有色冶炼二次含砷物料碱法脱砷工艺现状

Status of alkaline dearsenization technology in secondary arsenic-bearing materials in nonferrous metallurgy

分析了典型二次含砷物料化学成分特点,概括了当前有色冶炼工业中产生的二次含砷物料碱法脱砷工艺及原理,主要包括湿法脱砷工艺和火法—湿法联合脱砷工艺。其中,碱法脱砷工艺常用NaOH单碱浸出、NaOH-Na 2 S混合碱浸出和NaOH+Na 2 S混合碱两段浸出三种体系,并采用双氧水、加压、曝气、微波、球磨等氧化手段强化砷的浸出;火法—湿法联合脱砷工艺主要有低温碱性熔炼—水浸、焙烧预氧化—碱性浸出以及低温碱性焙烧—热水浸出工艺,低温碱性焙烧—热水浸出工艺选择性脱砷效果好,物料普适性广。最后,结合现有研究指出了碱法脱砷工艺存在的问题及二次含砷物料无害化、资源化研究方向。

In this paper,the chemical composition characteristics of typical secondary arsenic-bearing materials are analyzed.The alkaline dearsenization process of secondary arsenic-bearing materials produced in nonferrous smelting industry and its principle are summarized,including hydro-dearsenization process and combined pyro-hydro dearsenization process.Three alkaline hydro-dearsenization leaching systems are commonly used:NaOH single-alkali leaching,NaOH-Na 2S mixed-alkali leaching and NaOH+Na 2S mixed-alkali two-stage leaching.Hydrogen peroxide,pressure,aeration,microwave,ball milling and other oxidation methods are used to enhance arsenic leaching from secondary arsenic-bearing materials.The combined pyro-hydro dearsenization process mainly includes low-temperature alkaline smelting-water leaching,pre-oxidation roasting-alkaline leaching and low-temperature alkaline roasting-hot water leaching.Low-temperature alkaline roasting-hot water leaching process has good selectivity in arsenic removal and wide applicability of secondary arsenic-bearing materials.Based on all the existing research,the existing problems of alkaline dearsenization technology and the research direction of harmless treatment and resource utilization of secondary arsenic-bearing materials are pointed out.