Đang chuẩn bị liên kết để tải về tài liệu:
Extractive Metallurgy of Copper Part 12

Tham khảo tài liệu 'extractive metallurgy of copper part 12', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | CHAPTER 18 Solvent Extraction Transfer of Cu from Leach Solution to Electrolyte Written with Jackson Jenkins Phelps Dodge Morenci AZ The pregnant leach solutions produced by most leaching operations are a too dilute in Cu 1-6 kg Cu m3 and b too impure 1-10 kg Fe m3 for direct electrodeposition of high purity cathode copper. Electrowinning from these solutions would give soft impure copper deposits. Industrial electrowinning requires pure Cu-rich electrolytes with 35 kg Cu m3. This high concentration of Cu a ensures that Cu ions are always available for plating at the cathode surface b gives smooth dense high purity readily marketable cathode copper. Solvent extraction provides the means for producing pure high Cu electrolytes from dilute impure pregnant leach solutions. It is a crucial step in the production of -2.5 million tonnes of metallic copper per year. It continues to grow in importance as more and more Cu ore is leached. 18.1 The Solvent Extraction Process Copper solvent extraction Fig. 18.1 entails 307 308 Extractive Metallurgy of Copper Raffinate 0.3 kg Cu m Pregnant leach solution from leach 1-6 kg Cu m3 Depleted electrolyte from electrowinning 35 kg Cu m3 Fig. 18.1. Schematic plan view of copper solvent extraction circuit. The inputs arc pregnant leach solution and Cu-depleted electrolyte. The products are Cu-enrichcd electrolyte and low-Cu raffinate. Fig. 18.3 shows an industrial mixer-settler. Fig. 18.4 shows the most common industrial circuit. a contacting pregnant aqueous leach solution 1-6 kg Cu m3 0.5 to 5 kg H2SO4 1T13 with a Cu-specific liquid organic extractant - causing extraction of Cu front the aqueous solution into the organic extractant b separating by gravity the now-Cu-depIeted aqueous leach solution raffinate from the now-Cu-loaded organic extractant c sending the low-Cu raffinate back to leach d sending the Cu-loaded organic extractant to contact with strong-H2S04 electrowinning electrolyte 170-200 kg H2SO4 1T13 - causing Cu to be .