RU2814328C1 - Method of producing carbon-containing product - Google Patents

Abstract

FIELD: oil, gas and coke-chemical industry; various technological processes.

SUBSTANCE: invention relates to a method of producing a carbon-containing product. Method includes formation of coal charge, its loading into coke furnaces, subsequent layer coking. Method is characterized by the fact that the coal charge contains 57.0–99.0% of coals of one or more grades, conditionally suitable for coking, 0–40.0% of coking coals and 1.0–6.0% of fine coke additive, wherein fine coke additive consists of coke dust and/or crushed coke fines with fractional composition of not more than 1.0 mm, with content of class of not more than 0.5 mm in amount of not less than 35.0% of total amount of fine coke additive and is characterized by output of volatile substances of not more than 2.0% and ash content of 10.0–25.0%.

EFFECT: use of the proposed method enables to solve the problem of recycling coke dust and coke fines.

4 cl, 12 tbl, 3 ex

Description

The invention relates to the field of chemical technology of solid fuel and can be used in the coke industry to produce an analogue of coal coke and coke products. The invention makes it possible to obtain a product with specified quality characteristics suitable for use in the metallurgical industry.

The modern strategy of metallurgical enterprises is to produce steel at low costs and high quality products, while maximum attention is paid to environmental issues and social issues. Successful implementation of strategic plans requires the introduction of new technologies and the improvement of existing ones using low-cost or no-cost improvement projects. Projecting this strategy onto the first stage means reducing the costs of producing liquid iron, reducing the formation of gaseous, water and solid wastes and emissions. One of the directions for reducing the cost of the blast furnace process is the use of an innovative carbon-containing product (ICP) with specified characteristics from coals that are conditionally suitable for coking, when carrying out the layer coking process in coke batteries with gravity loading.

The economically feasible use of generated solid waste from coke production is another priority scientific and technical area for the development of coke chemistry. Coke dust (fine coke product) is one of the man-made wastes of coke-chemical enterprises generated during the operation of aspiration units when performing various technological operations associated with coke production (sorting bulk coke, dry quenching of coke, coke overloads, etc.).

There are known methods of using coke dust to produce fuel briquettes (RF patent No. 2560186, class C1, published on August 20, 2015, RF patent No. 2468071, class C1, published on November 27, 2012). The inventions make it possible to obtain smokeless fuel briquettes, improve the environmental situation and utilize coke dust, but the resulting product is not suitable for use in the metallurgical industry.

There is also a known method for producing coke from a mixture of coke breeze and coal charge. (USSR patent No. 1786056 A1, class C10B 57/04, published 01/07/1993). as well as the use in the mixture of crumb rubber processed by waste from coke production and mixed with coke dust (RF patent No. 2186823, class C10B 57/06.53/08 publ. 08/10/2002).

A significant disadvantage of these methods is:

- an increase in the cost of coke processing and the need for special technological measures in the process of preparing the charge for coking;

- minor use of coconut additive (1.0 -2.5%);

- a fixed and limited set of coal grades used in the coking charge.

A method for producing an innovative carbon-containing product was chosen as a prototype (RF patent No. 2733610, class C10B 57/04; 57/06 publ. 10/05/2020). An innovative carbon-containing product is obtained by carrying out the layer coking process in coke batteries with gravity loading; from 60% to 100% of coals of one or more grades conditionally suitable for coking and 0-40% of coking coals are used as feedstock.

The claimed method ensures: the removal of restrictions on the choice of the type of coal used in the charge, the qualitative characteristics of the carbon-containing product, but does not provide for the use of non-coal additives.

Therefore, a significant disadvantage of this method of obtaining a carbon-containing product for blast furnace production is:

- the inability to include waste from coke production into the coking charge, which in turn increases the environmental load on the coke production process;

- there is no possibility of minimizing the cost of production of the product by introducing waste from coke production into the mixture.

The problem solved by the proposed invention is the development of a method for producing a carbon-containing product applicable in blast furnace production, as well as the disposal of man-made waste from coke production.

The task is achieved by the fact that the method of obtaining a carbon-containing product includes the formation of a coal charge, loading it into coke ovens, subsequent layer coking, while the charge contains 57.0-99.0% of coals of one or more grades, conditionally suitable for coking, 0- 40.0% coking coals and 1.0-6.0% fine coke additive, and the fine coke additive consists of coke dust and/or crushed coke breeze with a fractional composition of no more than 1.0 mm with a class content of no more than 0.5 mm in an amount of no less than 35% of the total amount of finely dispersed coke additive and is characterized by a release of volatile substances of no more than 2.0% and an ash content of 10.0-25.0%.

