盐酸对冶金污泥中铜锌镉铅的浸出工艺优化

为了能够充分回收利用冶金污泥中的有价金属,采用盐酸作为浸取剂浸出污泥中的重金属,并进行浸出工艺的优化.首先对污泥性质进行分析,分别采用烘干法测定冶金污泥的含水率,用X射线荧光光谱仪测定试样中金属成分及质量分数,用X射线衍射仪对试样中各元素的物相特征进行定性和定量分析.结果显示:污泥含水率为75.88%;干污泥含铜和锌的质量分数分别是1.51%和1.71%;污泥矿物相中铜主要以单质形式存在,锌主要以闪锌矿形式存在.然后采用盐酸作浸取剂,在单因素条件下进行浸出反应.研究了冶金污泥中铜、锌、镉、铅等重金属的浸出规律,并考察了浸出温度、浸出时间、盐酸浓度、液固比、粒径等因素对浸出率的影响.盐酸浸出污泥中重金属最佳工艺参数:浸出温度为25℃,浸出时间为10 min,盐酸浓度为1mol/L,液固比为25∶1(mL/g),干污泥粒度小于150μm.在此条件下,铜、锌、镉、铅的浸出率可分别达到84.4%、88.1%、98.8%、85.4%.盐酸浸出最佳工艺条件的确定,对工业应用有一定实用价值.

Extract technology of heavy metals from metallurgical sludge by hydrochloric acid

Hydrochloric acid was using as leaching agent to extract heavy metals from metallurgical sludge, and extract technology was optimized to recycle heavy metals from sludge. Moisture content of the sludge was determined by drying method. Metal component and mass fraction were determined by X-ray fluorescence spectrometer. Phase characteristics of each element were analyzed by X-ray diffraction. The analysis results show that moisture content metallurgical sludge is 75.88~//oo of, mass fractions of copper and zinc are 1.51~ and 1.71~ in dry sludge, respectively. Copper exists in the form of simple substance, and zinc mainly exists in the form of sphalerite. Hydrochloric acid leaching process was studied to leach heavy metals such as copper, zinc, cadmium, lead from metallurgical sludge. Parameters such as leaching temperature, leaching time, concentration of hydrochloric acid, and grain diameter were investigated. The optimum results are 25 ℃ of leaching temperature, 10 minutes of leaching time, 1 mol/L of concentration of hydrochloric acid, 25 ： l（mL/g） of liquid- solid ratio and less than 150 μm of grain diameter. The recovery of copper, zinc, cadmium, lead is 84.4%, 88. 1%, 98. 8%, 85. 4%, respectively. The above investigation is valuable for industrial applications of leaching technology by hydrochloric acid.