硫酸浸出磷石膏中稀土的动力学研究

Leaching kinetics of rare earth elements from phosphogypsum with sulfuric acid

  • 摘要: 针对磷石膏中稀土元素的浸出,已有很多研究报道,但对于浸出动力学研究却很少。文章以硫酸为浸取剂深入研究了磷石膏中稀土浸出的动力学。研究表明:浸出温度和时间的增加均可提高稀土的浸出率,浸出温度80 ℃时,稀土总浸出率最大可达55.8%,其中Y的浸出率最大,为63.9%;稀土的浸出与二水硫酸钙的溶解具有很强的线性相关性;动力学模型拟合表明:磷石膏中稀土浸出反应是受扩散和界面传质混合控制的,浸出反应的表观活化能Ea=9.10 kJ/mol。

     

    Abstract: Researchers have done lots of work on the leaching of rare earth elements (REEs) from phosphogypsum (PG), but there are few studies on the leaching kinetics. Therefore, this paper studied the leaching kinetics of REEs from PG using sulfuric acid as the leaching agent. The study results showed that an increase in the leaching temperature and time could improve the REE leaching rate. At 80℃, the total leaching rate of REEs reached up to 55.8%, of which the leaching rate of Y was the largest of 63.9%. And the REE leaching had a strong linear correlation with the dissolution of calcium sulfate dihydrate. The kinetics model fitting showed that the interfacial transfer and diffusion was the rate-controlling step for REE leaching from the PG sample, and the apparent activation energy was 9.10 kJ/mol.

     

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