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R&D FOR INDIAN IRON & STEEL INDUSTRY: FUTURE DIRECTIONS. S.P. Mehrotra. Professor Indian Institute of Technology Kanpur -208 016 www.iitk.ac.in. R&D Drivers. R&D DRIVERS. Resource availability Complexity of raw materials Energy considerations Process efficiency Strategic reasons
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R&D FOR INDIAN IRON & STEEL INDUSTRY: FUTURE DIRECTIONS S.P. Mehrotra Professor Indian Institute of Technology Kanpur -208 016 www.iitk.ac.in
R&D Drivers R&D DRIVERS • Resource availability • Complexity of raw materials • Energy considerations • Process efficiency • Strategic reasons • Materials performance/properties • Resource conservation through R3 • Environmental impact
A COMPARISON • World Steel Production: Over 1300 MT • Indian Steel Production: Around 55 MT • Contributing only: 4.2% • World average steel consumption: 175 Kg/ capita • Indian consumption: 33 Kg/ Capita FURNACE PERFORMANCE
Proposed Production 2019-20 = 0.4 bt Will last for next 40-50 years ? 26 billion tonne Hematite-14 bt Downgrade cut off to 52% Fe and threshold to 40% Fe Concern Availability Consumption Initiative • High Alumina • Intricate nature • Poor liberation • Utilization of magnetite • Processing fines • Increase sinters/pellets Issues Options Indian Iron Ore Problems Challenges # Total beneficiation #Shift from lumps to beneficiated fines #Higher proportion of blue dust in sinter #Low grade fines for DR processes #Exploitation of low grade ores >45% Fe # Utilisation of residual slimes/ tailings Solutions Complex association of Hematite (white) with Goethite (dull grey), Quartz (gray) and Clay (brown) # Development of fine particle processing like Teetered Column, Packed column Jig, Centrifugal separators, Flotation, Magnetic Separation # Solid–liquid separation # Improved sintering # Pelletisation with improved properties
COAL • Low coking coal reserves at 5.3 bt • Low vol. semi-coking /non-coking at 120 bt • High Ash Content • High NGM • Poor liberation • Difficult to wash Issues • Beneficiation options • Low ash (8-10%) clean coal with low yield • Restriction of fines in coke making • Low ash, high sulphur NE coals Problems • Fine gravity separation • Flotation • Bio-beneficiation • Reagent regime • Dewatering Challenges
SPECIFICATIONS OF IRON ORE FOR I & S MAKING BF Fe - 63.5-65 % Al2O3 - <2 % Al2O3/SiO2 - <1.0 DR Processes Fe - >65% SiO2 + Al2O3 - 2% World Practice: Al2O3 <1 % for fines used for sintering The Problem : HIGH ALUMINA (Al2O3/SiO2 > 1.0) Affects Efficient operation of BF
OBSERVATIONS ON CURRENT INDUSTRIAL PRACTICE • With the availability of iron ore reserves most of the iron ore mines in India have been operated by selective mining for maintaining high grade of ore. • The current industrial practice of iron ore washing is oriented towards product with 2.5-3.0 Al2O3. • To maintain high grade ore, low grade lumps and laterites are rejected. Generally fines (-10+0.15 mm) are not being processed and if alumina content is high, these are dumped. • The present iron ore washing circuit produces slimes, particles below 0.15 mm which are discarded as waste. The generation of slimes is about 15-20% of the feed to the plant. • The present industrial practice causes huge loss of iron values and has adverse effects on environment. • No low grade ores are exploited.
PROBLEM OF HIGH ALUMINA IN LOW GRADE ORES (?) • Though the present scheme is ok for good grade ores and but it needs radical change in technology for exploitation of low grade ores/ fines and slimes • Due to preferential association of iron oxide minerals with finely disseminated alumina bearing minerals than siliceous minerals, Al2O3 : SiO2 ratio >1 • Alumina contributed by clay (koalinite, montmorillonite, illite, alunite), lateritic material and gibbsite • Aluminous minerals occur as coating, cavity fillings and also as solid solution in iron oxide minerals • In several cases fine grinding is required for liberation Mere Washing can not Reduce Alumina to Desired level in Low Grade Ores
High alumina Adverse effects on BF productivity Effect of alumina on RDI & Blast furnace productivity
FINANCIAL IMPLICATION • Increase in Fe in the boundary by 1% will increase hot metal productivity by 1.5% - 2%, decrease coke rate by 0.8 – 1.2%. This will result in reduction in production cost by Rs.60 – 70/thm • 1% reduction of alumina in iron burden will reduce the cost of hot metal by Rs.200 – 250/thm • lowering of silica in iron ore burden by 1% will reduce the cost of hot metal by Rs.50-100/thm • reduction in undersize in iron ore lump by 1% will lower hot metal production cost by Rs.50 – 60/thm • reduction in fluctuation in Fe chemistry by 1% will reduce the cost of hot metal by Rs.40 – 50/thm with even 0.5% reduction in alumina in burden, 5% reduction in undersize and improvement in physical and chemical consistency Expected saving is Rs.150 crorers for a 4Mtpa hot metal production plant
NML process for beneficiation of low grade iron ore to a high grade concentrate (65%Fe), suitable as feed to DRI pellet plant.
R & D PROPOSALS OF NATIONAL IMPORTANCE(As Identified by Ministry of Steel, Govt. of India) • Beneficiation/ Upgradation of low grade hematite and magnetite iron ore with improved yield and their economic utilization. • Exploration/ Beneficiation of Indian bauxite/production of fused magnesia using Indian Magnesite. • Utilization of slimes and over burden of iron ore and other minerals. • Beneficiation/ utilization of high ash Indian coking/ Non coking coal with improved yield. • Alternate iron making through rotary hearth furnace using ore/ coal composite pellets. • Mineral and plant waste utilization and recycling. • Use of sea water in iron & steel industry including mineral processing industry. • Development of ultra fine grained high tensile steel products (YS: 800-1000Mpa) • Co2 capture & sequestration in ferrous industry • Waste heat recovery • Novel joining techniques fro Steel – Steel / Steel – Other metals.
