UHP Graphite Electrode Raw Materials- Needle Coke
With the development of electric arc furnace steelmaking industry, the demands for HP graphite electrode or UHP graphite electrodes is becoming bigger and bigger. Therefore, the needs for needle coke increases day by day.
There are two types of needle coke, one is petroleum-based needle coke produced from petroleum slag, and the other is pitch needle coke (coal-based needle coke) produced from refined coal tar pitch.
Needle coke has a clear fibrous texture structure in appearance. Under a polarized light microscope, needle coke is observed in any section parallel to the direction of the fibrous texture. Most of the structure is anisotropic fibrous. The cross section perpendicular to the fiber direction is an anisotropic mosaic structure. Therefore, the anisotropy of the physical properties of the needle coke is very obvious. It has good electrical and thermal conductivity parallel to the long axis of the particles, and has a low linear expansion coefficient. During extrusion, most of the long axes of the particles are aligned along the extrusion direction.
We used pure needle coke to produce the UHP Grade Graphite Electrode 500mm-700mm. The resistivity is 4.6-5.8 uΩm. With a high mechanical strength, our graphite electrode performs well in the furnace.