以碱性焙烧—水浸工艺从白银炉电收尘中选择性除砷及浸出动力学研究

Selective Removal and Leaching Kinetics of Arsenic From Electric Dust Collection of Silver Furnace by Alkaline Roasting—Water Leaching

研究了采用碱性焙烧—水浸工艺从白银炉电收尘中选择性分离砷及回收有价金属,考察了碱性焙烧、浸出过程中各因素对金属浸出率的影响,并分析了碱性焙烧渣中砷的浸出动力学。结果表明:电收尘在碱料质量比1.2/1、温度600℃下焙烧2 h,再在液固体积质量比4 mL/1 g、温度60℃、搅拌速度250 r/min条件下用水浸出1.0 h,砷浸出率达91.55%,实现了与铅、锌等有价金属的选择性分离;浸出渣中的有价金属总质量分数高达59.60%,砷质量分数低于0.81%,可直接返回熔炼系统综合回收。砷浸出过程符合JMA模型,受扩散控制,浸出反应表观活化能为10.98 kJ/mol。

Selective separate arsenic and valuable metals from a electric dust collection of silver furnace alkaline roasting—water leaching process was studied.The influence of various factors in the process of alkaline roasting—water leaching on metal leaching rate were examined,and the leaching kinetics of the alkaline roasting slag was analyzed.The results show that the arsenic leaching rate reaches 91.55%under the conditions of alkali mass/material mass of 1.2/1,roasting at 600℃for 2 h;water volume/roasting slag mass of 4 mL/1 g,stirring rate of 250 r/min at 60℃for 1.0 h,and the arsenic is selective separated from lead,zinc and other valuable metals.The total mass fraction of valuable metals in the leaching residue is up to 59.60%and arsenic fraction is less than 0.81%.The leaching residue can be directly returned to smelting system for comprehensive recovery.The leaching process conforms JMA model and is mainly controlled by diffusion.The apparent activation energy is 10.98 kJ/mol.