低硫可膨胀石墨制备新工艺

A new technology including semisolid phase maceration for preparation of low surphur expandable graphite is presented, in which potassium permanganate and concentrated sulphuric acid are adopted as blended oxidants and ferric trichloride as an inserting agent. The optimum conditions of the process are as follows: mass ratio of graphite to sulfuric acid, potassium permanganate and ferric trichloride=1 03 00 80 2; reaction temperature and time: 50 ℃ and 1 h . The expandable graphite has an expanded volume of 230 mL/g and S content of 0 48%. By treating the product with sucrose borate solution and heating the flexible graphite plates also have been obtained with tensile strength of 7 5 MPa and oxidation loss of 11%. It is a green technology.

膨胀石墨的研究与应用现状

对膨胀石墨的制备方法、性能、应用进行了综合介绍,并对新技术的发展方向进行了讨论。

制备低硫高倍数膨胀石墨优化工艺条件的研究

研究了以化学氧化法制备膨胀石墨时 ,原料石墨含硫量、氧化剂、插层剂、酸化、水洗与干燥工艺、膨化工艺等因素对膨胀石墨含硫量和膨胀倍数的影响 ,提出了制备低硫高倍数膨胀石墨的优化工艺条件。即插层前对原料石墨进行降硫处理 ;选用 6 5 %的浓HNO3 或是 30 %的双氧水为氧化剂 ;以浓H2 SO4 与有机物混合液为插层剂 ;酸化反应的时间、温度随氧化剂、插层剂不同而变化 ;以 5 0～ 6 0℃的去离子水水洗石墨层间化合物至 pH为 6～ 7;在 5 5℃的烘箱内干燥 45min或在日光下晾干 (90min) ;膨化温度为 10 0 0℃ ;膨化时间为 6 0s。结果表明 :以此工艺制得的膨胀石墨 ,膨胀倍数在 2 30N以上 ,含硫量为 10 0 0× 10 -6左右。