WEL COME To Sri KLN Rao The General Manager DIOM, NMDC Limited Donimalai Township For the quest

Reduction of Wastage in Processes By Sri CK Megharaj Sr. Manager (MP)

What is Waste Reduction Waste reduction means decreasing the amount of solid waste Waste reduction means decreasing the amount of solid waste Waste reduction includes source reduction and recycling practices. Waste reduction includes source reduction and recycling practices. Source reduction activities attempt to eliminate waste or reduce the amount generated. Source reduction activities attempt to eliminate waste or reduce the amount generated. Recycling activities focus on the re-using wastes after they are generated. Recycling activities focus on the re-using wastes after they are generated. Waste reduction will help our business: Waste reduction will help our business:

Waste reduction will help our Business Save money by reducing waste disposal costs Save money by reducing waste disposal costs Reduce the number of waste regulations with which our business need to comply Reduce the number of waste regulations with which our business need to comply Reduce employees exposure to hazardous chemicals Reduce employees exposure to hazardous chemicals

Waste reduction techniques Good operating practices Good operating practices Material substitution Material substitution Process or Technology modification Process or Technology modification Product substitution Product substitution Recovery/Recycling/Reuse Recovery/Recycling/Reuse

What is mineral processing Mineral processing is the art of treating crude crust of earth to produce there from the primary consumer derivatives. Mineral processing is the art of treating crude crust of earth to produce there from the primary consumer derivatives. The essential operation in all such processes is separation of one or more valuable derived constituents of the crude from the undesired contaminants with which it occurs associated The essential operation in all such processes is separation of one or more valuable derived constituents of the crude from the undesired contaminants with which it occurs associated A crude is any mixture of minerals in the form in which occurs as a part of earth crust. A crude is any mixture of minerals in the form in which occurs as a part of earth crust.

An ore is a solid crude containing a valuable constituent such amounts as to constitute a promise of possible profit in extraction, treatment, and sale. An ore is a solid crude containing a valuable constituent such amounts as to constitute a promise of possible profit in extraction, treatment, and sale. The valuable constituent of an ore is ordinarily called valuable mineral, or often just MINERAL, the associated worth less material is called the gangue The valuable constituent of an ore is ordinarily called valuable mineral, or often just MINERAL, the associated worth less material is called the gangue The valuable product of the ore dressing treatment is called concentrate; the discarded waste as tailings. The valuable product of the ore dressing treatment is called concentrate; the discarded waste as tailings.

Fundamental operation of mineral processing are severance or breaking apart of the associated minerals or constituents of the crude, and separation of the several constituents. Fundamental operation of mineral processing are severance or breaking apart of the associated minerals or constituents of the crude, and separation of the several constituents.

Good operating practice Good operating practice generate less waste Good operating practice generate less waste Making existing processes more efficient Making existing processes more efficient Good business practices Good business practices Many good operating practices are easy and inexpensive to implement Many good operating practices are easy and inexpensive to implement Practical for business of all sizes Practical for business of all sizes

What are the waste generation from the mines Top soil Top soil Waste rejects Waste rejects Tailings from ore processing plant Tailings from ore processing plant Waste from service facilities Waste from service facilities

Top soil Top soil (generally 30 cms thickness) is stripped and staked superior in quality Top soil (generally 30 cms thickness) is stripped and staked superior in quality Can be used in future for stabilization Can be used in future for stabilization

Mining waste Cut of point for mining is fixed Cut of point for mining is fixed All the ore having Fe below cut off point is classified as waste/sub grade material All the ore having Fe below cut off point is classified as waste/sub grade material Future use if Techno-economics permits Future use if Techno-economics permits Iron ore deposits of eastern, central and southern zone do not contain much waste / rejects, except literate and some low grade ferruginous shales and BHQ patches Iron ore deposits of eastern, central and southern zone do not contain much waste / rejects, except literate and some low grade ferruginous shales and BHQ patches Western zone (Goa region), the waste is very high to the tune of 2.5 to 3.5 per tonne of ore excavated Western zone (Goa region), the waste is very high to the tune of 2.5 to 3.5 per tonne of ore excavated

Tailings from processing Beneficiation Beneficiation Improve Fe content Improve Fe content Decrease Alumina and silica Decrease Alumina and silica For smooth blast furnace For smooth blast furnace Disposal of tailings is a major environmental problem Disposal of tailings is a major environmental problem Becoming more serious with increasing extraction of low grade deposits Becoming more serious with increasing extraction of low grade deposits Tailing desposal as slurry of high water content with massive pond for cotainment Tailing desposal as slurry of high water content with massive pond for cotainment

