Study On Differential Utilization Of Medium-carbon Graphite Concentrate

China is rich in graphite resources,which is the largest producer of natural graphite in the world.China has given the first place to producing the graphite concentrate and primary processing products for along time,there are only 10%of highly processed products and High-grade graphite products rely on imports heavily.The significant problem is that the production enterprises are scattered,the utilization rate of resources is low,and the environmental pollution is serious.In order to solve the above problems,the comprehensive utilization of graphite resources and the added value of graphite concentrate is the starting point of this study.The corresponding mineral processing method is adopted,according to the difference of the properties,the fixed carbon content and recovery rate,the different target products in different graphite grades,to achieve the comprehensive utilization as much as possible.The flotation concentrate was selected as the research object,according to the size of the ore,prepare three grade test sample of +0.15mm,-0.15+0.074mm and-0.074mm.The size of +0.15mm grade and-0.15+0.074mm grade was purified by the method of grinding-classification and alkali-acid,to achieve the technology of the high grade graphite products.The size of-0.15mm grade was separated by the floatation to reach the Standard for high carbon graphite,it can provide a feasible method for utilizing fine-scaled graphite ore.The size of-0.15+0.074mm grade is purified by the method of grinding-classification firstly,The best conditions for primary grinding:grinding concentration is 35%,grinding time is 10min,grinding speed is 700r/min and zirconium ball filling capacity is 300g,fixed carbon content increase from 94.41%to 95.58%,recovery rate can reach 75.21%.Increase the number of grinding-classification to three,fixed carbon content is 96.50%,operation recovery rate can reach 88.71%.optimizing the conditions of grinding:grinding concentration is 35%,grinding time is 16min,grinding speed is 700r/min and zirconium ball filling capacity is 500g.fixed carbon content is 97.13%and operation recovery rate is 83.65%after three times grinding.There are many advantages to purify graphite by grinding-classification.for example,the graphite flake can be fully protected?no environmental pollution?low cost and simple operation process,which is a method deserve to study and extend.The concentrate which was acquired by three times grinding was used as experimental material.The best conditions for alkali-acid method:roasting temperature is 900?,roasting time is 60min,the mass ratio of NaOH to graphite is 0.2,immersion time is 60 min,immersion temperature 60?,the mass ratio of Hcl to graphite is 0.3,acid leaching time is 30min,acid leaching temperature 40?,fixed carbon content increase from 97.13%to 99.72%.The size of-0.074mm grade was purified by the method of flotation,including the roughing test?the selection test and the treatment process of middlings.The final experimental flow:one roughing?one scavenging?rough concentrate is handled by three times grinding and three times sorting,middling 3 and middling 4 is managed by the screening and classification,The size of+0.045mm on the screen is returned to concentrate as the final concentrate.The rest of middlings directly conduct medium carbon products and abandoned tailings.The final test flow can acquire high carbon products,fixed carbon content is 94.07%,recovery rate can reach 64.78%.The roughing process is direct flotation flowsheet,regime of agent:sodium silicate amount is500g/t?kerosene amount is 250g/t?two oil amount is130g/t?flotation concentration is 10%?The best conditions for grinding:grinding concentration is 30%,grinding speed is 700r/min and zirconium ball filling capacity is 300g,the first and second grinding time is 12min,the thrid grinding time is 15min.regime of agent:kerosene amount is 150g/t and two oil amount is 80g/t in the first cleaning,kerosene amount is 100g/t and two oil amount is 50g/t in the last two cleaning.kerosene amount is 125g/t and two oil amount is 60g/t in the scavenging.The size of +0.15mm grade is purified by the method of alkali-acid.The best conditions for alkali-acid method:roasting temperature is 600 ?,roasting time is 60min,the mass ratio of NaOH to graphite is 0.3,the mass ratio of Hcl to graphite is 0.3,acid leaching time is 20min,fixed carbon content increase from 95.57%to 99.62%.