NATIONAL TECHNICAL UNIVERSITY OF ATHENS SCHOOL OF MINING AND METALLURGICAL ENGINEERING SECTION OF METALLURGY AND MATERIALS TECHNOLOGY LABORATORY OF METALLURGY WP2: Technology Assessment Dimitrios Panias Ioanna Giannopoulou Metallurgical Industries under study Primary Copper production “Balkhash” Copper Plant – Cathodic copper production (Kazakhstan) “Geskazgan” Copper Plant – Cathodic copper production (Kazakhstan) Primary Zinc production “Balkhash” Zinc Plant – Cathodic zinc production (Kazakhstan) Primary Aluminum production “Zaporozhye Aluminum Mill” – Aluminum and Alumina production (Ukraine) Iron and Steel production Kosogorsky Metallurgical Plant – Cast iron production (Russia) West-Siberian Integrated Steel Mill – Steel production (Russia) JSC “Zaporozhstal” Integrated Iron & Steel Works – Iron & Steel production (Ukraine) “Temirtau” Metallurgical Plant – Cast iron and Steel production (Kazakhstan) Ferroalloys production Kuznetsk Ferroalloys Works – Ferrosilicium production (Russia) JSC “Zaporozhye Ferroalloy Plant” – Ferrosilicon and Silicomanganese production (Ukraine) Search for Best Available Techniques in the production stages, in which dusts are generated 2nd Progress Meeting Aachen - Germany, 31 - 08 - 2007 Definition of Best Available Techniques - BAT The term “Best Available Techniques” is defined in Article 2(11) of Council Directive 96/61/EC (IPPC Directive) as: “the most effective and advanced stage in the development of activities and their methods of operation, which indicate the practical suitability of particular techniques for providing in principle the basis for emission limit values designed to prevent and, where that is not practicable, generally to reduce emissions and the impacts on the environment as a whole”. Article 2(11) goes on to clarify further this definition as follows: “techniques” includes both the technology used and the way in which the installation is designed, built, maintained, operated and decommissioned; “available” techniques are those developed on a scale which allows implementation in the relevant industrial sector, under economically and technically viable conditions, taking into consideration the costs and advantages; “best” means most effective in achieving a high general level of protection of the environment as a whole. 2nd Progress Meeting Aachen - Germany, 31 - 08 - 2007 Methodology in WP2 on searching for production BAT 1. Typical flow diagram of the production process for each one of the industrial sectors under study 2. Identification of the production stages where dusts are produced 3. Search for Best Available Production Techniques in these stages: Reference Document of E.C. on BAT in Non-Ferrous Metals Industries Reference Document of E.C. on BAT in Iron and Steal Production Reference Document of E.C. on BAT in Ferrous Metals Processing Industry Other documents (publications, patents, etc.) 2nd Progress Meeting Aachen - Germany, 31 - 08 - 2007 The E.C. Reference Documents on BAT Article 16(2) of IPPC Directive requires the Commission to organize “an exchange of information between Member States and the industries concerned on best available techniques, associated monitoring and developments in them” and to publish the results of exchange. The aim of Reference Documents on BAT is to reflect accurately the exchange of information and to provide reference information for the guidance of industry, Member States and the public on achievable emission and consumption levels when using specific techniques. By providing relevant information on BAT these documents should act as valuable tools to drive environmental performance. Reference Documents on BAT do not set legally binding standards. The appropriate limit values for any specific case will need to be determined taking into account the objectives of the IPPC Directive and the local considerations. Best Available Techniques are influenced by a number of factors and for this reason, a methodology of examining the existing techniques is necessary for their consideration to BAT. 2nd Progress Meeting Aachen - Germany, 31 - 08 - 2007 Case study 1: Primary Copper Production Typical flow diagram of Primary Copper production process - Pyrometallurgical Route INPUTS PROCESS STAGES Charge Preparation Dust Drying Dust Concentrate Fluxes, Oxygen OUTPUTS Roasting Smelting Dust Slag SO2 H2SO4 plant Dust Matte Flux, Scrap, Air, Oxygen Slag treatment