RU2444556C1 - Coal charge for coking - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: coal charge for coking includes coals of the following grades in the following ratio, wt %: gas fat (GZh) 8.0-12.0; fat+gas fat (Zh+ GZh) 9.0-19.0; gas (G) 2.0-6.0; lean sintering+coking lean (OS+KO) 5.0-10.0; coking lean (KO) 12.0-20.0; lean sintering (OS) 10.0-14.0; coking low-sintering (KS) 15.0-22.0; coking+coking lean (K+KO) 4.0-8.0; coking (K) 3.0-7.0; granulated coal-tar pitch 3.0-12.0; at that, there used is granulated coal-tar pitch with fraction size of 0.1-10 mm.

EFFECT: creation of the charge for obtaining the coke of the proposed composition with improved quality properties and mechanical characteristics.

2 tbl

Description

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

Known mixture for producing metallurgical coke (see AS SU 1703674 A1, class С10В 57/04), including gas, fatty, coke and lean sintering coals, containing sintering additive - the remains of the process of heat treatment of sulphurous tar in the presence of iron ore concentrate in the following ratio of components in the mixture, wt.%:

- sintering additive (DM) - 2.0-4.0; - gas coals (G) - 45.0-55.0; - fatty coals (W) - 17.0-25.0; - coke coals (K) - 10.0-15.0; - lean sintering coals (OS) - the rest.

The disadvantages of the known composition include low coking ability, high yield of volatiles, low yield of gross coke, high sulfur content, which in turn leads to an increase in the content of fine coke fraction 0-25 mm in gross coke, as well as a decrease in cold and hot strength coke and to increase the sulfur content in coke.

A known mixture for producing coke, in which organic additives are added to increase sinterability, which are actively involved in chemical reactions, improve their plastic properties, generating the formation of the necessary compounds. See book Promising directions for the development of coke production. Brown N.V., Glushchenko I.M. M .: Metallurgy, 1989, pp. 196-197. The mixture with the addition of coal tar pitch, depending on the ratios of other components during the experimental coking, has the following composition by weight:

- gas coal (G) from 66.7 in the base charge to 33.3;

- lean sintering coal (OS) from 33.3 to 16.7;

- coke coal (K) was absent in the base charge and was introduced during experimental coking from 20.0 to 50.0 mass. units;

- coal tar pitch (KP) was absent in the base charge and was introduced during experimental coking from 5 to 7.5 mass. units

The properties of the mixture changed as follows:

- yield of volatile V ^Daf ,% from 30.0 in the basic charge to 31.0 with the charge, in the composition of which coal tar pitch was used;

- ash A ^d ,% from 5.4 in the base charge to 4.9-6.5 with the participation of coal

pitch;

- an expansion index from 1.5 in the base charge to 1.5-4.0 with the charge, in the composition of which coal tar pitch was used;

- density, kg / m ³ - was not taken into account in the base charge, and in the charge, in which the coal tar pitch was used was from 699-725.

The properties of coke obtained by known technology are characterized by:

- an indicator of mechanical strength M 40 in the base charge 48.0, and 70.5-74.6 with the charge, which was used coal tar pitch;

- the abrasion index M 10 in the base charge 26.0 and 6.0-8.7 with the charge, which was used coal tar pitch.

The disadvantages of the obtained coal charge include low coking properties, a relatively high yield of volatiles, a reduced yield of gross coke, which accordingly leads to a decrease in the cold and hot strength of coke, as well as to an increase in the reactivity of coke.

Known charge of a more advanced composition, in which to increase the sinterability using an organic additive - coal tar pitch, which is introduced into the charge up to 8%. See Coke and Chemistry. 1982, No. 7, authors: P.F. Gurtovnik, Yu.A. Larionov and others - the closest analogue. When this mixture has the following composition, in wt.%:

- (D) gas coal 37.7-41.0;

- (G) fat coal 26.7-29.0;

- (K) coke coal 11.0-12.0;

- (OS) thin-caked coal 12.0-13.0;

- (T) lean coal 4.6-5.0.

The quality of coke was expressed by the following indicators:

Additive pitch,% Coke quality,% Structural strength,% M 25 M 10 0,0 83.7 10.8 79.1 2.0 84.7 10.6 79.8 4.0 85.9 9.2 81.9 6.0 84.9 10.0 81.6 8.0 83.5 10.7 91.1

From the data obtained experimentally, it is seen that the maximum increase in the mechanical strength index (M 25) and the decrease in the abrasion index (M 10) were obtained with the participation of 4% coal tar pitch: M 25 increased by 2.2% and M 10 decreased by 1.6%. With an increase in the share of coal tar pitch, the structural strength of coke increased from 79.1% to 91.1%.

The disadvantages of the charge of this composition, despite the insignificant positive effect of coal tar pitch on cold strength, include low coking ability, a relatively high yield of volatile substances, low yield of bulk coke, which in turn leads to high abrasion of coke, low cold and hot strength.

The objective of the present invention is to provide a mixture that is optimal in sintering and coking properties to produce high-quality coke with high cold and hot strength, low ash content, low sulfur content and an increased yield of 40-60 mm fraction.

