (-5 mm) Productivity = M p /[(sintering time) * (cross sectional area of pot)] Where: M p is the total mass of sinter product (+5.0 mm less the hearth layer mass). Sintering Performance of Brockman s Marillana Fines Sample August

62 Balanced Productivity and Fuel Rate Normalised ( balanced ) productivities and fuel rates were used for comparisons in all pot grate test work. They were normalised with respect to the RFB, i.e. assuming RFB=1.0. This was done to enable accurate assessment and comparisons between blends. (a) If R out > R in, then RFB > 1, then Balanced Productivity = {Balanced mass of product sinter} / {time*pot area} = {M p + R out - R in } / {(sint. time)*(cross-sect. pot)} (b) If R out < R in, then RFB < 1, then Balanced Productivity = {Balanced mass of product sinter} / {time*pot area} = {M p - R out - R in } / {(sint. time)*(cross-sect. pot)} Balanced Fuel = {Mass of fuel (dry weight)} / {balanced mass of product sinter} = {kg coke/ t product sinter} % Yield = {M p /(M p + R out )} * 100 Sintering Time The sintering time is defined as the time elapsed from the commencement of the ignition cycle to the time when the waste gas temperature reaches a maximum. Sintering Performance of Brockman s Marillana Fines Sample August

63 APPENDIX B Summary Tables for Sintering Test Results Sintering Performance of Brockman s Marillana Fines Sample August

64 Results from Pilot Scale Pot Sintering Test Blend 1 & Blend 2 Blend Total Return Sintering Vertical Product ISO Solid Sinter product size distribution,% Balanced Balanced C sinter Yield Productivity fines No. time speed weight RFB TI fuel productivity Fuel rate % weight % t/m mins mm/min kg 2 d weight > AMD % kg/t t/m kg kg 2 d kg/t mm mm mm mm mm mm 1 # # # # # # # # Sintering Performance of Brockman s Marillana Fines Sample August

65 Blend 3, Blend 7 & Blend 14 Blend 3 No. Total Return Sintering Vertical Product ISO Solid Sinter product size distribution,% Balanced Balanced C sinter Yield Productivity fines time speed weight RFB TI fuel productivity Fuel rate % weight % t/m2d weight > AMD mins mm/min kg % kg/t t/m2d kg/t kg kg mm mm mm mm mm mm 9 # # # # # # # # # # # # Sintering Performance of Brockman s Marillana Fines Sample August

66 Blend 4, Blend 5 & Blend 6 Blend 4 No. C % Sintering time mins Vertical speed mm/min Total sinter weight kg Product weight kg Yield % Productivity t/m 2 d Return fines weight kg RFB ISO TI % Solid fuel kg/t >40 mm Sinter product size distribution,% mm mm mm 10-5 mm AMD mm Balanced productivity t/m 2 d 21 # # # Balanced Fuel rate kg/t 5 24 # # # # # # Sintering Performance of Brockman s Marillana Fines Sample August

67 Blend 12 & Blend 13 Blend Total Return Sintering Vertical Product ISO Solid Sinter product size distribution,% Balanced Balanced C sinter Yield Productivity fines No. time speed weight RFB TI fuel % weight % t/m mins mm/min kg 2 d weight > AMD productivity Fuel rate % kg/t t/m kg kg mm mm mm mm mm mm 2 d kg/t 30 # # # # # # # # # # Sintering Performance of Brockman s Marillana Fines Sample August

68 Blend 8 & Blend 9 Blend Total Return Sintering Vertical Product ISO Solid Sinter product size distribution,% Balanced Balanced C sinter Yield Productivity fines No. time speed weight RFB TI fuel % weight % t/m mins mm/min kg 2 d weight > AMD productivity Fuel rate % kg/t t/m kg kg mm mm mm mm mm mm 2 d kg/t 40 # # # # # # # # # # # # # # Sintering Performance of Brockman s Marillana Fines Sample August

69 Blend 10 & Blend 11 Blend Total Return Sintering Vertical Product ISO Solid Sinter product size distribution,% Balanced Balanced C sinter Yield Productivity fines No. time speed weight RFB TI fuel % weight % t/m mins mm/min kg 2 d weight > AMD productivity Fuel rate % kg/t t/m kg kg mm mm mm mm mm mm 2 d kg/t 54 # # # # # # # # # # # # # # Sintering Performance of Brockman s Marillana Fines Sample August

70 Blend 15 Blend No. C % Sintering time mins Vertical speed mm/min Total sinter weight kg Product weight kg Yield % Productivity t/m 2 d Return fines weight kg RFB ISO TI % Solid fuel kg/t Sinter product size distribution,% Balanced productivity t/m 2 d 68 # >40 mm mm mm mm 10-5 mm AMD mm Balanced Fuel rate kg/t # # # Sintering Performance of Brockman s Marillana Fines Sample August

71 Results from Granulation Test Blend 1 & Blend 2 Blend C Moisture Size distribution of mix,% Bulk density No. % % >10 mm 10-8 mm 8-5 mm 5-3 mm 3-1 mm <1 mm AMD (mm) kg/m 3 1 # # # # # # # # Sintering Performance of Brockman s Marillana Fines Sample August

