响应曲面优化某铜精矿碱浸除砷试验研究

Optimization Arsenic Removal from Copper Concentrate through Alkali Leaching Based on Response Surface

以云南某铜精矿为研究对象,利用XRD、化学多元素分析发现砷主要以硫砷铜矿的形式存在,采用NaHS碱性除砷法除砷。通过Design-expert 11. 0软件中的Miscellaneous模块进行设计并优化试验,以pH值、反应温度、NaHS用量为因子,砷浸出率为响应值,通过响应设计进行试验,得到砷浸出率的最佳条件为:pH值为11. 9,反应温度为90℃,NaHS用量为158. 6 g/L,砷浸出率模拟值为95. 10%,实际砷浸出率可达96. 21%。此外,浸出液中砷冷却后会变成有毒的硫代砷酸钠,通过在800℃下焙烧氧化钙和硫代砷酸钠晶体混合物料,固砷率能达到98. 23%,在达到固砷目的的同时也起到了环保作用。

A copper concentrate in Yunnan has been taken as the research object. The analysis results of XRD and chemical multielement demonstrate that arsenic mainly exists in the form of sulfur arsenic copper ore For sake of environmental protection, NaHS alkaline arsenic removal method is adopted. Through the Miscellaneous module in Design-expert 11.0 software, the design and optimization experiment are carried out. The pH value, reaction temperature and NaHS dosage are used as the factors, and the arsenic leaching rate is the response value. The optimum conditions for the arsenic leaching rate were obtained by the response design.The pH value is 11.9, the reaction temperature is 90 ℃, the NaHS dosage is 158.6 g/L, and the actual arsenic leaching rate is 96.21%, which is higher than the numerical simulation value of 95.10%.In addition, the arsenic in leaching solution will become toxic sodium thiosulfate after cooling, and the solid arsenic rate can reach 98.23% by calcining the crystal mixture of calcium oxide and sodium thiosulfate crystals at 800 ℃. It also plays an environmental role in the purpose of achieving arsenic fixation.