Waste Management at JSW Steel - An Innovative Approach. Dr Amit Ranjan Chakraborty

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1 Waste Management at JSW Steel - An Innovative Approach Dr Amit Ranjan Chakraborty

2 Wastes OR Byproducts??? All Integrated Iron and steel plants produce a wide range of by-products and Iron and steel making processes are being continually optimized to reduce the amount of byproducts generated. These by-products are often termed wastes. This has been especially true in the past when large quantity of these materials were land filled. In today s green manufacturing world it is becoming increasingly difficult, and costly, to continue land filling these by-products as environmental legislation become stronger. To term these materials as waste ignores the potential value that exists in them and the benefits that they can have on the iron ore and steelmaking process. Slags, dusts, fines, slurries and various scales can be processed to recover the iron units within these materials.

3 Utilization of Slags as Aggregates

4 Leading the Change With indiscriminate mining of river sand destroying the riparian ecology of many areas, the scientific community has been busy trying to find alternatives to river sand for construction. JSW has taken the lead in this environmental concern and introduced granulated slags as an eco-friendly alternative to river sand. This initiative is first of its kind in the country. JSW steel has carried out several tests in-house and with leading civil agencies to establish slags as aggregates which othewise was mostly dumped.

5 Slag Generation (Iron & Steel) is ~ 5 10 Mtpa stage at JSW Iron Making Slag Steel Making Slag 350 Kgs/T 200 Kgs/T 20 % 80 % Granulation ( 3 5 mm size) Granulation ( 3 8 mm size) Water quenching in open air Present Usage Grinding and Sized Present Usage Ground and Sized 2 5 mm 1 2 mm mm < 0.6 mm Metal Recovery (15 %) Cement Making Road Making Paver making Building Construction Cement Making Increased usage in Cement Making at Vijayanagar and Nandyal Road making Building Construction Steel slag asphalt concrete pavements Lime-fly ash slag road base Steel slag dry-mix mortar Steel Slag for Roads Shot Blasting 25 % Recovered through Sinter & IM making and rest is Dumped

6 Granulated Blast Furnace Slag Products mm Concrete Slag Sand mm Plaster Slag Sand JSW steel has become the first steel plant in the country to market and sell granulated slag as replacement of river sand.

7 Established Applications SLAG SOURCE NOMENCLATURE MANUFACTURING PROCESS APPLICATIONS IRON AND STEEL FURNACES CRUSHED SLAG (MANUFACTURED COARSE SLAG AGGREGATE) GRANULATED SLAG (MANUFACTURED FINE SLAG AGGREGATE) Crushing and Screening Rapidly Quenching and Granulation Base and Sub base Concrete aggregate Sealing aggregate (skid resistant) Asphalt aggregate Filter aggregate Construction fill and selected fill Shore Protection Subsoil drains Grit blasting Sub base Construction fill Stabilizing binder Fine aggregate Concrete and Mortar Asphalt aggregate Grit blasting Reinforced earth wall infill

8 Microscopic Examination Shape of the granulated slag sand is similar to river sand. Microscopically also, river sand and manufactured slag sand are similar. JSW steel is utilizing granulated BF slag 100 % individually and also in combination with River sand, Crusher Dust and M-sand

9 Usage of Slag at JSW F o u n d a tio n, F lo o rin g a n d R o a d s a t C R M -II C o m p le x R o a d s a t S M S -III P a v e r b lo c k s a t T o w n s h ip P la ste rin g a t B R M -II

10 Some Other Activities CSR Activities - Concrete Village Roads Roads & Canteen Building at ACC Kudtini Pavements / Roads at Ozone Urbana Bangalore

11 Manufactured Slag Sand JSW steel is promoting slag sand as Green Material: Slag is non hazardous, non toxic. Slag is free of any impurities like silt clay etc Used extensively for civil/road construction in developed countries Slag sand, if used can stop mining of river sand JSW steels initiative of utilizing slags provided an economically viable and environmentally acceptable future material for replacing river sand having tremendous economic impact, conservation of natural resources and gainful re-cycling of process wastes.

