Study Of Flotation Magnesium Reduction On Magnesium Silicate Copper-sulfide Ore

The major minerals in copper-sulfur are copper,sulfur and iron.Among them,copper which is one of the four non-ferrous metals,is the most important metals in China’s national economy and national defense science and technology.The main source of copper resources is copper-sulphide ore,with the increasing content of magnesium silicate gangue minerals in more and more copper-sulphide ore,how to reduce the MgO content in copper concentrate is the focus of the mineral processing engineers.In this paper,flotation of raw ore containing Cu 0.53%and MgO 13.58%was performed by SHMP（sodium hexametaphosphate）-CMC（carboxymethyl cellulose sodium）agent system.Under the condition of grinding fineness-0.074mm containing90.93%,the SHMP-CMC dispersion-depression agent system converts the depression of gangue minerals of polymineral agglomerations into depression of single mineral.The single-factor flotation experiment,orthogonal experiment,open-circuit experiment and closed-circuit experiment of copper-sulfur mixed flotation and copper-sulfur separation flotation of the raw ore were finally performed to obtain a copper concentrate with Cu content of 15.79%,a recovery rate of 84.06%and a MgO content of 3.02%.The X-ray diffraction of closed-circuit flotation concentrate showed that the main mineral in the concentrate is chalcopyrite and only a small amount of pyrite and talc,which proved that the SHMP-CMC agent system could effectively depress the floating of the magnesium-containing gangue,and enrich the target mineral.The pure mineral flotation experiment showed that the PAX collector had no effect on the gangue mineral flotation,while the Z-200 had a great influence on gangue minerals and chalcopyrite;The dispersion is more effectively than depression on equal propotion mixed gangue by single use of SHMP,and the single use of CMC has better depression but it couldn’t completely depress mixed gangue minerals.SHMP-CMC agent system could completely depress the mixed ore and reduce dosage;Under the chalcopyrite flotation system,mixing of the mixed ore would depress the floating of chalcopyrite,and the use of SHMP-CMC agent system could increase the recovery of chalcopyrite to 85%and reduce the MgO content to less than 1%.The turbidity experiment showed that there is a heterocoagulation effect between serpentine,talc and chalcopyrite,and the addition of SHMP could eliminate the effect of heterocoagulation;Zeta potential showed that SHMP is the key to eliminate heterocoagulation effect by altering surface electrical properties of serpentine;FTIR experiment showed that SHMP changes surface electrical properties of serpentine due to a large number of negatively charged PO₃^-groups absorbed on the surface of minerals,and CMC absorbs on the surface of minerals through chemical absorption;DLVO theoretical calculation showed that the heterocoagulation effect between serpentine,talc and chalcopyrite is due to the fact that the potential energy between mineral particles is expressed as gravitational force,after adding SHMP the potential energy which is expressed as repulsive force to achieve dispersion effect.