Preparation method of high purity graphite

Abstract

The invention discloses a preparation method of high purity graphite, comprising the following steps: adding water in a reactor, putting graphite materials in the reactor, and adding acid; opening an air pump, a compressed air valve and a tail gas valve, introducing compressed air into the reactor, and mixing the materials uniformly; opening a steam valve, introducing the steam into the reactor to, and heating the materials; keeping the reaction materials in the reactor after the primary reaction without discharging, and performing filtering and washing in the reactor until the reacted materials are neutral; and adding a small amount of mixed acid liquor into the reacted materials which are filtered and washed to be neutral, introducing the steam, heating the materials, causing the materials to be subject to secondary reaction, then discharging the materials, and performing centrifugal washing and filtering until the reacted materials are neutral. By utilizing the method in invention,the high purity graphite can be obtained by one-time feeding, discharging and centrifugal washing.

Description

technical field [0001] The invention relates to a production method of graphite, in particular to a production method of ultra-high-purity graphite. Background technique [0002] In the mid-1990s, with the rapid development of the global economy, the production of automobiles, aircraft and military supplies increased sharply. With the continuous development of science and technology, graphite, as a high-quality sealing material for military, aerospace and automobiles, has a large capacity. , Long life characteristics. The amount of lithium battery negative electrode materials is increasing, which puts forward higher requirements for the purity of graphite, and the research and development of high-purity flake graphite and high-purity spherical graphite have made great progress. [0003] The traditional method and production process are as follows: the temperature of the purification reaction is 80~150°C, the whole reaction is carried out twice, the acidic aqueous solution u...

AI Technical Summary

Problems solved by technology

[0004] The biggest problem of the above traditional production methods is that the reaction needs to be carried out twice, and the feeding and discharging and washing are respectively twice, which increases the workload of the personnel, prolongs the production time of one kettle, and the output per unit time is small; Putting the material twice requires washing twice, and the yield of each washing is only 93%, and the total yield of the two times is 93%*93%=86.4%, the yield is reduced and the total cost is greatly increased

[0005] The disadvantages of reacting twice are as follows: 1) The recovery rate of materials washed twice with a centrifuge is greatly reduced, and can only reach about 86%.

2) Two times of reaction and two times of discharging and washing are time-consuming and labor-intensive. Each time of discharging and washing takes 2 hours, and twice more than 4 hours, which increases the amount of labor out of thin air, greatly increases the production cost, and reduces the output instead.

[0007] The traditional purification reaction adopts a carbon steel agitator lined with anti-corrosion plastic, and the unidirectional mechanical agitation driven by a motor makes the materials evenly mixed. The purification process in the prior art has the following defects: first, two reactions are required, each The production of a pot of material needs to be put in and washed out twice to produce qualified products. The recovery rate is low, and the labor cost and cost are greatly increased. Second, the power consumption is high. The minimum motor power is 7.5KW, and the power consumption is 7.5 degrees per hour. ; Third, after the agitator is worn, if the anti-corrosion layer is broken, the carbon steel will react with the acid in the liquid material, which will greatly increase the iron content in the material, which will have a great impact on the product quality and greatly increase the failure rate of the product Fourth, once the anticorrosion layer of the agitator is broken, it can only be replaced with a new agitator, which not only increases the maintenance cost, but also takes time and labor for the replacement. According to statistics, 2 to 4 people are needed for each replacement, and it takes 6 to 10 hours; Five, the outer lining PTFE is expensive, which directly increases the production cost

[0008] This shows that the production method of above-mentioned existing high-purity graphite obviously still has inconvenience and defect, and urgently needs to be further improved

Images