碱酸湿法制备高纯石墨工艺研究

Study on the Preparation of High Purity Graphite by Alkali-Acid Wet Method

针对高纯石墨制备,提出碱酸湿法制备工艺。考察了加压碱浸和盐酸浸出除杂时各因素对制备高纯石墨的影响。结果表明,在碱浸温度220℃、碱浓度270 g/L、液固比8、时间2 h、搅拌转速500 r min,铝的脱除率为88.18%,硅的脱除率为89.69%。在常压酸浸温度80℃、酸浓度12%、时间4 h、液固比4的条件下,高纯石墨产品固定碳含量大于99.89%。进行200目标准筛筛分处理后,筛上物灰分含量0.092%、固定碳含量99.91%、水分0.15%,符合鳞片石墨GB T 3518—2008中高纯石墨LC(-)75-99.9产品牌号的技术要求。

A wet alkali-acid preparation process was proposed for preparation of high-purity graphite.The effects of various factors on the preparation of high-purity graphite during pressure alkaline leaching and hydrochloric acid leaching for impurity removal were investigated.The results show that removal rate of aluminum and silicon is 88.18%and 89.69%respectively under the conditions including alkaline leaching temperature of 220℃,alkali concentration of 270 g/L,L S of 8,time of 2 h,and stirring speed of 500 r min.The fixed carbon content of high-purity graphite products is 99.89%above under the atmospheric acid leaching conditions including temperature of 80℃,acid concentration of 12%,time of 4 h,and L S of 4.After sieving through a 200 mesh sieve,the residues on the sieve show an ash content of 0.092%,resulting in a fixed carbon content of 99.91%and a moisture content of 0.15%,which meet the technical requirements of medium high purity graphite LC(-)75-99.9 product of flake graphite(GB T 3518—2008).