What are the characteristics of petroleum coke?

The true density of petroleum coke calcined at 1300 ℃ is the main item to measure the quality of petroleum coke. Generally speaking, the higher the true density after calcination, the easier the graphitization of petroleum coke is. Moreover, after graphitization, the resistivity is lower and the coefficient of thermal expansion is smaller. 

The bulk density of petroleum coke indicates the density of coke structure and is proportional to the mechanical strength. 

The vibrating density is not only related to the bulk density of coke, but also to the particle size of coke. 

The resistivity of uncalcined coke is very high, which is close to that of insulator. After calcination, the resistivity decreases sharply, the resistivity of petroleum coke is inversely proportional to the calcination temperature, and the resistivity of petroleum coke calcined at 1300 ℃ is reduced to about 500 μ Ω m. 

The coefficient of thermal expansion of petroleum coke mainly depends on the properties of the residue, that is, the content of aromatics and asphaltene in the residue, the thermal expansion coefficient of petroleum coke is lower when the content of aromatics is high and the content of asphaltene and colloid is low. 

Needle coke is such petroleum coke, the same needle coke, the coefficient of thermal expansion is also different (see Table 1), the production of large specifications of ultra-high power graphite electrodes and joint billets should use needle coke with lower coefficient of thermal expansion. 

The thermal expansion coefficient of petroleum coke is related to the test temperature. The standard temperature for measuring the thermal expansion coefficient in China is 100 ℃ and 600 ℃. The results obtained at different test temperatures can not be compared directly. 

The mechanical properties of petroleum coke include "breakability", brittleness and wear rate. "breakability" and brittleness of petroleum coke have certain practical significance in electrode manufacturing process. 

Breakability can be evaluated by the size ratio of coke before and after crushing, while brittleness indicates the possibility of coke crushing during transportation and transportation. 

The drum test method is used to characterize the wear rate of petroleum coke. The wear rate of raw coke is proportional to its volatile content and inversely proportional to the bulk density, and the wear rate of calcined petroleum coke decreases significantly. 

Pay attention to Lianyungang Guanji mineral products graphitized petroleum coke manufacturers, learn more relevant information.