微粒矿物诱导疏水絮凝中的疏水作用

加入适当的表面活性剂使微粒矿物表面疏水化而使其悬浮体产生聚团的现象,称为诱导疏水絮凝。它与常规的胶体聚沉现象不同,不能为DLVO理论所解释。本文通过对颗粒间疏水粘着力及润湿接触角、zeta电位的测量和体系的疏水絮凝行为的研究,获得如下结论:疏水作用力对诱导疏水絮凝起支配作用;当微粒表面有足够大的润湿接触角而颗粒产生疏水吸引力时,才能使微粒悬浮体强烈聚团。

STUDY ON THE HYDROPHOBIC FLOCCULATION OF FINE MINERAL PARTICLES IN AQUEOUS SOLUTION

A aggregation phenomenon of fine particles of hematite,sidrite and rhodochrosite, rendered hydrophobic by surfactant absorption,or so called induced hydrophobic flocculation was studied. The flocculation-dispersion behavior, contact angle, hydrophobic adhesion force and zeta potential measurement were carried out. The experimental results show that the hydrophobication of particle surface is often accompanied by a distinct flocculation which can not be interpreted by DLVO theory. The aggregation behavior is in a good concordance with the changes of contact angle and hydrophobic adhesion force as well. A theoretical approach and calculation related to the hematite-NaO 1 system and the rhodochrosite-NaOl system demonstrate that the potential energy of hydrophobic interaction between hydrophobic particles is one or two orders of magnitude larger than that of electrical double layer or van der Waals interaction. It was concluded that the hydrophobic interaction between particles plays a predominant role in hydrophobic flocculation.