Converting Batch Continuous Converting Converting Slag SO2 Final Slag Slag Concentrate Dust Blister Copper (> 98,5 % Cu) Reductant, Scrap, Air Fire Refining & Anodes Casting Slag Dust Copper Anodes Anode scrap 2nd Progress Meeting Secondary Smelters Electrolytic Refining Anodic Slime Copper Cathodes Precious Metals Production Melting, Casting of Shapes, Wire-rod Aachen - Germany, 31 - 08 - 2007 Considering and determining BAT Charge Preparation Drying Roasting Smelting Methodology used in examining existing techniques on Primary Mainkey factors affecting the choice of BAT in Non-Ferrous Metals The environmental issues of the the refined copper industry are Copper Production Industry: Industry: air and water pollution: Is process industrially proven and reliable? The choice of process depends strongly on the raw materials that are SO emission 2the Are there limitations in the feed material that can be processed? (e.g. Dust Converting Fire-Refining & Anode Casting Slag treatment 2nd Progress Meeting available to a particular site (composition, presence of other included metals, sizesmelting distribution theare potential to form dust and in primary someincluding processes suited for “clean” concentrate Metal oxide fumes degree of contamination by organic material). Raw materials may be and others for complex feed smelting). primary raw materials available from single or multiple sources, Organic The typecompounds ofraw feed and other it (e.g. Pb, Zn) secondary materials of metals varyingcontained quality or in a combination of influences process selection. Wastewater primary and secondary raw materials. Are production level constraints? (e.g. a best proven a Residues (furnace sludge, filter dust, slag, etc.)limit or The there process must belinings, suitable for use with the gasupper collection and minimum required to be economic). abatementthroughput systems that are available. The fume collection and abatement processes will depend on the characteristics of the Can latest and efficientused collection and abatement techniques be main processes (processes that avoid ladle transfers are easier to applied to the process? seal, processes that are able to treat recycled materials more easily Can the process and abatement combinations achieve the lowest reduce the wider environmental impact by preventing disposal). emission levels? The water and waste issues have been taken into account, in Are there other aspects related to processes (such as safety)? particular the minimization of wastes and the potential to reuse residues and water within the process or by other processes. The energy used by the process and abatement processes. Aachen - Germany, 31 - 08 - 2007 BAT for “Charge Preparation” Charge Preparation Charge Preparation Best Available Techniques Raw materials Drying Coal and coke Fuel and other oils Roasting Fluxes Smelting Copper Products - Cathodes, wire-rod, copper billets and cakes Fine dust Converting Coars dust (raw material or granulated slag) Fire-refining & Anode casting Whole Items Lump (raw material or slag) Covered conveyors if non dusty. Pneumatic. Tanks or drums in bunded areas Secure pipeline or manual syste Open on concrete Enclosed conveyors with dust collection. Pneumatic Enclosed (Silo) if required If dust forming Concentrates Covered Bays, Silos Enclosed with dust collection. Pneumatic Enclosed unless non-dust forming S t o r a g e Open concrete area or covered storage Enclosed Covered Bays Open Open or Covered Bays H a n d l i n g Enclosed with dust collection. Pneumatic Mechanical loader Mechanical loader Mechanical loader Swarf Covered storage Charge skips Cable Open Mechanical loader Slag treatment Circuit Boards Covered Bays Process Residues for recovery Open, covered or enclosed depending on dust formation Depends on conditions Wastes for Disposal (e.g. furnace linings) Open, covered or enclosed bays or sealed (drums) depending on the material Depends on conditions 2nd Progress Meeting Mechanical loader Aachen - Germany, 31 - 08 - 2007 Blending with concentrates or other materials P r e t r e a t m e n t Blending using conveyors. Drying Blending, Agglomeration De-oiling if necessary Swarf drying or de-oiling De-coating Grinding + density separation BAT for “Drying” Drying Charge Preparation Best Available Techniques Drying Raw Materials Direct drying - heat from a burner or a steam jet. Indirectly - steam or hot air in