RU2516428C2 - Method to produce wustite product for flushing of blast furnace hearth - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention relates to ferrous metallurgy, namely, to production of a highly protoxidic product used for flushing of walls and hearths of a blast furnace. The method includes annealing of a charge from bulk concentrate of annealed siderite with a carbon-containing material in a rotary furnace at the temperature of 1250-1350°C in a restoration atmosphere, which is created by means of incomplete burning of a carbon-containing material due to limited access of oxygen with specific flow of natural gas 45.0-55.0 Nm³/t of the charge and efficiency of the furnace equal to 19.0-25.0 kg/hour with 1 m³ of furnace volume. The bulk concentrate of annealed siderite and carbon-containing material within the charge are mixed at the components ratio of 5:1 with size of 10-40 mm and 0-10 mm, accordingly. The carbon-containing material is coke fines, and/or coal, and/or anthracite, and/or crushed graphitised or carbon materials.

EFFECT: usage of the invention provides for production of a wustite product of increased strength with content of FeO>40%.

2 cl, 1 dwg, 6 tbl, 1 ex

Description

The invention relates to ferrous metallurgy, and in particular to the production of high-duty product used in washing walls and furnaces of blast furnaces.

When smelting cast iron, coke is partially destroyed by mechanical and thermal stresses. As a result, “coke debris” is formed in the high-temperature zone of the blast furnace, which accumulates in the furnace, reduces its volume, impairs the drainage capacity of coke layers and the development of melting products. Therefore, it is periodically necessary to flush the hearth of a blast furnace.

It is known to use iron ore materials based on sinter, pellets, ore, metal additives [1, I. Tovarovsky "Improving and optimizing the parameters of the domain process" - M .: Metallurgy, 1987, 192 S.].

Significant disadvantages of these materials are;

- various sizes and shapes of the material, leading to a decrease in the gas permeability of the column of charge materials in the blast furnace;

- low specific gravity of the material, preventing the rapid lowering of the charge materials in the furnace of a blast furnace;

- the lack of active oxygen in the materials, leading to incomplete combustion of soot carbon and graphite formed in the furnace and the lower part of the mine blast furnace.

It is known to use a mixture for washing a furnace furnace consisting of welding slag, iron ore, manganese ore and fluorspar. [2, Aut. St. No. 802365, class C21B 3/00, publ. 02/07/1981, BI No. 5]. The disadvantage of this technical solution is the use of expensive and scarce fluorspar. On blast furnaces with a volume of 2700-3200 m ^3, its daily consumption is 56-60 tons, and 350-450 tons are required for the entire washing. This leads to the accumulation of fluoride compounds in the furnace, which have a detrimental effect on the durability of the furnace lining, and in mass output from the hearth causes severe pollution of the working area. The use of welding slag, manganese and iron ores has the disadvantage that these materials are not effective enough when the furnace is heavily cluttered and are useful as preventive measures.

Also known is a briquette for washing the hearth of a blast furnace, obtained by pressing, including oxidized iron-containing material, a mineral binder and a plasticizer [3, RF Patent No. 2183679, IPC C21C 5/52, C21B 3/00, C22B 1/24, 1/23, 2002, publ. in BI No. 17].

After steaming, the briquette made from these materials in the indicated way has a fairly good strength and heat resistance and does not break when overloaded and when heated in a reducing atmosphere of a blast furnace to produce pig iron and slag from it.

The disadvantage of this technical solution is that it does not regulate the chemical composition of the briquette and does not take into account the mechanism of formation of flushing slag in a blast furnace. With the bicomponent composition of the charge (scale and cement), it does not have free silica, which, when combined with iron monoxide, forms fusible and hardly recoverable iron silicate - fayalit, which is the basis of washing slag in the furnace. Silica in cement is in the form of refractory calcium aluminosilicates, which complicates the formation of iron silicate.

In addition, the scale contains mainly ferric iron, which practically does not react with silica. This further complicates the formation of washing slag in the furnace.

The known technical solution also does not regulate the relations of basic and acidic oxides of materials that make up the mixture for the production of sinter for washing the hearth of a blast furnace. These relations determine the crystallization temperature and viscosity of the slag formed from the agglomerate, and determine its functional properties.

