Study On The Beneficiation Process For Protecting The Large Flaky Graphite From Yichang

With the continuous development of deep processing of graphite,the graphite will be applied more widely in high technology industry and new energy field tomorrow.The large flake graphite is the basic material in the manufacture of the high-level and sophisticated component.As a result it has a great economic and application value.However,large flake is damaged severely when being separated at present in domestic,leading a low yield of large flake and a short market supply.Therefore,exploring how to reduce the extent of damage in the beneficiation process and improve the yield of large flake and the grade of the comcentrate have a great significance for the exploitation of large flake graphite ore.Roughing,scavenging,cleaner,open-circuit and closed-circuit tests of the large flake graphite from Yichang were studied to reduce the extent of damage of large flake and improve the grade of the concentrate.The studies of ore properties show that the objective mineral is graphite and the content of fixed carbon is 6.50%.The main gangue minerals and their respective content are quartz 40%,biotite 19%,mica 11%and feldspars 12%.The+0.15mm fraction content of ore is 15.59%,and it is 5.35%when being crushed.It is supposed to protect the large flake as possible as we can when improving the content of concentrate by grinding.The experiments of roughing conditions and scavenging conditions suggested that the best conditions were the following:the rough grinding fineness is the-0.15mm fraction content 64.10%;the dosage of lime is 1500g/t;the dosage of kerosene is250g/t;the dosage of 2~#oil is 75g/t;the flotation concentration is 27%;the flotation time is 3 minutes;the consumption of kerosene and 2~#oil for scavenging are 100g/t and 38g/t respectively;and the flotation time for scavenging is 2 minutes.A coarse concentrate was obtained with the yield 17.65%,the content of fixed carbon 31.58%,the recovery 85.13%and+0.15mm fraction content 9.88%.The loss rate of tailings was 10.35%.The experiments of cleaner conditions showed that trying the rod mill when the grade of concentrate is lower to protect the large scales while trying the ball mill when the grade of concentrate is higher to improve the grade of final concentrate.And increasing the regrinding times would be beneficial to the improvement of the grade of concentrate but would be no doubt to damage the large scales at a certain degree.The optimal regrinding structure was that the coarse concentrate was regrinded directly without preliminary cleaner.The optimal craft was five-time regringding and six-time cleaner.The grinding medium of regrinding?,?,?was rod mill while the regrinding?and?was ball mill.Besides,the regringding fineness of regrinding?~?were-0.15mm fraction content 72.94%,80.74%,80.34%,90.58%and 93.22%respectively.The indexes of the open-circuit test were the following:the content of fixed carbon was 95.44%,the recovery was 59.41%and the+0.15mm fraction content was 1.85%.Through the closed-circuit test which contained a coarse grinding,a rougher flotation,a scavenging,then five-time regringding and six-time cleaner to the rough concentrate,one regrinding and scavenging to the mixture of middlings?~?,and the middlings?~?returned to the cleaner?~?respectively,the middling?of the scavenging returned to the cleaner?,final concentrate with the content of fixed carbon 94.22%,the recovery 87.56%and+0.15mm fraction content 1.67%was obtained to provide the technical reference and theoretical basis for the utilization of this type of graphite ore.