工业级磷酸二氢钾除砷制备食品级聚偏磷酸钾

发布时间：2018-05-10 13:01

本文选题：磷酸二氢钾 + 聚偏磷酸钾　；参考：《无机盐工业》2017年12期

【摘要】：介绍了以工业级磷酸二氢钾为原料,通过去除微量的砷杂质制备食品级磷酸二氢钾,再经过脱水聚合制备聚偏磷酸钾的方法。其中微量砷离子脱除是重要的一步。除砷方法是将工业级磷酸二氢钾加热至熔融状态,利用氢卤酸与砷离子反应生成低沸点的卤化砷,并在高温下气化分离出去,以达到脱除微量砷的目的,得到食品级磷酸二氢钾。考察了反应时间、搅拌转速、卤化氢用量对除砷效果的影响,当磷酸二氢钾与氢卤酸物质的量比低于16.7、搅拌转速大于250 r/min、反应时间在45 min以上时,可以使工业级磷酸二氢钾中的砷含量达到食品级磷酸二氢钾的要求。采用化学分析以及X射线衍射(XRD)、红外光谱(IR)、拉曼光谱(Raman)等表征手段,综合分析了聚偏磷酸钾实验样品的黏度、分子组成等,并与商业样品相比较,结果表明二者性质一致,并达到了国家标准的要求。
[Abstract]:The method of preparing food grade potassium dihydrogen phosphate from industrial grade potassium dihydrogen phosphate by removing trace arsenic impurity and then preparing potassium polymetaphosphate by dehydration polymerization is introduced. The removal of trace arsenic ion is an important step. The method of arsenic removal is to heat industrial grade potassium dihydrogen phosphate to melting state and to react with arsenic ion to produce low boiling point arsenic halide, which can be gasified and separated at high temperature to remove trace arsenic. Food grade potassium dihydrogen phosphate was obtained. The effects of reaction time, stirring speed and the amount of hydrogen halide on arsenic removal were investigated. When the ratio of potassium dihydrogen phosphate to hydrohalogenate was lower than 16.7, the stirring speed was more than 250rmin, the reaction time was more than 45 min. The arsenic content in industrial grade potassium dihydrogen phosphate can meet the requirements of food grade potassium dihydrogen phosphate. The viscosity and molecular composition of experimental samples of potassium polymetaphosphate were analyzed by means of chemical analysis, X-ray diffraction (XRD), X-ray diffraction (XRD), IR spectroscopy (IR) and Raman spectroscopy (Raman). Compared with commercial samples, the results show that the properties of the two samples are the same. And meet the requirements of national standards.
【作者单位】：武汉工程大学化工与制药学院绿色化工过程教育部重点实验室;湖北祥云(集团)化工股份有限公司;
【分类号】：TQ131.13;TS202.3

【相似文献】