(中南大學 冶金與環(huán)境學院，長沙 410083)
摘 要: 采用硫酸浸出鋅冶煉含鎘煙塵，得到含鎘硫酸浸出液，在硫酸鎘浸出液中加入雙氧水和FeCl3溶液，用NaOH溶液調(diào)節(jié)pH值后過濾，將濾液加入NaOH溶液中得到Cd(OH)2粉體，采用氫氣還原得到鎘粉。結(jié)果表明：當硫酸濃度為110 g/L、反應(yīng)溫度為65 ℃時，鎘浸出率達99.63%。雙氧水用量為理論量10倍、n(Fe)/n(As)為3:1、pH=5.5時，砷的去除率達99.5%，得到凈化的硫酸鎘溶液。將硫酸鎘溶液以緩慢加料方式加入濃度為2 mol/L的NaOH溶液中，反應(yīng)溫度為25 ℃，控制終點pH=10，過濾洗滌得到粒徑為10~20 μm的Cd(OH)2粉體，采用氫氣還原Cd(OH)2粉體，在反應(yīng)溫度為310 ℃、反應(yīng)時間120 min、氫氣流量40 L/h時，得到平均粒徑為49.61 μm的球形鎘粉。
關(guān)鍵字: 焙燒煙塵；除雜；化學沉淀法；氫氣還原；鎘粉；鋅冶煉
（School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:The CdSO4 solution was prepared by leaching roasting dust of zinc smelting with sulfuric acid, then, the CdSO4 solution was purified by adding hydrogen peroxide and ferric chloride and adjusting pH with sodium hydroxide. Cd(OH)2 powder was prepared after the purified CdSO4 solution mixed with NaOH solution, then, reduced with hydrogen. The results show that the leaching rate of Cd reaches 99.63% under the condition of H2SO4 concentration of 110 g/L, reaction temperature of 65 ℃. Under the condition that n(Fe)/n(As) is 3:1 and pH is 5.5, the removal rate of As can be higher than 99.5%. The obtained Cd(OH)2 particle size is 10-20 μm when the reaction temperature is 25 ℃, pH value of the solution is 10. High purified Cd powders were prepared from Cd(OH)2 particles reduced by hydrogen. The optimum process conditions are as follows: reaction temperature is 310 ℃, reaction time is 120 min and hydrogen flow is 40 L/h. The average particles size of spherical Cd powder is about 49.61 μm.
Key words: roasting dust; impurity; chemical precipitation; hydrogen reduction; Cd powder; zinc smelting
