磷钾伴生矿中的钾在HCl-H_3PO_4混酸溶液中的浸出动力学（英文）

Kinetics on leaching of potassium from phosphorus-potassium associated ore in HCl-H_3PO_4 media

为了减轻设备腐蚀,降低酸浸液中氯的含量及提高磷的含量,研究了磷钾伴生矿中的钾在HCl-H_3PO_4混酸溶液中的浸出动力学。考察了盐酸的质量分数、固液比、物料比(CaF_2添加量(g)与磷钾伴生矿质量(g)比)、浸出温度等几个因素对钾浸出率的影响,结果表明:在浸出温度95°C、盐酸浓度10%、浸出时间6 h、固液比1:6、物料比0.1的优化工艺条件下,钾浸出率可达86%以上。同时建立了基于经典缩合模型的半经验动力学模型,并用该模型成功地模拟了钾的浸出过程。结果表明:在65~95°C范围内,钾浸出过程属于内扩散控制步骤,表观活化能为54.67 kJ/mol。

In order to relieve the equipment corrosion,reduce chlorine and increase phosphorus contents in leaching solution,theleaching behavior of potassium from phosphorus-potassium associated ore in the mixed acids of hydrochloric acid and phosphoricacid was investigated.The effects of various factors,such as mass fraction of hydrochloric acid,solid-to-liquid ratio,material ratio(CaF2dosage(g)/mass of ore(g))and leaching temperature were comprehensively studied.It was found that the dissolution fractionof potassium can reach more than86%under the optimum conditions of leaching temperature95°C,HCl concentration10%,leaching time6h,solid/liquid ratio1:5,and material ratio0.1.In addition,the leaching kinetics of potassium was successfullymodeled by a semi-empirical kinetic model based on the classic shrinking core model.The data showed that the leaching process ofpotassium was controlled by the product layer diffusion and the apparent activation energy for the process was found to be54.67kJ/mol over the temperature range from65to95°C.