(中南大學(xué) 冶金與環(huán)境學(xué)院，長(zhǎng)沙 410083)
摘 要: 考察鋅粉置換鎵鍺渣草酸浸出過(guò)程中，草酸濃度、浸出時(shí)間、液固比、浸出溫度、雙氧水濃度對(duì)鎵、鍺、鋅、鐵、銅、硅浸出率及浸出料漿過(guò)濾性能的影響，揭示在草酸浸出體系下添加雙氧水促進(jìn)鎵、鍺浸出的作用機(jī)理。結(jié)果表明，采用草酸和雙氧水為浸出劑，不僅可實(shí)現(xiàn)鎵、鍺的選擇性浸出，還可顯著改善浸出料漿的過(guò)濾性能。雙氧水促進(jìn)鎵、鍺浸出的機(jī)理為其作為氧化劑使鎵、鍺單質(zhì)及其硫化物氧化為可溶的氧化物；草酸與鎵、鍺可生成穩(wěn)定絡(luò)合物，而與硅的作用較弱，從而促進(jìn)鎵、鍺的浸出，同時(shí)使浸出渣的過(guò)濾性能得以改善。在草酸濃度為110 g/L、雙氧水濃度為0.12 mol/L、液固比(L/S)為8、攪拌速度為 300 r/min、浸出溫度為40 ℃、浸出時(shí)間為30 min 的條件下，鎵和鍺浸出率分別為99.32%、98.86%，而銅、鋅、硅的浸出率分別在0.82%、0.84% 、0.43%，且浸出料漿的過(guò)濾速度由常壓硫酸浸出體系下的0.48 mL/min 提高到100 mL/min。
關(guān)鍵字: 鎵；鍺；草酸；雙氧水；浸出
（School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:The oxalic acid leaching of the zinc powder replacement residue containing gallium and germanium was carried out. The effects of oxalic acid concentration, leaching time, liquid-to-solid (L/S) ratio, leaching temperature, and hydrogen peroxide concentration on the leaching of gallium and germanium, together with the filterability of the leaching residues were investigated. The effective mechanisms of improving the leaching through adding hydrogen peroxide in oxalic acid leaching system were found out. The results show that using oxalic acid and hydrogen peroxide as leachant can effectively promote the leaching of Ga and Ge. Moreover, the filterability of leaching residues also can be obviously improved in the oxalic acid leaching system. These could be attributed to the fact that hydrogen peroxide oxidize elemental gallium and germanium, as well as their sulfides, while the oxalic acid promotes the formation of gallium and germanium complex, and oxalic acid has negligible effects on silica, thus the leaching of gallium and germanium and the filterability of the leaching residues were improved. The optimal leaching conditions are as follows: oxalic acid concentration of 110 g/L, hydrogen peroxide concentration of 0.12 mol/L, L/S ratio of 8, temperature of 40 ℃, stirring rate of 300 r/min, and leaching time of 30 min. Under the optimal conditions, 99.32% of Ga and 98.86% of Ge were leached out, while the leaching of Zn, Cu and Si were 0.815%, 0.842% and 0.430%, respectively. Moreover, the filtration rate of the leaching slurry increases from 0.48 mL/min in atmospheric pressure acid leaching system to 100 mL/min.
Key words: gallium; germanium; oxalic acid; hydrogen peroxide; leaching