The coal charge is characterized by a vitrinite reflectance of 0.7 - 0.9% and a volatile matter yield of 30.0 -37.0%.

The density of the coal charge before coking is 0.7-0.8 t/ ^m3 .

The coking speed of the coal charge is 7.0-15.0 mm/hour.

The component composition of the claimed charge was obtained experimentally.

The charge for the production of a carbon-containing product must include 57.0–99.0% of coal of one or more grades, conditionally suitable for coking. When using coal of one or more grades that are conditionally suitable for coking in an amount of less than 57.0%, the cost of production of a carbon-containing product increases (approaches the cost of producing coke). The upper limit (99.0%) is determined by the objective of the invention to utilize finely dispersed coke products.

The introduction of up to 40.0% coking coal into the charge provides the required strength of the carbon-containing product after reaction with carbon dioxide (CSR indicator from 25.0% to 45.0%).

The content of finely dispersed coke additive in the charge in an amount of less than 1.0% does not allow for proper disposal of finely dispersed coke waste and, as a result, does not solve environmental and economic problems in the production of a carbon-containing product.

The content of a finely dispersed coke additive in the charge of more than 6.0% leads to a significant decrease in the strength index of the carbon-containing product after reaction with carbon dioxide (CSR, %).

In laboratory conditions, the influence of the fractional composition of a finely dispersed coke additive on the quality of the resulting coke was established. The content of a fraction of more than 1.0 mm in a finely dispersed coke additive worsens the quality indicators of the resulting carbon-containing product. In laboratory conditions, it was also established that the minimum content of a fraction class of no more than 0.5 mm in a finely dispersed coke additive should be no less than 35.0%. At the same time, the negative impact on the strength index after reaction with carbon dioxide (CSR,%) is minimal. Laboratory data is confirmed by industrial tests.

The content of a fraction class of no more than 0.5 mm in an amount of more than 35% allows you to utilize a larger amount of coke dust and at the same time obtain a finely dispersed coke additive with a yield of volatile substances of no more than 2.0% and an ash content of 10.0-25.0% and a coal charge with a vitrinite reflectance of 0.70-0.90% and a volatile matter yield of 30.0-37.0%.

The coal charge is characterized by a vitrinite reflection index of 0.70–0.90% and a volatile matter yield of 30.0–37.0%, since it contains 57.0–99.0% of coals of one or more grades, conditionally suitable for coking.

The density of the coal cake is in the range of 0.7-0.8, which is due to the coking technology and the design solution of the coke oven battery - the gravitational method of loading the charge for coking. The specified density makes it possible to obtain a carbon-containing product suitable for further use in blast furnace production.

The speed of movement of the plastic layer - the coking speed of the coal charge is 7.0 - 15.0 mm/hour. A coking rate of less than 7.0 mm/hour leads to a long stay of the carbon-containing product in the furnaces and reduces the service life of the coke oven battery. At a speed greater than 15.0 mm/hour, the coking process will not be completed, and the resulting carbon-containing product will not meet the requirements of blast furnace production.

Implementation of the invention.

The finely dispersed coke additive (coke dust, crushed coke breeze) is stored at a specialized site, then loaded into railway cars by a forklift, the cars are unloaded through a car dumper into a specially prepared (selected from residual material) bunker of the dosing department. Next, the finely dispersed coke additive is dosed through an auto-doser in the same way as coal concentrates and, as part of the coal charge for coking, is pumped into sections of the coal tower for further feeding into coke batteries and carrying out the layer coking process.

To obtain a carbon-containing product, a coal charge is used, consisting of one or more grades of coal conditionally suitable for coking, coking coal, and fine coke additive.

The technological process for obtaining a carbon-containing product includes the following technological operations:

- loading prepared raw materials into coke ovens;

- coking of raw coal without air access;

- dispensing a carbon-containing product from the furnace;

- extinguishing process;

- sorting of carbon-containing product and transferring it to consumers (in particular, to blast furnace production).

Implementation example 1.

In the conditions of PJSC Severstal, a number of experiments were carried out in which a coal concentrate, conditionally suitable for coking and having the lowest purchase cost - concentrate No. 1, was selected as a raw material for the production of a carbon-containing product; coconut dust from aspiration plants of coke-chemical production was used as a fine additive. The work was carried out on coke batteries No. 3-4 with gravity loading of coal charge.

