Evaluation of coal-oil assisted gold flotation as a novel processing method for gold recovery

The study was aimed at investigating the effectiveness of the process of coal-oil agglomeration and gold flotation first individually and then in combination for enhancing gold recovery and for revealing the mechanism of the each processes. The process is still burdened by the disadvantages of the flotation process but it has been clearly shown that assistance of coal-oil agglomerates improves the gold flotation performance. Relatively high recoveries and superior grades can be obtained by coal-oil assisted gold flotation in comparison to the conventional flotation process. Such recoveries are possible by coal-oil assisted gold flotation even in the absence of any recycling stages (a concentrate assaying about 400 g /t with a recovery about 72 % was obtained by using the optimal parameters). However, recycling of the coal-oil-gold agglomerates further improves the grade of the concentrates while decreasing the coal and oil consumption (a concentrate assaying 1320 g/t with a recovery about 63 % was obtained after four cycles of the loaded agglomerates). The experiments show that employing the scavenger stages in the process enhances the gold recovery. The concentrate gold recovery was improved to 88 % and the grade of the concentrate decreased to 258 g/t by employing a scavenger stage. A concentrate assaying 178.27 g/t Au with 90.25 % gold recovery was obtained by employing secondary scavenger stage. Our results show that unlike previous work on coal-oil-gold agglomeration, our method requires very small amounts of coal and agglomerating agents. Therefore, it can be called as ?coal-oil assisted gold flotation? and seems to be quite effective for gold-ore processing. The test work demonstrated that use of oil and coal particles to assist gold flotation increases the process performance significantly. Presence of flotation collectors in the pulp helps coal-oil-gold agglomeration, which is in turn enhances the flotation and therefore increases the overall recovery. Keywords: Gold, agglomeration, oil, coal, flotation