Waste from services facilities There are three types wastes generated There are three types wastes generated Metallic – workshop Metallic – workshop Non-metallic – tyres tubes etc. Non-metallic – tyres tubes etc. Oil contaminated waste –waste cotton, oils, oil filters, hazardous waste Oil contaminated waste –waste cotton, oils, oil filters, hazardous waste

Benefits of Beneficiationin improving the quality of iron ore in hot metal production Increase in Fe content in iron ore burden by 1% will increase the productivity of the hot metal by 1.5 – 2.0 %, coke rate by % and there by reduction Rs per ton of hot metal. Increase in Fe content in iron ore burden by 1% will increase the productivity of the hot metal by 1.5 – 2.0 %, coke rate by % and there by reduction Rs per ton of hot metal. Lowering of alumina in iron ore burden by 1% will reduce the cost of the hot metal by Rs per ton hot metal. Lowering of alumina in iron ore burden by 1% will reduce the cost of the hot metal by Rs per ton hot metal. Lowering of silica by 1% in iron ore burden will reduce the cost of the hot metal by Rs per ton of the hot metal. Lowering of silica by 1% in iron ore burden will reduce the cost of the hot metal by Rs per ton of the hot metal.

The effect of high alumina is noticeable above 2% and following are the ill effects The sinter/ pellet strength is low The sinter/ pellet strength is low Reduction and degradation properties are high Reduction and degradation properties are high Higher slag volume and viscous slag formation ( draining problem) Higher slag volume and viscous slag formation ( draining problem)

Characterization and data analysis The chemical, mineralogical and granulometrical characterization. The chemical, mineralogical and granulometrical characterization. Bond’s work index determination. Bond’s work index determination. Ore variable data. The goethite %, hematite %, aluminous gangue mineral %, slimes (% <45 microns) Ore variable data. The goethite %, hematite %, aluminous gangue mineral %, slimes (% <45 microns) The size analysis. The size analysis.

Base line data (BLD) The plant in a custom mode with variable ore types in a discontinuous fashion affecting the operation. The plant in a custom mode with variable ore types in a discontinuous fashion affecting the operation. Due to slight change in ore mineralogy result in marginally high tail value and marginally low concentrate grade with reference to design values. Due to slight change in ore mineralogy result in marginally high tail value and marginally low concentrate grade with reference to design values. The plant designed rate. The plant designed rate. Little load on primary. Little load on primary. Operation at lower capacity. Operation at lower capacity.

Tonnage and grade of ROM in DIOM Tonnage and grade of ROM in DIOM YearROM L T Fe%SiO2%Al2O3% (Upto Feb 10)

Details of Ore Reserves Deposit Ore qty (MT) Fe% Waste qty (MT) Strip’g ratio SB BMMS W E W Total

Deposit-wise Q & Q of Ore & Waste - KIOM Deposit Ore qty (MT) Fe% Waste qty (MT) Strip’g ratio B-block C-block Total

4. Quality of Low Grade Ore Ore type Fe % SiO 2 % Al2O3 % P % Laterite 53 – Limonite 50 – BHJ Shale 18 – –

Deposit-wise Low Grade Ore Available Approx. Recovery AreaIn-situ Lump ( mm) LGF QtyQty Fe % Qty SB – 54 BMMX – 52 2W North Sub Total Sub Total Blue dust mixed with BHJ in 2E & 2W – 60 Total Generated Lump (7.05 LT) will be fed to crushing plant. Low grade fine ore of LT & BHJ lump of 9.20 LT generated through mobile screen will be stacked in respective deposits for feeding to the beneficiation plant. (Qty in LT)

Availability of in-situ Banded Hematite Jasper (BHJ) Area In-situ (MT) 2E0.50 3E1.79 2W0.07 3W0.21 Total2.57 In addition to above a total quantity of 11.4 MT of BHJ dumped in valley at five different locations in North Block. Total BHJ available is MT

DIOM PLANT CAPACITY Crushing plant is capable of handling 8 MTPA Crushing plant is capable of handling 8 MTPA Screening plant is designed to handle a Max of 7 MTPA. Screening plant is designed to handle a Max of 7 MTPA. Loading plant can handle upto 8.4 MTPA. Loading plant can handle upto 8.4 MTPA. Reclaimer with capacity of 2400 tph is adequate to handle. Reclaimer with capacity of 2400 tph is adequate to handle. S/P is the weakest link in the chain. S/P is the weakest link in the chain. 411 fine ore conveyor is presently not able to handle 800 tph as against the design requirement of 1000 tph 411 fine ore conveyor is presently not able to handle 800 tph as against the design requirement of 1000 tph

