不同链长有机膦酸阻垢剂对硫酸钡结晶过程的影响

Effect of Phosphate Inhibitors With Various Chain Length on the Formation of BaSO_4 Crystal

考察了二亚乙基三胺五亚甲基膦酸(DETPMP)和二亚己基三胺五亚甲基膦酸(BHMTPMP)阻垢剂对BaSO4结晶的影响。利用Zeta电位分析了2种阻垢剂对BaSO4晶体表面电荷的影响,运用经典的均相成核理论解释了阻垢剂的抑制机理,利用扫描电子显微镜表征了硫酸钡晶体的形貌。结果表明,在实验浓度范围内,2种有机膦酸阻垢剂通过提高BaSO4晶体析出时的表面自由能和结晶活化能抑制了BaSO4结晶,BHMTPMP的抑制效果更明显;2种阻垢剂使BaSO4晶体表面Zeta电位绝对值升高,pH=8时Zeta电位绝对值达到最大;2种阻垢剂使BaSO4晶体形貌发生显著变化,晶体表面出现明显台阶状生长特征。

The effects of diethylene triamine penta（methylene phosphonic acid）（DETPMP）and bis（hexamethylene triamine penta（methylene phosphonic acid））（BHMTPMP）on formation of BaSO4 crystal were studied.The surface structure and performance of BaSO4 crystal were characterized by Zeta potential analysis.The inhibitory mechanism was discussed according to the homogeneous nucleation theory.The morphology of BaSO4 crystal was characterized by means of SEM.It was found that the effect of the phosphonate inhibitors on the formation of BaSO4 crystal may be from the increase of surface free energy and activation energy of BaSO4 crystalline.The inhibition effect of BHMTPMP was better than that of DETPMP.When the inhibitors were added during precipitation of BaSO4,the absolute Zeta potential value of BaSO4 crystal increased and reached its maximum value at pH=8of the solution.The regular shapes of BaSO4 crystals were changed obviously in the presence of the phosphonate inhibitors.The step growth characteristics presented significantly on the surface of BaSO4 crystal.