Flotation Test Of Fine-grained Silver Ore And Mechanism Of Activated Carbon Enhanced Flotation

Silver is important for the international financial industry and manufacturing industry.With the rapid development of society and economy,the demand of silver resources continues to increase.There are a large number of silver resources in China,but the quality of silver accumulation is declining,so the refractory silver mines,such as fine particles of silver ore and complex associated silver ore have become an important source of silver.The research object is Yunnan silver ore.The process mineralogy of the ore samples shows that the mineral composition is diversity and its dissemination is complex.Lead,zinc and other metal content in the ore is low,and silver is the valuable element,its grade is 226.90g/t,but in fine particles(-0.038mm)where the silver distribution rate is as high as 33.64%.So it belongs to the fine silver ore.The paper researches the ore with the condition tests,the process structure tests and adding activated carbon adsorption flotation tests,then the mechanism witch activated carbon enhanced silver flotation was discussed.With the flotation condition tests and the process structure tests,the optimum process of the flotation recovery of the mine is determined as "one roughing-two scavenging-one cleaning" process.The optimum grinding fineness(-0.074mm)is 90%.In the roughing stage,the dosage of inhibitor that sodium hexametaphosphate and sodium silicate combined(the ratio is 1:2)is 1500g/t,the dosage of sodium sulfide is 600g/t,the dosage of collector that butyl xanthate and ammonium dibutyl dithiophosphate combined(the ratio is 2:1)is 150g/t,the dosage of pine camphor oil is 40g/t;in the first scavenging stage,the dosages are half of roughing stage;in the second scavenging stage,the dosage of inhibitor that sodium hexametaphosphate and sodium silicate combined(the ratio is 1:2)is 300g/t,the dosage of sodium sulfide is 150g/t,the dosage of collector that butyl xanthate and ammonium dibutyl dithiophosphate combined(the ratio is 2:1)is 45g/t.In the cleaning stage,just only add ammonium dibutyl dithiophosphate with 25g/t.After the test of locked circuit without activated carbon,obtains the concentrate which the silver's grade is 6084.68g/t and the recovery rate is 62.84%.By study on the mechanism of silver flotation adding with activated carbon,it showed that the locked circuit test with activated carbon 3000g/t adding in the mill,and the concentrate which the silver's grade is 5377.64g/t,and the recovery rate is 68.08%,the recovery of silver is higher than the recovery which the test without adding activated carbon 5.24%.The results show that the adsorption flotation tests with adding activated carbon can enhance the recovery rate of silver.With the scanning of SEM,it can be compared the concentrate adding activated carbon and the concentrate without activated carbon.The observations showed that the former recovery is higher because of recovering the fine particles of silver.With the analysis of FTIR and ultrasonic treatment,it showed that that activated carbon enhance the recovery of silver mainly by physical adsorption characteristics which adsorb the fine grained silver.