BLAST FURNACE IRDNMAKING Based on lectures delivered in the Advanced Course on "Blast Furnace Ironmaking' held at Jamshedpur 18-23 February 1991. TATA STEEL EDITED BY S S GUPTA AND AMIT CHATTERJEE
Contents PREFACE 1. IRON ORE RESOURCES OF TATA STEEL AND ITS QUALITY CONTROL A W Pradhan, Tata Steel, Jamshedpur 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 1.10 1.11 Introduction 1 History 2 Genesis 2 Proving the Deposit....... 2 o j*^»*» Reserves 2 Quality 2 Petrography of Iron Ores 3 Comparison between Noamundi and Joda Deposits 4 Ore Preparation 4 Future Planning 6 Conclusions 6 2. BENEFICIATION OF IRON ORES Ch V G K Murty and R Sripriya, Tata Steel, Jamshedpur 2.1 Introduction 2.2 Mineralogical Aspects 2.3 Beneficiation Methods 2.4 Iron Ore Beneficiation at Tata Steel 15 3. COKING COAL : ORIGIN, MINING AND QUALITY CONTROL S K Lonial, Tata Steel, Jamshedpur 3.1 3.2 3.3 3.4 3.5 3.6 3.7 Introduction 17 Origin and Characteristic Features of Indian Coals 17 Tata Steel's Coking Coal Captive Sources 18 Quality Control 18 Quality of Coal Despatched Imported Coal and its Quality Conclusions 20 20 21 4. COAL BENEFICIATION R Sripriya and V G. K Murty, Tata Steel, Jamshedpur 4.1 Introduction 4.2 Laboratory Sink-Float Tests 4.3 ' Washability Curves 4.4 Coal Washing Coarse Coal 4.5 Coal Washing Fine Coal 4.6 Scenario at Tata Steel 4.7 Conclusions 22 22 23 24 27 29 30
5. TECHNIQUES OF COAL PRE-CARBONISATION : A REVIEW Amit Chatterjee, Tata Steel, Jamshedpur 5.1 Introduction 31 5.2 Preheating of Coal 31 5.3 Briquette-Blending of Coal 32 5.4 Selective Crushing of Coal ; 34 5.5 Binderless Briquetting of Coal 35 5.6 Stamp-Charging of Coal 35 5.7 Conclusions 38 6. EXPERIENCES IN THE STAMP-CHARGED BATTERY AT TATA STEEL B K Singh, K C Banerjee and A S Dhillon, Tata Steel, Jamshedpur 6.1 Introduction 40 6.2 Stamped-Charged Battery- Learning Period 40 6.3 Performance of Stamp- Charged Battery 43 6.4 Appropriate Technology under Indian Conditions 45 6.5 Conclusions 45 7. SINTERING TECHNOLOGY IN TATA STEEL S G Bapat, Tata Steel, Jamshedpur 7.1 Introduction 49 7.2 Operation at Ore Curshing and Sintering Plant 49 7.3 Present Capacity 51 7.4 Bedding and Blending Plant 53 7.5 Sinter Plant No. 2 53 7.6 Future Trends 55 7.7 Conclusions 58 8. TESTING OF IRON OXIDES AND THEIR SELECTION FOR DIFFERENT APPLICATIONS IN IRONMAKING A K Jouhari, R K Sahoo and H S Ray, Regional Research Laboratory, Bhubaneswar 8.1 Introduction 60 8.2 The Iron Blast Furnace 61 8.3 Physical Tests.: 62 8.4 Chemical Tests 63 8.5 Mineralogical Characterisation 63 8.6 Thermal Analysis 64 8.7 Metallurgical Tests 69 8.8 Discrepancy in Tests and Correlation 72 8.9 Some Examples 72 8.10 Conclusions.'. 80
9. TESTING AND CHARACTERISATION OF SINTER FOR BLAST FURNACES K N Gupta, National Metallurgical Laboratory, Jamshedpur 9.1 Introduction 82 9.2 Desirable Qualities of Sinter 82 9.3 Conclusions 93 10. BLAST FURNACE IRONMAKING AT TATA STEEL L M Chatterjee, Tata Steel, Jamshedpur 10.1 Introduction 95 10.2 The Eighties a Decade of Progress 95 10.3 Burden Quality the First Step 98 10.4 Design and Equipment Modifications 99 10.5 Operating Philosophy 100 10.6 Maintenance 100 10.7 Coal Injection 101 10.8 Instrumentation and Models 101 10.9 Future Trends at Tata Steel 101 10.10 Conclusions 102 11. RAW MATERIALS FOR BLAST FURNACES : IMPLICATIONS AND OPPORTUNITIES FOR TATA STEEL Ashok Kumar and T Mukherjee, Tata Steel, Jamshedpur 11.0 Introduction 103 11.2 Impact of Raw Material Quality 103 11.3 Objectives for Ironmaking Facilities 104 11.4 Uniformity an Opportunity : 105 11.5 Coal 106 11.6 Iron-Bearing Materials 107 11.7 Fluxes and Alkali Loading..' 109 11.8 Conclusions 109 12. HIGH TEMPERATURE PROPERTIES OF IRON BEARING MATERIALS AND THEIR INFLUENCE ON BLAST FURNACE PERFORMANCE P K Roy, U N Mishra and S Pal, Research and Development Centre for Iron and Steel, SAIL, Ranch! 12.1 Introduction 110 12.2 Softening and Melting Phenomena Ill 12.3 Application of Test Results :... 112 12.4 Effect of Different Factors on Softening and Melting Properties 114 12.5 Practical Application of Test Results in Blast Furnace Operation 115 12.6 Work Done at RDCIS, SAIL 117 12.7 Application of Laboratory Findings 118 12.8 Conclusions 119
