羟肟酸类捕收剂对煤系石英浮选的机理研究

Study on the Mechanism of Hydroxamic Acid Collectors on Coal-Bearing Quartz Flotation

以马兰煤矿岩石矿物为研究对象,探究水杨羟肟酸钠、苯甲羟肟酸钠、辛基异羟肟酸钠3类捕收剂对岩石矿物的浮选效果及作用机理。通过浮选试验及XRD定量分析得出,辛基异羟肟酸钠的浮选效果最好,药剂用量为450 g/t,浮选精矿产率为67.05%,加入750 g/t的六偏磷酸钠调整剂后,浮选精矿产率能够达到了78.54%,尾矿中石英含量从原来的85.16%提高到了91.70%。通过密度泛函、接触角测试、红外光谱和分子动力学模拟分析了药剂与岩石矿物之间的作用机理。结果表明:3类捕收剂在石英表面的吸附位点均为可在溶液中电离出阳离子Na^(+)的头基部分;辛基异羟肟酸钠与石英之间的吸附绝对值大于水杨羟肟酸钠和苯甲羟肟酸钠与石英之间的吸附绝对值,说明辛基异羟肟酸钠更易吸附在石英表面,且和调整剂(六偏磷酸钠、本质素磺酸钠)在岩石矿物表面的吸附为物理吸附。研究成果可为选煤厂煤泥水处理及煤泥综合应用提供思路。

Taking the rock minerals of Malan Coal Mine as the research object, the flotation effect and mechanism of three collectors of sodium salicylhydroxamate, sodium benzohydroxamate and sodium octylhydroxamate on rock minerals were investigated. Through flotation test and XRD quantitative analysis, it is concluded that the flotation effect of sodium octyl hydroxamate is the best. The dosage of the reagent is 450 g/t, and the flotation concentrate yield is 67.05%. After adding 750 g/t sodium hexametaphosphate regulator, the flotation concentrate yield can reach 78.54%, and the quartz content in the tailings is increased from 85.16% to 91.70%. The mechanism of action between reagents and rock minerals was analyzed by density functional theory, contact angle test, infrared spectroscopy and molecular dynamics simulation. The results show that the adsorption sites of the three collectors on the quartz surface are the head groups that can ionize the cation Na^(+) in the solution. The absolute value of adsorption between sodium octylhydroxamic acid and quartz is greater than that between sodium salicylhydroxamic acid and sodium benzohydroxamic acid and quartz, indicating that sodium octylhydroxamic acid is more easily adsorbed on the surface of quartz, and the adsorption of sodium octylhydroxamic acid and regulator(sodium hexametaphosphate, sodium lignosulfonate) on the mineral surface is physical adsorption. The research results provide ideas for the coal slime water treatment and comprehensive application of coal slime in coal preparation plant.