老挝某金尾矿浮选—氧化浸出试验研究

Combined Experimental Study on Flotation-oxidation Leaching of a Gold Flotation Tailings in Laos

老挝某金矿浮选尾矿中金品位为2.99 g/t,含金量较高,为高效回收该尾矿中的金,开展了详细的选矿试验研究。尾矿中金主要赋存于硫化物中,其次是连生体金和单体金,决定采取浮选—氧化浸出联合选别流程。采用石灰作为pH调整剂,以六偏磷酸钠和水玻璃为脉石矿物抑制剂,以CuSO_(4)和Pb(NO_(3))_(2)为活化剂,以丁铵黑药和丁基黄药作为捕收剂,在条件试验的基础上对金矿浮选尾矿通过“一粗三精三扫”的闭路流程试验,获得了金品位为28.57 g/t、回收率为67.36%的金精矿;同时,所得尾矿金品位为1.05 g/t。再以高锰酸钾作为氧化剂,以氰化钠作为浸出剂对该尾矿进行氧化浸出,最佳条件下金的浸出率为43.57%,相对于原矿浸出率为14.22%,且浸渣中金品位仅为0.6 g/t,金总回收率为81.58%,取得了较为满意的试验指标。

The flotation tailing of a gold mine from Laos has a gold grade of 2.99 g/t,and the gold content is relatively high.Systematic beneficiation experimental studies were carried out to recover the tailings efficiently.Gold in tailings mainly occurs in sulfide,followed by intergrowth gold and monomer gold.Therefore,the flotation-oxidation leaching combined separation process was decided to employ upon that accountant above,and lime was used as pH regulator,sodium hexametaphosphate and sodium silicate were used as gangue dispersants,CuSO_(4) and Pb(NO_(3))_(2) were used as activators,and ammonium dibutyldithiophosphate and butyl xanthate were used as collectors.Through the closed-circuit process test of"one coarse,three cleaning and three scavenging"on the basis of condition tests,the gold concentrate with a gold grade of 28.57 g/t and recovery of 67.36%,and the gold tailings with a gold grade of 1.05 g/t were obtained respectively.Then by using potassium permanganate as the oxidant and sodium cyanide as the leaching agent for oxidize and leach the tailings,the leaching rate of gold,in the best performance,was 43.57%,which was 14.22%over the raw ore,and the gold grade was only 0.6 g/t in the leaching residue,and the total recovery of gold was 81.58%.The relatively satisfactory production index was obtained eventually.