Data on the quality of the feedstock and the ratio of components in the charge to obtain a carbon-containing product are given in Table 1.

Data on the quality of the resulting mixture for obtaining a carbon-containing product are given in Table 2.

Table 3 shows the operating parameters of coke oven batteries during the experimental charging period. The coking speed of the coal load was 14.2 mm/hour.

The qualitative characteristics of the resulting carbon-containing product are given in Table 4.

Implementation example 2.

In the coke shop No. 2 of PJSC Severstal, to obtain a carbon-containing product, a coal concentrate was selected that is conditionally suitable for coking and has the lowest purchase cost - concentrate No. 1, and concentrate 2 belonging to the group of coking coals, coconut fines, crushed to coarseness, were used as a fine additive less than 1.0 mm. The work was carried out on coke batteries No. 3-4 with gravity loading of coal charge. Data on the quality of the feedstock and the ratio of components in the charge to obtain a carbon-containing product are given in Table 5.

Data on the quality of the resulting mixture for obtaining a carbon-containing product are given in Table 6.

Table 7 shows the operating parameters of coke oven batteries during the experimental charging period. The coking speed of the coal load was 12.1 mm/hour.

The qualitative characteristics of the resulting innovative carbon-containing product are given in Table 8.

Implementation example 3.

In the coke shop No. 2 of PJSC Severstal, to obtain a carbon-containing product, a coal concentrate was selected that is conditionally suitable for coking and has the lowest purchase cost - concentrate No. 1, and concentrate 2 belonging to the group of coking coals; a mixture of coke dust was used as a fine additive (50, 0%) and coconut fines (50.0%), crushed to a particle size of less than 1.0 mm. The work was carried out on coke batteries No. 5-6 with gravity loading of coal charge. Data on the quality of the feedstock and the ratio of components in the charge to obtain a carbon-containing product are given in Table 9.

Data on the quality of the resulting mixture for obtaining a carbon-containing product are given in Table 10.

Table 11 shows the operating parameters of coke oven batteries during the experimental charging period. The coking speed of the coal load was 10.7 mm/hour.

The qualitative characteristics of the resulting innovative carbon-containing product are given in Table 12.

The resulting carbon-containing product is characterized by an average piece size of at least 50.0 mm, a yield of volatile substances of no more than 1.0%, and a strength index after reaction with carbon dioxide of at least 25.0%.

The technical and economic advantage of the proposed method is that the economic effect of using a carbon-containing product from coals conditionally suitable for coking and fine coke additives has a positive effect on reducing the cost of cast iron and finished rolled metal, and also allows solving the problem of recycling coke dust and coke breeze.

Table 1

Qualitative characteristics of raw materials for obtaining a charge of a carbon-containing product

Indicator name Concentrate No. 1 Coke additive Designation of the measurement procedure Mass fraction of total moisture, W ^r % 7.6 3.1 GOST 11014 Ash content, A ^d % 8.0 10.2 GOST 55661 The yield of volatile substances on a dry, ash-free state, V ^daf % 35.8 1.7 GOST 55660 Vitrinite reflectance index, Ro,% 0.800 GOST 55659 Size class “0-0.5 mm”,% 56 GOST 2093 Participation in the charge for coking,% 95 5

table 2

Qualitative characteristics of the charge for obtaining a carbon-containing product

Indicator name Meaning Designation of the measurement procedure Ash content, A ^d % 8.1 GOST 55661 The yield of volatile substances on a dry, ash-free state, V ^daf % 34.1 GOST 55660 Vitrinite reflectance index, Ro,% 0.76 GOST 55659 Bulk weight (density), t/m ³ 0.798

Table 3

Operating parameters of coke oven batteries

Period, h:mm Temperature, °C % of stoves extinguished Indicators 14:16 1359.9 81.6

Table 4

Qualitative characteristics of a carbon-containing product

Indicator name Measurement result Designation of the measurement procedure Ash content, A ^d % 10.8 GOST 55661 The yield of volatile substances on a dry, ash-free state, V ^daf % 0.8 GOST 55660 Mass fraction of carbon, % 82.3 GOST 2408.1 Average piece size, mm 62.8 GOST 5954.1-91 Strength indicator after reaction with carbon dioxide, % 36.2 GOST R 54250

