持续淋溶对磷矿废石磷素浸出特性影响的研究

Experiments on Phosphorus Leaching Characteristics of the Phosphate Waste Rock in Continuous Leaching Condition

为了研究持续淋溶作用下磷矿废石磷素浸出特性,进行了土柱模拟试验。结果表明,磷素的释放过程分3个阶段:第1阶段是废石颗粒与浸提液接触后,固相和液相之间的反应过程;第2阶段是废石颗粒与浸提液继续保持接触,磷矿废石颗粒逐渐形成了微孔状的硅酸盐质骨架;第3阶段是固相和液相之间的反应平衡。酸性浸提液能极大促进磷元素的浸出。液固比小于5时,液固比的变化对于固相和液相之间的反应影响较大,而液固比大于5时,固相和液相之间的传质过程趋于稳定。

In order to identify the phosphorus leaching characteristics of the phosphate waste rock in continuous leaching condition, a soil column leaching experiment was conducted. The test results show that the phosphorus release process is divided into three stages： The first stage of the reaction process between the solid and liquid phases; The second stage is the waste rock phosphate particles gradually formed a microporous silicate quality skeleton; The third stage is the reaction equilibrium between the solid and liquid phases. The phosphorus leaching can be greatly promoted under acidic conditions. When the ratio of the liquid to solid is less than 5, liquid-solid ratio can make noticeable effects on reaction between solid phase and liquid phase in continuous leaching condition. Conversely, the mass transfer between the solid phase and liquid phase will reach equilibriume if the ratio of the liquid to solid is more than 5.