The closest in technical essence is the method of production of high-sinter agglomerate [5, A.S. No. 1574656, cl. C21B 1/16, publ. 06/30/1990, bull. 24].

The method is characterized by a high content of sludge materials in the sinter charge (60-90), which contributes to an increase in the amount of iron oxide in the sinter above 35%.

As the thickening materials in the invention, mill scale containing more than 60% wustite and traditional iron ore concentrate were used. In order to increase the strength and content of FeO in the upper part of the ward, it is proposed to dose 80-100% of all mill scale in the charge into the upper layer (mass fraction 30%).

Limestone and lime are used as fluxes in an amount that ensures the basicity of the agglomerate in the ratio CaO / SiO2 = 0.7.

The solid fuel content is 7% (mass.) In relation to the ore-flux part of the charge.

The disadvantages of the method are:

1. The need to form two different composition of the charge for the lower and upper layers of the load, which complicates the whole technological scheme of the formation of the charge. To implement this method at existing sinter plants, they will need a radical reconstruction, in particular, the retrofitting of each sinter machine with another line of charge silos with metering weighing devices.

2. The use of mill scale containing more than 60% of wustite limits the production volume of high-grade product due to its insignificant amount. For example, in a plant with annual steel production of 7 million tons, the amount of such dross is 3-5 thousand tons.

3. Sintering of the mixture with a content in the upper layer of 0.8-1.0 mill scale of its total amount in the mixture leads to the formation of an uneven height structure of the agglomerate. The concentration of mill scale in the upper layer reduces the sintering intensity, because when cooling, the structure of the hardening mass of iron oxides is a crust with low gas permeability.

4. The method does not regulate the most important parameters of the chemical composition of the sinter intended for washing the hearth of a blast furnace. These include the values of the content of Fe and FeO, as well as the ratio of Ca and Mg oxides, which affect the softening temperature of the agglomerate and the viscosity of the melt.

5. The method does not indicate the thermal regime of sintering, in particular, the total fuel content in the charge and its distribution over the loading layers.

The technical task of the invention is to remedy these shortcomings of the known technical solutions - analogues and prototype, namely, obtaining a wustite product of increased strength with an FeO content of more than 40%, as well as providing high functional and metallurgical properties of the product for washing the furnaces and walls of blast furnaces smelting cast iron. The method is aimed at obtaining a washing product from iron ore concentrates without special use of additional iron-containing materials, such as scale.

The technical result is achieved by performing the firing of the mixture from lump concentrate of calcined siderite with carbon-containing material in a rotary kiln at a temperature of 1250-1350 ° C in a reducing atmosphere, which is created due to the incomplete combustion of carbon-containing material due to the limited access of oxygen at a specific consumption of natural gas 45 , 0-55.0 Nm ³ / t of charge and furnace productivity equal to 19.0-25.0 kg / h with 1 m ³ of furnace volume, lumpy siderite lump concentrate and carbon-containing material included in the charge yal is mixed at a ratio of components of 5: 1, while they have a particle size of 10-40 mm and 0-10 mm, respectively.

As the carbon-containing material, coke breeze and / or coal and / or anthracite and / or battle of graphitized or carbon materials are used.

An additional solution of the technical problem posed is improved by the fact that the firing of the charge components is carried out in a rotary kiln at a temperature of 1250-1350 ° C in a reducing atmosphere, which is created due to the incomplete combustion of carbon-containing material due to the limited access of oxygen at a specific consumption of natural gas of 45.0-55 , 0 Nm ³ / t of charge and capacity equal to 19.0-25.0 kg / h with 1 m ³ of furnace volume.

The solution to the technical problem is also improved by the fact that by calculation and further by experiment, the optimal values of the size of the loaded materials were selected, namely 10-40 mm - the size of the calcined siderite and 0-10 mm - the size of the carbon-containing component with a component ratio of 5: 1.

The uniform distribution of metal inclusions over the cross section of pieces of calcined siderite provides it with magnetic properties. The presence of minor losses during calcination in a non-magnetic material indicates that the residual content of the carbon-containing material does not exceed 1%, and its consumption remains optimal, because almost all of it is used for the recovery process and does not increase the mass of the non-magnetic fraction.

Thanks to the use of the features of the invention, not previously known from the technical field, the quality indicators of the woolen product have changed. Upon reaching the noted parameters, the content of total iron increased to 58%, and metallic - up to 15%.

