Preparation of the Sulfur-Free Expanded Graphite Using Induction Heating Method

The sulfur-free expansible graphite and expanded graphite were prepared by induction heating method at different temperature using natural flake graphite, nitric acid and phosphoric acid as the raw materials. Expansion effect and heating mechanism has been analyzed. The microstructure of expansible graphite and expanded graphite has been analyzed by means of a scanning electron microscope and an energy spectrum analyzer. The result shows that the expanded volume of the expansible graphite can reach 200mL/g. Expanded graphite is characterized by vermicular structure and more developed pore structure where the pore of internal level basically maintains the original layer appearance of natural flake graphite.