Abstract

In the present work, the leaching behavior of copper from an oxide/sulfide ore was assessed in two work phases including process optimization and kinetics modeling. In the first phase, the individual and synergistic impacts of the influential parameters such as sulfuric acid concentration, liquid/solid ratio, pulp mixing rate, temperature, and contact time were investigated on the dissolution rate of copper using response surface modeling. The findings demonstrated that the linear effects of dissolution time and temperature and the quadratic impact of acid concentration had the largest influence on the recovery and the linear impact of stirring speed had the least degree of importance. Process optimization was also performed utilizing the desirability function approach and more than 88.17% copper was recovered at the optimum conditions: ~ 17% acid concentration, ~ 11.3 mL/g liquid/solid ratio, ~ 390 rpm stirring speed, 50 °C temperature, and 60 min leaching time. In the second phase, the leaching kinetics was examined by heterogeneous shrinking core models and it was realized that diffusion through product layer was the dissolution rate controlling step with the activation energy of 28.92 kJ/mol and frequency factor of 6.155 min⁻¹. Ultimately, a mathematical kinetics model was developed and suggested to understand the leaching process.

Graphical Abstract

a 3D response surface graphs displaying the synergistic effects between “temperature and liquid/solid ratio” and “stirring speed and leaching time” on the leaching recovery of copper; b the optimum conditions of influential factors; c plot of diffusion through product layer versus leaching time for temperature effect.

中文翻译：

---

伊朗混合氧化物/硫化物铜矿溶解铜的实验和动力学建模研究

摘要

在目前的工作中，在两个工作阶段中评估了从氧化物/硫化矿中铜的浸出行为，包括工艺优化和动力学建模。在第一阶段，使用响应表面模型研究了影响参数（如硫酸浓度，液/固比，纸浆混合速率，温度和接触时间）的个体和协同影响对铜的溶解速率的影响。研究结果表明，溶解时间和温度的线性影响以及酸浓度的二次影响对回收率的影响最大，而搅拌速度的线性影响的重要性最小。还使用期望函数方法进行了工艺优化，并在最佳条件下回收了88.17％的铜：酸浓度约为17％，液/固比约为11.3 mL / g，搅拌速度约为390 rpm，温度为50°C，浸出时间为60分钟。在第二阶段中，通过非均质收缩核模型研究了浸出动力学，发现通过产物层的扩散是溶解速率的控制步骤，其活化能为28.92 kJ / mol，频率因子为6.155 min。^-1。最终，开发了数学动力学模型并建议理解浸出过程。

图形概要

一个三维响应面图显示“温度和液/固比”之间的协同作用，并且“搅拌速度和浸出时间”上铜的浸出回收; b影响因素的最佳条件；c通过产品层扩散对温度影响的浸出时间的图。