硅酸钠对煤和高岭石浮选行为的影响  

Effects of sodium silicate on flotation behavior of coal and kaolinite

作　　者：徐东方[1] 朱书全[1] 朱志波 崔浩然[1] 

机构地区：[1]中国矿业大学(北京),化学与环境工程学院,北京100083

出　　处：《煤炭科学技术》2016年第7期201-205,共5页Coal Science and Technology

基　　金：国家重点基础研究发展计划(973计划)资助项目(2012CB214901);国家自然科学基金资助项目(51404274)

摘　　要：为深入了解煤泥浮选过程中硅酸钠对黏土矿物的选择性抑制机理,以煤和高岭石为研究对象,通过单矿物浮选试验、Zeta电位测定、X射线光电子能谱(XPS)分析,研究了硅酸钠对煤和高岭石浮选行为的影响。试验结果表明:p H值在7左右、硅酸钠用量为1 000 g/t时,煤和高岭石的分离效果最好,煤的可燃体回收率可达60.44%,灰分为8.03%;硅酸钠使煤和高岭石表面电位负移,增大了矿物间的静电斥力,p H值为中性时,煤和高岭石表面电位分别降低了6 m V和16 m V;XPS分析结果显示,与硅酸钠作用后,煤与高岭石表面Si原子相对含量增加,并且硅原子2P原子轨道(Si 2p)结合能变化值分别为-0.02、-0.19 e V,证明了硅酸钠在煤和高岭石表面的吸附为物理吸附,吸附量的不同是造成硅酸钠选择性抑制的主要原因。In order to study the mechanism of selective inhibition of sodium silicate on clay minerals, the flotation behavior of coal and kao- linite with sodium silicate were investigated by flotation test, Zeta potential test and XPS analysis. The flotation experiment results show that the separation effect is the best,the recovery of coal is 60. 44% and the ash content is 8.03% with 1 000 g/t Na2SiO3 in the pH of 7. The Zeta potentials of coal and kaolinite shift negatively and the electrostatic repulsion between the two minerals increase in presence of sodium silicate. The surface potential of coal and kaolinite decreases 6 mV and 16 mV with neutral pH. The results of XPS show that the relative content of Si on the surface of coal and kaolinite increases with sodium silicate, the decrement of Si 2p binding energy of coal and kaolinite is -0. 02 eV and -0. 19 eV respectively. According to the results of XPS,it can be concluded that sodium silicate is absorbed on the sur- face of coal and kaolinite by physical adsorption, the different adsorption capacity of the two minerals makes sodium silicate own selective inhibition.

关 键 词：硅酸钠 煤泥浮选 选择性抑制 高岭石 黏土矿物 

分 类 号：TD94[矿业工程—选矿]