The grade of a gold ore from Luoyang is 4. 15 g/t. Gold is fine disseminated in the ore,and mainly in pyrite inclusions,it's difficult to be exposed for dissociation. This characteristic greatly affects the gold recovery. To provide basis for the development and utilization of the ore,beneficiation study was conducted. Under the grinding fineness of 66% -0. 074 mm, via closed-circuit flotation process of one roughing-two cleaning-two scavenging,middling back to the flowsheet in turn,gold concentrate with gold grade of 52. 25 g/t and recovery of 85. 90% was obtained,and the tailings contained 0. 625 g/t gold. Mineralogy analysis of intermediate product showed that there were many particles of undissociated pyrite in concentrate of scavenging 1. Thus,another closed-circuit test was carried out adding regrinding on the concentrate of scavenging 1 to 68% -0. 043 mm. The grade of the gold concentrate was 57. 40 g/t,with the recovery of 90. 88%,and the grade of the tailings was re-duced to 0. 4 g/t. The flotation result was significantly improved than original flotation test. Middling regrinding is a critical technique for beneficiation index improve of the ore.%洛阳某金矿石金含量达4．15 g/t,但金嵌布粒度细,且多以黄铁矿包体金形式存在,暴露解离较为困难,会影响金的回收。为给该矿石的开发利用提供依据,对其进行了选矿试验研究。在磨矿细度为-0．074 mm占66%条件下,经1粗2精2扫、中矿顺序返回闭路浮选,获得的金精矿金品位为52．25 g/t、回收率为85．90%,但尾矿仍含0．625 g/t的金。为提高金回收率,对原闭路浮选中间产品进行了分析,发现扫选1精矿中含有较多未单体解离的黄铁矿。为此,在原闭路浮选流程基础上,增加扫选1精矿再磨作业(-0．043 mm占68%),重新进行了闭路试验,最终获得了金精矿金品位为57．40 g/t、金回收率90．88%,尾矿含金0．4 g/t的指标,较原闭路浮选指标明显提高,证明中矿再磨是提高该金矿石选别指标的有效手段。
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