EA021524B1 - Charge mixture for producing coke - Google Patents

Abstract

The invention relates to charge mixture production for metallurgical coke. Increase of charge quality, decrease of ash content and improvement of its after-reaction strength are provided by using an oil coke additive in an amount of 50-70 wt% and coal concentrates of grades GZh - 7-10 wt%, GZhO - 12-20 wt%, G - 7-10 wt%, KS - 4-10 wt%. The charge mixture comprises 16-17% of volatile substances and has vitrinite index of reflection 1.8-2.4%.

Description

The invention relates to by-product coke production, in particular to the production of a charge for metallurgical coke.

Known mixture for producing metallurgical coke according to the patent of the Russian Federation for invention No. 2224782, СВВ 57/04, 2004, containing fatty, lean sintering coals and sintering additive. The mixture additionally contains gas-fatty coke low-caking coals. Sintering additive is obtained by mixing a pecky product with plastic waste. The disadvantage is the low hot strength of coke.

A known method of preparation for the coking of a coal charge according to the author's certificate of the USSR No. 1778137, СВВ 57/04, 1992. The mixture consists of greasy, coke, gas and lean sintering coals. To increase the mechanical strength of coke, the mixture is divided into classes by size and oil products with a certain yield of volatile substances are added as organic additives to the selected classes. The disadvantage is the complexity of the technology, the low quality of coke.

The invention was chosen as the closest analogue to the claimed technical solution according to the USSR author's certificate No. 1703674, СВВ 57/04, 1992. The mixture for producing metallurgical coke includes gas, fatty, coke, thin-caked coals and an iron-containing sintering additive. As a sintering additive, the residues of the heat treatment process of sulfur tars in the presence of iron ore concentrate with a softening temperature of 80-100 ° C and a boiling point above 530 ° C are used. The disadvantage is the high ash content in coke, low sulfur content, a large interval between the indicators of reactivity and post-reaction strength.

The technical task of the invention is to improve the quality of the charge.

The technical result consists in reducing the ash content of the coke obtained from the charge and in increasing its post-reaction (hot) strength by improving the properties of the charge.

The technical result is achieved due to the fact that in the charge for producing coke, including a mixture of coal and a coking additive, according to the invention, the coking additive is petroleum with a volatile content of 16-17% and a vitrinite reflection index of 1.8-2.4%, a coal mixture consists of coal concentrates in the following ratio of components in the mixture, wt.%:

petroleum coking additive 50 - 70 gas fatty coals (GF) 7-10 gas fat lean coal (GLC) 12-20 gas coals (g) 7-10 coking low-sintering coals (COP) 4-10.

Low-coking coke concentrate can be low-metamorphosed (SPF). The technical result is ensured due to the fact that a significant amount of petroleum coking additive and coking coal concentrates are used in the charge. As a coking additive, heavy waste oil cracking is used after additional heat treatment in special reactors. The addition of an oil coking additive with a volatile content of 16-17% and a vitrinite reflection index of 1.8-2.4% in an amount of 50-70% of the total mass of the charge significantly improves the properties of the charge and coke obtained from it. The coking additive in the temperature range from 200 to 550 ° C has a large plasticity range from 120 to 350 ° C, i.e. practically falls into the temperature range for the production of coke from coal blends. This makes it possible to use it as a coking component of the charge for metallurgical coke. In the process of coking, the components of the coal mixture are subjected to thermal destruction with the formation of a large number of fragments of macromolecules, which are able to be in a liquid state and form a plastic mass. The introduction of an oil additive with a high temperature range of plasticity into the charge promotes the formation of a large amount of plastic mass during coking, and relatively inert coal grains are cemented. The additive during the coking process softens, becomes viscous, envelops the pieces of the charge, bonding them together and forming pieces of coke. The use of petroleum coking additive with a volatile content of 16-17% and a vitrinite reflection index of 1.8-2.4% is due to the fact that it has a plastic layer thickness of the charge Υ = 14 mm and corresponds to carbon brand K. The coking conditions of the additive are similar to the coking conditions of the coal concentrate, but the additive has a much higher reflection index of vitrinite, which significantly increases the post-reaction (hot) strength of coke. In addition, the ash content in petroleum coking additive is less than 1%, and in coal concentrates - 9-10%, therefore, the carbon content in coke obtained from this mixture is higher than in coke obtained from coal concentrates alone. The amount of petroleum coking additive in the charge is not more than 70 wt.%, With a greater amount of it, the content of volatile substances in the charge will be lower than the permissible rate for coking, which may lead to coking of coke ovens. To ensure the necessary balance between the quality of the obtained coke and the technological possibilities of coking, the optimal range of the content of petroleum coking additive in the charge, which is 50-70 wt.% Of its total amount, was selected. The organic additive introduced into the charge in precisely such an amount actively participates in chemical reactions, improves its plastic properties and generates the formation of necessary compounds. The use of coking coal concentrates, i.e. a mixture of enriched coal, lowers the ash content of coke. The optimal content of each coal concentrate is determined experimentally.

To obtain the inventive charge for metallurgical coke, pre-enriched coals of the grades GZh, GZhO, G, KSN, KSN are prepared, subjected to crushing to a class (class) of 50 mm. After crushing, coal concentrates are fed into metering bins. An oil coking additive is selected with the necessary quality indicators, such as a volatile content of 1617%, an expansion index (VI) of 5-10 mm, a vitrinite reflection index of 1.8-2.4%. Oil coking additive complies with TU 0258-229-00190437-2008 Coking additive. The coking additive content in the charge is quite high, therefore, for additional averaging, the additive is loaded into several separate bunkers of the dosage compartment. Coal concentrates and petroleum coking additive are fed from the dosing unit to the conveyor and to the final crushing unit. A predetermined weight ratio of the components is provided by weight dispensers. Oil coking additive is 50 wt.%, Coal concentrates: GF - 10 wt.%, GF - 20 wt.%, G 10 wt.%, KS - 10 wt.%. In the final crushing compartment, the mixture is ground with a hammer mill until the content of grinding particles of cl. 3 mm not less than 75%. The content of the ground part in the coal charge is 79-82%. All quality indicators of the obtained mixture are checked by the method of express analysis, the conveyors feed the mixture into a coal tower for subsequent loading into coke ovens for coking.

The use of petroleum coking additive in the charge allows to obtain metallurgical coke with increased indicators of mechanical strength M25, M40, M10, increase the post-reaction (hot) strength of C8P coke and improve the reactivity of SKT

Coke obtained for smelting metals has the following technical indicators and characteristics:

Quality indicators Blast furnace coke Special Cox Moisture % 6.0 5.2 Ash content, A,% 12.5 6.8 Sulfur, 8,% 0.6 2,8 Strength, M25,% 82.0 85.6 Hot strength, S8K,% 55.0 62.3 Reactivity, SI,% 30.7 30,4

Thus, the claimed invention allows to improve the quality of the mixture, to reduce the ash content of coke obtained from it and to increase its post-reaction strength.

Claims (2)

CLAIM 1. The mixture for producing coke, comprising a mixture of coal and a coking additive, characterized in that the coking additive is petroleum with a volatile content of 16-17% and a reflection coefficient of vitrinite of 1.8-2.4%, the coal mixture consists of coal concentrates at the following ratio of components in the mixture, wt.%: petroleum coking additive 50 - 70 gas fatty coals (GF) 7-10 gas fat lean coal (GLC) 12-20 gas coals (g) 7-10 coking low-sintering coals (COP) 4-10. 2. The mixture according to claim 1, characterized in that the coke low-caking concentrate is low metamorphosed.