Blast concentrate (the best quality of row materials for blast furnace)
raw materials into the furnace before processing preparation and handling in the physical, chemical and metallurgical properties as possible to meet the blast furnace to strengthen the charge of smelting requirements World Steel Pipe News . The blast furnace ironmaking using the fine material, you can get a good technical and economic results. The facts prove that in the preparation of raw materials to pay for all costs can be compensated for the economic benefits of the blast furnace ironmaking. The focus of the fine material in iron ore and iron ore fines agglomeration, but also can not ignore the blast furnace fuel, especially in recent years. Pulverized coal injection increasing the level of blast furnace coke load has been increasing, metallurgical coke quality requirements should be more strict. Of course the quality of the flux can not be ignored.
Process blast furnace concentrate natural high-grade ore, sinter and pellets of three categories. Some countries require: the whole control of particle size limit, and has a good screen powder metallurgical properties, smelting slag of less than 300kg / t. Although China in different historical periods had different contents of the Xia points, but can be summarized in four aspects: high, ripe net, uniform. Ferrous raw materials, high grade, clinker (man-made high-grade ore), charging the net and into the furnace raw material and fuel particle size and composition of uniform. Each increase of 1%
high grade iron grade of raw materials, coke rate can be reduced by about 2%, blast furnace productivity increased by about 3%. Smelting conditions, not strictly 1%, 2% and 3% of the relationship, but it reflects the overall trend. The relationship between the iron grade of raw materials and metallurgical value, is no simple linear relationship, the higher the iron content of metallurgical value will be higher. The former Soviet Union, the famous metallurgist Pavlov (MWorld Steel Pipe .A.ПaBJOB,) evaluation of iron ore, metallurgical value of mathematical formulas p1 = (F / f) (P-Cp2-Cp3-g) The
type p1 is the value of raw materials; F is the iron content of raw materials; f pig iron in the iron; p is the cost of pig iron plant; C is the coke rate; c is the unit of pig iron consumed in the flux; p2, for the price of coke; p3, for the flux prices; g production costs per ton of pig iron plant. This type of three different grade iron ore, metallurgical valuation results included in Table 1. It can be seen when the grade of iron ore from 65.18% to 55.25%, and its iron content declined by about 10% of its smelting value decreased by 43%; if the grade is reduced by 10%, would have no the Smelting value. In addition, coke is more expensive, the higher the wages of workers, improve the grade the greater the economic benefits of iron ore, iron. Different types of raw materials into the furnace iron in the blast furnace production practice, the alkalinity of different, and therefore must be deducted in order to compare the iron content of alkaline oxides of CaO, MgO. Blast furnace workers are used to measure the grade of iron ore to the amount of tons of iron slag, advanced tons of iron blast furnace slag is between 200 ~ 300kg, most of the blast furnace slag at 400 ~ 500kg, which shows China into the furnace grade of iron ore and the gap between the world's advanced level. Improve the iron content of iron ore into the furnace, has a new understanding. Used to think that tons of iron slag should not be too low, otherwise into the heat of the hearth, when the temperature fluctuation, the slag composition and nature of change in prices too much, difficult to operate the blast furnace, and the amount of slag is too small pig iron sulfur content requirements can not be guaranteed. Nearly 30 years of practice, the amount of tons of iron slag declining blast furnace technical and economic indicators continue to rise, the Nordic Sweden and Finland, blast furnace slag is kept at 150 ~ 170kg / t, normal operation of blast furnace pig iron of good quality. The key is to remain stable into the furnace of iron ore chemical composition and physical properties, increase the level of monitoring and control of the blast furnace process.