PRE- FEASIBILITY REPORT terms of provision of EIA Notification. For

Transcription

1 PRE- FEASIBILITY REPORT (In terms of provision of EIA Notification 2006) For Amendment to Zinc Smelter (2, 50,000 TPA) and CPP (100 MW) (F. No. J-11011/279/2006-IA. II (I) dated 6 th December 2006) By: HINDUSTAN ZINC LIMITED, CHANDERIYA LEAD ZINC SMELTER, PUTHOLI , CHITTORGARH, RAJASTHAN To: Ministry of Environment & Forests (MoEF) New Delhi July,

2 TABLE OF CONTENTS 1. Executive Summary Need for Proposal Technology &Process description The major raw materials, products, byproducts and residues are as under Environmental aspect and pollution control... 8 A. Air:... 8 B. Water:... 9 C. Solid /Hazardous waste: Legal Aspect Site Analysis: Proposed infrastructure Rehabilitation and Resettlement(R&R) Plan Project Schedulee and Cost Estimates Analysis of Proposal

3 1. Executive Summary Chanderiya Lead-Zinc Smelter (CLZS)is the one of the largest zinc-lead smelting complexes in the world. At CLZS, Zinc is produced by hydrometallurgical route in Hydro-1 & Hydro-2 and Pyro-metallurgical route in Pyro unit. The hydrometallurgical smelting process is a Roast, Leach and Electro-winning process. In this process, Zinc concentrate is oxidized in the roaster and sent to leaching & purification plant to produce a zinc sulphate solution and through electrolysis zinc cathodes are produced which are furtherr melted and casted into zinc ingots. Main Iron residuee generated from leaching is Jarosite which is being stabilized by addition of lime and cement. The product is called Jarofix which is stockpiled at Jarofix yard and needs recurring land. In Fuming process the weak acid leach residue containing zinc, iron and sulfur are fed to fuming furnace. Zinc is fumed, iron is slagged, and Sulfur is oxidized to SO 2, characterized in the Zinc fuming furnace. The iron slagging and Sulfur oxidation are performed in a single step process, by smelting the residues in a furnace comprising an oxidizing gas mixture (oxygen), and by feeding a solid reducing agent (coal) to the melt. The process achieves the oxidation of Sulfur and the slaggingg of Iron, while simultaneously achieving the reduction and the fuming of metals such as Zinc. Zinc bearing residues are transported to the fume oxide treatment plant where zinc is leached and lead/silver is recovered for further treatment. Waste heat generated in the above process is converted to steam and the same is utilized in producing ~ 21MW power. To accomplish this project, HZL has conducted an operational feasibility study from Xmetech Zinc, South Korea and found to be feasible. Fuming technology is established technology, now-a-days used to eliminate Jarosite formation and improve zinc & lead recovery and to produce environmentally friendly clean slag which is used in the cement industry. The project is proposed to be installed within the existing factory premises and hence no additional land is to be acquired. This project will generate additional power from waste heat and will be self- sufficient. Water requirement for this project will be met within the quantity of 11000M 3 as specified in the Environment Clearance. (Referencee EC NO- F. No. J /279/2006-IA. II (I) dated 6 th December 2006). 3

