Abstract
The mechanism by which moraines influence the flotation process in high-altitude porphyry copper-molybdenum deposits was investigated. Micro-flotation experiments and tests using actual ore samples revealed that moraines significantly reduced the recovery and selectivity of copper-molybdenum ores. As the moraine content increased, the entrainment of gangue minerals also rose considerably. However, the addition of sodium silicate effectively mitigated this entrainment. At a sodium silicate dosage of 10 mg/L, copper recovery reached 90.42 % with a grade of 8.93 %, and gangue entrainment was reduced from 7.58 % to 4.01 %. Molybdenum recovery reached 96.56 % with a grade of 12.89 %, and the gangue entrainment rate decreased from 13.30 % to 1.93 %. Measurements of slurry rheology, viscosity, zeta potential, and slime coating tests further clarified that moraines affect the flotation of copper-molybdenum ores through a slime coating effect. At pH 4, moraine particles adhered to chalcopyrite and molybdenite surfaces, hindering effective collector-mineral interaction and reducing flotation efficiency. The addition of sodium silicate effectively mitigated both the mechanical entrainment and slime coating effects, promoting better separation of copper-molybdenum ores from moraines and improving the recovery and selectivity of target minerals. This study elucidates that the detrimental effects of moraine on the flotation of copper-molybdenum ores are predominantly attributed to entrainment and slime-coating phenomena. It further proposes an effective strategy to enhance the flotation efficiency of copper-molybdenum ores under moraine influence by incorporating sodium silicate.
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