Method used for preparing expansible graphite low in sulphur content

The invention relates to a method used for preparing expansible graphite low in sulphur content. According to the method, an environment-friendly mild oxidizing agent is used for replacing a high-pollution strong oxidant used in the prior art, and a specific acidic phosphorus-containing compound is adopted for secondary oxidation intercalation, so that oxidation intercalation of natural crystalline flake graphite is realized, the expansion rate of the obtained expansible graphite is increased, destroy on the layer structure of natural crystalline flake graphite sheet is reduced, and the sulphur content of the obtained expansible graphite is reduced greatly. The method is green, and is friendly to the environment. 本发明涉及种低硫含量的可膨胀石墨的制备方法。本发明采用特定的环境友好型温和氧化剂替代现用的高污染强氧化剂及采用特定的酸性含磷化合物进行二次氧化插层，不仅实现对天然鳞片石墨的氧化插层和提高了可膨胀石墨的膨胀率，而且较少对天然鳞片石墨片的层结构的破坏及大幅度降低了可膨胀石墨的含硫量。本发明所提供的制备低硫含量的可膨胀石墨的方法是种对环境友好("绿色")的可膨胀石墨的制备方法。