Coking coal is used to smelt coke, that is, it is the raw material of coke. Coke is used in blast furnace ironmaking in steelmaking plant. Together with iron ore, it plays the role of heating, skeleton support and reducing agent in steelmaking furnace.
Thermal coal is used for power generation, that is, coal used for burning power generation. Power coal generally refers to power coal.
Extended data:
The calorific value of coke is mostly 26380 ~ 31400 kj /kg (6300 ~ 7500 kcal/kg). According to different uses, there are metallurgical coke, casting coke and chemical coke. According to the size, there are lump coke, broken coke and coke chips. It is mainly used for smelting steel or other metals, and can also be used as raw materials for making water gas, gasification and chemical industry.
Coke quality index:
1. Sulfur content in coke: Sulfur is one of the harmful impurities in pig iron smelting, which reduces the quality of pig iron. When the sulfur content in steelmaking pig iron is more than 0.07%, it is waste. 1 1% of the sulfur brought into the furnace by blast furnace burden comes from ore; 3.5% comes from limestone; 82.5% comes from coke, so coke is the main source of sulfur in charge. The sulfur content of coke directly affects the blast furnace ironmaking production.
When the sulfur content of coke is more than 65438 0.6%, for every 0.65438 0% increase in sulfur content, the consumption of coke increases by 65438 0.8%, the addition of limestone increases by 3.7%, the addition of ore increases by 0.3%, and the output of blast furnace decreases by 65438 0.5-2.0%. The sulfur content of metallurgical coke is not more than 1.
2. Phosphorus content in coke: The phosphorus content in metallurgical coke for ironmaking should be below 0.02-0.03%.
3. Ash in coke: The ash in coke has a significant influence on blast furnace smelting. The ash content of coke increased by 65438 0%, and the consumption of coke increased by 2-2.5%. Therefore, it is very necessary to reduce the ash content of coke.
4. Volatiles in coke: The maturity of coke can be judged according to the volatile content of coke. If the volatile matter is greater than 1.5%, it means coking; If the volatile content is less than 0.5-0.7%, it means overheating. Generally, the volatile content of mature metallurgical coke is about 65438 0%.
5. Moisture in coke: Moisture fluctuation will make the measurement of coke inaccurate, thus causing furnace condition fluctuation. In addition, the increase of coke moisture will make M40 higher and M 10 lower, which will bring errors to drum index.
6. Screening composition of coke: The particle size of coke is also very important in blast furnace smelting. In the past, there were requirements for coke particle size in China: the coke particle size of large coke oven (1300-2000 square meters) was more than 40mm, and that of small and medium blast furnace was more than 25 mm.
However, tests in some steel mills show that the particle size of coke is 40-25mm. Coke larger than 80 mm should be complete, so that its particle size range does not change much. In this way, the coke is broken evenly, the gap is large, the resistance is small, and the furnace runs well.
References:
Baidu encyclopedia-cola