以黄磷炉渣为原料,经HNO<,3>溶液浸出,SiO<,2>以无定形水合二氧化硅的形式分离,钙元素以Ca(NO<,3>)<,2>的形式进入到浸出液,浸出液经H<,2>SO<,4>沉淀,然后经洗涤、干燥可得到优质的CaSO<,4>产品.讨论了H<,2>SO<,4>质量分数、H<,2>SO<,4>与Ca(NO<,3>)<,2>体积比、搅拌速度、反应时间等因素对CaSO<,4>产品质量的影响,采用了FTIR,TG-DTA,XRD等测试方法对CaSO<,4>的表面结构进行了表征.研究表明:产品中CaSO<,4>质量分数达到99.66%,H<,2>O质量分数19.43%,经FTIR,TG-DTA,XRD分析为CaSO<,4>·2H<,2>O产品.最佳工艺条件:H<,2>SO<,4>质量分数20%,H<,2>SO<,4>与Ca(NO<,3>)<,2>体积比0.6:1,搅拌速度200 r/min,反应时间30 min.%With yellow phosphorus slag as the raw material and nitric acid as leaching agent, SiO2 was separated from the yellow phosphorus slag in the form of amorphous hydrated silicon dioxide.The calcium was entered into leaching liquor in the form of calcium nitrate, which was precipitated with sulphuric acid, and the high quality calcium sulfate product was obtained after washing and drying.The influence of the factors like mass concentration of sulphuric acid, the volume ratio of H2SO4 to Ca( NO3 )2, the stirring speed and the reaction temperature on the product quality of calcium sulfate was discussed.The characterization of the surface structure of calcium sulfate was performed by FTIR, TG-DTA and XRD.The result shows that the mass fraction of CaSO4 in the product can reach 99.66％, and the mass fraction of H20 is 19.43％, which was analyzed to be the product of CaSO4 · 2H20 by FTIR, TG-DTA and XRD.The optimum technical conditions are as follows: H2SO4 mass fraction 20％, the volume ratio of H2SO4 to Ca( NO3 )2 0.6: 1, stirring speed 200 r/min, reaction time 30 min.
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