(中南大學(xué) 冶金與環(huán)境學(xué)院，長沙 410083)
摘 要: 以銅陽極泥處理中的沉鉑鈀后液為原料，經(jīng)過氫氧化鈉沉淀、酸浸沉淀渣、SO2還原后，得到碲粉和還原碲后液，在還原碲后液中加入氫氧化鈉沉淀后過濾得到氯氧鉍，在氯氧鉍中加入氫氧化鈉溶液脫氯制得氧化鉍。結(jié)果表明：加入氫氧化鈉調(diào)節(jié)沉鉑鈀后液pH為6、反應(yīng)溫度20~25 ℃、反應(yīng)時間為1 h時，沉鉑鈀后液中碲和鉍沉淀率分別達到99.91%和99.96%；沉鉑鈀后液得到的沉淀渣混酸浸出適宜條件是3 mol/L鹽酸和1.5 mol/L硫酸體積比為2:1，H+濃度為3 mol/L，反應(yīng)溫度為50 ℃，反應(yīng)時間為2 h，鉍和碲的浸出率分別為99.93%和98.21%；在富集碲鉍的浸出液中通入SO2還原，當SO2流量為0.25 L/min、反應(yīng)溫度為70 ℃、反應(yīng)時間為50 min時，碲的還原率為96.59%，還原碲粉中碲含量達到79.45%，砷和鉍含量僅為0.003%和0.067%(質(zhì)量分數(shù))；在SO2還原碲后液中加入氫氧化鈉調(diào)節(jié)溶液pH值為2，過濾后得到氯氧鉍；在氯氧鉍中加入6 mol/L氫氧化鈉溶液，當液固比為3:1、反應(yīng)溫度為80 ℃、反應(yīng)時間為2 h時，所得氧化鉍產(chǎn)物中氧化鉍含量達到93.80%。
關(guān)鍵字: 碲；鉍；沉淀；酸溶；還原
（School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:Tellurium powder and tellurium reduction liquid were obtained through a sets of steps including precipitation process of NaOH, HCl leaching process of slag producing in the previous process, and the reduction process of SO2. The BiOCl was obtained after reduction tellurium liquid was precipitated using sodium hydroxide and then the slurry was filtered. The Bi2O3 was obtained by using NaOH to remove chlorine from BiOCl. The results show that the precipitation rates of Te and Bi are 99.91% and 99.96%, respectively, using NaOH as pH regulator, when the pH value is 6, temperature is 20-25 ℃ and the reaction time is 1 h. The leaching rates of Te and Bi are 98.21% and 99.93%, respectively, when the volume ratio of 3 mol/L HCl to 1.5 mol/L H2SO4 is 2:1, the concentration of H+ is 3 mol/L, the reaction temperature is 50 ℃ and the reaction time is 2 h. The reduction rate of Te is 96.59%, and the contents of Te, As and Bi in the tellurium powder are 79.45%, 0.003% and 0.067% (mass fraction), respectively. The BiOCl is obtained by filtering when the pH of Te reduction solution is 2. Finally, the Bismuth content reaches 93.80% after adding 6 mol/L NaOH to the BiOCl when the ratio of liquid to solid is 3:1, the reaction temperature is 80 ℃ and the reaction time is 2 h.
Key words: tellurium; bismuth; precipitation; acid dissolution; reduction
