砷锑铋中和富集渣中铋浸出行为及动力学

Leaching Behavior and Kinetics of Bi from the Neutralization Enrichment Residues of As,Sb and Bi

砷锑铋中和富集渣是阳极泥全湿法处理工艺中重要中间产物,富含Bi、Sb等有价金属,具有较高的回收价值,但因富集渣中金属种类较多,且赋存行为复杂,Bi及有价金属高效提取面临较大挑战。提出采用盐酸全溶法处理该富集渣,主要考察了HCl浓度、液固比、反应温度及反应时间对Bi及其余金属浸出行为的影响,同时研究了Bi的浸出过程动力学。结果表明:在HCl浓度6.0 mol/L、液固比(mL/g)6、温度80℃、浸出时间15 min的条件下浸出时,Bi、Cu、Pb、As、Sb的浸出率分别为97.4%、96.1%、75.9%、93.6%、96.0%;Bi在盐酸浸出过程中的动力学控制条件可分为两个阶段,浸出过程前期受界面传质与扩散混合控制,后期受化学反应控制,其反应活化能分别为14.50 kJ/mol和82.80 kJ/mol。

Neutralization enrichment residues containing As,Sb and Bi is an important intermediate product in the hydrometallurgy process of anode slime,which is rich in valuable metals such as Bi and Sb with a high recovery value.However,the efficient extraction of Bi and other valuable metals faces challenge due to existence of multiple metals and complex occurrence behaviors.In view of this,hydrochloric acid total leaching process was proposed to treat the enrichment residue.The effects of HCl concentration,liquid-to-solid ratio,reaction temperature and reaction time on the leaching rate of Bi,Cu,Pb,As and Sb were investigated.Moreover,the leaching kinetics of the Bi was also explored at the same time.The results show that the leaching rate of Bi、Cu、Pb、As and Sb are 97.4%,96.1%,75.9%,93.6%,and 96.0%respectively under 6.0 mol/L HCl with liquid-to-solid ratio(mL/g)of 6 at 80℃for 15 min.It is determined that the kinetic control conditions of Bi in the hydrochloric acid leaching process can be divided into two stages.The early stage of the leaching process is affected by interface mass transfer and diffusion.The leaching of Bi is controlled by the chemical reaction in the later stage.The activation energy of the reaction is 14.50 kJ/mol and 82.80 kJ/mol in these two stages,respectively.