The Study On Flotation Behavior Of Pyrite Carrying Gold And Its Industrial Application

Gold is a kind of important raw material. With the gradual extinction of the easy-processed ores, the extraction of gold has gradually turned into refractory gold ores. The floatation method has been adopted as the major way to extract gold in most gold mines in our country. But with the degradation of the gold and the complication of properties of ores, it has become an important task in flotation study to use properly the flotation method to get a maximum and comprehensive recovery of the gold in the gold ores.Taking the gold-bearing pyrite ores of Shuangqishan as the research object, this thesis researched the influence of the three single collectors(QF, butly xanthate, Ammonium dibuyl dithiophosphate),two mixed collectors(QF+ butly xanthate, butly xanthate+ Ammonium dibuyl dithiphosphate)and pH conditions on the activity of mineral flotation in the case of single mineral. The mechanism of mixed collector (QF+butly xanthate) on the gold-bearing pyrite was investigated by testing the infrared spectrum and the absorption amount. On the basic of researches of above, practical mineral flotation and industrial experiments were done to solve the problem of the low recovery rate of gold mineral.The result of single mineral flotation experiment shows that: the collecting gold ability of QF from the gold-bearing pyrite is the strongest, and the collecting ability of Ammonium dibuyl dithiophosphate is the weakest. The collecting effect of mixed collectors (QF + butly xanthate and butly xanthate +Ammonium dibuyl dithiphosphate) is better than that of one of them used alone .This shows the applicability and collecting ability of mixed reagents are intensified. With the increasing amount of the collectors, the mineral's flotation rate is increased. And the flotation pH of gold-bearing pyrite is the natural pH.A small lab experiment based on the practical ore from Shuangqishan gold ores shows that: under the condition of the gold grade 3.87 g/t of the sample and the particle size of 74μm -65 %, gold grade 101.95g/t and recovery 94.02% are achieved by flowsheet of two roughs-two cleaners-one scavenger with mixed collector of QF and butyl xanthate. The above-mentioned technical flowsheet was adopted to the industrial experiments, the recovery rate of gold is increased by 1.82%, and also the cost and amount of the collectors have been lowered together with a soil-defending ability and a much simpler technique.By testing the absorption amount and infrared spectrum, the mechanism of mixed collector's (QF+butly xanthate) interaction with the gold-bearing pyrite has been systematically investigated. The results show that: the absorption amount of the pyrite surface increases with increase of the density of the collectors;when QF is mixed into the collector, the absorbed ability of butly xanthene to the pyrite surface is increased. the analysis of the infrared spectrum of pyrite mineral shows that, both butly xanthate and QF have been absorbed on the ores surface, and the synergistic effect has happened.