Xanthate collector is the main metal sulfide flotation, but only in the presence of oxygen takes place only xanthate. When flotation of metal sulfide ore, the role of oxygen mainly has the following two points: Therefore, the repulsion of the negative electricity can be eliminated, and the adsorption of the flotation agent on the mineral surface is facilitated. The role of galena and xanthate can be written as: Wuxi Changchen Technology Co., Ltd , https://www.wxchangchen.com
1. Formation of semi-oxides on the surface of sulfides During the flotation process, the surface of the sulfide minerals is slightly oxidized to facilitate flotation, and excessive oxidation will reduce the floatability. Most of the sulfide ore is oxidized on the surface after oxidation. Galena e.g. surface oxidation film formed PbSO 4, reaction formula:
PbS+2O 2 →PbSO 4
Since the solubility of the sulfate is much larger than the corresponding sulfide, this facilitates the ion exchange between the xanthate collector and SO 4 2- . For example, the surface of galena is slightly oxidized. When it is collected by xanthate, the following replacement reactions exist:
PbS] Pb 2+ 2A - +2X - →PbS] Pb 2+ 2X - +2A -
In the reaction formula, X - represents a xanthate anion, and A - is SO 4 2- or SO 3 2- .
However, the oxidized galena has a thick lead sulfate shell formed on its surface, and the solubility of lead sulfate is too large and unstable. The collector ions cannot be strongly adsorbed and floated, so galena oxidation Too deep, its buoyancy is worse.
The degree of oxidation is affected by the following factors: the temperature of the pulp, the application of the oxidant, the presence of oxidation products on the surface of the mineral, the pH of the slurry, the strength and time of the aeration, and the oxygen content of the water.
2. The presence of oxygen eliminates the potential grid on the surface of the sulfide mineral and promotes the electrochemical reaction of the mineral surface.
Since sulfide minerals contain more or less impurities, there are various lattice defects, which make it have semiconducting properties, and have both a positive and a cathode region. For example, galena generally contains silver in a cyanide-containing slurry. Silver reacts as follows:
Ag+2CN - →Ag(CN) 2 - +e
Free electrons are generated and transported to the cathode region, causing more electrons in the vicinity of the cathode region to accumulate, resulting in a negative potential grid. In this way, it is bound to generate an electrostatic repulsion to the xanthate anion X- near it, preventing it from adsorbing on the mineral surface. However, in the presence of oxygen in the slurry, the following reactions can occur: 