PRODUCTION DETAILS Production (In lakh Tons) ( Upto Feb, 2010) Excavation ROM Lump Fines Slimes

Screening Plant details Built 30 years back with 3 screening lines. Built 30 years back with 3 screening lines. Each line capable of handling 600 tph. Each line capable of handling 600 tph. 4 th line was added recently during th line was added recently during Designed for 100 % wet operation. Designed for 100 % wet operation. Live stock pile capacity tons. Live stock pile capacity tons. Present maximum level of production achieved from the plant is 6.2 MTPA Present maximum level of production achieved from the plant is 6.2 MTPA

WATER 7.45 Cu Sec. is the sanctioned quantity from Narihalla Dam Cu Sec. is the sanctioned quantity from Narihalla Dam. Presently water is being pumped from Narihalla dam at the rate of 400 Cu m/hr. Presently water is being pumped from Narihalla dam at the rate of 400 Cu m/hr. A scheme with a total pumping capacity of 800 cu m/hr is already approved to meet the water requirement for processing ore from DIOM and KIOM. A scheme with a total pumping capacity of 800 cu m/hr is already approved to meet the water requirement for processing ore from DIOM and KIOM.

LUMP ORE PRODUCTION AND GRADE, SCREENING PALNT Year Lump. LT Fe% SiO2 % Al2O3 % Upto Feb

PRODUCTION OF FINE ORE GRADE, REC % SCREENING PLANT Year Lakh Tons Fe % Fe % SiO2 % Al2O3% Rec. % Upto Feb

Performance of primary classifier Classifier under flow sample analysis Fe % SiO2Al2O3PLIO Classifier over flow sample analysis Fe % SiO2Al2O3PLIO

Performance of slow speed classifier Classifier under flow sample analysis Fe % SiO2Al2O3PLIO Classifier under flow sample analysis Fe % SiO2Al2O3PLIO

Performance of hydrocyclones under flow at P.D Fe % SiO2 % Al2O3% P % LIO

Performance of hydrocyclones over flow at P.D Fe % Sio2 % Al2O3 % P % LIO

Energy consumption units per ton in the mine and plant Total Exc. mine C/plantw.r.t.ROM S/Plant w.r.t ROM L/Plant w.r.t ROM % Wet Screen- ing Upto Feb’

Details of cost of Production Production cost per ton C/P Rs. cpt S/P Rs. cpt L/P Rs. cpt Haulage/ Transportat ion Rs. cpt upto Feb

Plant, Cost per ton

Industrial water consumption YearCu.m/T.E.S/PlantCu.m Wet screening % (Upto Feb,10)

Industrial water consumption

Mines and industrial operation energy cost w.r.t. ROM Power cost Rs. Per ton w.r.t. ROM upto Feb

Screening plant performance Year Wet screening % Upto Feb’

Screening plant % wet screening

Conclusion The grade Fe content of lumps and fines improved in screening plant and reduced Al2O3 and SiO2 The grade Fe content of lumps and fines improved in screening plant and reduced Al2O3 and SiO2 Beneficiation improving the quality of iron is advantages to the end user and reduces the wastages. Beneficiation improving the quality of iron is advantages to the end user and reduces the wastages. The low grade reserve with Fe content < 58 can be further treated by beneficiation process for recovery of Fe. The low grade reserve with Fe content < 58 can be further treated by beneficiation process for recovery of Fe. Recycling of water from the HRT and tailing pond increased the efficiency of the wet process Recycling of water from the HRT and tailing pond increased the efficiency of the wet process Al2O3 as alumina is the most deleterious mineral in iron ore and maximum benefit comes from removing this gangue Al2O3 as alumina is the most deleterious mineral in iron ore and maximum benefit comes from removing this gangue

Acknowledgement The author is thankful to the CMD, Directors, and senior management of NMDC ltd, for giving me an opportunity to present this paper. The author is thankful to the CMD, Directors, and senior management of NMDC ltd, for giving me an opportunity to present this paper. The author is thankful to the General Manager, DIOM, DGM(Min) HRD for giving me this opportunity to present the paper. The author is thankful to the General Manager, DIOM, DGM(Min) HRD for giving me this opportunity to present the paper. The author is thankful to DGM (MP) and all HOD’s and the audience for your presence and patience hearing while presenting this paper and thankful to my dear colleagues who have helped directly or indirectly in presenting this paper. The author is thankful to DGM (MP) and all HOD’s and the audience for your presence and patience hearing while presenting this paper and thankful to my dear colleagues who have helped directly or indirectly in presenting this paper.