水热合成金属硫化物的浮选行为及微观性质分析

张海静¹，闵小波^{1, 2}，柴立元^{1, 2}，梁彦杰^{1, 2}，袁翠玉¹

(1. 中南大学 冶金科学与工程学院，湖南 长沙，410083；
2. 国家重金属污染防治工程技术研究中心，湖南 长沙，410083)

摘 要：石灰中和沉淀法处理重金属废水中会产生大量的中和渣，采用化学试剂模拟中和渣，利用元素硫的歧化反应，在水热条件下将模拟渣中的氢氧化物转变成硫化物，进而，可将产生的硫化矿利用常规浮选工艺加以回收。采用X线衍射(XRD)、激光粒度仪和扫描电镜(SEM)对3种硫化物的微观性质进行分析。试验结果表明：硫化铜和硫化铅有较好的可浮性，回收率分别为91.00%和72.78%，而硫化锌浮选效果较差，回收率为28.31%；硫化铜和硫化铅比硫化锌的水热结晶好，粒径大，表面光滑。在水热过程中添加矿化剂NaOH能提高硫化锌的结晶度，水热温度提高使硫化锌的晶粒增大、表面光滑，改进后硫化锌的回收率提高至63.92%。

关键词：水热合成；金属硫化物；模拟中和渣；浮选行为；微观性质

Hydrothermal synthesis and flotation performance and microscopic properties of metal sulfides

ZHANG Hai-jing¹, MIN Xiao-bo^{1, 2}, CHAI Li-yuan^{1, 2}, LIANG Yan-jie^{1, 2}, YUAN Cui-yu¹

(1. School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China;
2. Chinese National Engineering Research Center for Control and Treatment of Heavy Metal Pollution,
Changsha 410083, China)

Abstract:There is a huge amount of lime neutralization sludge in the process of wastewater treatment. Hydrothermal- sulfidation treatment can convert metal hydroxides contained in the sludge to metal sulfides, and then recovered by conventional flotation. The flotability of metal sulfides synthesized by chemical reagents simulating lime neutralization sludge was investigated. The microscopic properties of synthetic metal sulfides were analyzed by X-ray diffraction (XRD), laser diffraction particle size analyzer and scanning electron microscopy (SEM). The results show that CuS and PbS have good flotability, and the recovery is 91.00% and 72.78%, respectively. The synthetic ZnS possesses poor floatability with a recovery of 28.31%. In respect of crystallinity, crystal size and surface smoothness, CuS and PbS are superior to ZnS. It is shown that the crystallinity, the crystal size and the surface smoothness of ZnS crystals are improved when the mineralizer NaOH is added and temperature enhanced in the hydrothermal-sulfidation process of ZnS. According to analysis, the hydrothermal process of ZnS is improved, and the recovery increases to 63.92%.

Key words:hydrothermal synthesis; metal sulfides; simulated lime neutralization sludge; flotation performance; microscopic properties