Surface chemistry features in the flotation of KCl

Despite the successful industrial practice to recover KCl by flotation, the adsorption state of collectors at KCl salt surfaces is still not fully understood. In this paper, the flotation behavior of KCl and NaCl using different collectors and captive bubble contact angle measurements at KCl and NaCl crystal surfaces in their saturated solutions are reported. The influence of collector concentration and collector structure is considered. The results show that both cationic and anionic collectors produce a hydrophobic state at the structure breaking KCl salt surface, with finite contact angle values of between 30 degrees and 60 degrees. In contrast, the contact angle at the structure making NaCl salt surface is zero at all collector concentrations, suggesting that no collector adsorption occurs, a supposition that is supported by results from molecular dynamics simulation (MDS). Further, it appears that the presence of surface defects such as edges and corners promote the adsorption of collectors at the KCl surface, and that the flotation is achieved by bubble attachment at the edges/corners of KCl particles with the formation of aeroflocs. (C) 2009 Elsevier Ltd. All rights reserved.

尽管通过浮选回收氯化钾在工业上已取得成功实践，但捕收剂在氯化钾盐表面的吸附状态仍未完全被了解。本文报道了使用不同捕收剂时氯化钾和氯化钠的浮选行为，以及在其饱和溶液中氯化钾和氯化钠晶体表面的俘获气泡接触角测量结果。考虑了捕收剂浓度和捕收剂结构的影响。结果表明，阳离子和阴离子捕收剂在结构被破坏的氯化钾盐表面均产生疏水状态，接触角在30度到60度之间有确定的值。相比之下，在所有捕收剂浓度下，结构完整的氯化钠盐表面的接触角均为零，这表明没有捕收剂吸附发生，分子动力学模拟（MDS）的结果也支持这一假设。此外，似乎边缘和角落等表面缺陷的存在促进了捕收剂在氯化钾表面的吸附，并且浮选是通过气泡附着在氯化钾颗粒的边缘/角落并形成气絮体而实现的。（C）2009爱思唯尔有限公司。保留所有权利。