The transition of iron into the metal phase contributed to the achievement of iron oxide content of up to 40% or more.

The results are explained by the fact that, subject to distinguishing features, the height of the calcined layer increases, and this creates conditions for less access of oxygen to the calcined pieces and increase the reduction potential of the gas inside the layer of the ore-fuel mixture. Since the layer is a kind of heat insulator, the temperature in the furnace rises to 1350 ° C while reducing the specific consumption of natural gas to 45.0-55.0 Nm ³ / t of charge.

A simultaneous increase in the firing temperature and the degree of metallization of iron leads to intensive sintering of the material in the furnace. The release of small amounts of melt on the surface of the pieces of KOSa moving in the furnace ensured the formation of strong granules.

Carbon-containing material rolled into the granules, and there was practically no non-magnetic phase.

When the temperature in the furnace is less than 1250 ° and more than 1350 ° C, and also when the productivity of the furnace changes (less than 19.0 or more than 25.0 kg / h with 1 m ³ of the furnace volume), the quality parameters of the fired product deteriorated due to a decrease in it FeO content.

The essence of the claimed invention is as follows

Ore materials for reducing firing in a rotary kiln were lumpy siderite concentrate (KOS) with a grain size of 10–40 mm and a carbon-containing material with a grain size of 0–10 mm. To reduce the three iron oxides that form the basis of WWTP, as well as to preserve siderite iron oxide, the atmosphere in the furnace is maintained by the incomplete combustion of carbon materials due to the limited access of oxygen.

As the carbon material for the conditions of experimental studies of the claimed technical solution, coke breeze of the Magnitogorsk Iron and Steel Works (OJSC MMK) was used.

Since the material can enter the furnace through only one production line, to ensure uniform distribution of coke breeze between siderite pieces on Bakalskoye RU, piles of ore and fine coke were formed, transported to the TsOMP site of OJSC Magnesit Combine, and from there delivered to bins of rotating furnace number 3.

The ore-coke ratio was selected based on the stoichiometric amount of carbon needed to recover three iron oxides in 1 ton of ore before nitrous oxide, and previously obtained experimental data on a small rotary kiln of the Mednogorsk copper-sulfur plant with a length of 16 m.

Table 1 shows the chemical and particle size distribution of KOS and coke breeze, and Table 2 shows the physical properties of coke breeze and experimental mixtures of ore with coke according to Bakalsky RU.

Table 1. Chemical and granulometric composition of siderite concentrate and coke breeze. Indicators The value of indicators for materials: Calcined Siderite Lump Concentrate (CBS) Coke trifle Chemical composition, wt.% Fe _common 51.0 7.4 FeO 8.5 - Fe ₂ O ₃ 67.8 10.5 SiO ₂ 4.8 48.5 Al ₂ O ₃ 1,0 22.3 MnO 1.8 0.2 CaO 2.1 12,4 MgO 15.1 4.0 PMPP 3.6 0.5 R 0.015 0.5 Total 98.6 99,4 Granulometric composition, wt.% + 40 mm 14.1 - +20 mm 42,2 - +15 mm 17,2 - + 13 mm 6.3 - + 10 mm 7.0 - +5 mm 5,4 - +3 mm 2.2 - - 3 mm 5,6 - Total 100.0 -

Table 2. Physical properties of siderite concentrate and coke breeze. Type of material Bulk weight, t / m ³ Humidity, wt.% Ash content, wt.% The mass ratio of "concentrate: coke", units Calcined Siderite Lump Concentrate 1,50 0.5 Coke trifle 0.68 22.5 20.7 A mixture of CBS with coke 1.30-1.40 4.2 3.8 5: 1

From the above data it follows that the iron content when using KOSA - will reach 50 - 51%, and this determines the high content of iron oxide in the wustite product when using KOSA as the ore component of the stack.

In addition to fine coke, materials such as coal, anthracite, and graphite or carbon materials were also tested as carbon-containing materials.

The processing of the mixture to obtain a wustite product from lumpy siderite lump concentrate was started immediately after the processing of raw siderite. KOS firing differed from raw siderite, mainly by the content of coke breeze in the initial ore-fuel mixture. In case of WWTP, the consumption of coke was 16.5% (relative) less and did not exceed 200 kg / t of WWTP.

