关键词: 极难选蚀变, 工艺矿物学, 嵌布粒度, 黏土矿物

Abstract: In order to make effective use of an extremely refractory gold ore,systematic process mineralogy tests have been carried out aiming at the raw ore. The material composition,particle size composition,texture and structure,main mineral distribution characteristics and gold particle characteristics of the ore have been studied. The results showed that:① The main available element in raw ore is gold,and the content of harmful impurity As is high with some carbon. Gold mainly exists in the form of sulphide coated gold,followed by exposed gold. ② The natural gold in raw ore is of trace amount,and the content of main gold-bearing minerals pyrite and pyrrhotite are 3. 829% and 0. 111%,respectively. Gangue mineral is mainly quartz,accounting for 45. 176%,in addition to containing arsenopyrite of 0. 779%. ③ The content of -0. 01 mm and the distribution rate of Au in the raw ore are less than 10%,and the grade of Au in each grain size has little change. The gold is only enriched in 0. 043 ~ 0. 02 mm of water precipitation sand. ④ The main texture of the ore include euhedral and semi-euhedral grains,heteromorphic grains,heteromorphic fragmentation and emulsion drops,and the main structure include sparsely disseminated,banded,brecciform and veined. ⑤ Gold is mainly contained in sulfide minerals such as arsenopyrite and pyrite,followed by gangue minerals such as quartz and sericite. 90% of the gold particle size is less than 8 μm,mainly fine and ultra-fine gold. ⑥ The distribution size of main gold-bearing minerals from coarse to fine is pyrite,pyrrhotite and arsenopyrite. The distribution size of arsenopyrite is very fine. Attention should be paid to the recovery of fine arsenopyrite in flotation. ⑦ When the grinding fineness is -0. 075 mm accounting for 62. 57%,the dissociation degrees of pyrite,arsenopyrite and sulfur and arsenic minerals are 90. 04%,81. 95% and 90. 04%,respectively. According to the research results of process mineralogy,free gold and sulfide minerals were recovered by flotation with a theoretical recovery of about 89%. The research results have important guiding significance for formulating reasonable beneficiation process.