A new electro– chemical processing to produce expansible graphite with reduced environmental pollution

Abstract

Expansible graphite, as a new generation of sealing materials, can be used in a wide temperature range. Because it is important in modern carbon industry, its production has been studied extensively in recent years. In this paper, we report a newly developed novel process for producing expanded graphite. The process was by means of anodic oxidation in sulfuric acid electrolyte. The difference between our process and other techniques is that electrolyte used in this process included less toxic chemicals, which in turn considerably reduced pollution to the environment. Varions electric parameters during processing and their effects on the quality of final products were studied. The property of expanded graphite showed an expansion volume: > 200 ml/g; suefur contect: < 2wt%; moisture: < 1.5wt.%; volatiles: < 14 wt.%. Besides, the microscopic structures of the obtained expansible graphites with various expanded volumes were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD).