利用自制外控电位浮选槽研究了矿物粒度、矿浆pH值、外控电位大小等因素对黄铜矿和辉钼矿浮选行为的影响,从而找到二者分离的条件并进行了铜钼混合精矿的外控电位浮选分离,采用循环伏安测试和腐蚀电偶测试验证了上述试验结论. 研究结果表明,-150+31 μm的黄铜矿受外控电位影响大,容易被抑制,而辉钼矿则不容易被抑制. -31 μm的黄铜矿和辉钼矿可浮性均较差,受外控电位影响较小. 外控电位浮选在碱性条件下进行有利于实现抑铜浮钼. 在pH值11的条件下,抑铜浮钼的最佳分离外控电位为-1100~-700 mV(vs Ag/AgCl). 在pH值为11、外控电位-800 mV(vs Ag/AgCl)的条件下对多宝山铜钼混合精矿进行浮选分离,经过一次浮选分离可得到钼回收率80.57%、铜回收率10.19%的钼粗精矿,辉钼矿和黄铜矿的浮游差达到70.38%,这使外控还原电位下浮选分离黄铜矿和辉钼矿成为可能. 另外,腐蚀电偶测试结果表明:黄铜矿和辉钼矿间的电偶腐蚀对于抑铜浮钼浮选有促进作用.
Chalcopyrite-molybdenite separation has always been a major difficulty in mineral processing. At present, chemical agents are commonly used to regulate the pulp potential. However, the air flowing into the flotation process easily destroys the reducing atmosphere, resulting in the increase in reagent dosage. Externally controlled potential flotation can reduce the consumption of reagents by adding electrodes to the pulp to control the pulp potential. The effects of mineral size, pulp pH, and externally controlled potentials on the flotation behavior of chalcopyrite and molybdenite were investigated in the present work using a self-made externally controlled potential flotation cell. Under the optimal conditions, the separation test of Cu-Mo concentrate was conducted using the externally controlled potential flotation. The results were verified by cyclic voltammetry and galvanic corrosion tests. The results show that chalcopyrite with -150+31 μm fraction is considerably affected by externally controlled potentials and is easily inhibited, whereas molybdenite with -150+31 μm fraction is not easily inhibited. Chalcopyrite and molybdenite with -31 μm fraction have poor floatability and are less affected by externally controlled potentials. Externally controlled potential flotation is conducted under alkaline conditions to facilitate the inhibition of chalcopyrite and the flotation of molybdenite. In the case of pH 11, the optimal externally controlled potential for chalcopyrite-molybdenite separation is -1100 to -700 mV (vs Ag/AgCl). Under the conditions of pH 11 and externally controlled potential of -800 mV (vs Ag/AgCl), the Duobaoshan chalcopyrite-molybdenite mixed concentrate was separated by flotation. After one flotation cycle, the primary molybdenum concentrate with 80.57% recovery of molybdenum and 10.19% recovery of copper can be obtained. The flotation difference between molybdenite and chalcopyrite reaches 70.38%, which makes it possible to separate chalcopyrite and molybdenite by externally controlled reduction potential. In addition, galvanic corrosion between chalcopyrite and molybdenite promoted the flotation of molybdenite and the inhibition of chalcopyrite.