Fan Zhi-Yu, Wu Yi-Yi, Nie Deng-Pan, Zhang Yu, Zhou Lan
School of Chemical Engineering, Guizhou Minzu University, Guiyang, 550025, China; School of Materials and Metallurgy, University of Science and Technology Liaoning, Anshan, 114051, China.
School of Chemical Engineering, Guizhou Minzu University, Guiyang, 550025, China.
Chemosphere. 2023 Dec;344:140437. doi: 10.1016/j.chemosphere.2023.140437. Epub 2023 Oct 12.
Barite ore is typically associated with difficult-to-remove vein minerals, but commercial barite products require a high BaSO content. We investigated the occurrence state of fluoride in barite ore using various analytical techniques, which indicated that elemental fluorine in barite predominantly exists as fluorite. Fluoride was then leached from barite ore via complexation. The effects of HCl and AlCl concentrations, temperature, time, and liquid-solid ratio on the leaching rate were examined, and the leaching conditions were optimized using an orthogonal array method. The fluorine leaching rate approached 93.11% after stirring for 30 min at 90 °C and 300 rpm with 3 mol/L HCl, 0.4 mol/L AlCl, a liquid-solid ratio of 10:1 mL/g, and an ore sample size of -75 μm + 48 μm. According to the leaching kinetics, the process conformed to the solid membrane diffusion control model at a high temperature and the joint chemical reaction-diffusion control model at a low temperature. The apparent activation energy was 56.88 kJ/mol. Furthermore, aluminum and fluorine coordination numbers increased with increasing Al/F molar concentration ratios. Competing complexation reactions of Al, H, and F occurred at three levels. This complexation approach effectively leaches fluoride from barite, improves barite product quality, and reduces environmental pollution.
重晶石矿通常与难去除的脉石矿物共生，但商业重晶石产品需要高硫酸钡含量。我们使用各种分析技术研究了重晶石矿中氟的赋存状态，结果表明重晶石中的元素氟主要以萤石形式存在。然后通过络合作用从重晶石矿中浸出氟。考察了盐酸和氯化铝浓度、温度、时间以及液固比对浸出率的影响，并采用正交试验法优化了浸出条件。在90℃、300rpm搅拌30min，使用3mol/L盐酸、0.4mol/L氯化铝、液固比为10:1mL/g以及矿石粒度为-75μm+48μm的条件下，氟的浸出率接近93.11%。根据浸出动力学，该过程在高温下符合固体膜扩散控制模型，在低温下符合联合化学反应-扩散控制模型。表观活化能为56.88kJ/mol。此外，铝与氟的配位数随铝/氟摩尔浓度比的增加而增加。铝、氢和氟在三个水平上发生竞争络合反应。这种络合方法有效地从重晶石中浸出氟，提高了重晶石产品质量，减少了环境污染。
