从熔炉渣中氯盐浸出铅的参数优化和动力学（英文）

研究采用氯盐浸出法从传统熔铅炉渣中回收铅的可行性和动力学。考察工艺参数如浸出时间、NaCl浓度、FeCl_3浓度、液/固比、搅拌速度、浸出温度、颗粒尺寸对铅回收率的影响。基于中心复合设计模型,利用响应面法对上述参数进行优化,得到优化工艺条件如下:浸出时间60 min、浸出温度80℃、搅拌速度800 r/min、NaCl浓度200 g/L、FeCl_3浓度80 g/L、液固比16、颗粒尺寸小于106μm。在此优化条件下96%Pb被回收。基于方差分析法,确定浸出温度、液固比和NaCl浓度为影响浸取过程的最有效参数。动力学研究结果表明,方铅石的氯盐浸出过程为一级反应过程。反应机理为固态反应产物的扩散和化学反应。采用Arrhenius模型计算得到从方解石中氯盐浸出铅的激活能为27.9 kJ/mol。

黄铜矿精矿在甘氨酸介质中的循环伏安及动电位极化研究

采用循环伏安及动电位极化方法研究黄铜矿在甘氨酸介质中的浸出反应机理及动力学。使用黄铜精矿−碳糊电极研究pH值(9~12),温度(30~90)及甘氨酸浓度(0~2 mol/L)对腐蚀电流密度、腐蚀电位及循环伏安曲线的影响。结果显示,甘氨酸浓度从0增加到2 mol/L导致氧化峰电流密度增加;在相同条件下,腐蚀电流密度从约28μA/cm2增加至约89μA/cm2,同时腐蚀电位由−80 mV降至−130 mV。在温度不高于60℃的条件下,电流密度随温度的增加而增加;当温度高于60℃时,电流密度随温度增加而降低。电流密度随pH值的变化与温度相似,当pH值从9增至10.5时电流密度增加,pH值高于10.5时电流密度降低。此外,铜氧化物及铁氧化物的热力学稳定性在较高温度下增加。

Dynamic simulation of the effect of time-dependent variation of pH on response variable of the tailing thickener of coal washing plant

Dynamic simulation approach can be used for understanding the nonlinear behavior in mineral processing circuits. In this study, the gel point, the main parameters of batch flux density function and the main parameters of effective solid stress were determined at different conditions (pH, flocculant dosage and particle size). Therefore, the main parameters of phenome no logical model of sedimentation and thickening were determined as a functio n of particle size, pH and flocculant dosages using the result of experimental tests and Curve expert professional software. Then, the dynamic simulation was carried out for the industrial thickener of coal washing plant and the time-dependent variation of response variables was investigated by time-dependent variation of pH of input feed to thickener using the obtained equations. It was observed that it is possible to predict the thickener behavior as a function of time for time dependent variation of pH of input feed to the thickener of coal washing plant using obtained equations that it was not possible using phenomenological model of thickener alone.