铅锌混合矿烧结烟尘提硒工艺研究

Study on process of selenium extraction from sintering dust of lead-zinc mix concentration

摘要:

采用一段酸浸分离回收锌镉、二段氧化酸性浸硒、SO2还原含硒溶液制取粗硒的工艺，用于处理铅锌混合矿烧结烟尘，提取其中所含的硒．结果表明：以稀硫酸浸出分离烟尘中的锌与镉，锌与镉的浸出率分别达98．5，与99．1，；以硝酸钠为氧化剂在硫酸体系浸取硒，在硫酸浓度为2．0 mol/L、搅拌速度为150 r/min、反应温度为80℃的条件下，硒的浸出率大于94，；采用SO2气体还原溶液中所含硒，在75℃下反应，控制还原时间100 min ，溶液中硒的还原率大于95，；在优化条件下，在对烧结烟尘的提硒过程中，硒的直接回收率为89．42，，所得粗硒含硒89．2，．

Abstract:

Crude selenium was prepared from sintering dust of lead-zinc mix concentration using two-step leaching technology and reduction-extraction selenium by sulfur dioxide gas .The results shows that ,in the process of separation zinc and cadmium from materials via dilute sulfuric acid leaching route w hen the condition of liquid-solid ratio and leaching time are controlled well ,the leaching rate of Zn and Cd can be a-chieved up to 98 .5， and 99 .1， ,respectively .In the process of oxidation-leaching of selenium w hile sodi-um nitrate as oxidant ,the leaching rate of Se is above 94， w hen the optimum operation parameters are de-termined as follow s :temperature of 80 ℃ ,stirring speed of 150 r/min and ratio of liquid to solid of 5︰1 , sulfuric acid concentration of 2 .0 mol/L .T he reduction rate of selenium reaches 95， under the reductive temperature is 80 ℃ and the reaction time is 100 min w hile sulfur dioxide gas as the reducing agent .In the w hole process under optimum conditions ,the recovery rate of selenium is above 89 .42， ,and the ultimate selenium content in the crude selenium is 89 .2，.