Discussion on energy saving ways of blast furnace

Discussion on the energy-saving ways of antimony smelting blast furnace

discussion on the application of saving energy in

analysis making blast furnace Xia Jiaqun Xu Jiang

(Department of metallurgy, Kunming University of Technology) abstract:according to the determination result of heat balance in the antimony making blast furnace, This paper studies the e pointed out that we should focus on the effective way of saving energy

keywords:antimony-making blast furnace energy-saving 1 preface there are two 0.84m2 antimony smelting blast furnaces (one for operation and one for standby) in Muli Antimony Mine, Wenshan Prefecture, Yunnan Province. It was completed and put into operation in 1986, with a design capacity of 1500 tons/year. It uses Guizhou Anlong coke as fuel, pellet or lump ore as raw material, iron ore as flux, limestone as slag forming agent for volatile smelting, and the product is antimony oxide powder. The blast furnace is equipped with water-cooled fire cabinet, surface cooling system and bag dust collection system. Antimony oxide powder is mainly collected at surface cooling and bag dust collection places. Since the blast furnace was put into operation, there has been no energy-saving technical transformation, resulting in serious waste of energy and extremely low thermal efficiency. With the rising price of purchased coke, its production cost is also getting higher and higher. In order to find out the thermal condition of the blast furnace for antimony smelting and find out the energy-saving ways and key parts of the furnace, according to the literature [1], we cooperated with Muli Antimony Mine to carry out a comprehensive and serious thermal measurement and calculation of the blast furnace, defined the key parts of energy saving, and pointed out the direction for the best operation and energy-saving technical transformation of the blast furnace. After the implementation of some measures, the effect is better. 2. Heat balance calculation results of blast furnace according to literature [1] [2], the heat balance measurement and calculation results are shown in Table 1. Table 1 heat balance calculation results of antimony smelting blast furnace heat income heat expenditure symbol item MJ/T% symbol item MJ/T% Q1 coke combustion heat 32417.9078.80q '1 antimony oxygen physical heat 471.151.15q2 air physical heat 210.650.51q' 2 Slag physical heat 4066.919.88q3 chemical reaction heat 9535.6320.74q '3 antimony gun and crude antimony physical heat 511.591.24 Q' 4 fire cabinet ash physical heat 72.520.18 Q '5 flue gas physical heat 19127.2446.47 Q' 6 moisture endothermic 1086 0.232.62 Q ′ 7 cooling water Heat taken away 4136.9710.05 Q '8 incomplete combustion loss heat 8734.0521.22 Q' 9 chemical reaction heat absorption 1821.304.43 Q '10 furnace surface heat dissipation 156.820.38 Δ Q others 985.412.39 Σ Q total 41164.18100 Σ Q 'total 41164.18100 thermal efficiency: ton of antimony oxygen burn up: 3 blast furnace heat utilization analysis and energy saving ways 3.1 from the perspective of production process and structure

since the main heat of antimony smelting blast furnace comes from the chemical heat of coke, how to make full use of the heat of coke is the key to energy saving. From the field measurement, the main problems are as follows. After reading the above introduction, I don't know whether you have a new understanding of how to choose a good or bad tension machine

(1) the furnace top is not tightly sealed. The gas containing Sb2O3 and Sb2S3 on the top of the furnace has seriously escaped due to the use of single bell feeding and years of wear and tear. The measured direct yield is only 54.62%, which not only wastes antimony ore, but also loses coke in vain. It can be seen that strengthening the sealing of the furnace top is the key to saving coke and ore in the blast furnace. In this regard, it is suggested that the single bell of the blast furnace for antimony smelting should be changed into a double bell, and the operation should be strengthened to minimize the escape gas from the furnace top and greatly improve the direct yield of antimony

(2) the height control of material column in the furnace is not good. According to literature [1], for antimony smelting blast furnace of volatile smelting, the production process of hot top should be adopted, and the temperature should be controlled within the range of 900 ~ 1000 ℃. However, the actual measurement shows that the material column control of the blast furnace in Muli Antimony Mine is very unreasonable, and its top temperature is only 700 ℃, which is far from the better production process of hot top. Therefore, it is suggested to strengthen the production operation of blast furnace, ensure the operation of low charge column, and realize better hot top production process

3.2 from the perspective of heat expenditure

(1) the physical heat carried away by flue gas is as high as 46.47%, which is mainly due to the excessive amount of gas escaping from the top of the furnace and the high amount of flue gas. It can also realize various functions by computer, conduct data processing and analysis, and print the experimental results. Therefore, as long as the sealing of the furnace top and the air volume adjustment are strengthened, the physical heat taken away by the flue gas can be greatly reduced, so as to improve the efficiency of the heat or resin and a little rubber composition of the blast furnace

(2) the heat loss of chemical incomplete combustion is high. The measured results show that the content of combustible CO in flue gas is 5.4%, and the heat loss of chemical incomplete combustion is as high as 21.22%. According to the literature [1], the coke rate of antimony smelting blast furnace should be controlled at 20% - 25%, and the coke rate of Muli Antimony Mine blast furnace is estimated to be 30.73%. In this regard, it is recommended to appropriately reduce the amount of coke into the furnace, maintain the low material column operation in the furnace, strictly control the particle size and strength of raw materials and fuels into the furnace, so that the coke can fully contact the air to produce a more complete combustion reaction, and finally reduce the heat loss of chemical incomplete combustion

(3) the heat taken away by cooling water is large and wasted seriously. The heat taken away by the cooling water of blast furnace wall and other water-cooled walls accounts for 10.05% of the total heat expenditure. All of its heat is used to produce hot water. Except for a small amount for the bath of workshop staff, most of the other hot water is directly discharged. This not only causes a lot of heat loss, but also wastes more water, indirectly increasing the excessive consumption of pump power. Considering that the blast furnace workshop is located in Guangnan County, in order to further save energy, it is suggested to change its water-cooling system to vaporization cooling, and the produced steam is used by the county residents. At the same time, it can save water and reduce the consumption of pump power

3.3 from the perspective of production operation and management

(1) the water cooling intensity of the fire cabinet is too large, and the surface cooling intensity is too small. According to the literature [1], the temperature of the fire cabinet should be kept within the range of 700 ~ 800 ℃ in order to make Sb2S3 change better