柠檬酸对萤石和方解石的抑制效果研究

通过单矿物浮选试验、人工混合矿试验、Zeta电位测定、接触角测试及X射线光电子能谱(XPS)测试分析,考察了柠檬酸对萤石和方解石在浮选中的作用机理。结果表明,在油酸钠体系下,柠檬酸对萤石的抑制效果强于方解石,柠檬酸抑制两种矿物受pH值的影响较小。对于萤石和方解石的混合矿,随着pH值的升高,萤石精矿的品位和回收率开始下降。Zeta电位、接触角测试及XPS分析结果表明,萤石比方解石表面电位高,Ca 2p轨道的电子结合能大,更容易与柠檬酸结合。柠檬酸作用后,萤石比方解石电位负移大,接触角降低明显,Ca 2p轨道中Ca-COOR的相对含量占比多。萤石与方解石混合时,随着矿浆pH值的升高,Ca 2p轨道中Ca-CO3的相对含量占比逐渐升高。

Study on the inhibitory effect of citric acid on fluorite and calcite

In this paper, the mechanism of citric acid on fluorite and calcite in flotation was investigated by single mineral flotation test, artificial mixed ore test, zeta potential measurement, contact angle test and X-ray photoelectron spectroscopy (XPS). The results show that in the sodium oleate system, the inhibitory effect of citric acid on fluorite is stronger than that of calcite, and the inhibitory effect of citric acid on the two minerals is less affected by pH value. For the mixed ore of fluorite and calcite, the grade and recovery of fluorite concentrate begin to decrease with the increase of pH value. Zeta potential, contact angle test and XPS analysis show that fluorite has higher surface potential and higher electron binding energy of Ca 2p orbital than calcite, which is easier to bind to citric acid. After the action of citric acid, the negative potential shift of fluorite is larger than that of calcite, the contact angle decreases obviously, and the relative content of Ca-COOR in Ca 2p orbit accounts for more. When fluorite and calcite are mixed, the relative content of Ca-CO3 in Ca 2p orbit gradually increases with the increase of pulp pH value.