4 2. Need for Proposal The proposed project will be set up at Hydro-2 Zinc smelter which is within CLZS premises. The proposal is for the Amendment in Environmental clearance of2,10,000mt (Phase 2)hydro II Zinc smelter which was a part of environmental clearance granted for 2, 50,000 TPA, Zinc and CPP of100 MW. Jarosite process is currently used in hydrometallurgical Zinc smelters to remove iron from Zinc concentrate. Jarosite as a hazardous waste is neutralized and fixed by addition of lime & cement and converted into Jarofix which is stable material and then stored in Jarofix yard. With this proposed project, recurring land requirement and generation of hazardous waste are eliminated wherein Iron is slagged and utilized in Cement Industry. Existing Hydro 1 smelter having capacity MT of Zinc metal will continue to operate through Jarosite process route. 3. Technology &Process description The hydrometallurgical smelting process is a Roast, Leach and Electro-winning process. In this process, Zinc concentrate is oxidized in the roaster and sent to leaching & purification plant to produce a zinc sulphate solution and through electrolysis to produce zinc cathodes which are further melted and casted into zinc ingots. Iron residue generated from leaching is Jarosite, a waste which is being stabilized by addition of lime and cement. The product is called Jarofix which is stockpiled at Jarofix yard and needs recurring land. To eliminate Jarosite generation, it is proposed to set up fuming process (Pyro metallurgical process) within existing leaching circuit of hydro -2 Zinc Smelter. Leaching Process: The leaching section includes neutral leaching, where zinc oxide along with other metal oxides are leached with weak sulphuric acid. The solution goes to purification section whereas the neutral leaching thickener underflow is pumped to weak acid leaching to dissolve part of zinc oxide. The residue containing zinc ferrite is pumped to Jarosite section where at high temperature zinc ferrite is disintegrated into Zinc sulphate and Iron sulphate. Iron is precipitated as Jarosite which after addition of 4

5 lime and cement converted into Jarofix and stored in Jarofix yard. The zinc sulphate solution is recycled to neutral leaching via pre neutralization section. Details of processes: S No. Existing Process Proposed Process 1 Roaster and acid plant Roaster and Acid plant(no change) 2 Leaching Leaching(No change) Iron removal as Jarofix via Jarosite Iron removal as a Slag via Fumer 3 Route Route (Amendment) 4 Purification Purification(unchanged) 5 Electrolysis Electrolysis(No change ) Coal Based Thermal Power Plant 6 Coal Based Thermal Power Plant (No change) A flow diagram of Existing flow sheet (Hydro metallurgy process) and proposed flow sheet (Pyro metallurgical fuming process) is attached as Annexure I. Pyro Metallurgical fuming Process is composed of three areas, zinc fuming area, fume oxide treatment area and halide removal area. Zinc fuming Process: In the fuming process the weak acid leaching underflow is filtered, dried and fed to fuming furnaces (2 No s)in series where at elevated temperatures Zinc is fumed and Iron is converted into slag. Coal is added for raising the temperature and also creating reducing atmosphere. Air/Oxygen is added for combustion. The slag so produced is removed from the bottom of the furnace. The zinc oxide from furnaces in form of off gas is captured in boiler and gas cleaning section &used for SO 2 scrubbing and the same slurry will be sent to the fume oxide treatment section. In the process of the zinc fuming, saturated steam is generated at the waste heat boiler and the saturated steam is used to produce electricity (~ 21 MW) from the waste heat. The main equipments in this section are as follows: 1. Fuming Furnaces with Hygiene Stack 2. Waste heat recovery boilers 3. Turbine- Generator set with auxiliaries 4. ESP & Bag Filter 5. Filter Pressess 6. Quench Tower 7. Raw material section with Stack 8. Coal Handling & Pulverizing Plant 5

6 9. Oxygen & Nitrogen Plant 10. Slag Granulation system Zinc Oxide Treatment Process: The off gases are scrubbed by zinc oxide slurry in the scrubber before discharging to atmosphere throughh stack. The scrubbed slurry is thickened and filtered to recover cake which is treated in Decomposition tower. The slurry is filtered; the ZnSO 4 solution is recycled to neutral leaching section whereas Lead and Silver is recovered in the form of cake. The SO 2 gas generated in Decomposition tower is sent for further treatment in existing acid plant. The Major Equipments in this section are: 1. Scrubber with Stack 2. Thickeners 3. Filter pressess 4. Reactors 5. Decomposition Tower Halide Removal section Halide removal process is needed to remove halide (Halides are compounds containing halogens). When halide (including the other impurities) in the zinc solution (which was earlier recycled to neutral leaching section from zinc oxide treatment section) increases, the hydrolysis process will be applied to remove halide. After then, de-halide fume oxide leaching solution will be fed to the neutral leaching section. The solid residues collected in the bottom of the hydrolysis thickener are filtered and cake (Geothite residue) is produced. Annually 2000 MT of goethite cake shall be generated which shall be disposed in SLF area. The major equipments in this section are: 1. Filter pressess 2. Thickeners 3. Reactors Flow sheet of the Fumer Process is attached as Annexure II 6