72 Blend 3, Blend 7 & Blend 14 Blend 3 C Moisture Size distribution of mix,% Bulk density No. % % >10 mm 10-8 mm 8-5 mm 5-3 mm 3-1 mm <1 mm AMD (mm) kg/m 3 9 # # # # # # # # # # # # Sintering Performance of Brockman s Marillana Fines Sample August

73 Blend 4, Blend 5 & Blend 6 Blend 4 C Moisture Size distribution of mix,% Bulk density No. % % >10 mm 10-8 mm 8-5 mm 5-3 mm 3-1 mm <1 mm AMD (mm) kg/m 3 21 # # # # # # # # # Sintering Performance of Brockman s Marillana Fines Sample August

74 Blend 12 & Blend 13 Blend C Moisture Size distribution of mix,% Bulk density No. % % >10 mm 10-8 mm 8-5 mm 5-3 mm 3-1 mm <1 mm AMD (mm) kg/m 3 30 # # 3, # # # # # # # # Sintering Performance of Brockman s Marillana Fines Sample August

75 Blend 8 & Blend 9 Blend C Moisture Size distribution of mix,% Bulk density No. % % >10 mm 10-8 mm 8-5 mm 5-3 mm 3-1 mm <1 mm AMD (mm) kg/m 3 40 # # # # # # # # # # # # # # Sintering Performance of Brockman s Marillana Fines Sample August

76 Blend10 & Blend 11 Blend C Moisture Size distribution of mix,% Bulk density No. % % >10 mm 10-8 mm 8-5 mm 5-3 mm 3-1 mm <1 mm AMD (mm) kg/m 3 54 # # # # # # # # # # # # # # Sintering Performance of Brockman s Marillana Fines Sample August

77 Blend 15 Blend C Moisture Size distribution of mix,% Bulk density No. % % >10 mm 10-8 mm 8-5 mm 5-3 mm 3-1 mm <1 mm AMD (mm) kg/m 3 68 # # # # Sintering Performance of Brockman s Marillana Fines Sample August

78 APPENDIX C Detailed Results of RI, RDI, and Softening and Melting Properties Sintering Performance of Brockman s Marillana Fines Sample August

79 The following charts plot the change in reducibility (%) and weight loss (g) against reduction time (min) for each blend Weight loss (g) Weight loss Reducibility Reduction time(min) Reducibility (%) Blend 1 Weight loss (g) Weight loss Reducibility Reduction time(min) Reducibility (%) Blend 2 Sintering Performance of Brockman s Marillana Fines Sample August

80 Weight loss (g) Weight loss Reducibility Reduction time(min) Reducibility (%) Blend 3 Weight loss (g) Weight loss Reducibility Reduction time(min) Reducibility (%) Blend 7 Sintering Performance of Brockman s Marillana Fines Sample August

81 Weight loss (g) Weight loss Reducibility Reduction time(min) Reducibility (%) Blend 14 Weight loss (g) Weight loss Reducibility Reduction time(min) Reducibility (%) Blend 4 Sintering Performance of Brockman s Marillana Fines Sample August

82 Weight loss (g) Weight loss Reducibility Reduction time(min) Reducibility (%) Blend 5 Weight loss (g) Weight loss Reducibility Reduction time(min) Reducibility (%) Blend 6 Sintering Performance of Brockman s Marillana Fines Sample August

83 Weight loss (g) Weight loss Reducibility Reduction time(min) Reducibility (%) Blend 12 Weight loss (g) Weight loss Reducibility Reduction time(min) Reducibility (%) Blend 13 Sintering Performance of Brockman s Marillana Fines Sample August

84 Weight loss (g) Weight loss Reducibility Reduction time(min) Reducibility (%) Blend 8 Weight loss (g) Weight loss Reducibility Reduction time(min) Reducibility (%) Blend 9 Sintering Performance of Brockman s Marillana Fines Sample August

85 Weight loss (g) Weight loss Reducibility Reduction time(min) Reducibility (%) Blend 10 Weight loss (g) Weight loss Reducibility Reduction time(min) Reducibility (%) Blend 11 Sintering Performance of Brockman s Marillana Fines Sample August

86 Weight loss (g) Weight loss Reducibility Reduction time(min) Reducibility (%) Blend 15 Sintering Performance of Brockman s Marillana Fines Sample August

87 Low temperature reduction degradation data for each blend Blend RDI +6.3 mm % RDI mm % RDI -0.5 mm % RDI mm % Blend Blend Blend Blend Blend Blend Blend Blend Blend Blend Blend Blend Blend Blend Blend Sintering Performance of Brockman s Marillana Fines Sample August

88 Softening & Melting Performance - the following charts plot the changes to displacement (mm) and pressure (Pa) against temperature ( C) for each blend Blend 1 Blend 2 Sintering Performance of Brockman s Marillana Fines Sample August

89 Blend 3 Blend 7 Sintering Performance of Brockman s Marillana Fines Sample August

90 Blend 14 Blend 4 Sintering Performance of Brockman s Marillana Fines Sample August

91 Blend 5 Blend 6 Sintering Performance of Brockman s Marillana Fines Sample August

92 Blend 12 Blend 13 Sintering Performance of Brockman s Marillana Fines Sample August

93 Blend 8 Blend 9 Sintering Performance of Brockman s Marillana Fines Sample August

94 Blend 10 Blend 11 Sintering Performance of Brockman s Marillana Fines Sample August

95 Blend 15 Sintering Performance of Brockman s Marillana Fines Sample August