(中南大學(xué) 冶金與環(huán)境學(xué)院，長沙 410083)
摘 要: 針對(duì)現(xiàn)行的濕法煉鋅渣中萃取鎵工藝存在調(diào)酸復(fù)雜、添加絡(luò)合劑成本高、有機(jī)相損失嚴(yán)重等弊端，采用新型萃取劑HBL121 從鋅置換渣的高濃度硫酸浸出液中直接萃取鎵，考察料液酸度、萃取劑濃度、萃取溫度、萃取時(shí)間和相比對(duì)萃取的影響以及H2SO4 濃度、反萃溫度、反萃時(shí)間和反萃相比對(duì)反萃的影響，分別繪制萃取平衡等溫線和反萃平衡等溫線，并對(duì)萃取劑轉(zhuǎn)型條件進(jìn)行研究。結(jié)果表明：以有機(jī)相組成為40%HBL121(質(zhì)量分?jǐn)?shù))+20%癸醇(體積分?jǐn)?shù))+磺化煤油作為萃取劑，料液酸度為108.67 g/L H2SO4，其最佳萃取條件為萃取溫度25 ℃、萃取時(shí)間10 min、相比O/A=1:1，經(jīng)過4 級(jí)逆流萃取，鎵萃取率達(dá)到98.14%。負(fù)載有機(jī)相用200 g/L 的H2SO4 溶液可選擇性反萃鎵，得到高純度硫酸鎵溶液，其最佳反萃條件為反萃溫度25 ℃、反萃時(shí)間8 min、相比O/A=4:1。經(jīng)過5 級(jí)逆流反萃，反萃率可達(dá)到99.18%。反萃鎵后負(fù)載有機(jī)相再用7 mol/L 鹽酸溶液反萃共萃的鐵并轉(zhuǎn)型，控制反萃溫度25 ℃、反萃時(shí)間2 min、O/A=1.5:1，經(jīng)過3 級(jí)逆流反萃，鐵反萃率可達(dá)到99.23%并完成轉(zhuǎn)型，萃取劑循環(huán)使用。
關(guān)鍵字: 鎵；HBL121 萃取劑；鋅置換渣；高濃度硫酸浸出液；萃取；反萃
（School of Metallurgy and Environment,Central South University,Changsha 410083,China）
Abstract:The extraction of gallium from high sulfuric acid leach solution of zinc replacing slag by a new extractant HBL121 was carried out based on the problems in the existing extracting process of gallium from zinc smelting slag in hydrometallurgy,such as complex acidity adjusting step,high complexing agent cost,and serious organic phase loss. The effects of feed acidity,extractant concentration,extraction temperature,extraction time and extraction phase ratio on the extraction,and the effects of H2SO4 concentration,stripping temperature,stripping time and stripping phase ratio on the stripping of gallium were investigated. The isotherms of the extraction and stripping were plotted,and the conditions of extractant transformation were researched. The results show that with 40% HBL121 (mass fraction) and 20%(volume fraction) in sulphonated kerosene as extractant,the extraction rate of gallium from the solution with 108.67 g/L H2SO4 reaches 98.14% in four-stage counter current extraction with O/A ratio of 1:1 at 25 ℃ for 10 min. Gallium in loaded organic phase can be selectively stripped using 200 g/L H2SO4 solution and the stripping rate reaches 99.18% in five-stage counter current stripping with O/A ratio of 4:1 at 25 ℃ for 8 min. After gallium stripping,the iron in loaded organic phase can be stripped using 7 mol/L HCl solution and the stripping rate of iron reaches 99.23% in three-stage counter current stripping with O/A ratio of 1.5:1 at 25 ℃ for 2 min. The extractant returns to extraction circularly.
Key words: gallium; HBL121 extractant; zinc replacing slag; high concentration sulfuric acid leaching liquor; extraction; Stripping
