硫酸酸浸法除磷石膏中杂质氟的研究

以H2SO4为浸取剂对磷石膏进行热浸取,考察磷石膏中杂质氟的去除情况,为磷石膏综合利用提供基础数据。研究在均匀设计实验的基础上,进一步考察了温度、时间、硫酸质量分数、含固量(质量浓度)、粒度5个因素对杂质氟去除率的影响规律。结果表明:温度、时间、硫酸是影响氟去除率的主要因素,而含固量、粒度对结果影响较小。较理想的除氟条件为浸取温度88℃,浸取时间45 min,H2SO4质量分数30%,含固量0.43 g/mL,在优化实验条件下杂质氟的去除率可以达到84.50%,处理后的磷石膏含氟仅为0.036%。采用硫酸酸浸处理磷石膏,杂质氟去除效果好,且提高了净化磷石膏的白度。

Removing impurity fluorine from phosphogypsum by sulfuric acid leaching method

Phosphogypsum heat was leached with H2SO4 as leaching agent,and the removal of fluoride impurity in the phosphogypsum was studied to provide the basic data for the comprehensive utilization of the phosphogypsum.Based on the uniform design experiment,the effects of temperature,time,mass fraction of sulfuric acid,solid mass content,particle size of five factors on the removal rate of impurity fluorine were further researched.The results show that temperature,time,mass fraction of sulfuric acid are the main factors affecting the fluorine removal rate,but solid mass concentration and particle size have smaller effect on the results.The ideal conditions of removing fluorine are as follows: leaching temperature 88 ℃,leaching time 45 min,mass fraction of H2SO4 30%,solid mass concentration 0.43 g/mL.Under the optimized experimental conditions,the removal rate of impurity fluorine can reach 84.50%,and the fluorine content in the phosphogypsum processed is only 0.036%.Processing the phosphogypsum with the sulfuric acid leaching method has good removal effect of the impurity fluoride,and improves the whiteness of phosphogypsum purified.