graphite electrode rp500
Production process of graphite electrode rp500-calcination
Calcining is the high-temperature dry distillation of various coke and anthracite that are used to produce graphite electrode rp500 and graphite products under the condition of basically isolating air. Various carbon raw materials have undergone a series of profound changes from elemental composition to organizational structure during the calcination process.
The purpose of calcination (1) to eliminate the volatiles in the raw materials. Except for pitch coke and metallurgical coke, other carbon raw materials (petroleum coke, anthracite, etc.) all contain a considerable amount of volatiles, and the mass fraction of volatiles of petroleum coke with delayed coking is as high as 12%-16%. The more volatile matter in the raw material, the lower the degree of carbonization or coking of this raw material. Since the existence of a large number of volatiles has a great impact on a series of physical and chemical properties of raw materials, eliminating volatiles in raw materials and increasing carbon content is one of the purposes of calcination, and it is also a prerequisite for improving the physical and chemical properties of raw materials. Generally, when raw materials are heated to above 200°C, volatiles begin to be discharged. As the temperature increases, the amount of volatiles discharged increases. The discharge of petroleum coke volatiles is the largest at 600~800°C, and it basically ends at about 1200°C. After 1250- The volatile content of various raw materials calcined at 1350°C is generally less than 0.5%.
Improve the density and strength of raw materials. Under the high temperature of calcination, when the volatiles are discharged, the polymer hydrocarbon undergoes complex decomposition and polycondensation reactions, the molecular structure is constantly changing, and the volume of the raw material itself gradually shrinks. The result of the volume shrinkage increases the density and strength of the raw material. Regarding the raw materials after combustion, both the density and mechanical strength of the materials have been improved to a considerable extent. If a variety of carbon graphite products are produced with unburned or insufficiently burned raw materials, the formed green products will produce larger volume shrinkage during the firing process, and this shrinkage will destroy the complete structure of the product and cause cracked waste. Sampling analysis results show that the false density and mechanical strength of the product are relatively low.
Improve the conductivity of raw materials. Improving the electrical conductivity of the raw materials is a comprehensive result of the emission of volatiles and changes in the molecular structure of the raw materials after calcination. Most graphite electrode rp500 and graphite products are used as conductive materials, and the conductivity of the products depends to a large extent on the degree of heat treatment of several heat treatment processes (calcination, roasting and graphitization), and how to determine the conductivity of the raw material after calcination (That is to measure the size of the powder resistivity) can directly judge the quality of the raw material sintering. In general, the finished products produced from raw materials with better conductivity after calcination also have better conductivity.
Remove the moisture in the raw materials. The moisture content of incoming raw materials is generally 3%-10%. If the raw material contains more water, it is not conducive to the operation of crushing, screening, grinding, etc., and will affect the adsorption of the raw material particles to the binder. Therefore, although some raw materials (such as metallurgical coke and pitch coke) have been coked at a high temperature in the coke oven, it should not be calcined, but because the coke is pushed, water is used to quench the coke, and some moisture is added during transportation and storage. It must be dried before it can be used. It is generally required that the moisture content of the raw materials after being burned (or dried) is not more than 0.3%.
CGM New Materials Co., Ltd. is a manufacturer of graphite electrode rp500. Its products include graphite electrode rp500 (normal power graphite electrode rp500, high power graphite electrode rp500, ultra high power graphite electrode rp500) graphite products, recarburizers, graphite crucibles, graphite plates, etc. !