With a furnace capacity of 19 kg / h with 1 m ³ of furnace volume, the iron content in the calcined KOS product increased to 54.2%. At the same time, most of the iron at the set temperature in the furnace 1250 ° C was in the form of nitrous oxide (wustite), the content of which reached an average of 47.3%. An insignificant part of iron (about 8%) was in the metal phase.

The uniform distribution of metal inclusions over the cross section of pieces of calcined material provided him with magnetic properties. The presence of insignificant losses during calcination in a non-magnetic material (about 14%) indicates that the residual content of coke did not exceed 1%, and its consumption was optimal, because almost all of it was used for the recovery process and did not increase the mass of the non-magnetic fraction.

An increase in furnace productivity of more than 25 kg / h from 1 m ³ of furnace volume has changed the quality indicators of firing products. The total iron content increased to 58%, and metallic - up to 15%. The transition of iron into the metal phase naturally lowered the content of iron oxide to 38%. The results are explained by the fact that with an increase in furnace productivity, the height of the fired layer increased by 1.5 times. This created the conditions for less access of oxygen to the fired pieces and increase the reduction potential of the gas inside the layer of the ore-fuel mixture. Since the layer is a kind of heat insulator, the temperature in the furnace rose by almost 100 ° C while reducing the consumption of natural gas by 20%.

Table 3 shows data on the chemical composition and magnetic properties of the samples of the calcined material.

A simultaneous increase in the calcination temperature and the degree of metallization of iron led to intensive sintering of the material in the furnace. Isolation of small amounts of melt on the surface moving pieces of KOSa in the furnace ensured the formation of strong granules 10–40 mm in size. The remaining coke rolled into the granules, and there was practically no non-magnetic phase.

To use the calcined product as a washing material for blast furnaces, it is not advisable to reduce the iron oxide content due to additional metallization. Obviously, the constant firing upon receipt of a wustite product with a furnace capacity of 19.0-25.0 kg / h with 1 m ³ of furnace volume requires a consumption of carbon-containing material in the range of 200 kg / t of WWTP, the optimal ratio of concentrate: carbon-containing material is equal to 5: 1.

From the above data it follows that the chemical composition of the wustite product from KOSa to a greater extent meets the requirements for washing material of blast furnaces. The iron content in it is 56.4%. Accordingly, the content of iron oxide (FeO) in the wustite product from KOSa reached the required level of 43-45%. As is clear from the previous statement, this value could approach 50% in the event that there was the possibility of an operational reduction in the consumption of coke breeze.

As the burnt material accumulated in the bunker of furnace No. 3 of the TsOMP of OJSC Magnesit Combine, it was transported by road to the ore warehouse of Bakalsky RU. Representative samples were taken from each pair of dump trucks for analysis of magnetic properties, chemical and particle size distribution. Magnetic properties were determined directly on the industrial separators of Bakalsky RU. For this, the material was loaded by a loader onto a conveyor, through which the calcined ore was fed from the coolers of the shaft furnaces to a magnetic separator. During the test, the supply of calcined ore from the shaft furnaces was interrupted.

Thus, the work performed allowed us to obtain an experimental batch of wustite product suitable for use as washing material for blast furnaces. The most acceptable feedstock was KOS, which underwent preliminary firing in shaft furnaces and magnetic separation at Bakalsky RU. It had a higher iron oxide content and had little fines.

To analyze the effectiveness of the use of wustite product from siderite ores as washing material for blast furnaces, tests were carried out at furnace No. 1 of ChMZ. The results will be presented below.

Results of pilot blast furnace melts of the wustite product from bakal siderite ores.

For the production of iron ore material from Bakalsky siderite ores, which have flushing properties during smelting in blast furnaces, a reduction firing of lump fractions of oxidized concentrate of calcined siderite in tube furnaces of OJSC Plant Magnesite in the presence of coke breeze was performed. Firing conditions made it possible to transfer over 80% of three iron oxide to its nitrous oxide (FeO), which implies the presence of washing properties of the obtained material.

Annealed siderite concentrate with viscous properties was produced in rotary kilns of OJSC “Magnesit Combine” in the amount of 552.7 tons. A large class of 10–40 mm was selected from it, suitable for loading into blast furnaces. Ready for shipment, the product was stored in an open area of the BRU.

