陕西某微细粒浸染型金矿选矿试验研究

微细粒浸染型金矿床往往富含砷、汞、锑、碳等难处理矿物，其中细粒金常赋存于黄铁矿等硫化矿物中，属于难处理矿石。陕西省某金矿床金矿物粒径非常细小，主要为次显微金，通过传统浮选方法难以获得高品位的金精矿产品，为有效提取细粒金矿石，开展了工艺矿物学及选矿试验研究。工艺矿物学研究表明，矿床主要载金矿物为黄铁矿，在-0.074 mm占60％的细度条件下，黄铁矿的解离度达93.48％，自然金以次显微金及晶格金存在，属于微细粒浸染型难处理矿石。综合对比选矿试验结果表明，该金矿宜采用“研磨-焙烧-研磨-氰化”的流程方案，首先将原矿磨细到-0.075 mm占80%，然后在650 ℃的温度下焙烧2 h，再将焙烧矿磨细到-0.075 mm占95%，在NaCN用量为4 kg/t、氰化时间为36 h的条件下，金浸出率可达73.36%。该试验方案适合微细浸染型金矿石的浮选，选矿效果较为理想。

Mineral Processing Experiments on Fine-disseminated Gold Ore from Shaanxi Province

Fine-disseminated type gold deposits are often rich in arsenic，mercury，antimony，carbon and other minerals difficult to deal with，fine grained gold is commonly used in sulfide minerals such as pyrite，belong to refractory ore.Gold mineral particle size is very small in a gold deposit in Shaanxi Province，mainly for sub-micro gold.It is difficult to obtain high grade gold concentrate by traditional flotation method，for the effective extraction of fine grained gold ore，technological mineralogy and mineral processing tests were carried out.Process mineralogy research shows the main gold bearing minerals are pyrite.Under the condition of -0.074 mm accounting for 60% of the fineness，the dissociation degree of pyrite was 93.48%.The form of natural gold is sub-micro gold and lattice gold，belonging to fine grain disseminated type refractory ore.Comprehensive comparison of mineral processing test shows that the gold mine is suitable for the process of “grinding-roasting-grinding-cyanide”，and under the condition of the ore grinding to -0.075 mm accounted for 80%，and then roast 2 h at 650 ℃，the calcined ore grinding to -0.075 mm accounted for 95%，NaCN dosage of 4 kg/t and cyanide time of 36 h， the gold leaching rate can reach 73.36%.The test scheme is suitable for the flotation of fine disseminated gold ores，mineral processing effect is more ideal.