关键词: 金矿, 粒度分析, 尼尔森选矿机, 重—浮联合工艺

Abstract: The gold grade of a gold mine is 4. 66 g / t,and single flotation was adopted for recycling the gold in the concentrator. The study of ore properties showed that the gold in the ore mainly exists in the form of bare and semi-bare gold,and the natural gold yield of 0. 295~ 0. 074 mm is as high as 59. 82%,which is suitable for gravity separation recovery. Therefore, the Knelson concentrator was chosen as the main equipment,and the beneficiation test was carried out by gravity separation and flotation combined process. The appropriate conditions for gravity separation are determined as follows:the grinding fineness of -0. 074 mm accounting for 45%,gravity multiple of 60 G,backwash waterflow of 5. 5 L / min,feeding speed of 500 g / min and feeding amount of 20 kg. The yield of heavy sand is 0. 048 9%,and the gold grade and recovery rate is 4 018. 14 g / t and 42. 07%,respectively under the conditions. Aiming at the gravity tailings obtained under suitable conditions, the flotation process of " one roughing,two cleaning and three scavenging" was adopted to concentrate the flotation gold concentrate with 7. 60% of yield,32. 43 g / t of gold grade and 52. 78% of gold recovery rate,and the total gold recovery rate was 94. 85%. The results of particle size analysis showed that the Knelson gravity separation mainly recovered products above 0. 097 mm particle size,and the recovery ability of fine particle size products was limited.