13. BLAST FURNACE BURDEN DISTRIBUTION : MODEL STUDIES Anjan De, Tata Steel, Jamshedpur 13.1 Introduction 121 13.2 Model Studies with Movable Throat Armour 121 13.3 Development of Mathematical Model to Estimate Burden Distribution 128 13.4 Model Study for'g'blast Furnace with PW-BLT Charging System 129 13.5 Conclusions 130 14. MANAGING THE ALKALI PROBLEM A K Das, Tata Steel, Jamshedpur 14.1 Introduction : 135 14.2 The Alkali Cycle Inside a Blast Furnace 135 14.3 Properties of Raw Materials Affected by Alkali Adsorption 136 14.4 Fundamentals of Alkali Management 136 14.5 Steps Taken at Tata Steel, 136 14.6 Results Achieved 138 14.7 Conclusions 138 15. OPTIMISATION OF BLAST FURNACE SLAG REGIME S S Gupta, Tata Steel, Jamshedpur 15.1 Introduction 140 15.2 Basic Requirements of Slag for Normal Operation of a Blast Furnace 140 15.3 Liquidus Temperature 141 15.4 Viscosity of Slag : 143 15.5 Desulphurisation Capacity of Slags 144 15.6 Alkali Removal Capacity of Slags 146 15.7 Slag Alumina 146 15.8 Conclusions. 146 16. COAL INJECTION IN BLAST FURNACES : THEORETICAL CONSIDERATIONS B D Pandey, Tata Steel, Jamshedpur 16.1 Introduction 148 16.2 Coal Quality 148 16.3 Coal Combustion 149 16.4 Coal Injection Mode-Position of Coal Lance in the Blow Pipe 150 16.5 Rate of Coal Injection 151 16.6 Heat Compensation 151 16.7 Surplus Oxygen Coefficient 151 16.8 Replacement Ratio 152 16.9 Effect of Coal Injection 152 16.10 Considerations at Tata Steel 155
16.11 Ultra High Rates of Coal Injection 158 16.12 Conclusions, 160 17. COAL INJECTION INTO BLAST FURNACES : INJECTION EQUIPMENT G K Taneja, Tata Steel, Jamshedpur 17.1 Introduction 162 17.2 PCI System at Tata Steel 162 17.3 Safety Precautions 164 17.4 Other Coal Injection Systems 165 17.5 Conclusions :! 166 18. MODEL STUDY OF HEARTH DRAINAGE IN A BLAST FURNACE A K Roy, S Govindarajan and Amit Chatterjee, Tata Steel, Jamshedpur 18.1 Introduction 167 18.2 Study of the Drainage Phenomenon 167 18.3 Objectives of the Tata Steel Study 167 18.4 Experimental 168 18.5 Observations.- 168 18.6 Results and Discussion.' 169 18.7 Conclusions 170 19. STUDY OF HOT METAL DRAINAGE IN THE HEARTH OF AN OPERATING BLAST FURNACE USING RADIOTRACERS A S Prasad, Tata Steel, Jamshedpur 19.1 Introduction : 1 /I 19.2 Theoretical Considerations 171 19.3 Experimental Details 172 19.4 Discussion 173 19.5 Conclusions 173 20. MATHEMATICAL MODELS OF BLAST FURNACES S K Ajmani and S S Gupta, Tata Steel, Jamshedpur 20.1 Introduction 174 20.2 Model for Determination of Top Gas Analysis 174 20.3 Model for Prediction of Coke Rate, Blast Rate and Top Gas Rate -. : 175 20.4 Burden Distribution Model 179 20.5 Conclusions 179 21. BLAST FURNACE HOT METAL QUALITY : MECHANISM, PREDICTION AND CONTROL B N Singh, Indian Iron and Steel Company Limited, Burnpur and Amit Chatterjee, Tata Steel, Jamshedpur 21.1 Introduction 183 21.2 Silicon Content in Hot Metal : 184 21.3 Manganese Content in Hot Metal.-.,. 187 21.4 Control of Sulphur in Hot Metal :. 188 21.5 Conclusions 190
22. PRETREATMENT OF HOT METAL A S Venkatadri, R & D Centre for Iron & Steel, Steel Authority of India Limited, Ranchi 22.1 Introduction 192 22.2 Objectives of Pretreatment 192 22.3 Need for Hot Metal Pretreatment 193 22.4 Physico-Chemical Aspects 194 22.5 Desiliconisation 198 22.6 Pretreatment Processes 200 22.7 Refractories 203 22.8 Status of Hot Metal Pretreatment India 204 22.9 A Strategy for India : Future Tasks and Prospects 206 23. IRONMAKING THROUGH TATA KORF'S MINI BLAST FURNACE P Jayaram, V K Lakshmanan and P K Date, Tata Korf, Jamshedpur 23.1 Introduction 209 23.2 Mini Blast Furnace Process! 209 23.3 Significance of Mini Blast Furnaces in India 210 23.4 Tata Korf Mini Blast Furnaces: Basic Plant and Equipment '. 210 23.5 The Tata Korf MBF Compared to the Conventional Blast Furnace 211 23.6. Performace of the MBF 212 23.7 Economics of the MBF : 213 23.8 Low-Energy Input Achieved by Coke Economy 214 23.9 High-Energy Utilisation 214 23.10 MBF as the Basis of a Mini Steel Plant 216