白铅矿与硫磺在高温下的硫化机理

Sulfidation mechanism of cerussite in the presence of sulphur at high temperatures

本文采用微浮选、X射线粉末衍射(XRD)、电子探针(EPMA)和X射线光电子能谱(XPS)等分析手段,研究了高温下硫磺与白铅矿的硫化机理。浮选试验结果表明,在适宜的浮选条件下,处理后的白铅矿浮选回收率提高到80%以上。S/PbCO3摩尔比和pH值对浮选回收率有明显影响。XRD分析结果证实,硫化焙烧后的白铅矿分解为氧化铅,然后转化为以PbS为主和PbO·PbSO4的含铅物种。EPMA分析结果表明,获得的铅黄表面光滑,但合成的人工方铅矿表面粗糙,甚至孔隙较多。随着S/PbCO3摩尔比的增加,氧含量降低,硫含量增加。XPS分析结果表明,表面生成了以PbS为主以及PbSO4和PbO·PbSO4的多种含铅物种。PbS的形成有利于处理后白铅矿的浮选。基于这些研究结果,提出了白铅矿与硫磺在高温条件下的反应模型。

In this paper,sulfidation mechanism of cerussite in the presence of sulphur at high temperatures was investigated based on micro-flotation,X-ray powder diffractometry(XRD),electron probe microanalysis(EPMA)and X-ray photoelectron spectroscopy(XPS).The micro-flotation test results showed that flotation recovery of the treated cerussite increased to above 80%under a suitable flotation condition.It was found that the S/PbCO3 mole ratio and pH obviously affected flotation recovery.XRD analysis results confirmed that the cerussite was decomposed into massicot and then was transformed into mainly PbS and PbO·PbSO4 after sulfidation roasting.EPMA analysis results demonstrated that surface of the obtained massicot was smooth,but surface of the artificial galena was rough and even porous.Content of oxygen decreased,whereas content of sulphur increased with an increase in the S/PbCO3 mole ratio.XPS analysis results revealed that various lead-bearing species,including mainly PbS,PbSO4 and PbO·PbSO4,were generated at the surface.Formation of PbS was advantageous to flotation of the treated cerussite.Based on these results,a reaction model of the cerussite sulfurized with sulphur was proposed.