7 3.1 The major raw materials, products, byproducts and residues are as under: Capacity Treatment S No Item as per Revised /Disposal Unit Remarks Description Earlier capacity EC Product 1 Zinc MTPA No Change 2 Thermal Power By product MW No Change 3 Pb-Ag cake MTPA Amended 1 4 Cu Spiess MTPA Amended 1 5 Sulphuric acid(98.5%) MTPA No Change 2 6 Slag MTPA Amended 2 Waste heat Internally 7 power MW Amended Consumed Hazardous waste 8 Jarosite 9 Geothite cake Utilities 10 Water 11 Land Raw Material MTPA Amended* MTPA Amended M No Change Ha No Change 12 Coal For power MTPA No Change 13 Coal for Fumer MTPA Amended 14 Fuel(HSD) KLPA Amended * Jarosite Process will be adopted till process stabilization and during Process upsets. 1. Processed in existing Pyro smelter for recovery of metal. 2. Sold to fertiliser industry Disposed in SLF Hazardous wastes like RO rejects, ETP sludge, Cobalt cake, cooler cake, anode mud, enrichment cake, and spent catalyst etc., will continue to generate as per existing authorization and will continue to dispose in the existing secure land fill. The quantity of waste oil /used oil generated will remain the same and will be sold to 7

8 registered recyclers. Ash generation from CPP will remain the same and will be sold to cement/brick manufacturers. Details attached as per annexure III 3.2 Environmental aspect and pollution control A. Air: SO 2 generated from furnaces get treated in zinc oxide scrubber and shall be vent out through stack of suitable height. The acid mist emission shall be within the prescribed limit. The gases from the decomposition unit will go to existing acid plant, which is fully adequate to treat the same. The Acid plant is designed to treat gases so as to produce 900 MTPD of acid. The overall acid production will remain within the approved capacity of 900MTPD.In Acid plant, we have adopted state of the art of Double conversion and double absorption technology and Super Cesium coated V 2 O 5 catalyst at our acid plant. The pollution control equipment/facilities are having adequate control and interlocks to limit the process variations and trip in case of process upsets. Hygiene bag filter will be used for collection of particulate matter in Coal handling area, RMH area and all transfer points and gases shall be vent out through stack of suitable height. The particulate emission shall be within the prescribed limit of CPCB norms. Hygiene bag filter will be used for collection of particulate matter in furnace tapping floor, lance port, feed port and all transfer points and gases shall be vented through stack of suitable height. The particulate matter emission shall be within the prescribed limit of CPCB norms. The following measures shall continue to be adopted in the proposed plant also: All the plant roads will be made of concrete. Mechanized truck mounted vacuum sweeper will continue to be deployed to sweep and collect the dust from road Monitoring of fugitive emission during internal transportation Material transfer points will be provided with de-dusting system Raw material will be transported through special trippers Existing truck tyre washing system shall continue to be used Bag filters and other pollution control equipments be adequately installed for operation and maintained properly. 8

9 B. Water: Water requirement will be around 2400m 3, which will be within Environment Clearance No. F. No. J-11011/279/2006-IA.II (I) dated 6 th December 2006 for Zinc Smelter (2, 50,000 TPA) & CPP (100 MW). The revised water balance is attached: Annexure IV C. Solid /Hazardous waste: The proposed Projectwill generate MTPA of non-hazardous slag which is saleable. The same will be a used as a raw material in cement industry and further conserve natural resources MTPA of Goethite cake will be generated from halide removal section. It will be disposed in existing Secured land Fill after stabilization. 3.3 Legal Aspect There is No litigation in the proposed project boundary 4. Site Analysis: It s already an industrial site. Annexure V 5. Proposed infrastructure The proposed amendment is planned within the existing Chanderiya smelting complex and existing infrastructure is sufficient to cater the need. 6. Rehabilitation and Resettlement(R&R) Plan No R&R is envisaged as no land is being acquired. 7. Project Schedule and Cost Estimates Project will commissioned within 24 months from the date of issuance of consent to establish. Project cost ~Rs. 500 Cr. 8. Analysis of Proposal Environmental Improvement after Fumer Circuit 9