Table 5

Qualitative characteristics of raw materials for obtaining a charge of a carbon-containing product

Indicator name Concentrate No. 1 Concentrate No. 2 Coke additive Designation of the measurement procedure Mass fraction of total moisture, W ^r % 7.6 8.6 2.2 GOST 11014 Ash content, A ^d % 8.2 7.9 11.3 GOST 55661 The yield of volatile substances on a dry, ash-free state, V ^daf % 35.8 21.5 1.1 GOST 55660 Vitrinite reflectance index, Ro,% 0.800 1.24 GOST 55659 Size class “0-0.5 mm”,% 56 GOST 2093 Participation in the charge for coking,% 80 15 5

Table 6

Qualitative characteristics of the charge for obtaining a carbon-containing product

Indicator name Meaning Designation of the measurement procedure Ash content, A ^d % 8.3 GOST 55661 The yield of volatile substances on a dry, ash-free state, V ^daf % 31.9 GOST 55660 Vitrinite reflectance index, Ro,% 0.83 GOST 55659 Bulk weight (density), t/m ³ 0.778

Table 7

Operating parameters of coke oven batteries

Period, h:mm Temperature, °C % of stoves extinguished Indicators 16:50 1300.9 100

Table 8

Qualitative characteristics of a carbon-containing product

Indicator name Measurement result Designation of the measurement procedure Ash content, A ^d % 10.9 GOST 55661 The yield of volatile substances on a dry, ash-free state, V ^daf % 0.8 GOST 55660 Mass fraction of carbon, % 82.3 GOST 2408.1 Average piece size, mm 56.4 GOST 5954.1-91 Strength indicator after reaction with carbon dioxide, % 41.9 GOST R 54250

Table 9

Qualitative characteristics of raw materials for obtaining a charge of a carbon-containing product

Indicator name Concentrate No. 1 Concentrate No. 2 Coke additive Designation of the measurement procedure Mass fraction of total moisture, W ^r % 7.7 8.0 1.5 GOST 11014 Ash content, A ^d % 8.0 7.9 11.0 GOST 55661 The yield of volatile substances on a dry, ash-free state, V ^daf % 35.0 24.5 1.1 GOST 55660 Vitrinite reflectance index, Ro,% 0.745 1.28 GOST 55659 Size class “0-0.5 mm”,% 78 GOST 2093 Participation in the charge for coking,% 85 10 5

Table 10

Qualitative characteristics of the charge for obtaining a carbon-containing product

Indicator name Meaning Designation of the measurement procedure Ash content, A ^d % 8.1 GOST 55661 The yield of volatile substances on a dry, ash-free state, V ^daf % 32.3 GOST 55660 Vitrinite reflectance index, Ro,% 0.76 GOST 55659 Bulk weight (density), t/m ³ 0.789

Table 11

Operating parameters of coke oven batteries

Period, h:mm Temperature, °C % of stoves extinguished Indicators 18:55 1306 100

Table 12

Qualitative characteristics of a carbon-containing product

Indicator name Measurement result Designation of the measurement procedure Ash content, A ^d % 11.4 GOST 55661 The yield of volatile substances on a dry, ash-free state, V ^daf % 0.9 GOST 55660 Mass fraction of carbon, % 82.8 GOST 2408.1 Average piece size, mm 60.1 GOST 5954.1-91 Strength indicator after reaction with carbon dioxide, % 38.8 GOST R 54250

Claims (4)

1. A method for producing a carbon-containing product, including the formation of a coal charge, loading it into coke ovens, subsequent layer coking, characterized in that the coal charge contains 57.0-99.0% of coal of one or more grades, conditionally suitable for coking, 0- 40.0% coking coals and 1.0-6.0% fine coke additive, wherein the fine coke additive consists of coke dust and/or crushed coke breeze with a fractional composition of no more than 1.0 mm, with a class content of no more than 0, 5 mm in an amount of at least 35.0% of the total amount of fine coke additive and is characterized by a volatile substances yield of no more than 2.0% and an ash content of 10.0-25.0%. 2. The method according to claim 1, characterized in that the coal charge is characterized by a vitrinite reflectance of 0.7-0.9% and a yield of volatile substances of 30.0-37.0%. 3. The method according to claim 1, characterized in that the density of the coal load is 0.7-0.8 t/ ^m3 . 4. The method according to claim 1, characterized in that the coking speed of the coal charge is 7.0-15.0 mm/hour.