The chemical composition of the constituent product at the time of shipment, adjusted according to the control laboratory of Uralmekhanobr OJSC, is presented in table 4.

Table 4. The chemical composition of the combined wustite product at the time of shipment to ChMZ (wt.%) Fe _commonly Fe _meth FeO SiO ₂ CaO MgO MnO S P 52-55 8-10 48-50 8-12 3-4 14-15 1-2 0,086 0.014

Fines content: 0-10 mm - 10%.

Strength: B ₊₅ - 84-88%, B _-0.5 - 8.5-9.0%.

The product was delivered to ChMZ OJSC in mid-September 2011, i.e. six months later, after being exposed to precipitation and temperature changes, in the amount of 174.6 tons. The remaining volume of material was used at Bakalskoye RU for sale as sinter ore.

Table 5. Technological work schedule of rotary kiln No. 3 during regenerative firing of a mixture of KOS with coke breeze for the production of wustite product. No. p / p Options Dimension Parameter Value one. Type of source ore material KOS with a size of 10-40 mm 2. Type of reducing agent Coke breeze with a particle size of 0-10 mm 3. Coke breeze consumption t / t CBS 0.2 four. Drum speed rpm 1,0 5. Performance on a mixture of CBS with coke breeze kg / hour 25.0 6. Natural gas consumption common Nm ³ / hour 800 specific Nm ³ / t charge 53.5 7. Power consumption kWh / t charge 52.00 8. Process water consumption m ³ / t charge 6.0 9. Manifold natural gas pressure mm of water. Art. 1.8-2.2 10. Temperature in the oven ° C 1350 in the dust chamber 900 in front of the waste heat boiler m 750 after the recovery boiler 250 in front of the electrostatic precipitator 180 after electrostatic precipitator 150 eleven. Underpressure in the flue mm of water. Art. 1.0-2.0 after electrostatic precipitator 200-300

The higher content of iron and iron oxide in the products of KOSa firing is explained by the fact that it was loaded into the furnace after preliminary magnetic enrichment, which made it possible to remove a significant part of the gangue (shales, limestone, etc.).

A large wustite product had high strength at the level of iron ore pellets, which allows it to be loaded into blast furnaces without destruction. The strength of a wustite product containing at least 50% FeO, when tested in a standard drum according to GOST 15137-87, reached 87% in yield of cell. more than 5 mm and exceeded the strength of the agglomerates.

The full natural basicity of the wustite product in relation to (CaO + MgO) / (SiO ₂ + Al ₂ O ₃ ) is several times larger and allows raising the iron content in the blast furnace charge to the same level as when using Mikhailovsky pellets due to the removal of crude limestone or sinter reduction;

- the presence of more than 40% iron oxide in the wustite product determines its flushing properties and makes it possible, with continuous introduction into the blast furnace charge, to avoid overgrowth of the mine shaft and furnace hearth with non-fusible masses, which saves coke and increases the productivity of the blast furnace;

- the location of the production site of the wustite product near large Ural metallurgical plants (ChMK, MMK, ChMZ, etc.) allows saving transportation costs compared to Mikhailovsky pellets, which must be delivered from Central Russia.

The technological method of washing the blast furnace hearth is performed when signs appear that confirm the blocking of the central part of the furnace hearth.

As a rule, the clutter of the hearth is preceded by a deterioration in the quality of coke, the appearance of a disturbance in the course of the furnace, and the operation of the furnace at a low speed and reduced blast. At the same time, in the central part of the hearth, due to the deterioration of gas-dynamic conditions, coke of small fractions begins to accumulate. It should be noted that small particles of coke are not wetted by either slag or drops of cast iron. As a result, a slag metal suspension with coke breeze is formed in the central part of the hearth, the appearance of which practically negates the axial gas flow, and the filtration of cast iron through the slag belt is reduced. As a result of this, the output of smelting products deteriorates, there is a more rapid appearance of slag during the production of pig-iron, and there is an uneven release of pig-iron.

When the above symptoms appear, a special flushing product is introduced into the blast furnace charge.

The technological sense of washing the hearth lies in the water in its central part of materials containing iron oxides, which actively interact with coke breeze and eliminate clutter.

