HEDP防垢剂对CaCO3表面Zeta电位的影响

为探讨HEDP防垢剂的防垢机理，将等量的Ca^2＋和CO3^2-的水溶液混合，适时测定了CaCO3生成过程中的表面Zeta电位。结果表明，CaCO3表面带负电；生成过程中加入的防垢剂，对CaCO3的表面Zeta电位没有明显影响。此外，也测定了由等量的Ca^2＋和CO3^2-的水溶液混合所制备的CaCO3粉末在溶解过程中的表面Zeta电位，发现在溶解过程中，CaCO3的表面Zeta电位值和溶液pH值不断降低。制备CaCO3粉末时，防垢剂加入与否，对所生成的CaCO3粉末在溶解过程中的Zeta电位没有明显影响；在CaCO3粉末溶解时，分散体系中防垢剂加入与否，所测表面Zeta电位值也没有明显差别。

THE EFFECT OF HEDP ON Zeta POTENTIAL OF CALCIUM CAEBONATE

To investigate the scale inhibition mechanism of HEDP,a classic scale inhibitor,the Zeta potential of fresh CaCO_3 originated from admixture of equimolar of Ca~(2 ) and CO~(2-)_3 was measured in time during precipitating process.The results showed that the produced CaCO_3 was negatively charged and HEDP had no obvious effect on Zeta potential of CaCO_3 when it was added during precipitation.In addition,Zeta potential of CaCO_3 originated from admixture of equimolar of Ca~(2 ) and CO~(2-)_3 was also measured during dissolution.With the proceeding of dissolution,Zeta potentials of CaCO_3 and the values of pH continuously decreased.Whether the scale inhibitor was added or not during CaCO_3 precipitation,and whether the dispersion contained HEDP or not,Zeta potentials always had no obvious difference.