The main raw material used in the production of graphite electrode is calcined petroleum coke. So what kind of calcined petroleum coke is suitable for the production of graphite electrode?
1. The preparation of coking raw oil should meet the principle of producing high-quality petroleum coke, and the labeling of high-quality petroleum coke should have more fibrous structure. Production practice shows that adding 20-30% thermal cracking residue coke into coking raw oil has better quality, which can meet the production requirements of graphite electrode.
2. Sufficient structural strength.
The raw material diameter pre-crushing, melting, crushing time to reduce pulverization, meet the requirements of batching square grain size composition.
3. The volume change of coke should be small after breaking, which can reduce the internal stress in the product caused by the backswelling of the pressed product and the shrinkage in the roasting and graphitization process.
4. Coke should be easy to graphitization, products should have low resistance, high thermal conductivity and low coefficient of thermal expansion.
5. Coke volatilization should be less than 1%, The volatile matter indicates the coking depth and affects a series of properties.
6. Coke should be roasted at 1300℃ for 5 hours, and its true specific gravity should be no less than 2.17g/cm2.
7. The sulfur content in coke should not be higher than 0.5%.
North America and South America are the major producers of petroleum coke in the world, While Europe is basically self-sufficient in petroleum coke. The main producers of petroleum coke in Asia are Kuwait, Indonesia, Taiwan and Japan and other countries and regions.
Since the 1990s, with the rapid development of China’s economy, the demand for oil has been increasing year by year.
When the amount of crude oil processing increases greatly, a large amount of petroleum coke, a by-product of crude oil refining, will inevitably be produced.
According to the regional distribution of petroleum coke output in China, the east China region ranks the first, accounting for more than 50% of the total output of petroleum coke in China.
It is followed by the northeast region and northwest region.
The sulfur content of petroleum coke plays a significant role in its application and price, and the production of graphitized petroleum coke is limited by stringent environmental regulations abroad, which restrict the burning of petroleum coke with high sulfur content in many refineries and power plants in the country.
The high quality and low sulfur petroleum coke is widely used in the steel, aluminum and carbon industries. The increasing demand increases the value of petroleum coke by several times.
In recent years, the apparent consumption of petroleum coke in China continues to grow at a high speed, and the demand for petroleum coke in all consumer markets keeps expanding.
Aluminum accounts for more than half of the total consumption of petroleum coke in China. It is mainly used in pre-baked anode, and the demand for medium and low sulfur coke is great.
Carbon products account for about one fifth of the demand for petroleum coke, which is mostly used to prepare graphite electrodes. The advanced graphite electrodes have high value and are highly profitable.
Fuel consumption accounts for about one tenth, and power plants, porcelain and glass factories use more.
Smelting industry consumption ratio of one – twentieth, steelmaking iron steel mill consumption.
In addition, the demand of silicon industry is also a force to be reckoned with.
The export part accounts for the smallest proportion, but the demand for high-quality petroleum coke in the overseas market is still worth looking forward to. There is also a certain share of high-sulfur coke, as well as the consumption of domestic consumption.
With the development of China’s economy, China’s domestic steel mills, aluminum smelters and other economic benefits gradually improved, in order to increase the output and quality of products, many large enterprises have gradually purchased graphenized petroleum coking carbonizer.Domestic demand is increasing.At the same time, due to the high operating cost, large investment capital and high technical requirements in the production of graphitized petroleum coke, there are not many production enterprises and less competitive pressure at present, so relatively speaking, the market is large, the supply is small, and the overall supply is almost less than demand.
At present, China’s petroleum coke market situation is, high sulfur petroleum coke products surplus, mainly used as fuel;Low sulfur petroleum coke products are mainly used in metallurgy and export;Advanced petroleum coke products need to be imported.
The foreign petroleum coke calcination process is completed in the refinery, the petroleum coke produced by the refinery goes directly into the calcination unit for calcination.
Since there is no calcination device in domestic refineries, petroleum coke produced by refineries is sold cheaply.At present, China’s petroleum coke and coal calcining are carried out in the metallurgical industry, such as carbon plant, aluminum plant, etc.
Post time: Nov-02-2020