RU2403295C1 - Briquette for washing of blast furnace (versions) and manufacturing method thereof - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: briquette for washing blast furnace includes flux materials, scale as iron-bearing material, Portland cement as binding agent and hardening catalyst. Slags of blast smelting of nickel and/or copper matte are used as flux materials, and solution of calcium chloride and/or solution of calcium nitrate is used as hardening catalyst. In order to obtain briquette, iron-bearing, flux components, binding agent and hardening catalyst are added to charge; charge is mixed and pressed in roller briquette press at specific pressure of 30-100 MPa.

EFFECT: obtaining briquette with high washing characteristics at its being used during blast-furnace smelting with low costs.

7 cl, 3 tbl, 1 ex

Description

The invention relates to the field of ferrous metallurgy and can be used in the production of washing materials and in the smelting of pig iron in blast furnaces.

Three variants of a technical solution are claimed, which according to each of the variants is a solution to the same problem in principle in the same way that cannot be covered by one general claim.

Known mixture for the production of briquettes for washing the hearth of a blast furnace [1], including oxidized iron-containing materials, cement and plasticizer. The mixture additionally contains carbon-containing and manganese-containing materials and fluxing additives in an amount providing the content of carbon, iron oxides, manganese, calcium, silicon, magnesium and aluminum, in which the mass ratios of elements and oxides are C: Fe, Mn: Fe, CaO: SiO ₂ , MgO: Al ₂ O ₃ in the charge is in the range of 0.05 ... 0.15, 0.03 ... 0.2, 0.6 ... 1.2, 0.2 ... 0.6, respectively. The carbon-containing materials included in the charge have a fineness of up to 10 mm, and the iron-containing, manganese-containing materials and fluxing additives have a fineness of up to 3 mm. As a carbon-containing material, the mixture contains coke breeze, and / or anthracite, and / or coal, and / or a battle of graphite or carbon electrodes, and / or a battle of electrolysis baths, and / or carbon-containing sludge and dust. As iron-containing materials, the mixture contains iron ore concentrate, and / or iron ore, and / or scale, and / or steel sludge, and / or blast furnace sludge. As a manganese-containing material, the mixture contains manganese concentrate, and / or manganese ore, and / or dust from gas treatment furnaces for smelting ferromanganese and / or silicomanganese. As fluxing additives, the charge contains steelmaking slags, and / or slag from silicomanganese production, and / or slag from ferromanganese production, and / or slag from ferrosilicon production, and / or welding flux wastes.

The disadvantage of the mixture for the production of briquettes for washing the hearth of a blast furnace is the high cost of producing briquettes and low efficiency when used as a washing material in a blast furnace, due to the high reducibility of the iron-containing material in the briquette and the low content of iron oxides after heat treatment of the briquette in the mine of the blast furnace, as well as high CaO / SiO ₂ ratio.

The closest in technical essence and the achieved result is a briquette for metallurgical production, a briquette for washing the hearth of a blast furnace [2]. The briquette for metallurgical production contains oxidized iron-containing material, crushed iron-carbon alloy, a carburizer, a binder, alloying and fluxing additives and plasticizer in the following ratio of components, wt.%: Oxidized iron-containing material 5-57; crushed iron-carbon alloy 1-30; carburetor 20-30; a binder 10-20; alloying additive 1-15; fluxing additive 1-10; plasticizer in excess of 100% in an amount of 0.1-0.5% by weight of the binder. As an oxidized iron-containing material, the briquette contains mill scale, iron ore concentrate, sintering sludge, pyrite cinder, blast furnace dust. As a crushed iron-carbon alloy, the briquette contains sifting of cast iron fractions or cast iron dust. As a carburizer, the briquette contains coke breeze, coke dust, anthracite bayonet, graphite spel, and graphite electrode electrodes. As a binder, the briquette contains an organic or mineral binder. Cement and water glass are used as a mineral binder, and sulfide-alcohol stillage or lignosulfonate is used as an organic binder. As an alloying additive, the briquette contains scrap, dust and sludge formed during the smelting of ferromanganese, ferrosilicon and ferrochrome, and a metal screening for the production of ferrovanadium. As a fluxing additive, the briquette contains limestone or dolomitic flour. As a plasticizer, the briquette contains sulfide-yeast mash, molasses, etc.

