Wang Yongwei, Zhang Shen'ao, Wang Lijue, Qin Wenqing, Han Junwei
School of Minerals Processing & Bioengineering, Central South University, Changsha 410083, China.
School of Minerals Processing & Bioengineering, Central South University, Changsha 410083, China.
J Hazard Mater. 2024 Sep 5;476:135168. doi: 10.1016/j.jhazmat.2024.135168. Epub 2024 Jul 10.
High-grade heavy metal elements in copper slag (CS) are worth recovering. Unfortunately, the high viscosity of leaching solution, low leaching efficiency, difficult filtration and low separation efficiency of valuable components exist in the traditional sulfuric acid leaching process. In this study, the above problems are solved by sulfuric acid pretreatment + curing + water leaching. Moreover, iron, cobalt and copper ions in solution are separated by stepwise precipitation. The final iron, cobalt, copper and silicon recoveries are 99.01 %, 98.45 %, 93.13 % and 99.52 %, respectively. Thermodynamic calculations show that HSiO can be converted to insoluble SiO to improve filtration properties under curing conditions of sulfur dioxide partial pressures of 10∼0 atm, oxygen partial pressures of 10∼0 atm and 400-600k. Simulation studies of the phase equilibria of the components of the leach solution by Visual MINTEQ showed that the oxidation of Fe to Fe is necessary for the removal of Fe from the solution by precipitation. This study provides a new idea for the efficient utilization of CS.
铜渣（CS）中的高品位重金属元素值得回收。遗憾的是，传统硫酸浸出工艺存在浸出液粘度高、浸出效率低、过滤困难以及有价成分分离效率低等问题。本研究通过硫酸预处理+养护+水浸出解决了上述问题。此外，溶液中的铁、钴和铜离子通过分步沉淀进行分离。最终铁、钴、铜和硅的回收率分别为99.01%、98.45%、93.13%和99.52%。热力学计算表明，在二氧化硫分压为10∼0 atm、氧气分压为10∼0 atm和400 - 600K的养护条件下，HSiO可转化为不溶性SiO以改善过滤性能。通过Visual MINTEQ对浸出液成分的相平衡进行模拟研究表明，Fe氧化为Fe对于通过沉淀从溶液中去除Fe是必要的。本研究为铜渣的高效利用提供了新思路。
