白烟灰浸出液砷与锌的分离与回收

对硫化法共沉淀浸出液中的锌和砷的工艺进行了研究,在优化条件下,锌和砷的沉淀率分别为100%和99%;进一步研究了加铁盐氧化脱砷并分离锌和砷,分别得到砷酸铁及硫化锌产品。浸出液用氢氧化钠调节pH可分离出90%以上的砷,再加入硫化物可将锌沉淀完全。而采用氢氧化钙调节pH为1左右,加入硫酸铁,可将95%以上砷分离。再调节脱砷液pH为4以上,控制Na2S/Zn摩尔比为1.5,可将Zn2+沉淀完全。在沉锌后的滤液中未检测出砷。

RECOVERY AND SEPARATION OF As AND Zn FROM THE LEACHING SOLUTION OF WHITE ASH

Zn and As in leaching solution of white ash from copper smelting process are co-precipitated and formed sulfide by sulfuration precipitation method. Under the optimal experimental conditions,100% of Zn and 99% of As are co-precipitated.By adjusting pH of leaching solution with NaOH and adding Fe2(SO)4, the precipitation of ferric arsenate is formed,and over 90 % of As is removed.Finally,Zn is completely precipitated by adding sulfide.By adjusting pH to 1 with Ca(OH)2 to substitute NaOH,over 95% of As is separated,and then adding Na2S,Zn is precipitated when mole ratio of Na2S/Zn is 1.5 and pH of the solution is 4.Arsenic is not detected in the filtrate obtained finally,which illustrates that arsenic is completely precipitated.