low resistance graphite electrode

Resistivity analysis of low resistance graphite electrode

Resistivity analysis of low resistance graphite electrode Most graphite products are used as conductive materials, so the higher the conductivity, the better the specific resistance, the lower the resistance, and the greater the current density allowed to pass.

The factors that affect the specific resistance of the product are as follows:

1. The influence of raw materials: the better the conductivity of the raw materials, the higher the conductivity of the product. The conductivity of the raw material generally refers to the conductivity of the raw material after calcination. For example, the specific resistance of some petroleum coke when calcined at 1300℃ is ohm·mm/m, while the specific resistance of pitch coke is ohm·mm 2/m when calcined at the same temperature. Therefore, if you use pitch coke to produce graphitized low For the resistance graphite electrode, the specific resistance of the product will increase significantly, and the high-quality product rate (in terms of specific resistance) will relatively decrease. In the past, the pitch coke produced by looogo was compared with the graphite anode plate low resistance graphite electrode produced by 50% pitch coke and petroleum coke. The use of high-sulfur oil coke also had a great influence on the specific resistance of the finished product. For example, some products are trial-produced with polysulfide coke with a sulfur content of 1-11% (analysis after calcination), and only 50% polysulfide coke is used in the formulation (the other half is 1/4 pitch coke and 1/4 pitch coke after calcination). Mixture of 3/4 oil coke V).

2. The final heat treatment temperature of the product: the higher the calcination or graphitization temperature, the lower the specific resistance of the product, but the reason for the decrease of the specific resistance is different. During the firing process, due to the release of volatiles, the coking of the binder and the continuous shrinkage of the product itself, the specific resistance of the product decreases. The decrease in the specific resistance during the graphitization process is the result of the conversion of amorphous carbon to graphite crystals.

3. Ingredients composition: When producing carbon products and low resistance graphite electrode paste, such as adding graphitized scraps, graphitized metallurgical coke or natural graphite with good conductivity, the conductivity of the product is significantly improved.

4. Impregnation: After the product is calcined, it is impregnated, then calcined or graphitized. Because the non-conductive pores are replaced by conductive carbon particles, the specific resistance can be reduced to varying degrees. Regardless of whether it is an extruded product or a molded product, the specific resistance measurement of the graphite anode plate and the low resistance graphite electrode must pay attention to the directionality of the sample. For extruded products, the specific resistance parallel to the extrusion direction is smaller than the specific resistance perpendicular to the extrusion direction, while for molded products, the opposite is true.