The charge material for washing the hearth of a blast furnace is formed in the form of a briquette and contains oxidized iron-containing material, a mineral binder and a plasticizer in the following ratio of components, wt.%: Oxidized iron-containing material 80-90; mineral binder 10-20; plasticizer in excess of 100% in an amount of 0.1-0.5% by weight of the binder. The charge material contains scale as oxidized iron-containing material, Portland cement as a mineral binder, and sulfide-yeast mash, molasses, stripped after-yeast bard, water-soluble preparation, alkaline stock of caprolactan or soap oil production as a plasticizer.

The disadvantage of the briquette for washing the hearth of a blast furnace is its low washing effect, due to the high reducibility of the scale in the briquette and the low content of iron oxides after heat treatment of the briquette in the mine of the blast furnace, as well as the high cost of producing briquettes.

The objective of the invention is to create a briquette with high flushing characteristics when used in blast furnace smelting at low cost.

The technical result is achieved by the fact that in the first embodiment, the briquette for washing the blast furnace contains scale as an iron-containing material, Portland cement as a binder, additionally contains a hardening catalyst, and as flux materials, slag mine nickel and copper matte and in the following ratio of components, wt .%: dross 20.0-40.0; nickel matte mine smelting slag 26.5-37.0; copper matte smelting slag 26.0-39.0; a binder of 2.5-5.0; hardening catalyst 1.5-2.5. As a hardening catalyst, a solution of calcium chloride and / or calcium nitrate is used.

The washing effect in a blast furnace is achieved by melting a refractory oxide material having a low melting point, which can assimilate refractory highly basic slags and actively chemically destroy coke debris. For these purposes, the most suitable material, the bulk of which consists of minerals based on olivines and iron silicates. The main source of olivines and iron silicates are flux components - slag mine smelting of nickel and copper matte. A certain combination of these slags provides the necessary amount of olivines and iron silicates in the wash briquette. The second flushing component is liquid metal iron, which is obtained by descaling. A stream of liquid metallic iron physically flushes the coke nozzle, displacing debris and refractory masses.

The briquette for washing the blast furnace differs from the prototype in that it contains slag from the mine smelting of nickel and copper matte and additionally a hardening catalyst as a flux. The difference of the claimed invention is the limits of the content of slag mine smelting of Nickel and copper matte and a hardening catalyst.

The limits of the scale content in the briquette are determined by the required mineral composition, which ensures the maximum flushing effect in blast furnace smelting. When the scale content is less than 20%, the washing properties deteriorate due to metal drainage in the furnace. With a dross content of more than 40%, the flushing effect due to the low content of iron silicates is reduced.

The limits of the slag content of the mine smelting of nickel matte in the briquette are due to the required mineral composition, providing the maximum flushing effect in blast furnace smelting. When the content of nickel matte mine smelting slag in the briquette is less than 26.5%, the amount of olivines decreases and does not provide the necessary flushing effect. When the slag content of mine smelting nickel matte in the briquette is more than 37%, the content of CaO and MgO in the briquette increases, which leads to an increase in the melting temperature and a decrease in the washing properties.

The limits of the slag content of mine matte of copper matte in the briquette are due to the required amount of iron silicates, providing the maximum flushing effect in blast furnace smelting. When the slag content of mine matte of copper matte in the briquette is less than 26%, the amount of iron silicates is reduced and does not provide the necessary flushing effect. When the slag content of mine matte of copper matte in the briquette is more than 39%, an unfavorable mineral composition of primary slag is formed, which leads to a decrease in flushing properties.

