金川二矿区铜镍混合精矿中含镁脉石的进入途径

为了查明金川二矿区铜镍混合精矿镁含量高的原因，对现场混合精矿进行了工艺矿物学研究。结果表明：混合精矿中主要含镁脉石矿物为蛇纹石，其次是辉石、橄榄石、绿泥石和滑石等；混合精矿中主要铜、镍矿物粒度虽然微细，但其解离度均不高，仅有60%左右，强化对铜、镍矿物的回收客观上为易浮含镁脉石矿物单体及与铜、镍矿物的连生体进入混合精矿创造了条件；混合精矿中含镁脉石矿物多以视同单体的形式存在，其次是以磁铁矿连生体的形式存在，这是造成混合精矿镁含量较高的主要原因；主要含镁脉石矿物可浮性从高到低的顺序是滑石＞菱镁矿＞辉石＞蛇纹石＞绿泥石＞橄榄石。因此，要降低铜镍混合精矿的MgO含量，提高铜、镍矿物的解离度虽然重要，但有针对性地抑制含镁脉石矿物单体及与磁铁矿的连生体上浮是关键。

Approaches for Magnesium-containing Gangue Enter into Copper-nickel Concentrate from Jinchuan No.2 Mine Area

In order to find out the reason for high content of magnesium in copper-nickel concentrate from Jinchuan No.2 mine area，the process mineralogy of copper-nickel concentrate from the on-site process had been researched.The result showed that：the magnesium-containing minerals in the mixed concentrate was mainly serpentine，secondly pyroxene，olivine，chlorite，talc and so on；The particle size of the main copper and nickel minerals in mixed concentrate was fine，but the liberation degree was low，only about 60%，objectively.Strengthening the recovery of copper and nickel minerals created the conditions for easy-floating magnesium-containing gangue minerals and it's intergrowth with copper and nickel minerals into the mixed concentrate；The magnesium-containing gangue minerals in mixed concentrate mostly exist in monomeric form，and there was a certain amount of intergrowth with magnetite，which was the main reason for the mixed concentrate with high magnesium content；The floating order of main magnesium-containing gangue minerals from high to low was：talc> magnesite>pyroxene>serpentine>chlorite>olivine.Therefore，it was important to improve the liberation degree of copper and nickel minerals for reducing the MgO content in copper-nickel mixed concentrate，but it's the key to be targeted to inhibit the magnesium-containing gangue minerals monomer and its intergrowth with magnetite.