heat exchanger coils. Roasting Drying at low temperatures. Furnaces Concentrates. Flash dryers. Steam coil dryers. Fluidized Bed Dryers. Ores, Concentrates. Rotary Kiln. Smelting Converting Fire-refining & Anode casting Slag treatment 2nd Progress Meeting Aachen - Germany, 31 - 08 - 2007 Comment Extraction and abatement system for collecting dusty gases is necessary. BAT for “Roasting and Smelting” Charge Preparation Roasting and Smelting Best Available Techniques OutokumpuDrying Flash Furnace (high oxygen enrichment for normal copper concentrate) smelting to matte Matte conversion in Peirce-Smith Converter (or similar) to blister copper Roasting Raw materials Concentrate and copper scrap. Abatement Advantages techniques High smelting rate. High quality matte. Long furnace lining life (5-10 years). Gas Collection Disadvantages Comparatively higher Sealed Furnace. investment but lower operating cost. Slag cleaning in Electric Furnace or by flotation Process gas: According to the E. C. Reference Document on BAT in the Non-Ferrous Acid Plant. Smelting Partial roasting of concentrates in a Fluid Bed Roaster Normal and complex Collection and Metals Industry: concentrates, Electric Furnace Smelting to matte cleaning Compact.techniques Two low grade secondary Sealed Furnace. stages process. “the information available for the Baiyin and the Vanyucov smelting for fumes. Matte conversion to blister copper in Peirce-Smith Converter materials, Waterallow treatment Converting copper scrap. processes is limited and at the moment, it does not an evaluation to Slag cleaning by fuming plants. produce matte ISA Furnace beSmelt made intoregard to their potentialConcentrate as BAT”. High smelting rate. and Requires a settler to Hooded. Variety of fuels. copper scrap. separate matte and slag. Matte conversion to blister copper in Peirce-Smith Converter [tmFire-refining 137, Copper & Expert Group 1998]. Noranda / EI Teniente Furnace Smelting to matte Anode casting Matte conversion to blister copper in Peirce-Smith Converter Contop Smelting Furnace to produce matte Slag treatment Peirce-Smith Converter for matte conversion to blister copper Concentrate and copper scrap. Compact. Low cost. Short furnace lining life Hooded. (~ 2 years). Copper concentrate. High Bi and Zn removal. Sealed. Low throughput. Copper concentrate. High smelting rate. High quality matte. Autogeneous 100% O2 used resulting in a Sealed. narrow operating window. INCO Flash Furnace smelting to matte Peirce-Smith Converter for matte conversion to blister copper 2nd Progress Meeting Aachen - Germany, 31 - 08 - 2007 BAT for “Roasting and Smelting” Integrated Smelting Processes Best Available Techniques Mitsubishi Continuous, Coupled Process Outokumpu - Kennecott Flash Smelting and Converting Process Continuous, Uncoupled Process Furnaces Advantages Disadvantages 3 interconnected furnaces: Bath Smelting furnace, Electric slag cleaning furnace and Converting Furnace. High smelting rate. Do not depend on ladle transfer of molten matte and other materials and is therefore inherently cleaner technique. Some limitations in feed. Coupled unit operation with effect on efficiency of the complete line. Sulphur content of blister copper. Outokumpu Flash furnace for smelting and converting. Surge storage of ground matte. No ladle transfer. Comparatively higher investment cost but low direct operating cost. Outokumpu - Kennecott Process Mitsubishi Process Sealed furnaces, capacity up to ~ 300000 t of copper/year Sealed furnaces, capacity up to ~ 240000 t of copper/y 2nd Progress Meeting Aachen - Germany, 31 - 08 - 2007 BAT for “Converting” Converting Charge Preparation Drying Best Available Techniques Batch Converting Raw material Advantages Capacity Disadvantages Gas collection Peirce-Smith Converter Roasting Simple proven technology. Melting of anodes and other scrap. ~ 100 - 250 t per Relies on land Primary and Secondary hoods. Robust and flexible. Good metallurgical performance. Fuming off batch of copper transfers. included metals, such as Pb and Zn, which can then be recovered. Hoboken Smelting Converter Molten matte Gas collection easier. ISA Smelt Furnace Operation under reducing conditions (oxidization of Fe, Hoofs, gas cooling and cleaning ~ 40 000 t per year elimination of Zn or Sn). Converting The Peirce - Smith Converter Fire-refining Best Available& Techniques Anode casting Mitsubishi process Converter