What are the criteria for coke classification and how to distinguish between primary and two grade coke?
The use of coke:Shanxi sales of various specifications of foundry coke, metallurgical coke, high sulfur coke or motor transport cars can be. The specific indicators are as follows:More than 83 of the fixed carbon; sulfur below the volatile content of less than 1.5; ash around 15 e:Mechanism coke: used in metallurgy; steel plantFiddle coke size 8cm-150cm: of molten iron for casting {;} of motor shell, radiator, mechanical counterweightCoal tar: molten iron; used in the casting of motor shell, radiator, mechanical counterweightLarge modified coke: {for ordinary casting; mechanical parts such as rough parts for 2-3.5 tons of furnace type}The shape of coke size 25cm:{is used for ordinary casting and slightly rigid casting products, such as water pump pipe fittings, such as fire fastenerMore than 85 of the fixed carbon; volatile 1.5.; ash content of less than 13.5 sulfur; less than 0.5:A fiddle coke size above 8cm for ordinary casting: {}Setting coke size 25cm; {for precision casting and ductile castingImproved coke: (Jiao Meilian) {for precision casting and ductile castingCoal tar: molten iron; used in the casting of motor shell, radiator, mechanical counterweight
4, coke in volatile coke: according to the volatile content of coke can determine maturity. Such as volatile than 1.5%, said coke; volatile matter less than 0.5 - 0.7%, said too much, generally mature metallurgical coke volatile is about 1%.5, the moisture in the coke: water fluctuation will make coke measurement is not allowed, thus causing the furnace condition fluctuation. In addition, coke moisture will increase the M04 high, M10 low, to the drum index error6, coke screening composition: grain size of coke in blast furnace smelting. It is very important to China in the past, coke size requirements: on the coke oven (1300 - 2000 square meters) of coke particle size greater than 40 mm; medium and small blast furnace coke particle size greater than 25 mm. But some mills tests show that the coke 40 - 25 mm in size as well. More than 80 mm coke to whole, little change in its size range. So the coke size uniform, large gap, small resistance, the furnace is running well.
Evaluation of coke quality1, sulfur content in coke: sulfur is a harmful impurity of iron smelting, which reduce the quality of pig iron. In the steel-making pig iron sulfur content greater than 0.07% is waste. By blast furnace furnace into sulfur from 11% ore; 3.5% from limestone; 82.5% from coke, so coke is the main source of sulfur in charge coke. Sulfur directly affects the production of blast furnace coke. When the sulfur content 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 sulfur content of large and medium-sized metallurgical coke the blast furnace is less than 0.4 - 0.7%.2, the phosphorus in the coke: iron metallurgical coke coke content should be in the 0.02 - 0.03% or less
Quality index of cokeCoke is the solid product of high temperature carbonization, the main ingredient is carbon, is the pore structure has a crack and irregular (or pore porous). The crack number directly affects the coke strength and crushing strength, the index generally refers to the unit volume of the crack (crack number within the coke grain length). To measure the pore structure of the main indicators to measure with porosity (only coke pore volume accounted for percentage of the total volume) that it affects the coke reactivity and strength. The different uses of the coke porosity index for different requirements, the general metallurgical coke gas hole rate in 40 ~ 45%, foundry requirements in 35 ~ 40%, coke export requirements in 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 and coking coal as a base; Coke coal refining. Crack less, low porosity and high strength. The strength of coke is used to denote the crushing strength and abrasion resistance of two indicators. The coke crushing strength is that coke can resist foreign impact force without ability along cracks or defects at the broken table, shown by M40 wear; strength of coke coke refers to the ability to resist external friction without surface of glass forming debris or powder, by the M10 value. The effect of the crack of coke crushing strength, M40 value, M10 value and abrasion strength influence of coke pore structure. M40 and M10 were determined by lot. In China the migon drum test in Germany.
