SU740834A1 - Charge for blast furnaces - Google Patents

Description

one

The proposal relates to the technology of blast furnace production of cast iron of various grades and can be used in the steel industry, 5

The closest to the invention in technical essence and the achieved results is the sposbb of obtaining the charge, in which its coke contains coke with a high content of silica in the zinc part, which allows to improve the condition of restoring silicon IJ.

However, this charge does not provide an increase in the rate of silicon absorption by cast iron, a decrease in coke consumption, and also does not contribute to the intensification and growth of production of blast furnace iron.

In order to provide the main conditions for silicon recovery, it is necessary to have in the charge and donkeys a sufficient amount of silica, high temperature and heat reserve in the bottom of the furnace, an increased amount of fuel in the charge mixture of 25% (coke). Such conditions are achieved by a high consumption of coke and heating by blowing using acidic iron, ores (ferruginous quartzites), silica additives (welding slag).

The disadvantages of the known charge are significant fuel costs (coke), the more, the more silicon should be produced in the iron (it is estimated that the coke consumption increases by 10-15% for each percentage of silicon in the iron); The degree of silicon reduction and its transfer to cast iron is not high enough due to the small reaction surface (contact) of lump cremery materials and coke, silica transfer to 35–40% into slag, volatilization as monoxide (it is established that the degree of silicon iron uptake is not more than 0.600, 65 ) In addition, silica-ferrous and acidic materials, used in the charge, give rise to an increase in the number of primary, intermediate and final slags, which makes it difficult to recover the iron contained in them, impairs the gas permeability of the charge and heat. their horizons. Furnaces, Iron 1) chemically pure components of the charge contain relatively little iron, besides, some of it is in a silicate form that is difficult to repair and therefore goes into slag, thus all silica ferrous additives and acid fluxes reduce ore load compared to richer and more good all raw materials (agglomerate, pellets, etc.), and all silica materials do not carry carbon and do not gasify, which does not allow them to increase the useful iron ore load on coke - fuel. The aim of the proposed method is to intensify the blast-furnace production and improve the technical and economic indicators of smelting by supplying the liver with a high degree of silicon recovery and assimilation by hone without costing this recovery of coke fuel, reducing the amount of slag, improving warming up of the gas and gas permeability of the charge, eliminating from it poor ferruginous quartzites, silica additives and acid fluxes, reducing the total relative amount of the coke part of the charge, reducing the volume of smelting materials by cnite iron smelted. The goal is achieved by the fact that the charge as a multi-purpose technological package contains shungite-flux, in which the ratio of carbon and silicon contained in it is (0.8-1.2): 2.00, i.e. close to the stoichiometric ratio required for the reduction of silicon by the general reaction: 2C + Si + 2CO The proposed charge is formed as follows. Iron-ore materials are injected crushed, necessary for lumpiness flux-schungite, in amounts that correspond to their stoichiometric reduction reactions in the following ratio of components in charge, weight,%: Fuel-coke1.5-28 Shungit-flux0.01-15 Iron ore Remaining materials Example 1, In the smelting of pig iron with a high silicon content, for example 3.5%, which often happens during blowing to ennoy furnace after repair or capital smelting foundry Ugunai hot stamps need remnezema is, kg / t: 1GG0 ... 22 0.67 28 "iron or ferriferous quartzite where 0.67 degree perehoa silicon iron. In case of using shungite Eben, silica, kg / t: 151 is required. BO and crushed stone consumption qes 28 ° will be As a result of the removal of quartzite from the charge, the consumption of sinter increases 0.70.295-0 (.., on OS in - - kg / t and sos-d-140 tons 1500 + 146 1646 kg / t. Assuming that the coke consumption remains at the level of 535 kg / t, then the charge will be, kg / t; Fluxed sinter 1646 Skip coke536 Metal additives SOU Shungit 146 Total 2428, i.e. The consumption of shungite is (146/2428) 100 6% of the total charge. Example 2. When using sinter with a greater basis of CaO / SlO2, for example, 1.29, rather than 1.25, K is indicated in the calculation for smelting of cast iron of brand LK-2, it is required to increase the consumption of quartzite, and therefore, in the case of 3S1meny shungite, the consumption of the latter also increases. The calculation of the amount of slag-forming materials using an agglomerate with a basic amount of 1.25 and the calculation of the slag basicity .

Taking into account the transition to cast iron, 1445-60 1385 kg of silica remains. Slag basicity 1310: 1385 0.95.

