The Experimental Study On Knelson Separation-Tailings Flotation Of Low Sulfur Gold Ore

A Gold Mine in Tongguan,Shaanxi Province is low sulfur quartz-vein type gold ore.Currently,the technological process that combination of common gravity separation and all-slime cyanidation is adopted by the mine.In terms of all-slime cyanidation,the process is simple as well as high recovery,however,it is greatly harmful to the environment.Meanwhile,the capacity of tailings reservoir of mine is insufficient,and tailings are difficult to deal with.Therefore,it is urgent that the mine need to take the place of the initial technological process.In this paper,our main research on the recovery of thickener underflow gold ore,gold grade is 4.1 g/t,low sulfur content is only 0.6%,67.70%is silicon dioxide,using Knelson separation and tailings flotation joint method,at the same time,providing some theoretical basis and new process for industrial application.The research on the process mineralogy of the gold ores showed that the main metal minerals were gold,pyrite,chalcopyrite,bismuthinite,bismuth and sphale rite.Quartz,muscovite and a small amount of chlorite,calcite were the main gang ue minerals.The occurrence state of the ores was inclusion gold,semi-inclusion g old,fissure gold,crystal fractured gold and single gold.The grain size of gold ore s ranged from 0.2?m to 300?m,where the gold particle size-45 ?m account for48.9%,45-75 ?m account for24.4%,+75 ?m account for 26.7%.The morphology of gold minerals included spherical,grainy,long strip,angular,irregular shape.Based on the process mineralogy,a research on the enrichment and gold recovery by means of Knelson separation and tailings flotation.Through a series of studies on the Knelson separation,it was shown that the optimal experimental conditions of the Knelson separation were the ore feed 2 kg,gravity value 60 G,fluidization water flow3.5 L/min,slurry concentration 40%,eventually concentrate grade was 44.73 g/t,tailings grade was 1.76 g/t,gold recovery 59.50%.And the optimal experimental conditions of Knelson separation tailings flotation were collector amyl xanthate 120 g/t,foaming agent No.11 oil 14 g/t,slurry concentration 40%,flotation time 5 min,eventually concentrate grade was 46.53 g/t,tailings grade reduce to 0.48 g/t,recovery 73.49%.The whole process experimental results indicated Knelsonconcentrate grade was 572.75 g/t,flotation gold concentrate grade was 45.53 g/t,tailing grade was 0.53 g/t,total gold recovery was 87.77%,which had a significant effect on recovery of gold,and provided a reliable theoretical support and guidance for the development of a new green technology for gold extraction.