The limits of the content of Portland cement in the briquette are determined by the required strength of the briquette and the mineral composition. The lower limit of the content of Portland cement in the briquette, i.e. 2.5%, due to the lower limit of required strength. When the content of Portland cement in the briquette is more than 5.0%, the formation of refractory slag masses that settle on the coke nozzle and impair the drainage of smelting products in the furnace is possible.

The limits of the content of the curing catalyst in the briquette are determined by the technology of briquette production. The lower limit of the content of the curing catalyst in the briquette, i.e. 1.5%, due to the maximum possible time of curing, at which there is no destruction of the briquette during transportation from the briquette press. When the content of the curing catalyst in the briquette is more than 2.5%, the cost of production of briquettes increases.

According to the second variant, the briquette for washing the blast furnace contains scale as an iron-containing material, Portland cement as a binder, additionally contains a hardening catalyst, and as flux materials, slag from mine nickel matte in the following ratio, wt.%: Scale 42.0-48 0; nickel matte mine smelting slag 44.5-54.0; Portland cement 2.5-5.0; hardening catalyst 1.5-2.5. As a hardening catalyst, a solution of calcium chloride and / or calcium nitrate is used.

Nickel matte mine smelting slag is a source of olivines. The introduction of this slag into the briquette mixture provides the necessary flushing properties in the blast furnace. Dross is the source of the second flushing component - liquid metallic iron. To create the necessary complex of flushing properties, the ratio of the scale and slag of the mine smelting of nickel matte must be changed in comparison with the first option.

The limits of the scale content in the briquette when introducing one slag of the mine smelting of nickel matte into the charge as a flux are determined by the required mineral composition, which ensures the maximum flushing effect in blast furnace smelting. When the scale content is less than 42%, the washing properties deteriorate due to the drainage of the metal in the furnace. With a dross content of more than 48%, the flushing effect due to the low olivine content is reduced.

The limits of the slag content of the mine smelting of nickel matte in the briquette when entering it alone as a flux are due to the required mineral composition, providing the maximum flushing effect in blast furnace smelting. When the slag content of mine smelting nickel matte in the briquette is less than 44.5%, the amount of olivines decreases and does not provide the necessary flushing effect. When the slag content of mine smelting nickel matte in the briquette is more than 54%, the content of CaO and MgO in the briquette increases, which leads to an increase in the melting temperature and a decrease in the washing properties.

According to the third variant, the briquette for washing the blast furnace contains scale as an iron-containing material, Portland cement as a binder, additionally contains a hardening catalyst, and as flux materials, copper matte smelting slag in the following ratio, wt.%: Dross 7.5-21 0; copper matte smelting slag 75.0-85.0; Portland cement 2.5-5.0; hardening catalyst 1.5-2.5. As a hardening catalyst, a solution of calcium chloride and / or calcium nitrate is used.

Copper matte mine smelting slag is a source of iron silicates. The introduction of this slag into the briquette mixture provides the necessary flushing properties in the blast furnace. Due to the high flushing properties of the matte of smelting of copper matte, the content of the second flushing component - the scale requires adjustment in comparison with the first and second options.

The limits of the scale content in the briquette when one slag of copper matte mine smelting is introduced as a flux into the charge are determined by the required mineral composition providing the maximum flushing effect in blast furnace smelting. When the scale content is less than 7.5%, the washing properties deteriorate due to metal drainage in the furnace. With a dross content of more than 21%, the flushing effect due to the low content of iron silicates is reduced.

The limits of the slag content of mine matte of copper matte in the briquette when introducing it alone into the charge are determined by the required amount of iron silicates, providing the maximum flushing effect in blast furnace smelting. When the content of copper matte slag in the briquette is less than 75%, the amount of iron silicates decreases and does not provide the necessary flushing effect. When the content of copper matte slag in the briquette is more than 85%, the washing properties of the briquette deteriorate.

The claimed composition of the components and their quantitative content guarantee the necessary metallurgical properties of the briquette to achieve the objective of the invention - the creation of a material with high flushing characteristics when used in blast furnace at low cost.

