辛基羟肟酸浮选锡石的机理

Flotation mechanism of cassiterite with octanohydroxamic acid

为探明辛基羟肟酸对锡石的捕收性能及其吸附机理,本文通过单矿物浮选实验,考察了辛基羟肟酸、水杨羟肟酸和苯甲羟肟酸体系中锡石的浮选行为,通过吸附量测定、红外光谱测试、动电位、光电子能谱分析、溶液化学计算研究了辛基羟肟酸对锡石的作用机理.浮选实验结果表明:辛基羟肟酸对锡石的捕收能力明显强于水杨羟肟酸和苯甲羟肟酸,当辛基羟肟酸质量浓度为50mg/L,pH为10左右时,锡石的回收率最高达到91.79%.吸附量测试结果显示:在pH为10时,辛基羟肟酸在锡石表面的吸附量最大为0.23mg/g,与浮选结果一致.XPS分析,Zeta电位和红外光谱测试结果表明:辛基羟肟酸在锡石表面主要发生化学吸附,同时也可能存在物理吸附.辛基羟肟酸的溶液化学计算得出:对锡石浮选起主导作用的是离子-分子缔合物.辛基羟肟酸在锡石表面形成强疏水性的缔合物,可作为锡石的强效捕收剂.

To explore the collecting capacity of octanohydroxamic acid on cassiterite,flotation tests using octanohydroxamic acid,benzohydroxamic acid and salicylhydroxamic acid as collectors were conducted.The adsorption mechanism was analyzed by adsorption measurement,infrared spectroscopic analysis,Zeta potential measurements,X-ray photoelectron spectroscopy detection and solution chemistry calculations.The flotation experiment results show that the collecting ability of the octanohydroxamic acid is stronger than that of benzohydroxamic acid and salicylhydroxamic acid.The best flotation recovery of 91.79% can be obtained with octanohydroxamic mass concentration of 50 mg/L and pH value at about 10.The adsorption capacity test results show that the maximum adsorption amount of octanohydroxamic acid is 0.23 mg/g when the pH value is 10,which is in line with the flotation tests of cassiterite.XPS detection,Zeta potential and FT-IR spectra results show that the chemical adsorption mainly occurs on the surface of cassiterite for octanohydroxamic acid,while the physical adsorption may also exist.Floatability of cassiterite is dominated by the ion and molecular association component formed by the interaction between octanohydroxamic acid and cassiterite surface.Octanohydroxamic acid can be used as an efficient collector because of the formation of strong hydro-phobic association component on the surface of cassiterite.