When the basicity of the sinter is changed from 1.25 to 1.30, its chemical composition changes,%: SiO2CaOCaO / SiOji 6.68,21,25 6,48,31,30 New sinter adds calcium oxides 1600 kg t8.3% 1330 kg of silica 1600 , 4% 1010 kg with regard to other materials of silica 1010 + 15 + 6V + 310 1400 kg with regard to the transition of silicon to cast iron silica 1400-60 1340 kg remains To maintain the basicity of the slag at the same level (0.95) it is necessary to introduce silica , kg: IZO, 95 gAeL - oo or additionally shungite. Consequently, the charge for smelting a ton of LC-2 cast iron (in the case of

Aglomerat16006,4

Metal supplements10015

Coke 4505.8

A total of 2150, with a degree of transition of silicon to cast iron of 0.85, would require silica, kg / t: J.bO OjB5 28 silica remains in the slag 1286 13 1273. The slag basicity in the smelting of pig iron is assumed to be 1.04. Then, in order to maintain the required basicity, it will require silica, kg: ... V-T, 04, X-7. or shungite of pig iron. The total weight of the charge for smelting 1 ton of pig iron will be 1600 + 450 + 100 + 12.5 2162.5 kg, including shungite 0.58%. With a lower basicity of sinter, the consumption of shungite may be even less significant. With the value of the iron ore part of the feed (in the conditions of the Cherepovetsky metal factory) 20 tons on a furnace with a volume of 100 meters and 55 tons on a furnace with a volume of 2,700 meters, the output of pig iron from the feed is 11.5 tons and 34 tons, respectively. the guna and the necessity of the use of schungite in small quantities, nap

8.3

1330

1330 lb of agglomerate povipennoy ovnost) will be, kg: Agglomerate with a basicity of 1.301600 Skip coke536 Metal supplements. Shungit KL214 Total2450, including shungite 8.7% Example 3 When smelting a feather, nog iron or cast iron with the thin content of silicon, the consumption of gee will be less. For example, for smelting 1 ton of pig iron with cream content, 5%, the charge will be, kg: Agglomerate with basicity of 1.301600 Skip coke 450 Metal additive 100 ShungitX We calculate the number of sludge: iron in quantity of 12.5 kg / ton of pig iron (example 3) , it will be dispensed on a 1000 m furnace in each second flow in the amount of (12,, 5) “2. -300 kg, and on a furnace with a capacity of 2700 MB each feed is in quantities of 12.5 x 34 S400 kg. With a smaller consumption of shungite to provide a sufficiently large weight of a single portion of the material, it can be dosed into every fourth to fifth or sixth to seventh filings. The proposed charge allows to improve the technology of smelting iron; New shungite mineral raw materials are involved in the blast furnace production, which expands the raw material base. A high degree of reaction of the contacts of silica and carbon is provided in each piece of the schungite used, both in solid and softened states; Silicon loss on volatilization in the form of monoxide decreases with oxidation in the tuyere zone to dioxide and goes into slag, and, therefore, silicon regenerator is intensified under blast conditions, smelting increases, and the degree of silicon transition to iron transfer {90% from schungite vs. 60-C5% of silica-black additives and slags). In addition, coke consumption is reduced when raising both pig iron and silicon iron, the iron poor silica components are excluded from the blast furnace smelting and charge, which reduces the relative yield of the final slags, improves the heating of the lower horizons of the furnace, decreases the volume smelting materials per unit of cast iron, and, consequently, the ore load is useful. The productivity of the blast furnace during the smelting of siliceous iron will increase by 4-6%, the coke consumption will decrease by 6-9%, and KIPO will improve by 0.004-0.06, i.e. The blast furnace capacity and the consumption of skip cooker are the same as in the smelting of the standard 4yrytta. The sulfur content in the iron decreases, the cost price / iron decreases, and the use of siliceous iron in the MHC conditions in the oxygen-j but convertible redistribution, since with a low sulfur content (and phosphorus), silicon is a cheaper and more efficient fuel than manganese and scarce manganese ore used to produce it in iron. The invention for blast furnaces, including fuel-coke, iron ore materials, fluxes, characterized in that, in order to improve the conditions for silicon recovery, cast iron desulfurization and economy, the fuel charge also contains schungite with a C: Si ratio (0.8 -1.2): 2.00 in the following ratio, components, weight,%: Fuel-coke1.5-28 Shungit-flux0.01-15 Iron-ore materials Else Information sources taken into account during the examination 1 USSR Author's Certificate 281496, cl. From 21 to 5/00, i960.

Claims (1)

Claim A mixture for blast furnaces, including fuel-coke> iron ore materials, fluxes, characterized in that, in order to improve the conditions for the recovery of silicon, desulphurization of cast iron and economy; fuel, the mixture additionally contains schungite with a ratio of C: Si = (0.8 -1.2): 2.00 in the following ratio of components, weight,%: Fuel coke 1,5-28 Shuigit flux 0.01-15 Jelly guns materials Rest