磷石膏煅烧-酸浸除杂增白实验

Removal Impurity and Whitening of Phosphogypsum viaCalcination and Acid Leaching

这是一篇冶金工程领域的论文。磷石膏产量及堆存量大,已成为制约磷化工行业绿色、健康发展的重要因素。磷石膏除杂增白是其高消纳综合利用的必经途径。对浮选除杂脱硅磷石膏进行分析发现其中仍存在少量的黑色有机物质,影响其白度。本文采用煅烧-酸浸法对其进行处理,在煅烧温度600℃、煅烧时间70 min、酸浸时间2 h、硫酸浓度1.5 mol/L、酸浸液固比5:1和酸浸温度90℃条件下,增白磷石膏的白度由51.5%增加到了92.7%,增白效果显著。增白磷石膏主要是CaSO_(4),并含有少量的CaSO_(4)·2H_(2)O和CaSO_(4)·0.5H_(2)O,颗粒呈15~20μm的不规则形状,且表面光滑。本研究对磷石膏规模化综合利用具有重要指导意义。

This is an article in the field of metallurgical engineering.Large production and storage capacity of phosphogypsum has become an important factor restricting the green and healthy development of phosphorus chemical industry.Removing impurity and whitening of phosphogypsum is a necessary way for its high consumption.Analysis results showed that there was still a small amount of black organic matter in the phosphogypsum after removing impurity and desilication by flotation,which affected its whiteness.In the paper,calcination and acid leaching were adopted to treat the phosphogysum.The whiteness of whitened phosphogysum significantly increased from 51.5%to 92.7%at the conditions of calcination temperature 600℃,calcination time 70 min,acid leaching time 2 h,sulfuric acid concentration 1.5 mol/L,acid leaching liquid to solid ratio 5∶1 and acid leaching temperature 90℃.The whitened phosphogypsum was mainly CaSO_(4),and contained a small amount of CaSO_(4)·2H_(2)O and CaSO_(4)·0.5H_(2)O.The particles of the whitened phosphogypsum were irregular in shape of 15~20μm,and the surface was smooth.The study provided a guidance for the comprehensive utilization of phosphogypsum with high consumption.