Graphite purification method

Abstract

The invention relates to a graphite purification process, in particular to a method for purification of natural graphite by ion exchange resin under the assistance of an external direct-current electric field. The preparation process includes: mixing graphite serving as the raw material with a sodium hydroxide solution evenly, raising the temperature from room temperature to 450-650DEG C, and maintaining the temperature for 60-90min; conducting cooling and washing to neutral; mixing the product with hydrochloric acid, performing stirring at 70DEG C for 4h; conducting washing to neutral; placing the graphite sample and high purity water at both poles of a direct current power supply to form a closed loop system, the direct current power supply positive pole and negative pole of which are respectively fixed with water treatment anion exchange resin and water treatment cation exchange resin that are coated with fine gauze or semi-transparent film; applying a constant voltage and letting the voltage act for 30-60min, and carrying out filtering and drying. The method provided by the invention has the advantages of simple technological operation, small energy consumption, short time, small pollution and low production cost, and is in accordance with industrial development requirements of fluorine-free production, and the purified graphite has fixed carbon content up to 99.9%-99.99%.

Description

technical field

[0001] The invention relates to a method for purifying graphite, in particular to a method for purifying natural graphite by applying ion exchange resin under the assistance of an external direct current electric field. Background technique

[0002] As an important non-metallic material, graphite has been widely used in metallurgy, chemical industry, oil refining, machinery, light industry, electronics, aerospace and nuclear industries. The carbon content of graphite required by these industries is as high as 99.9%, while the carbon content of natural graphite can only reach about 95%, which is far from meeting the high-purity requirements. Therefore, the graphite industry needs to develop in wider and deeper fields. The core problem of high purity of graphite raw materials must be solved.

[0003] At present, the main purification methods of natural graphite are flotation method, high temperature method and chemical method, among which chemical method is w...