Slag treatment Kennecott - Outokumpu Flash 2nd Progress Meeting ~ 50 - 100 t per batch of copper Siphon for primary gasBlockages collection in goose neck. Ladle transfer. Transfer of materials is a potential source of fugitive fume that contains dust, metals and sulphur dioxide. Continuous Converting • The ladle or skip used for feeding can interfere with the efficient positioning of the fumematerial collector hoods.Capacity Raw Gas Advantages Disadvantages • Good operation of the converter therefore relies collection on the use of primary and arrangement in to ~ during 240000 Clean process. EmissionUp control does not rely as andDifficult secondary fume collection hoods charging pouring to collect as existing plants. Closely Ground t of operation copper percare. much onmatte. maintenance and much fugitive fume as possible. Dusts, fluxes, carburant, scrap etc. can be coupled with smelting High SO2 in off-gases. added through the hood. year. Sealed. process. • Automatic controls can prevent blowing during the periods that the To day only applied in to ~ 300000 converter is “rolled out” orUp“rolled in” again. one smelter in EU. t of copper per Molten High SOmatte. 2 in off-gases. Surge storage of matte. Converter A second one under These processes and the techniques for control and fume collection are issuitable year Sealed. construction. for use with new and existing installations and are techniques to be consider. Aachen - Germany, 31 - 08 - 2007 BAT for “Fire-refining & Anode casting” Charge Preparation Fire-Refining & Anode Casting Best Available Techniques Drying Anode Furnace Reverberatory Furnace Roasting Smelting Contimelt (continuous process) Furnace Raw material Rotary furnace with submerged tuyeres. Blister or black copper. Molten feed. Rectangular or circular Bath furnace Blister copper. Copper scrap. Solid and molten feed. 2 interconnected furnaces: a hearth shaft furnace and a drum furnace. Blister copper. High grade copper scrap. Anode scrap. Solid feed. Gas collection Enclosure system. Hoods and covered launders. Enclosure system. Comment Satisfactory recovery rate. Low melting efficiency. Controlled operating conditions. Heat recovery. Converting • Casting of molten copper from the Anode Furnace into a casting wheel: a series of anode shaped moulds on the circumference of a rotating table. • As Fire-refining an alternative to&the stop-to-cast mould on a wheel system, copper anodes are produced Anode casting continuously using a Hazelett twin belt caster. A copper strip with the desired anode thickness is produced. From the strip anodes can be obtained by shearing into the traditional anode shape or, • According to the “Contilanod” system by casting anode lugs in special side dam blocs spaced in Slag treatment defined intervals in the caster. The pre-formed anodes plates are cut off using a plasma torch or special shears. Advantage: uniformity of the anodes produced – Disadvantage: carefully maintenance, high operating cost. 2nd Progress Meeting Aachen - Germany, 31 - 08 - 2007 BAT for “Slag treatment” Charge Preparation Slag treatment Process sources of slag: Smelter, Converter, Slag Furnace, Refining (anode) Furnace Drying Comment Best Available Techniques Decopperized slag (from slag furnace) has several useful properties that allow its use in civil engineering sector (abrasive and construction materials) and as a short-blasting medium. Roasting Electric Furnace Smelting Slow cooling – separation of copper rich portion (concentrate flotation unit) Good operation for slags rich in copper, such as converter slag. InternalConverting Recycle Re-circulation of slags from smelter, converter and refining furnace into the smelting furnace. Rotary Furnace - injection of coal into the slag bath Fire-refining & Anode casting The Slag use and the recycling of slags produced in the different production treatment stages is considered to be part of the process. 2nd Progress Meeting Aachen - Germany, 31 - 08 - 2007 Future Work on WP2 for production BAT 1. Complete the search for production BAT in the case of Primary Copper production 2. Perform same work for the following industrial sectors: • Primary Zinc production • Primary Aluminum and Alumina production • Iron and Steel production • Ferroalloys production 2nd Progress Meeting Aachen - Germany, 31 - 08 - 2007 Thank you for your attention! 2nd Progress Meeting Aachen - Germany, 31 - 08 - 2007