Research Of Flotation Solution Chemistry And Regulation About A Molybdenite

According to the characteristics of big amount of clay minerals and gypsum in the molybdenite,as the breakthrough point to the solution chemistry,doing the research of the flotation behavior of molybdenite.The micro-flotation tests of pure molybdenite and kaolinite and the mixed molybdenite-kaolinite were used to investigagte the effects of different chemical environments solutions for both the flotation behavior.By the means of zeta potential tests,surface wettability measurements and the adsorption quantity tests,further studies of the impact of different solutions chemical environment on the surface properties of minerals, the action between the particles and reagent and the particles interaction were carried on.Based on these studies,the following conclusions:The micro-flotation tests results showed that: in acidic and neutral conditions, molybdenite showed good floatability.Gypsum may go against the flotation of molybdenite, more obvious in alkaline conditions.The mixed molybdenite-kaolinite flotation results showed that: kaolinite particles that coat on the molybdenite surface, which is called slime coating, can affect the molybdenite flotation. The slime coating would be induced much more easily in the addition of gypsum,lowering the pH of the pulp were in favor of flotation. Three regulator, sodium hexametaphosphate, sodium silicate and sodium carbonate were helpful for improving the environment of the pulp and improving flotation effect to a certain extent.The surface hydrophobicity of molybdenite decreased with pH increased. Combined mineral crystal structure analysis,then according to the results of zeta potential tests, surface wettability measurements and the adsorption quantity of Ca²⁺ tests,it can be identified that Ca²⁺ working with the MoO₄^2- on molybdenite surface resulting in the surface properties changing was the major reason of gypsum affecting the flotation of molybdenite,reducing pH helped to reduce the impact caused by gypsum.X-ray photoelectron spectroscopic（XPS） analyses also provided strong evidence for this conclusion. Lowering the pH of the pulp can help reduce the impact of gypsum on molybdenite and kaolinite.EDLVO theoretical calculations showed that: when adding gypsum,the Ca²⁺ can compress electric double layer on the surface of mineral particles,and then it caused the attraction and aggregation between mineral particles much more easily.The results of zeta potential tests also confirmed this point."Two grinding,one roughing and eight concentrate" flotation process can get qualified products.Lowering pH at the process of concentration was helpful for flotation.Through the simple open flotation tests can make the concentrate of molybdenite grade 48.05% and recovery 36.32% when pH was 6-7.