3 rd International Conference on Alternate Fuels and Raw Materials in Cement Industry on March 23-24, 2017

Transcription

1 3 rd International Conference on Alternate Fuels and Raw Materials in Cement Industry on March 23-24, 2017 Best Practices in Utilization of Alternate Raw Materials : Utilization of wastes Jarosite and Lead Zinc Slag Presented by Akhilesh Shukla Head R&D Hindustan Zinc Limited 1

2 Hindustan Zinc Hindustan Zinc Snapshot 2

3 Hindustan Zinc A Sustainable Enterprises 3

4 Defining the Benchmark 4

5 Safety & Sustainability 5

6 Portfolio of Tier 1 Assets 6

7 Strong Track Record of Growth 7

8 Community Engagement 8

9 Hindustan Zinc Major Waste Profile Particular Approx Generation (MT/year) Locations Jarosite 45,000 60,000 Debari SLF Jarofix Lac Dariba, Chanderiya SLF ISF Slag 70,000 80,000 Chanderiya Sold Current Status Fuming Slag Lac Dariba Partly sold MCTP Slag 40,000 50,000 Debari Yard Flyash 3.0 Lac Chanderiya, Dariba, Zawar Gypsum cake 8,000 10,000 Dariba, Chanderiya, Debari Sold SLF 9

10 Hindustan Zinc Major Waste Profile Constituents ISF Slag FF Slag Flyash* SiO % 30-35% 50 60% Fe 2 O % 30 35% 4 6% Al 2 O 3 7-9% 8 10% 25 30% CaO 15-19% 16 19% <1% MgO % 4 7% <1% ZnO 4-10% 2 2.5% - PbO % - - SO % <0.1% <0.5% Carbon 0.5-1% - <1% Alkali <1% 2 3% <2% LOI - 2.5% 8.8% IR - ~ 1.34% 85-90% * Already being used in PPC. 10

11 Hindustan Zinc Major Waste Profile Constituents Jarosite Jarofix Gypsum SiO % 11.16% 20.74% (silica + IR) Fe 2 O % 25.18% 0.59% Al 2 O % 6.72% 0.37& CaO % 12.78% 26.5% MgO % 0.45% 0.33% ZnO 2 2.5% - - PbO % - - SO % 20.80% 33.26% Carbon Alkalki <1% <3% <0.2% LOI 8 10% 27.15% - IR % 16.10% - 11

12 Characterization of Major Wastes ISF Slag Glass Content : 42% Glass Content of Devitrified Slag : 72% (1350 o C, water quenched) Bond Grindability Index : kwh/short-ton Blast Furnace Slag Glass Content : 97% Bond Grindability Index : 15.8 kwh/short-ton Flyash Lime Reactivity : 6.4 Mpa Blaine s fineness : 406 m 2 /kg FF Slag Glass Content : 88% Jarosite Blaine fineness : >600 m 2 /kg 12

13 Initiatives for ISF Slag Utilization Cement & Construction Industries by NCBM, Ballabhgarh Properties of concrete prepared from ISF slag S.No. Properties PSC-Control PSC Slag OPC-Control OPC Slag 1 Compressive Strength (N/mm 2 ) Flexural Strength (N/mm 2 ) Carbonation Nil Nil Nil Nil Modulus of Elasticity (N/mm 2 ) 2.36x x x x Drying Shrinkage(%) Chloride Ion Permeability (Coulombs)

14 Initiatives for ISF Slag Utilization Cement & Construction Industries by NCBM, Ballabhgarh Weight Loss of cement mortar cured in different environment S.No. Sample 1. Control OPC 2. OPC Slag 3. Control - PSC 4. PSC Slag Curing Loss on ignition at different ages (%) Environment 14 days 28 days Normal Sulphate Chloride Alkali Normal Sulphate Chloride Alkali Normal Sulphate Chloride Alkali Normal Sulphate Chloride Alkali

15 Initiatives for ISF Slag Utilization Raw material that can be substituted with ISF slag in cement plant (Tentative Calculation) Source Fe 2 O 3 CaO SiO 2 Al 2 O 3 Bauxite Makeup for Al 2 O MT slag can substitute 34 MT 18 MT 12.5 MT 7.68 MT MT (to be added) Coal Saved 2.67 MT 15

16 Initiatives for ISF Slag Utilization Current Status BIS approval received for using Lead Zinc slag as performance improver in OPC (IS 269). RSPCB consent available with HZL for its sale for cement manufacturing, road construction, bricks & tiles manufacturing. More than 4 Lac MT slag sold to nearby cement manufacturers in last 5 years, mainly to Shree Cement, Lafarge, JK cement, Aditya Cement, Birla Cement etc. 16

17 Initiatives for ISF Slag Utilization Road Construction Studies by CRRI, New Delhi Feasibility study were done for using ISF slag as fine aggregate for construction of embankments, GSB, cement concrete and bituminous layers Geotechnical properties of ISF slag and local soil Property ISF Slag Local Soil MoRTH Specifications Embankment MoRTH Specifications Subgrade classification Poorly Graded Sand Sandy Clay - - Sp. Gravity Liquid Limit,% Less Than 70 Less Than 70 Plasticity Index, % Non plastic 21 Less than 45 Less than 45 Density, kn/cu.m Min. 15.2, h < 3m Min. 16, h > 3m Min Angle of internal Friction, φ 37 deg. 25 deg. - - Cohesion, c, kn/sq.m zero CBR, % Permeability, m/sec 1.4 x