Known briquettes for washing the hearth of a blast furnace [3], which is obtained by pressing under a pressure of 500-1000 MPa. As a binder of organic nature, the briquette contains lignosulfonate or VAT residues of fatty acids.

The disadvantages of the method of manufacturing briquettes are low productivity due to the use of stamping presses, and high production costs.

The closest in technical essence and the achieved result is a method of manufacturing briquettes for metallurgical production and briquettes for washing the hearth of a blast furnace [2], which includes preparing the mixture, mixing, moistening the mixture with an aqueous solution of plasticizer and pressing with a specific pressure of 0.02-0.1 MPa with simultaneous exposure to the mixture by vibration with a frequency of 30-70 Hz and an oscillation amplitude of 0.2-0.6 mm until irreversible thixotropic changes occur in the mixture.

The disadvantage of the method of manufacturing briquettes is the high consumption of binder, which leads to a high cost of production of briquettes, and additional heat and moisture treatment for 15 hours, reducing productivity.

The objective of the invention is to create a material with high flushing characteristics when used in blast furnace smelting at low cost.

The technical result is achieved by the fact that the method of manufacturing a briquette for washing a blast furnace includes introducing iron-containing, fluxing components, a binder into the charge, mixing and pressing, which is carried out in a roller briquette press at a specific pressure of 30-100 MPa, and the content of the charge components corresponds to the composition as shown above options.

The method for the production of a briquette for washing a blast furnace differs from the prototype in that the mixture is pressed in a roller briquette press at a specific pressure of 30-100 MPa, and nickel and copper matte smelting slag and optionally a hardening catalyst are introduced into the charge as a flux.

Pressing briquettes in a roller briquette press is due to the task of reducing costs and obtaining the required strength. The limits of changes in the specific pressure of the pressing are due to the requirements of the strength of the briquettes and the reduction of production costs.

The lower limit of the change in the specific pressing pressure, i.e. 30 MPa, due to the minimum specific pressure at which the required strength of the briquettes is provided and corresponds to the maximum consumption of binder and curing catalyst. At less than 30 MPa specific pressure, the consumption of the binder increases, which leads to an increase in costs. The upper limit of the change in the specific pressing pressure, i.e. 100 MPa, due to design features and technical characteristics of roller briquette presses. At a specific pressure of more than 100 MPa, the costs of repair and maintenance of equipment increase.

In the production of a briquette for washing a blast furnace, the introduction of nickel and copper matte slags into the charge as flux is caused by the task of creating a material with high washing characteristics. The use of slag for mine smelting of nickel and copper matte also provides a reduction in costs in the production of briquettes.

In the production of a briquette for washing a blast furnace, the introduction of a hardening catalyst into the mixture is caused by the task of obtaining a briquette of the required strength and minimal destruction during its transportation from the briquette press. The use of a hardening catalyst also provides increased productivity and reduced costs in the production of briquettes.

The search for scientific, technical and patent sources of information and the prototype selected from the list of analogues allow us to identify the above differences in the proposed technical solution. The proposed technical solution "Briquette for washing a blast furnace (options) and the method of its production" meets the criteria of the invention of "novelty."

An additional analysis of the known technical solutions to determine the features in them, similar to the features of the characterizing part of the claims of the claimed technical solution, showed that these signs were not found among the known solutions. Thus, the claimed technical solution meets the criteria of the invention "inventive step".

