Influence Mechanism Of Of High Calcium Water On Flotation Desulfurization Of Magnetite And Its Regulation

The sulfur in the iron ore has a serious impact on the performance of its smelting products.Therefore,sulfur content is an important measure of the quality of iron concentrate,and desulphurization is also a necessary process in the process of iron ore selection.The main sulfur in iron ore is pyrite,pyrrhotite and other metal sulfides,under normal circumstances most of the sulfide can be removed in the magnetic separation process,but the ferromagnetic pyrrhotite is easy to acess the magnetic concentrate,so it often needs to be further removed with flotation.A high sulfur magnetite concentrate of Shaanxi Danfeng reached 1.16%.The sulfur-containing minerals are almost pyrrhotite.It is still difficult to obtain the ideal effect in flotation desulfurization process under a number of selection.According to analyzing the impact of the scene factors found,as the water itself has plenty of Ca²⁺ and the dissolution of calcium-containing minerals,resulting in high content of Ca²⁺ in pulp.It is thought that Ca²⁺ may affect the flotation performance of pyrrhotite and thus affect the flotation desulfurization of magnetite concentrate.This paper focuses on the desulfurization of magnetite flotation in high calcium water,using the solution chemical analysis and contact angle test,XPS,SEM-EDS,ICP-MS and other micro-test analysis means,to explore the mechanism that the influences of Ca²⁺ to pyrrhotite flotation characteristics.And study the appropriate control method to strengthen magnetite flotation desulfurization effect of high calcium water.The effect of Ca²⁺ on the flotation behavior of pyrrhotite was investigated by pure mineral flotation test,it was found that the floatability of pyrrhotite in high calcium water was significantly reduced.Comparison of activation effect of copper sulfate under different Ca²⁺ contents,Ca²⁺ seriously affected the activation of Cu²⁺ on pyrrhotite.The detection results showed that with the increase of calcium concentration,the adsorption capacity of copper ions on the mineral surface was significantly decreased.The SEM picture shows the pyrrhotite in the high calcium water attach to a large number of white small particles on the surface,EDS and XPS test results show calcium content increased significantly on the surface of minerals,at the same time,oxygen,sulfur content also increased,indicating that Ca²⁺ to produce a layer of calcium sulfate hydrophilic film on the surface of pyrrhotite,this layer of hydrophilic film forms a surface footprint,preventing the activation of Cu²⁺on pyrrhotite.To eliminate the effects of Ca²⁺ by the method of complexing Ca²⁺,the complexing agents such as ammonium nitrate,ammonium citrate and citric acid were tested respectively,we found that citric acid complex Ca²⁺ and then activated with copper sulfate,the floatability of pyrrhotite significantly improved.The amount of citric acid was 1×10-3mol/L,the ratio of citric acid and copper sulfate was 1: 2,the pH was between 4-5,the dosage of butyl yellow was 1.2×10-4mol/L,the recovery rate of pyrrhotite reached 92.90%.Analysis shows that,citric acid complex Ca²⁺ in the pulp,hinder the production of CaSO4 hydrophilic film;simultaneously it can clean Fe?OH?3 produced by pyrrhotite surface oxidation,which effectively improves the activation effect of Cu²⁺ on pyrrhotite.In the actual mineral test,when the amount of citric acid was 600g/t,the amount of copper sulfate was 300g/t,the amount of butyl xanthatethe was 300g/t,the content of sulfur in iron concentrate was 0.14%,and the indicators were ideal.The study provides a new solution to high sulfur magnetite desulfurization involved pyrrhotite flotation problem.