A method for preparing graphite crucible from recycled materials

Abstract

The invention discloses a method for preparing a graphite crucible from recycled materials. In the method, regenerated graphite powder is obtained by pulverizing unused damaged graphite material, and the small particle size part in the regenerated graphite powder is mixed with pitch with low softening point and gas phase Calcined white carbon black and calcined petroleum coke are mixed and pulverized to obtain graphite mixture powder A; while the large particle size part of the regenerated graphite powder is roasted under the condition of 1800-2300°C to obtain graphite mixture powder B, and the graphite mixture Powder A, graphite mixture powder B and natural graphite powder are dry mixed, then added to the prepared asphalt material for wet mixing, and after wet mixing, the billet is made and roasted, and the finished graphite crucible is obtained after trimming. The invention can effectively recover the damaged graphite material, and prepare the graphite crucible with better quality and service life.

Description

technical field [0001] The invention relates to the technical field of regeneration and utilization of damaged graphite raw materials, in particular to a method for preparing graphite crucibles from recycled materials. Background technique [0002] Graphite crucible has good thermal conductivity and high temperature resistance. During high temperature use, the thermal expansion coefficient is small, and it has certain strain resistance to rapid heating and rapid cooling. It has strong corrosion resistance to acid and alkaline solution and has excellent chemical stability. Graphite crucible, because of the above excellent properties, is widely used in metallurgy, casting, machinery, chemical industry and other industrial sectors in metal smelting, lithium battery negative electrode material purification, polysilicon material smelting, ingot casting and other operations. Good technical and economical effect. [0003] The main raw material of graphite crucible is crystalline ...

AI Technical Summary

Problems solved by technology

Among them, the traditional graphite crucible is mainly made of graphite profiles. Calcined petroleum coke is calcined, pulverized by a pulverizer, and then sieved, hot mixed with coal tar pitch and pressed to form a crucible blank, and the product is put into a roasting kiln for roasting After taking it out, it is powered on for high-temperature graphitization treatment to obtain graphite profiles, and finally it is machined into shape. The whole process is complicated, consumes a lot of energy, and has a long production cycle, which is difficult to meet actual use needs.

In addition, due to the brittle nature of graphite, a large amount of graphite fragments and damaged graphite crucibles will be produced due to various uncontrollable factors during the process of graphite molding, transportation and storage, and these graphite crucibles are usually refurbished. The regenerated graphite material is recovered, and the regenerated graphite material is used to prepare regenerated graphite products; in the invention patent: a method for preparing a graphite crucible with regenerated graphite (patent number: 201510666751.1) and the invention patent: a method for manufacturing a graphite crucible with regenerated graphite ( Patent No.: 201010298907.2) provides a means and method for re-preparing graphite crucibles using the above-mentioned regenerated graphite materials as raw materials. The graphite crucibles that can be used for normal use can be obtained by using the above-mentioned method. The heat treatment process, the internal system has been formed, and after the secondary crushing and compacting again, but whether it has been subjected to the graphitization treatment of the secondary roasting, its structural stability will deteriorate. Although the formed graphite crucible can also Refer to the use method of the new graphite crucible for normal use, but the service life of the regenerated graphite crucible under high temperature conditions will be significantly inferior to that of the new graphite crucible. After a large number of experiments, it is found that it is only 1 / 3 of the new graphite crucible with the same material and the same process. 1 / 2, the fatigue damage form of this recycled graphite crucible is the generation and diffusion of internal cracks

Especially when it is used for smelting polysilicon materials, after a period of use, the rate of cracks in the graphite crucible body will increase, and the surface oxidation rate will be significantly faster than that of the new graphite crucible. but it doesn't work well

It also restricts the scope of secondary utilization of graphite materials