At the same time, the ore and coke feed parts are loaded into the blast furnace using washing material and blast furnace smelting is carried out, releasing the smelting products, monitoring the temperature difference in the hearth and bream refrigerators and the heat flux density. The use of washing material is stopped after increasing the water temperature difference to 1.5 ° C and the heat flux density to 5 kW / m ² .

It should be noted that the temperature difference in the hearth and bream refrigerators, as well as the heat flux density were obtained experimentally, as a result of tests.

The flushing material has a minimum melting point and low viscosity. Due to this, it easily penetrates into the space between the pieces of the charge components in the lower part of the shaft, in steam, in the shoulders and between the pieces of coke in the furnace of the blast furnace. At high temperatures, Fe is reduced from FeO of fayalite and Mn from MnO of tephroite with the consumption of coke breeze and sang: 2FeO 2SiO ₂ + 2C = 2Fe + SiO ₂ + 2CO; 2MnO SiO ₂ + 2C = 2Mn + SiO ₂ + 2CO with the appropriate washing from coke breeze and sang.

Example

The pilot testing of the patented washing product was carried out on a blast furnace No. 1 of the Chusovsky Metallurgical Plant. The washing product was loaded into the furnace by replacing in the feed the ore components of the charge (iron ore sinter, pellets, ore components) while reducing the ore load on the coke. The flow rate and temperature of the blast, fuel and oxygen consumption were varied depending on the magnitude of the lower differential pressure of gases in the furnace and the physical heating of cast iron and slag.

At a blast furnace No. 1 of ChMZ with a volume of 225 m ^3, 174.6 tons of wustite product were melted. Its content in the charge reached 5%. It was established that the introduction of a wustite product led to an increase in the temperature of the smelting products with a constant consumption of coke. Repeatedly descending the skull from the lining of the mine is noted, which indicates the presence of flushing properties of the wustite product from Bakal siderite ores. 1

Table 6. Technical indicators of the blast furnace №1 ChMZ in the base and experimental periods. The name of indicators Periods Base Experienced Production, daily average, t 348 353 Specific consumption of skip coke, kg / t 508 506 Specific consumption of natural gas, Nm ³ / t 81.6 81.2 Specific limestone consumption, kg / t 67.2 33.7 The specific consumption of the ore part of the charge, kg / t 1801.0 1875.6 Including: KGOK agglomerate 684.7 799.0 KGOK pellets 510.1 311.7 smelter ChMZ 585.6 697.6 metal concentrate 18.9 0.9 metal product 1,5 0 woolen product 0 66,4 The iron content in the mixture,% 55.5 55.0 Cast iron temperature, ° С 1421 1425 The chemical composition of cast iron,% Si 0.35 0.38 Mn 0.81 0.87 S 0,023 0,021 The chemical composition of the slag,% SiO ₂ 30.3 31,4 Al ₂ O ₃ 13.0 12.9 CaO 29.9 29.1 MgO 12.3 12.5 MnO 1.4 1,5 TiO ₂ 8.5 8.4 V ₂ O ₅ 0.16 0.18 Slag basicity, units 0.99 0.93

Figure 1 shows the change in the composition of cast iron and slag, as well as the temperature of cast iron in each of the releases of the experimental period and several releases before and after the experimental period.

Using vyustitnogo product in an amount of 3% in the charge of the blast furnace commenced from 7 ^th feed ^2nd shift of 20-09-2011 Since proplavki first volume wash with the batch materials vyustitnym product increased iron temperature. Due to this, the content of Si and Mn increased to 0.46% and 0.97%, respectively, with base values of 0.35% and 0.81%. S content decreased to 0.020% (baseline 0.023%). Other changes in addition to high heat, has not been noticed, so decided to 7 ^th feed 24.09.2011 ^2nd shift was increased to 5% share in the burden vyustitnogo product.

The chemical composition of cast iron confirms an increase in heating. The average Si content is 0.38% (base - 0.35%), Mn - 0.87% (0.81%), S - 0.021% (0.023%), with a reduced slag basicity of 0.93 units. (0.99 units).

