【摘要】 以硝酸铈铵为引发剂,以淀粉、顺丁烯二酸酐为基材,合成具有一定相对分子质量范围的阴离子型水溶性淀粉,作为湿法磷酸防沉降剂。考察了反应温度、反应时间、单体配比、引发剂用量对相对分子质量及羧基度的影响;对合成产品进行了红外检测、热性能、防沉降性能测试,并与一些市售分散剂对湿法磷酸在储存过程中产生的固体杂质防沉降效果进行对比。通过实验得出(1)当反应温度为70℃,反应时间1.5h,单体摩尔比1∶1,引发剂用量为3wt%时,控制合成产物的相对分子质量为10万左右、羧基度为15%左右;(2)控制反应条件合成相对分子质量为10万左右、羧基度为15%左右的产物,当添加量为5wt‰时,能较好地分散湿法磷酸中磷酸钙、硫酸钙等沉淀物,并能有效地防止含铁的复盐沉淀。更多还原

【Abstract】 In order to reduce precipitate in wet-process phosphoric acid,choosing Ce(Ⅳ) as initiator,anionic water-soluble starch with controlled-relative molecular mass was synthesized with alkalized starch and maleic anhydride.The product as antisedimentation agent was applied in wet-process phosphoric acid.The effects of reaction temperature,reaction time,monomer molar ratio and initiator on relative molecular mass and carboxyl degree were investigated.Its structure was confirmed by FTIR.The thermal properties and anti-sedimentation properties of the product were studied and compared with the anti-sedimentation agents sold in the market for wet-process phosphoric acid.It was found that:(1) when the reaction temperature was 70 ℃,reaction time was 1.5 h,monomer molar ratio was 1∶1,initiator content was 3wt%,the relative molecular mass and carboxyl degree of synthetic products were about 100,000 and 15%;(2) starch Maleate with relative molecular mass of 100,000 had an obvious anti-flocculation effect on wet-process phosphoric acid.更多还原