硫酸-氢氟酸分步法提纯石墨的工艺研究

Study on Preparation of High-Purity Graphite by Stepwise Purification with Sulfuric Acid/Hydrofluoric Acid

用硫酸与氢氟酸分步对原料石墨进行酸浸提纯,分别研究了硫酸和氢氟酸的反应温度、用量、反应时间对提纯效果的影响。采用外加磁场的反应器,大大缩短反应时间,提高反应效率。制取高纯石墨的最佳条件为:硫酸反应温度为80℃,6 mol/L的硫酸用量90 m L,反应时间为2 h;氢氟酸反应温度为50℃,质量分数20%的氢氟酸用量为80 m L,反应时间为2 h。经过硫酸-氢氟酸提纯之后的石墨,固定碳质量分数从79.03%可提高到98.65%,此工艺能有效缓解我国高纯石墨依靠进口的局面,应用前景广阔。

The raw material graphite was purified by sulfuric acid and hydrofluoric acid.The effects of temperature,the concentration of acid and the reaction time were discussed.A reactor with magnetic field was applied in this reaction,the reaction time was greatly reduced and the reaction efficiency was highly increased.The optical process conditions were as follows:sulfuric acid reaction temperature was80℃,the mole fraction of sulfuric acid was6mol/L,the amount of sulfuric acid was90mL and the reaction time of sulfuric acid was2h;the reaction temperature of hydrofluoric acid was50℃,the mass fraction of hydrofluoric acid was20%,the amount of hydrofluoric acid was80mL,and the reaction time was2h.After sulfuric acid-hydrofluoric acid fractional step method,the fixed carbon content of graphite could be improved from79.03%to98.65%.This process can effectively alleviate the country to rely on imports of high-purity graphite and has a broad application prospects.