18 Initiatives for ISF Slag Utilization Geotechnical properties of ISF slag and local soil mixes Property 75% Slag 25 % Soil 50 % Slag 50 % soil 25 % Slag 75 % Soil MoRTH Specifications Embankment/Subgrade Liquid Limit,% Less Than 70 Plasticity Index, % Density, kn/cu.m Angle of internal Friction, φ Cohesion, c, kn/sq.m Non plastic Non plastic 13.5 Less than Min. 15.2, h < 3m Min. 16, h > 3m Min. 17.5(subgrade) 34 deg. 32 deg zero CBR, % Permeability, m/sec 6.7 x x x Geotechnical properties of cement stabilized mixes Mix 25 % ISF, 75 % Soil 50 % ISF, 50 % Soil 75 % ISF, 25 % Soil Cement Content, % Avg. UCS kn/m

19 Initiatives for ISF Slag Utilization ISF Slag is a sand size material with good density, high angle of friction and good drainage property. ISF Slag and slag-soil mixes satisfies the specified density and plasticity requirements for embankment and subgrade applications. 50% Slag and 50% soil mix has better CBR and permeability and may be used in sub-base layer. ISF Slag may be used in cement stabilized sub-bases. 15% Slag may be used in WMM layer. 10% Slag may be used in BM Grade I & II. 25% Slag may be used in DBM Grade I & II % Slag may be used in SDBC and BC Mixes. 20 to 40% slag may be used in PQC mixes. Up to 20% slag may be used in DLC mixes. Meets all required specs of MORTH in embankment, GSB, BM, etc. Proven material for road construction in many layers. Contractors are very much willing to lift the material, but constrained by the lack of mention of slag in BOM / TOR with NHAI and statutory permits to utilize the same. Easily available in huge quantities vis-à-vis soil and stones in the vicinity. Natural soil is sparely available. Cheaper material Lead distance almost same as for soil and stones. Road construction is much economical as compared to that of road constructed with soil & stone aggregates. 19

20 Initiatives for Jarosite Utilization Jarosite as Set Controller in Cement Industry by NCBM, Ballabhgarh Control sample - OPC clinker was inter ground with 5% mineral gypsum. Further study was taken up on roll of Jarosite as set retarder of OPC by total/part replacement of gypsum. Different cement samples were prepared by inter grinding of clinker of different doses of Jarosite in ball mill (1-5% replacement). Blain fineness is 3360/3220 at 5% replacement against 3110 in control. At 3% replacement LOI/SO3/IR is %/ %/ %. This comply IS: Blain fineness increased with increased dose of Jarosite Heat of hydration decreased with 3% Jarosite load Differential leaching of toxicants is not remarkable as compared to Control OPC Compressive strength in different curing media increased with Jarosite cement as compared to control cement, remarkably in alkali soln by 6-7 Mpa. 3% replacement was observed to be optimum and ideal. BIS recommended that Jarosite can be used within the 1% of additions along with set retarder, which is not harmful. 20

21 Initiatives for Jarosite Utilization Jarosite as Mineralizer in Cement Industry by NCBM, Ballabhgarh % of typical Jarosite in cement raw mixes with different limestone grades & other conventional materials were studied The clinker parameters such as LSF, SM and AM were maintained in the range of 0.92, and respectively. The mineral phase developments and micro-structures of laboratory clinkers fired at 1400±5 o C were found to be adequate in presence of optimum dose of 1.5% Jarosite and were comparable to control clinker (without Jarosite addition) prepared at 1450±5 o C. The presence of Fe 2 O 3, SO 3 and ZnO in Jarosite has led to fluxing and mineralizing effect on clinkerization reaction. Burnability studies of cement raw mixes utilizing 1.5% optimised dose of o C showed: Lowering in clinkerization temperature by ~50 o C, Increase in the rate of lime assimilation, Increase in the formation of C 3 S Physical performance of ordinary Portland cement prepared using Jarosite at ~50 o C lower temperature was found to be comparable to control cement. The leaching of heavy elements including zinc and lead was found to be negligible indicating its fixation in hydrated phases. 21

22 Other Initiatives Hindustan Zinc is exploring different avenues for consumption of its wastes. One of the opportunity lies in Paste Fill plant of underground mines. FF slag, Jarosite and Flyash consumption is being explored with partial replacement of cement in paste fill plants. The results are positive. Proportion of solid powders Compressive Strength, (MPa) Tailing, % OPC, % 7 Days 28 Days Proportion of solid powders Tailings% OPC, % FF Slag, % Compressive Strength (MPa) 7 Days 28 Days Proportion of solid powders Compressive Strength (MPa) Tailings % OPC, % Flyash, % 7 Days 28 Days Proportion of solid powders Compressive Strength (MPa) Tailing% OPC, % Jarosite, % 7 Days 28 Days Studies are also being done for usages of Jarosite in Concrete and Mortar. 22

23 Thanks... 23