tailieunhanh - Extractive Metallurgy of Copper Part 2

Tham khảo tài liệu 'extractive metallurgy of copper part 2', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Overview 7 a including SiO2 flux in the furnace charge to promote matte-slag immiscibility b keeping the furnace hot so that the slag is molten and fluid. Matte smelting is most often done in flash and submerged tuyere furnaces Figs and . It is carried out to a lesser extent in top lance furnaces Mitsubishi Isasmelt Ausnielt shaft furnaces reverberatory furnaces and electric furnaces. In two cases concentrate is flash smelted directly to molten copper Chapter 12. . Converting Chapters 9 and 10 Copper converting is oxygen enriched-air or air oxidation of the molten matte from smelting. It removes Fe and s from the matte to produce crude 99 Cu molten copper. This copper is then sent to fire- and electrorefining. Converting is mostly carried out in the cylindrical Peirce-Smith converter Fig. . Liquid matte 1200 C is transferred from the smelting furnace in large ladles and poured into the converter through a large central mouth Fig. . The oxidizing blast is then started and the converter is rotated - forcing oxygen enriched-air or air into the matte through a line of tuyeres along the length of the vessel. The heat generated in the converter by Fe and s oxidation is sufficient to make the process autothermal. The converting takes place in two sequential stages a the FeS elimination or slag forming stage 2FeS 3O- SiO2 - 2FeOSiO2 2SO2 heat in molten in flux molten slag in matte blast offgas b the blister copper forming stage Cu2S o2 2Cu 2SO2 heat liquid in molten in . matte blast copper offgas Coppermaking b doesn t occur until the matte contains less than about 1 Fe so that most of the Fe can be removed from the converter as slag before copper production begins. Likewise significant oxidation of copper does not occur until the sulfur content of the copper falls below . Blowing is terminated near this sulfur end point. The resulting molten blister copper 1200 C is sent to refining. Blast Off-Gas Hood Matte 8 Extractive Metallurgy of .