铁矾渣精准制砖资源化利用研究

Study on resource utilization of jarosite slag by precise brick making

某铅锌冶炼厂针对该厂铁钒渣大量堆存及目前常用铁矾渣处理工艺投资高、运行成本高、经济效益低的问题,经过长期考证和实验室试验,探索出铁矾渣两段弱酸浸出-水洗渣制砖的工艺路线。该工艺中的滤液和水洗渣水均可返回系统循环使用,产生的沉锌渣返回锌冶炼湿法系统,产生的水洗渣进行制砖;通过对传统的制砖工艺及物料配比进行改进,压制的免烧砖在养护28 d以后抗压强度达到MU15,超出国家相关标准,而且一次成品率由改造前的37.3%提升到98.63%。该项目建成投产后,年均总成本费用2 579.8万元,年收益3 915.9万元,铁矾渣经济正效益1 336.1万元。改造后的工艺具有投资少、成本低的优点,而且制成的产品成砖不易坍落,是一种新型环保材料,市场认可度高,值得在铜、铅、锌等冶炼企业进行推广。

In view of the problems of jarosite slag, such as the large amount of jarosite slag stockpiled in the plant, and the routine treatment process with high investment, high operating cost and low economic benefit, a lead-zinc smelter explored the process route of two stages weak acid leaching-washed slag making bricks after long-term research and laboratory tests. The filtrate and washing slag water in the process can be returned to the system for recycling, and the zinc sediment slag is returned to the zinc hydrometallurgy system, and the washed slag is used to make bricks. By improving the traditional brick-making process and material ratio, the compressive strength of pressed non-fired brick reaches MU15 after 28 days of curing, which exceeds the national standards, and the qualified rate of products increased from 37.3% to 98.63%. After the project was completed and put into operation, the average annual total cost was CNY 25.798 million, the annual income was CNY 39.159 million, and the positive economic benefit of jarosite slag was CNY 13.361 million. The reformed process has the advantages of less investment and low cost, and the bricks are not easy to collapse. It is a new type of environmental protection material with high market recognition, and the process is worthy of promotion in copper, lead and zinc smelting enterprises.