Research direction of needle coke
Domestic needle coke can not be compared with Japanese needle coke. To change the current situation, we should start from the following aspects to make a breakthrough.
1. Raw material pretreatment
Raw materials are the key to the production of needle coke. Without good raw materials, good needle coke products cannot be produced. At present, there are two raw material pretreatment methods: thermal condensation polymerization method and solvent method. Thermal condensation polymerization method is more effective in removing impurities and solvent method is more effective in removing quinoline insoluble substances. However, both methods have the same problem: heterocyclic compounds cannot be removed, The sulfur, nitrogen and some metal elements in heterocyclic compounds have a serious impact on the quality of needle coke. Therefore, how to remove heterocyclic compounds from raw materials and select different proportions of raw materials to produce different needle coke to meet the needs of electrode production has become the key of research.
2. Delayed coking
At present, although the CTE of domestic needle coke is reduced, the anisotropy of CTE is poor and the product quality is unstable. The main reason for this situation is that there is no reasonable control of coking pressure, time and temperature. Choosing reasonable pressure, temperature, reaction time and coke drawing degree has become the research direction of needle coke production.
The higher the calcination temperature, the better the quality of needle coke. High calcination temperature can not only improve the true density of needle coke, but also reduce the content of nitrogen and sulfur in needle coke. Limited by domestic refractories, the maximum calcination temperature can only reach 1450 ℃ at present. Increasing the calcination temperature is the next research direction of domestic needle coke manufacturers.
Investigate the existing needle coke enterprises in China to understand the production technology of existing enterprises (especially the raw material ratio, H / C ratio of raw materials, aromatization degree, N and s content, delayed coking operation temperature, pressure, time, calcination temperature, etc.)