The technical result of the claimed invention is the creation of a mixture for producing coke of the proposed composition with improved quality indicators and improved mechanical properties.

The task is achieved in that the mixture contains coals of the following grades in the specified ratio, wt.%:

- gas fatty (GF) 8.0-12.0 - greasy + gas greasy (F + GF) 9.0-19.0 - gas (G) 2.0-6.0 - lean sintering + coke lean (OS + KO) 5.0-10.0 - coke lean (KO) 12.0-20.0 - lean sintering (OS) 10.0-14.0 - slightly coking coke (COP) 15.0-22.0 - coke + coke lean (K + KO) 4.0-8.0 - coke (K) 3.0-7.0 - granular coal tar pitch 3.0-12.0,

while using coal tar pitch fraction of 0.1-10 mm

The novelty of the proposed coal charge for coking is its implementation in the above percentage ratio, which consists in reducing the composition of the coal charge by 8.0-15.0 wt.% Gas coals, reducing costly, scarce fatty coals by 16-26 wt.%, exclusion of lean coals from the charge, introduction of slightly coking coke, lean coke, coke + coke lean coal, with a total content of 30.0 - 55.0 wt.% in the charge, while an organic additive - granular coal tar pitch is introduced into the charge in the amount of 3 0-12.0 wt.%.

So, the introduction of coal tar pitch in the amount of 3.0-12.0 wt.% In combination with the introduction of the proposed grades of coke coal into the coal charge allows sintering the coals to significantly increase the plastic properties of the charge, to obtain optimal sintering, coking ability, which this leads to an increase in the cold and hot strength of coke, a decrease in the ash content of coke, as well as a decrease in its sulfur content. Ultimately, this leads to a decrease in coke consumption per ton of smelted pig iron in the blast furnace process.

The proposed coal charge for coking is obtained as follows.

The mixture in the following ratio of components, wt.%:

- gas fatty (GF) 8.0-12.0 - greasy + gas greasy (F + GF) 9.0-19.0 - gas (G) 2.0-6.0 - lean sintering + coke lean (OS + KO) 5.0-10.0 - coke lean (KO) 12.0-20.0 - lean sintering (OS) 10.0-14.0 - slightly coking coke (COP) 15.0-22.0 - coke + coke lean (K + KO) 4.0-8.0 - coke (K) 3.0-7.0 - granular coal tar pitch 3.0-12.0,

with a reduced content of 8.0-15.0 wt.% gas coals, a decrease in costly, scarce fatty coals by 16-26 wt.%, excluding lean coals, the introduction of coke, low caking, coke lean, coke + coke lean coals, with a total their content in the charge is 30.0-55.0 wt.%, and the introduction of additives - coal tar pitch granulated into the charge in the amount of 3-12.0 wt.% is prepared at the charge feeding section, where the coals included in the charge are crushed to the specified grinding (grade content from 0 to 3.0 mm) with hammer crushers and subjected subsequent separation in a fluidized bed with separation from the crushed mixture of coal fractions more than 3 mm and return them to re-crushing.

The supply of coal tar pitch to the prepared charge is carried out from the hopper through a metering device, which ensures uniform distribution of granular coal tar pitch on the surface of the conveyor belt. Mixing the finished mixture with coal tar pitch is carried out after separation of pneumatic separation in the process of several charge overloads at reloading stations.

During the passage of the charge through several transshipment stations, the granular coal tar pitch is evenly distributed over the volume of the charge entering the coal tower. Next, the prepared mixture is loaded into coke ovens using a coal-loading machine and its coking is carried out. In the future, operations to obtain finished coke are carried out according to well-known technology: heating and sintering without air access to a temperature of 950-1050 ° C, coke delivery, quenching, sorting and loading into cars.

At present, the enterprise has developed the design and technological documentation for the charge of the proposed composition, conducted experimental and pilot industrial work on the production of coke, and obtained positive results (see table 1).

As can be seen from the characteristics of the obtained coke, the mechanical strength increased to 87.5%, hot strength to 66.9%, while abrasion decreased to 6.6%, reactivity to 24.5%, and the ash content decreased to 9 , 9% and sulfur up to 0.38%. Coke in terms of particle size distribution is very uniform, there are practically no classes of more than 80 mm, which is very important for the blast furnace process.

Claims (1)

Coal charge for coking, including fatty, gas, lean sintering, coke coals and organic additive - coal tar pitch, characterized in that the charge contains coals of the following grades in the indicated ratio, wt.%:
gas fatty (GF) 8.0-12.0 greasy + gas greasy (W + GF) 9.0-19.0 gas (g) 2.0-6.0 lean sintering + coke lean (OS + KO) 5.0-10.0 coke lean (KO) 12.0-20.0 lean sintering (OS) 10.0-14.0 low coking coke (COP) 15.0-22.0 coke + coke lean (K + KO) 4.0-8.0 coke (K) 3.0-7.0 granular coal tar pitch 3.0-12.0,
while using coal tar pitch granular fraction of 0.1-10 mm