10 Being concerned with the upkeep of environmental safety and ecological balance, the proposed projects is environmental improvements in nature in the existing CLZS smelters within its premises and mainly aims at waste minimization. Following are the environmental key features of the project: A. Saving of land Resources Currently process is generating Jarosite as waste which is neutralized and fixed by addition of lime & cement and converted into Jarofix whichh is stable material and then stored in jarofix yard. Zinc ferrite Fumer will generate usable slag and remove the liability of land, for storage of Jarofix B. Saving of other resources Jarofix process consumes other resource like cement & lime. Fumer operation will reduce the consumption of lime and cement. C. Usable Slag Generation Fumer slag will be used in cement industry and following will be the benefit to zinc industry and cement industry C.1 Slag consumption before Kiln Fumer Slag contains ~7.6% lime and ~43% Fe 2 O 3. This willl reduce consumption of CaCO 3 of 17000MTPA in cement industry and reduce carbon footprint by ~7700 MT C.2 Slag consumption after Kiln as Clinker As slag will be used after Clinker it will reduce carbon foot print of cement industry by ~ MT along with of CaCO 3 of ~17000MTPA D. Power generation from waste Heat Waste heat recovery based power generation would be ~21 MWH of energy. Out of ~ 21 MWH productions, ~11 MWH will be used in Fumer project. Therefore, fumer is self-sufficient for energy requirement and will provide extra Approx 10 MWH which will be utilized in complex E. Recovery of metals Fumer process in addition to improving the environment also helps in recovering Lead, silver & copper from zinc concentrate. 10

11 LIST OF ANNEXURES 1. ANNEXURE - I Flow diagram of Existing flow sheet (Hydro metallurgy process) and proposed flow sheet (Pyro metallurgical fuming process) 2. ANNEXURE - II Flow sheet of Fumer process 3. ANNEXURE - II II Solid waste generation 4. ANNEXURE - IV Water Requirement 5. ANNEXURE - V Location maps showing CLZS location, Hydro-2 location, and project site layout 11

12 ANNEXURE - I 12

13 Existing flow sheet and amended flow sheet 13

14 ANNEXURE II Flow sheet of Fumer process 14

15 ANNEXURE III Solid waste generation S No Hazardous waste 1 Process Residue 1.1 Cooler cake 1.2 Anode mud 1.3 Enrichment cake 2 ETP sludge 3 Spent catalyst 4 Waste oil 5 Used oil Category of HW Unit Authorised Quantity Revised Quantity 7.2 MTPA MTPA MTPA MTPA MTPA KL KL KL Hazardous waste disposal practice Sold to Registered Recyclers / Disposed off in SLF Disposed off in SLF Recycled in leaching process/ Disposal in SLF Sold to Registered Recyclers /Disposed in SLF Disposed off in SLF Disposed off in SLF Sold to Registered Recyclers Sold to Registered Recyclers 15

16 ANNEXURE IV Water Requirement Water requirement of CLZS location S. No Section Quantity 1 Pyro ( ISF + Sinter) Ausmelt H CPP (154 MW) H-II CPP (100 MW) 6000 Total CLZS Complex Water requirement of H-II & 100 MW CPP Existing S. No Section Quantity 1 H-II CPP (100 MW) 6000 Total Water requirement after amendment ( H-II & 100 MW CPP) S. No Section Quantity 1 CPP (100 MW) Fumer H-II 4200 Total UOM UOM UOM 16

17 ANNEXURE V Location maps showing CLZS location, Hydro-2 location, and project site layout Files attached separately Chanderiya layout.pdf Hydro-2 layout with project site.pdf project site.jpeg 17