High-efficiency Magnesium Reduction Technology For A Copper-nickel Sulfide Mine In Xinjiang

With the continuous deepening of ore mining,the content of magnesium silicate-like gangue minerals in a copper-nickel sulfide ore in Xinjiang continues to increase,and the easy-floating magnesium-containing gangue minerals are difficult to be depressed,resulting in excessive magnesium oxide content in concentrates?MgO?6.5%?.The nickel concentrate index does not meet the requirements of subsequent smelting operations.Therefore,it is extremely urgent to improve the process conditions and reduce the magnesium content in nickel concentrate.In this paper,the copper-nickel sulfide ore is studied,and its process mineralogy is studied in detail.Based on this,small-scale ore dressing experiments are carried out.By optimizing the process and adjusting the pharmaceutical system,acidified water glass is used as depressants to reduce the content of MgO in the nickel concentrate and obtain qualified copper concentrate and nickel concentrate.The mechanism of magnesium reduction in acidified water glass was analyzed by means of X-ray diffraction,slurry potential test and DLVO theory.Process mineralogical research shows that copper minerals mainly include chalcopyrite,trace copper ore and arsenic copper.Nickel minerals mainly include pentlandite,trace amounts of arsenic-nickel ore and needle-nickel ore,and magnesium-containing gangue minerals.Mainly composed of talc,serpentine,chlorite,amphibole,pyroxene,olivine and other minerals,and magnesium gangue minerals?talc and serpentine?and copper-nickel sulfide minerals closely associated with,and mainly in the form of massive Mainly with disseminated structure.According to the measurement of the particle size of the inlay and the dissociation parameters,the average particle size of the chalcopyrite is 0.028 mm,and the dissociation is relatively good in the range of-0.045 mm+0.038 mm,and the dissociation degree is 75.82%;The average size of the ore is 0.029 mm,and the degree of dissociation in the range of+0.074 mm reaches 75.53%.The new technology accounts for 75%of grinding fineness-74?m,acidified water glass and CMC as depressants,copper sulfate as activator,ammonium butyl aerofloat and amyl xanthate as collector,and two rough selections-Two times of mixed selection-copper-nickel separation process,copper concentrate containing 28.45%copper,82.36%copper recovery,0.32%nickel and 0.27%nickel distribution;nickel content 10.48%,nickel recovery rate 79.31%Nickel concentrate containing 0.31%copper and 7.93%copper distribution has better depressant effect on calcium-magnesium minerals and high-efficiency reduction of magnesium oxide content to 5.09%.The new process eliminates the rapid flotation process compared to the original process,and reduces the type and amount of chemicals,avoiding excessive chemicals from deteriorating the flotation environment and increasing the cost of beneficiation.X-ray diffraction and mineral composition and relative content analysis of copper and nickel concentrates showed that serpentine and talc were depressed.Zeta potential analysis and DLVO theoretical calculations show that the addition of acidified water glass enhances the electronegativity of the serpentine surface over a wide range of pH values,while enhancing the dispersion between mineral particles and eliminating"heterogeneous condensation".And acidifying water glass on the surface of serpentine can depress the formation of Cu?OH?₂ and Ni?OH?₂ precipitates.Finally,effective depressant of the magnesium-containing gangue minerals was achieved,and qualified nickel concentrates were obtained.