Experimental Study On Flotation Of Large Scale Graphite In Tanzania

Graphite is widely used in metallurgy,casting,machinery,aerospace and national defense industries because of its excellent conductivity,acid and alkali resistance,ductility,plasticity and lubricity.In recent years,graphene and new energy industries have sprung up,and the application value of graphite has attracted more and more research and attention.Through the research on the flotation process of Tanzanian large flake graphite,we can provide appropriate beneficiation process for the graphite ore and provide technical basis and reference for the development of local graphite resources.(1)The process mineralogy of Tanzanian large scale graphite ore was studied.The results showed that the loss on ignition of the sample was 12.87% and the content of fixed carbon was 8.53%;the ore was composed of graphite,quartz,kaolinite,feldspar,hematite,limonite,mica and other minerals;under the microscope,it was found that the graphite sheet was thick,curved and broken,and a little kaolinite,quartz and feldspar were embedded between the graphite layers or between several pieces of graphite;when the grinding fineness was-0.180 mm,the monomer dissociation of the sample was 93.42%,and when the grinding fineness was-0.150 mm,the monomer dissociation of the sample was 97.00%;the content of graphite +0.150 mm in the sample was 73.10%.(2)Based on the study of process mineralogy,the test of conventional flotation process was carried out.The grinding fineness,flotation process and flotation conditions of conventional flotation were determined through a single factor condition test.The test showed that the conventional flotation process could obtain concentrate with a yield of 7.88%,fixed carbon content of 95.67% and recovery of89.56%,and the content of + 0.150 mm in graphite concentrate was 42.23%.(3)In view of the problems in conventional flotation,such as complicated process,large number of regrinding and reselection sections and serious damage of large scales,optimization was carried out.The results of routine optimization test showed that after rough separation,rough grinding,scavenging and two regrinding for five times,the final concentrate yield was 8.29%,the fixed carbon content was95.64%,the recovery was 90.55%,and the content of + 0.150 mm in graphite concentrate was 47.10%.(4)In view of the serious scale destruction of gangue minerals in regrinding I,it was proposed to separate gangue from coarse concentrate twice.The results showed that after twice regrinding and five times cleaning,the graphite concentrate with a yield of 8.28%,fixed carbon content of 93.11% and recovery of 90.35% was obtained,and the content of concentrate + 0.150 mm was 57.12%.(5)The ultrasonic assisted process test shows that in the conventional optimized flotation process,ultrasonic 10 min replaces the process of regrinding II for 12 min,and other flotation conditions remain unchanged.The concentrate with yield of8.31%,fixed carbon content of 95.43% and recovery of 90.17% can be obtained.Ultrasonic can be considered to replace the conventional optimized flotation process regrinding II;in the separation gangue test process,the ultrasonic technology for 10 min replaces the separation gangue test process for regrinding II,and the grinding time for 20 min.the concentrate with yield of 8.22%,fixed carbon content of 92.79%and recovery of 90.53% can be obtained.The ultrasonic technology can be considered to replace the separation gangue process for regrinding II.(6)The research results of graded grinding and flotation process show that through regrinding I,the grinding time is 4 minutes,and then the coarse particles are screened into coarse and fine particles.The coarse particles are separated from gangue by cleaning I and II,regrinding once and ultrasonic cleaning process for five times.The graphite concentrate with yield of 5.32%,fixed carbon content of 93.34%,recovery of 58.24% and + 0.150 mm content of 58% is obtained;the graphite concentrate with yield of 2.73%,fixed carbon content of 96.84% and recovery of31.09% was obtained after twice regrinding and six times cleaning process.Tanzania’s large scale graphite ore is subject to graded grinding and flotation process to protect the large scale and improve the fixed carbon content of the concentrate,with good indicators.