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Extractive Metallurgy of Copper 4th ed. - W. Davenport_ et. al. (2002) WW Part 8

Tham khảo tài liệu 'extractive metallurgy of copper 4th ed. - w. davenport_ et. al. (2002) ww part 8', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | CHAPTER 12 Direct-To-Copper Flash Smelting Previous chapters show that coppermaking from sulfide concentrates entails two major steps smelting and converting. They also show that smelting and converting are part of the same chemical process i.e. oxidation ofFe and sfrom a Cu-Fe-S phase. It has long been the goal of metallurgical and chemical engineers to combine these two steps into one continuous direct-to-copper smelting process. The principal advantages of this combining would be a isolation of so2 emission to a single continuous gas stream b minimization of energy consumption c minimization of capital and operating costs. This chapter i describes direct-to-copper smelting in 2002 and ii examines the degree to which its potential advantages have been realized. The chapter indicates that the principal problems with the process are that a about 25 of the Cu entering a direct-to-copper smelting furnace ends up dissolved in its slag b the cost of recovering this Cu will probably restrict future expansion of direct-to-copper smelting to low-Fe concentrates e.g. chalcocite Cu2S and bornite Cu5FeS4 concentrates rather than high-Fe chalcopyrite concentrates. 12.1 The Ideal Direct-to-Copper Process Fig. 12.1 is a sketch of the ideal direct-to-copper process. The principal inputs to the process are 187 188 Extractive Metallurgy of Copper concentrate oxygen air flux and recycles. The principal outputs are molten copper low-Cu slag high-SO2 offgas. The process is autothermal. With highly oxygen-enriched blast there is enough excess reaction heat to melt all the Cu-bearing recycle materials from the smelter and adjacent refinery including scrap anodes. The process is continuous. The remainder of this chapter indicates how close we have come to this ideality. Scrap copper Concentrates Flux and reverts Fig. 12.1. Ideal single-furnace coppermaking process. Ideally the copper is low in impurities the slag is discardable without Cu-recovery treatment and the offgas is strong .