From the data given in Figure 1 shows that after 15-16 hours after a sudden growth of Si and Mn contents ranging from 7 ^th feed 20.09.2011 g, evidencing the admission to the charge vyustitnogo product fixed converging first ledge from the mine lining. This effect is confirmed by an increase in the content of Al ₂ O ₃ in the slag by 1.0-1.5% (see Fig. 4.1). The increase in the mass fraction of alumina is associated with the disappearance of the skull. Al ₂ O ₃ is part of the refractory spinel and is concentrated in the refractory masses of the skull.

An increase in the consumption of wustite product on September 23, 2011 led to the second and third disappearance of the skull on September 24 and September 27, 2011, which affected the increase in the content of aluminum oxide in the slag. It is characteristic that at the last gathering of the skull on September 27, 2011, the appearance of slag on the tuyeres was noted. During this period, a long and intense increase in the Al ₂ O ₃ content in the slag was noted (see Fig. 4.1.).

Thus, the general data on the effect of wustite product from Bakal siderite on blast furnace smelting are positive for the following reasons:

1. Increasing the heating of cast iron when using CBS creates the opportunity for a potential reduction in coke consumption. During the experiment, the high heat was sick initially was kept consciously to eliminate the likely mass disappearance of the skull. At the final stage, the decrease in heating occurred due to an increase in the amount of ore materials, in the absence of the ability to control the coke consumption, it was dosed volumetricly using loading bowls. At the same time, the ore load increased to 3.66 t / t. coke, at a base of 3.54 t / t. coke;

2. The increased content of FeO in the wustite product and its washing properties were not fully realized due to the shortness of the experimental period and due to changes in the composition of the charge. Nevertheless, two cases of the disappearance of the skull were recorded and noted in the smelting magazine. Both cases were accompanied by a decrease in the content of Si, Mn in cast iron and an increase in Al ₂ O ₃ in the slag.

Thus, the conducted experimental swimming trunks showed:

1. The quality of the calcined siderite concentrate with a high FeO content after being in the open area did not change, and it turned out to be suitable for blast-furnace smelting.

2. The use of wustite product in the charge of a blast furnace leads to increased heating of cast iron and, as a result, to a decrease in coke consumption.

3. The washing properties of the wustite product were recorded according to the descent of the skull.

A comparative analysis of the proposed technical solution with known washing materials showed that the composition of the washing vustitnogo product includes lumpy concentrate of calcined siderite with a grain size of 10-40 mm and a carbon-containing material with a grain size of 0-10 mm. The mixture of components is fired in a rotary kiln at a temperature of 1250-1350 ° C in a reducing atmosphere, which is created under conditions of incomplete combustion of carbon-containing material due to the limited access of oxygen at a furnace capacity of 19.0-25.0 kg / h from 1 m ³ furnace volumes and specific consumption of natural gas 45.0-55.0 Nm ³ / t of charge. In addition, the ratio of KOS and carbon-containing material is in the range equal respectively to 5: 1.

These signs in the known analogues and prototype no.

Thus, the proposed technical solution fully meets the criterion of "novelty."

The analysis of patents and scientific and technical literature did not reveal the use of new significant features used in the proposed invention for its functional purpose.

Therefore, the present invention meets the criterion of "inventive step".

Based on the description and specific application examples, the applicant and the authors of the application consider that the proposed technical solution for patenting is new and industrially applicable. The proposed wustite product is tested in the blast furnace shop of ChMZ on blast furnace No. 1.

Claims (2)

1. A method of manufacturing a wustite product for washing the hearth of a blast furnace, including introducing iron ore materials into the charge, mixing them, loading into the furnace and subsequent firing of the mixture to obtain a high-oxide product with an FeO content of more than 35%, characterized in that the mixture is fired from lump concentrate calcined siderite with carbon-containing material in a rotary kiln at a temperature of 1250-1350 ° C in a reducing atmosphere, which is created due to incomplete combustion of the carbon-containing material due to the limited access of oxygen at a flow rate of natural gas 45,0-55,0 Nm ³ / t and the charge capacity equal to 19,0-25,0 kg / hr to 1 m ³ of the furnace volume included in the charge and siderite concentrate calcined carbonaceous material is mixed in a ratio of 5: 1 and the components have a particle size of 10-40 mm and 0-10 mm, respectively. 2. The method according to claim 1, characterized in that coke breeze, and / or coal, and / or anthracite, and / or the battle of graphite or carbon materials are used as the carbon-containing material.

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