聚丙烯酰胺对磷酸钙结垢的影响研究

Influence of polycrylamide on calcium phosphate scale

以氯化钙和磷酸钠为原料配制磷酸钙,分析磷酸钙在部分水解聚丙烯酰胺（HPAM）溶液中的结晶行为,并且考察了分别改变φ（HPAM）、反应时间、pH值和温度等条件时HPAM对磷酸钙成垢的影响,并对相对分子质量为800万、2 500万的HPAM进行实验分析。结果表明：不同相对分子质量的HPAM对磷酸钙的形成有一定影响,高相对分子质量HPAM的加入均能使溶液中剩余ρ（Ca2＋）低于空白样中剩余ρ（Ca2＋）;随着加入φ（HPAM）的升高,溶液中剩余ρ（Ca2＋）先升高后降低,并在φ（HPAM）=300×10-6时达到最大值;2~6h时溶液中的剩余ρ（Ca2＋）逐渐降低,反应稳定后,随着反应时间的延长,溶液中剩余ρ（Ca2＋）先增高后降低,并在12h时达到区间内的最高值;随着pH值的增大,HPAM对磷酸钙生成的影响减小;温度为60℃,HPAM对磷酸钙的影响最大。低相对分子质量的HPAM加入时,在φ（HPAM）=100×10-6时,对磷酸钙的影响最大,反应时间为10h时,对磷酸钙的生成影响最大;温度为60℃时,对磷酸钙的促进作用最强;在pH=7~9时,溶液中的剩余ρ（Ca2＋）低于空白溶液中的剩余ρ（Ca2＋）,pH=10~12时,溶液中的剩余ρ（Ca2＋）高于空白溶液中的剩余ρ（Ca2＋）。

In this paper,using calcium chloride and sodium phosphate as the raw material prepared calcium phosphate,examined its crystallization behavior in HPAM solution,and investigated the effect of changing the HPAM concentration,reaction time,pH and temperature on calcium phosphate into scale,and took the HPAM with 8million and 25 million molecular weight HPAM to carry experiment analysis.The results showed that,different molecular weight of HPAM has certain influence on the formation of calcium phosphate,high molecular weight of HPAM can make residual calcium ion concentration in the solution be lower than the remaining calcium ion concentration in blank sample;with adding HPAM concentration increased,residual calcium ion concentration in the solution reduced after rising first,and peaked at 300×10-6,at the time of 2~6hreducing the residual calcium ion solution.After reaction stability,with the extension of reaction time,the remaining calcium ion concentration in the solution increased,and at the time of 12 hat the peak of range;with the increase of pH,HPAM has less effect on calcium phosphate generated;when the temperature was 60℃,the influence of HPAM on calcium phosphate is the largest.When adding low molecular weight of HPAM,in the reaction solution solubility of 100×10-6,the effect on calcium phosphate is the largest;when the biggest influence on the formation of calcium phosphate for 10h;strongest promoting effect of calcium phosphate of 60℃;When the pH value of 7~9,the remaining calcium ions in solution concentration is lower than the blank residual calcium ion concentration in the solution.