An example of a specific implementation. The production of a briquette for washing the blast furnace was carried out under industrial conditions at the briquette factory LLC Tormag. The components of the mixture for the production of briquettes were dosed, mixed in a mixer and loaded into the receiving hopper of the roller briquette press PBV 700 / 300-200. The oxide content in the components of the mixture are given in table 1. 400 grade Portland cement was used as a binder. A solution of calcium chloride and calcium nitrate was used as a hardening catalyst. After the production of pilot batches, the briquettes were tested for strength and flushing properties were determined in laboratory conditions. The main indicators that determine the flushing properties of the charge materials of blast furnace smelting are the reducibility and filterability of the smelting products through the coke nozzle. The lower the reducibility and the greater the filterability of the melting products, in particular slag, through the coke nozzle, the higher the washing properties of the material. The recoverability and filterability of smelting products was determined by a specially developed technique. To compare the indicators, the method was tested according to the prototype. The cost of the production of briquettes was determined by calculating the cost of pilot batches. The test results are presented in table.2-3.

Analysis of the results shows that the use of the inventive briquette for washing the blast furnace and the method of its production provides increased washing properties in terms of filterability of slag through the coke nozzle compared with the prototype from 70.5 to 90.2-98.5%. The cost of the production of briquettes for washing the blast furnace is reduced from 3400 to 1330-2000 rubles / t.

The claimed technical solution is implemented in industry, and the technical result follows from the totality of the essential features of the invention, which indicates compliance with the criterion of "industrial applicability".

Table 1. The content (wt.%) In the components of the charge Elements, oxides Scale Nickel matte mine smelting slag Copper matte mine smelting slag Fe _commonly 73.16 16.5 37.3 FeO 61.10 21,2 48.0 Fe ₂ O ₃ 36.60 - - SiO ₂ 1.33 42.5 32,5 Al ₂ O ₃ 0.30 9.6 8.2- Cao 0.20 19.2 5.5 MgO 0.40 6.0 4.8

Information sources

1. Pat. RF №2244013, declared. 07/03/2003, publ. 01/10/2005, IPC C21B 3/00.

2. Pat. RF No. 2183679, declared. 06/28/2001, publ. 06/20/2002, IPC C21C 5/52, C21B 3/00, C22B 1/24, C22B 1/242.

3. Pat. RF №2241759, declared 07/03/2003, publ. 12/10/2004, IPC C21B 3/00.

Claims (7)

1. The briquette for washing the blast furnace containing flux materials, as an iron-containing material - scale, and as a binder - Portland cement, characterized in that it additionally contains a hardening catalyst, and as flux materials - slag mine smelting of Nickel and copper matte when the following ratio of components, wt.%:
scale 20,0-40,0 nickel matte mine smelting slag 26.5-37.0 copper matte smelting slag 26.0-39.0 Portland cement 2.5-5.0 hardening catalyst 1.5-2.5 2. The briquette according to claim 1, characterized in that a solution of calcium chloride and / or a solution of calcium nitrate is used as a hardening catalyst. 3. The briquette for washing the blast furnace containing flux materials, as an iron-containing material - scale, and as a binder - Portland cement, characterized in that it additionally contains a hardening catalyst, and as flux materials - slag mine nickel matte in the following ratio components, wt.%:
scale 42.0-48.0 nickel matte mine smelting slag 44.5-54.0 Portland cement 2.5-5.0 hardening catalyst 1.5-2.5 4. The briquette according to claim 3, characterized in that a solution of calcium chloride and / or a solution of calcium nitrate is used as a hardening catalyst. 5. A briquette for washing a blast furnace containing flux materials, as an iron-containing material - scale, and as a binder - Portland cement, characterized in that it additionally contains a hardening catalyst, and as flux materials - slag of mine matte of copper matte in the following ratio components, wt.%:
scale 7.5-21.0 copper matte smelting slag 75.0-85.0 Portland cement 2.5-5.0 hardening catalyst 1.5-2.5 6. The briquette according to claim 5, characterized in that a solution of calcium chloride and / or a solution of calcium nitrate is used as a hardening catalyst. 7. A method of manufacturing a briquette for washing a blast furnace, comprising introducing iron-containing, fluxing components, a binder and a curing catalyst into the mixture, mixing and pressing the mixture, which is carried out in a roller briquette press at a specific pressure of 30-100 MPa, and with the content of the mixture components corresponding to composition according to claim 1, or 3, or 5.