用细鳞片石墨制备无硫可膨胀石墨

Preparation of Sulfur-free Expandable Graphite with Fine Flaky Graphite

以天然鳞片石墨为原料,硝酸、磷酸为插层剂,高锰酸钾为氧化剂,采用化学法经氧化酸化插层制备无硫可膨胀石墨,利用正交试验方法确定较佳工艺条件,并对产品进行XRD、SEM测试。结果表明:在反应温度75℃,反应时间30min,石墨(g):KMnO_4(g):HNO_3(mL):H_3PO_4(mL)=10:1.0:22:32条件下,可以制备出膨胀体积达150mL/g的无硫膨胀石墨。相关影响因素的大小依次为:高锰酸钾、反应温度、反应时间、硝酸用量、磷酸用量。XRD测试表明膨胀石墨晶体未受破坏,SEM可见蠕虫状膨胀石墨结构。

Expanded graphite was prepared by chemical method using natural flake graphite, concentrated nitric acid and phosphoric acid as intercalation agent, and potassium permanganate as oxidant. The conditions for preparing the expanded graphite was optimized by an orthogonal test method and XRD, SEM testing of products. Results showed that sulfur-free and expanded graphite of 150 mL/g could be produced under the optimum conditions with the ratio of natural flake graphite（g） ： potassium permanganate（g） ： concentrated nitric acid（mL） ： phosphoric acid（mL） being 10 ： 1.0 ： 22 ： 32,reaction time of 30 min,and reaction temperature 75℃. The descending order of affecting factors is potassium permanganate, reaction temperature, reaction time, concentrated nitric acid and phosphoric acid. XRD tests show that the expanded graphite crystal unspoiled, graphite structure of SEM visible wormlike expansion.