煤矸石低温中和过程铁、钙、镁的溶出及动力学

立足于贵州盘州丰富的煤矸石资源，为探求其高值化开发利用途径，采用硫酸浸取法对煤矸石中铁、钙、镁的提取过程进行研究。研究结果表明：在中和反应过程中，随着温度的升高，铁、钙、镁的溶出逐渐增加，最后趋于平稳，温度对铁、镁溶出率的影响较为显著，对钙溶出的影响相对较小。因此，选择低温中和过程作为铁、钙、镁溶出动力学研究。动力学研究结果表明：煤矸石中和过程中铁、钙、镁溶出的活化能分别为19.523kJ/mol、8.300 kJ/mol和27.565 kJ/mol，E_a钙＜E_a铁＜E_a镁，说明在煤矸石硫酸浸出中和反应过程中钙的溶出最容易，铁次之，镁的溶出相对较难；浸出过程的动力学控制类型属于内扩散控制，可用动力学方程\mathrm{1}\text{-}\frac{\mathrm{2}}{\mathrm{3}}x\text{-}{\left(\mathrm{1}\text{-}x\right)}^{\frac{\mathrm{2}}{\mathrm{3}}}\text{=}kt来描述。通过对固相物质XRD、SEM的表征，初步对煤矸石中的碳酸盐酸浸溶出过程进行了机理分析，为工业生产中煤矸石的高效利用提供了技术指导和理论支撑。

Dissolution kinetics of iron,calcium and magnesium from coal gangue during low-temperature neutralization

Panzhou in Guizhou province, is rich in coal gangue resources, in which there are valuable elements, such as iron, calcium and magnesium. The extraction of iron, calcium and magnesium from coal gangue was studied by sulfuric acid leaching. The results showed that in the process of neutralization, the dissolution of iron, calcium and magnesium increased gradually with the increase of temperature and finally reached a plateau. The temperature had a significant effect on the dissolution rate of iron and magnesium, but it had a relatively small effect on that of calcium. Therefore, the neutralization process at low temperature was selected for kinetics study of iron, calcium and magnesium dissolution. The kinetic results showed that the activation energies of iron, calcium and magnesium during the neutralization of gangue were 19.523kJ/mol, 8.300kJ/mol and 27.565kJ/mol, respectively. Therefore, calcium was the easiest to be dissolved, followed by iron, and magnesium was relatively difficult to be dissolved. The kinetics of the leaching process is internal diffusion control, which can be described by an kinetic equation of \mathrm{1}\text{-}\frac{\mathrm{2}}{\mathrm{3}}x\text{-}{\left(\mathrm{1}\text{-}x\right)}^{\frac{\mathrm{2}}{\mathrm{3}}}\text{=}kt. Through the characterization of solid phase materials by XRD and SEM, the mechanism analysis of carbonic acid leaching process in gangue was preliminarily carried out. It provided a technical guidance and theoretical support for the efficient utilization of gangue in industrial production.