Standard grade two grade coke standard
5, the moisture in the coke: water fluctuations will make the measurement of coke is not allowed, resulting in fluctuations in furnace conditions. In addition, the increase in the moisture content of Coke will make the M04 high, M10 is low, the drum index error.6, the screening of coke composition: in the blast furnace coke particle size is also very important. In the past, the particle size of coke in our country is as follows: the coke size of large coke oven (1300 - 2000 square meters) is greater than 40 mm; the coke size of medium and small blast furnace is larger than 25 mm. However, some of the steel test shows that the coke particle size of 40 - 25 mm as well. Larger than 80 mm of coke to be whole, so that the particle size range. The coke block is uniform, the gap is large, the resistance is small, and the furnace condition runs well.
2, the phosphorus in the coke: iron metallurgical coke coke content should be in the following 0.02 - 0.03%.3, the ash content of coke: Coke Ash on the impact of the blast furnace smelting is very significant. Coke ash increased by 1%, coke consumption increased by 2 - 2.5%, therefore, the reduction of coke ash is very necessary.4, volatile in coke: according to the volatile content of coke can determine the maturity of coke. Such as volatile content is greater than 1.5%, is said to produce coke; volatile less than 0.5 - 0.7%, it is said to be overdone, the general maturity of metallurgical coke volatile is divided into about 1%.
Evaluation of coke quality1, sulfur content in coke: sulfur is a harmful impurity of iron smelting, which reduce the quality of pig iron. The sulfur content in the pig iron is more than 0.07%. 11% of the sulfur from the blast furnace charge into the furnace comes from the ore, and the other comes from the limestone; the other is from the coke, so the coke is the main source of sulfur in the charge of the 82.5% of the charge. Sulfur content in coke directly affects the production of blast furnace. When the sulfur content in coke is greater than 1.6%, sulfur increased 0.1%, the amount of coke increased 1.8%, limestone amount increased 3.7%, 0.3% increase in amount of ore blast furnace output to reduce the sulfur content under 1.5 - 2.0%. metallurgical coke is not greater than 1%, the use of large and medium-sized metallurgical coke content in blast furnace is less than 0.4 - 0.7%.
Quality index of cokeCoke is a solid product of high temperature carbonization, the main component is carbon, is a crack and irregular pore structure (or porous). The number of cracks has a direct impact on the strength and crushing strength of the coke, the index is generally measured in terms of crack degree (the number of cracks in the unit volume coke). The index of pore structure is mainly expressed by the porosity rate (the percentage of the total volume of coke), which affects the reactivity and strength of coke. Different uses of different coke porosity index requirements, the general requirements of metallurgical coke porosity in the 40 ~ 45%, 35 ~ 40% in coke, coke export demand in about 30%. Coke crack degree and the porosity level, and the coking coal has a direct relationship, such as coal based coke refining, crack, high porosity, low strength; with coal as the foundation of the coal refining coke crack less, low porosity and high strength. The strength of coke is usually represented by two indices of crushing strength and abrasion resistance. Coke crushing strength refers to coke can resist foreign impact force without ability along cracks or defects at the broken, represented by the M40 value; wear strength of coke coke refers to the ability to resist external friction without surface of glass forming debris or powder, said M10. The cracking degree of coke affects the M40 value of its breaking strength, and the pore structure of coke affects the M10 value. There are many methods for determination of M40 and M10 value method, commonly used in our country the German migon drum test.
