In this paper, the beneficiation of rejected phosphate washing sludges (Ps) was investigated using acid leaching methods. Chemical analysis showed that these sludges are a low-grade ore (15.84% P₂O₅). The optimum milling parameters have helped to increase the P₂O₅ grade to 18.51%. Then, the effects of three different organic acids (acetic, lactic, and citric acid), acid concentrations, reaction temperatures, reaction times, and solid concentrations on the beneficiation of P₂O₅ were evaluated. Single-factor experiments indicate that with the optimal conditions: leaching for 60 min with an acetic acid concentration of 7%, a solid concentration of 25%, and a temperature of 40 °C, Ps could reach 30.1% P₂O₅ with a CaO/P₂O₅ ratio of 0.58. Taguchi experimental design, Pareto plot, desirability function, and Analysis of Covariance (ANCOVA) showed that the acid type has the most significant impact on the leaching and the optimized leaching conditions: 7% of acetic acid, a solid concentration of 30%, a reaction time of 100 min, and a temperature of 40 °C, helped to produce a Ps with 30.7% P₂O₅. The kinetic study showed that the leaching process was controlled by a chemical reaction, with an activation energy of 48.9 kJ/Mol, which confirms the chemical reaction’s control of the process.

中文翻译：

---

通过有机酸浸提法对低品位磷酸盐尾矿进行选矿：工艺优化和动力学研究

本文采用酸浸法研究了废磷酸盐洗涤污泥（Ps）的选矿。化学分析表明，这些污泥是低品位矿石（15.84％P ₂ O ₅）。最佳研磨参数有助于将P ₂ O ₅等级提高到18.51％。然后，三种不同的有机酸（乙酸，乳酸和柠檬酸），酸浓度，反应温度，反应时间和固体浓度对P ₂ O ₅选矿的影响被评估。单因素实验表明，在最佳条件下：以7％的乙酸浓度，25％的固体浓度和40°C的温度浸出60分钟，Ps可以达到30.1％P ₂ O ₅。 CaO / P ₂ O _5的比率为0.58。Taguchi的实验设计，帕累托图，合意函数和协方差分析（ANCOVA）表明，酸类型对浸出和优化浸出条件的影响最大：7％的乙酸，30％的固体浓度， 100分钟的反应时间和40°C的温度有助于生成具有30.7％P ₂ O ₅的Ps。动力学研究表明，浸出过程受化学反应控制，活化能为48.9 kJ / Mol，证实了化学反应对过程的控制。