北衙金矿金银铁矿石特性与选矿回收的关系

对北衙金矿矿石矿物组成、主要矿物嵌布关系、粒度特征、元素赋存状态和工艺特性等进行分析,研究不同磨矿细度下磁选对矿物分流的内在富集规律。结果表明:金、银粒度微细,磁赤铁矿、褐铁矿和铅硬锰矿是金、银、铁的主要载体矿物,其粒度和可磨度等工艺特性具有明显差异。为综合回收金、银、铁,围绕其载体矿物先进行磁选分流,再将各产品异性化地精细分选。在磨矿细度-0.074 mm占70%条件下磁选,可获得铁质量分数62.41%、铁回收率29.49%的磁铁精矿,金、银回收率分别为22.75%、24.99%的非磁产品,59.82%的金、67.49%的银和55.71%的铁富集至强磁产品,金、银、铁分流与富集效果明显,为后续分类提取金、银创造有利条件。

Relationship between the properties and beneficiation of Au-Ag-Fe ore in Beiya Gold Mine

The mineral composition, dissemination of primary minerals, grain size characteristics, valuable ele-ments occurrences and process property are determined for the gold ore from Beiya,and the intrinsic enrichment regu-larities of minerals divided by magnetic separation under different grinding fineness are researched.The results show that the gold-bearing and silver-bearing minerals particles are superfine; maghemite,limonite and coronadite are the primary carriers of gold,silver and iron whose difference in characteristics of grain size and grinding degree is signifi-cant.Aimed at the comprehensive recovery of gold,silver and iron,a process is proposed which first divides carrier minerals by magnetic separation and then each product obtained is treated by detailed beneficiation according to their difference in nature.A magnetic separation under 70 % -0.074 mm fineness is carried out,obtaining the magnetite concentrate with Fe grade of 62.41 % at the recovery of 29.49 %,the non-magnetic product with Au recovery of 22.75 %and Ag recovery of 24.99%,and the ultra magnetic product with Au enriched at 59.82%,Ag at 67.49%and Fe at 55.71 %.The dividing and enrichment effect of Au,Ag and Fe is significant,and it is helpful to divide and extract gold and silver in the follow-up tests.