12 BOF Slag: Approach world over Conditioning, Washing, Crushing, Screening Replace Natural Aggregates Artificial Aggregate

13 Applications Elsewhere

14 Use of Granulated BOF Slag 1. With granulation, physico-chemical properties of slag have been altered and new avenues of its applications have been identified 2. Extensive studies have been carried out by our R&D and confirmedbynccbmuseofbofslagas Raw Material in Cement Manufacture(upto 4.25%) Performance Improver in cement making(upto 5%) Blending Materials in cement making(upto 40%) Replacement of Natural Sand in Cement Mortar(upto 100%) Low free lime content suitable for construction Reduced crushing - better separation of metallics

15 Use of Granulated BOF Slag AsPerformanceImproverincementmaking(upto5%) For OPC(Not for Slag cements) Applied for BIS Certification for commercialization AsBlendingMaterialsincementmaking(upto40%) AlreadyinuseatJSWupto10% Applied for BIS Certification for commercialization AsReplacementofNaturalSandinCementMortar(upto100%) Requires grinding and sieving Applied for BIS Certification for commercialization AsRawMaterialinCementManufacture(upto4.25%) Does not require BIS Certification

16 Way Forward. COARSE FRACTION (+ 5 MM) Cement Making Road Making Paver and Building Blocks SLAG USAGE MEDIUM FRACTION ( 1-5 MM ) Building Construction Steel slag asphalt concrete pavements Lime-fly ash slag road base Steel slag dry-mix mortar Steel Slag for Roads Shot Blasting FINE FRACTION ( -1 MM ) BIS Certification will provide a range of specification to producers provide comfort to users on quality provide ~ 20 mtpa artificial construction material Cement materials Concrete materials Metallurgical additives Filter media

17 Utilization of Dust, Sludge & Slag as Micro-pellets

18 Micro-pelletization About 1600 tpd of micro fine dust, sludge are generated from the air and water pollution control equipments Dust-Bag filter, ESP, Fume extraction Sludge BOF, BF Slag LD slag after metal recovery Lime & Dolo dust from calcined lime plants. These are agglomerated by mixing them in definite proportion to produce 6 mm size micro pellets having adequate strength and chemical properties suitable for sinter making to improve the productivity of agglomeration. The capacity of the micro pellet plant is 0.6 MTPA.

19 Micro-pellets By-products Moisture (%) Bulk density (T/m3) Disposal of micro fines dust from bag filter will be a regular process. No heat input as there is any indurations involved. Inlet dust concentration gets reduced and substantial reduction in dust emission observed An equivalent amount of natural resources will be conserved. Recipe (%) BOF sludge Bag filter dust Flue dust <6mm LD slag Lime & Dolomite dust Burnt lime Water TOTAL

20 Utilization of Mill Scale Briquettes

21 Mill Scale Briquettes JSW steel is the first plant in the country and one of the very few in the world to adopt mill scale briquetting. Mill scale, caster scale, CRM dust and similar high iron containing wastes are mixed and briquetted. Presently mill scale briquettes are being used in both the steel making shops as secondary coolant replacement of Iron ore

22 Mill Scale Briquetting About 600 tpd of mill scale, dust from CRM, cast house dust from BF and secondary fume extraction dust from SMS are generated Mill Scale-HSM, SMS & Mills Dust-Bag filter, ESP, Fume extraction Molasses As Binder These are mixed in definite proportion using molasses as binder to produce briquettes of definite strength and used directly as coolant in LD converters. Capacity of the Mill Scale Briquetting plant is 0.2 MTPA Usage of Mill scale briquettes replaces iron ore or DRI as coolants in converters. Reduces Roof top emissions from Steel Melting Shops

23 Comparison with Iron ore Iron Ore Mill Scale Briquettes Fe (Total) % % Silica Load 5-6 % % Sulphur % % Sulphur Form In-Organic Organic Moisture 3-5 % < 2% Fines % 5-10 % Intangible Benefits Flame Shoot-up X Difficult to handle in Rainy Season X Source of Hydrogen X Red Fumes X ID Fan Perfomance Improved Bunker Jammng X

24 JSW Steel Approach towards Zero Waste At JSW Steel, adopting innovative technologies have helped to reduce our operational costs and has improved our environmental credentials by improving the sustainability of the steelmaking process and conserving natural resources.

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