RU2348680C1 - Method of partially briquetted charge preparation for coking - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention concerns method of preparation for charge coking, involving binding agent preparation by mixing coal-tar resin obtained by high-temperature coal charge coking, raw antracene and lignite resin obtained by express pyrolysis of lignite and exposed to thermal processing; charge processing by binding agent in amount of 3-10 wt % for partial charge briquetting; and adding humic acids obtained from lignite and exposed to thermal processing, to partially briquetted charge in amount of 2-4 wt % of total coked coal weight in charge and binding agent.

EFFECT: extended raw material base for coking due to the use of accessible thermal and chemical processing products of lignite and increase of widespread gas and thin baking coals content in coking charge along with reduction of rare bituminous and coke coals, simplified cost-effective process of high quality coke.

3 cl, 1 tbl, 1 ex

Description

The invention relates to the coke industry, in particular to methods for preparing a partially briquetted charge for layer coking, used for the production of metallurgical coke from burden with a high content of gas and / or low-sintering coals while reducing the content of fatty and coke coals in the burden.

Coke and fat coals, which are the main sintering components of coking blends, are scarce coals. In addition to these coals, less scarce gas and low-sintering coals are introduced into the coking charges. However, the maximum allowable amount of the latter in the blends is limited by the fact that with a high content (relatively optimal) of gas coals in the coking blends, the yield of gross coke decreases and its coarseness decreases. The limit content of weakly sintering coals that practically do not turn into a plastic state is also limited in order to avoid a decrease in the strength characteristics of marketable coke due to the reduced yield of nonvolatile liquid products due to the presence of thinning components in the charge. In this case, its own binder is not enough for the optimal "melting" of the charge. Therefore, when coking partially briquetted blends, it is extremely important to choose an effective binder.

Closest to the claimed is a method of preparing the charge for coking (A.S. USSR No. 1114693, BI No. 35, 1982 / I.A. Grinevich, I.Yu. Ryvkin, P.Ya. Nefedov, N.A. Ivanov, A .Ya. Eremin and N.K. Chevlytko), including the preparation of a binder, its mixing with coals and subsequent briquetting (prototype). According to the prototype use a binder of the following composition (wt.%): Medium temperature coal tar pitch (STP) - 38-40; coal tar - 46-49; crude anthracene 12-14.

The disadvantages of the prototype:

1) the composition of the binder uses a rather scarce STP, the need for which of the electrode plants is higher than the volumes of its production by coke-chemical enterprises of Russia.

2) the structural strength of marketable coke is not high enough (84-86%), which does not always satisfy consumers.

Recently, non-radiation products, for example, semi-coking products of low-metamorphosed brown coals, have been trying to involve coking blends. Thus, there is a known method of preparing a charge for coking with the inclusion of a semi-coke (A.S. USSR No. 1214718, BI, publ. 02.28.1986 / V.M.Dinelt, M. B. Shkoller, I.V. Timofiva, E. B. Ushakov /. It is reported that the addition of 5 wt.% Brown coal semicoke to the coking charge can increase the mechanical strength of coke by 2.2% and reduce its abrasion by 1.4%.

However, brown coal semicoke has an increased ash content and it can be added to a limited extent to avoid exceeding the allowable limit for this indicator in commercial coke. On the other hand, brown coal semi-coke is a thinner additive that practically does not release liquid products (binder) during coking, and increased additives of the latter to the charge will require adjusting the composition of the charges to increase the content of "fat" components (K and G coals).

Chemical processing of brown coals (alkali treatment) makes it possible to extract low-ash humic acids from them, and their thermal treatment with a partial loss of functional groups leads to the production of low-ash carbon reducing agents, similar in properties to brown coal semi-cokes. But unlike semicoke, heat-treated humic acids have several advantages: a) they have sintering ability; b) they are low ash. Heat treatment of humic acids consists in their uniform heating in a heated metal pipe to a temperature of 500 ° C for 1 hour and exposure at this temperature for 5 minutes.

The objective of the invention is to expand the coking feed base by involving in the coking charge available products of thermal and chemical processing of brown coal and using high content of non-deficient grades of gas (G) and lean sintering (OS) coals in the charge while reducing the content of deficient fat (G) ) and coke (K) coals, as well as the simplification and cheapening of the method for producing high quality coke.

This object is achieved by the fact that the proposed method of preparation for the coking of the charge, including the preparation of a binder by mixing coal tar high-temperature coking of coal coking blends, crude anthracene and heat-treated brown coal tar high-speed pyrolysis of brown coals, processing the mixture with a binder in the amount of 3-10 wt.% For partial briquetting charge and the introduction into a partially briquetted charge of heat-treated humic acids isolated from brown coal in an amount of 2-4% by weight of coked coal batch and binder.

The task is also achieved by the fact that for briquetting the mixture using a binder of the following composition (wt.%): Coal tar - 43; heat-treated brown coal pyrolysis resin - 43, crude anthracene - 14 and the fact that the mixture prepared for coking consists of 40% of the non-briquetted part and 60% of the briquetted part.

To isolate humic acids, we used ordinary and oxidized coals of Russia and Mongolia (the Berezovsky deposit of the Kansk-Achinsky basin, Baganuursky and Tugrugnuursky deposits of the Mongolian people's republic).

The novelty of the invention lies in the involvement of non-deficient brown coals in the composition of the blends of the products of pyrolysis and chemical processing (humic acids), as well as in the involvement in the blends of an increased amount of gas and low-caking coals while reducing the content of fatty and coke coals. The combination of these techniques allows you to get better coke, to simplify and reduce the cost of its production, as well as expand the raw material base of coking. The structural strength of coke increases compared with the prototype with almost the same yield and the same fractional composition. Note that the starting and heat-treated humic acids have a certain sintering ability, which favorably affects the strength characteristics of marketable coke.

The proposed solution has a novelty, inventive step and is industrially applicable.

The following are the characteristics of the starting products used by us for the preparation of the binder used in the inventive method:

1) coal tar: density - 1220 kg / m ³ ; water content - 0.51%; ash content - 0.3%; group composition (%): γ-fraction - 65.3; β-fraction - 25.7; α-fraction - 9; volatile yield - 78.3%;

2) crude anthracene consists of anthracene (30.7%), phenanthrene (20.2%), carbazole (26.5%) and oil (22.6%);

3) heat-treated brown coal pyrolysis resin (Berezovsky deposit of the Kansk-Achinsk basin): density - 1248 kg / m ³ ; water content - 0.03%; ash content - 7.6%; the beginning of boiling - 270 ° C; softening temperature - 86 ° C; volatile yield - 68.4%; group composition (%): γ-fraction - 22.7; β-fraction - 44.7; the α fraction is 32.6.

Characterization of the initial humic acids: 1) humic acids isolated from oxidized brown coal (soot layer) of the Berezovsky deposit of the Kansk-Achinsk basin (%): ash content - 1.3; C ^daf 55.4; H ^daf - 4.78; N ^daf - 0.51; S ^daf - 0.3; About ^daf - 39.01; the content of functional groups (mEq / g): carboxyl - 3.23; phenolic - 4.25; carbonyl - 5.01; 2) humic acids isolated from oxidized brown coal of the Baganuursky deposit of the MPR (%): ash content - 2.198; O ^daf - 63.65; H ^daf - 4.93; N ^daf - 1.35; S ^daf - 1.02; O ^daf - 29.05. The content of functional groups (mEq / g): carboxyl - 4.3; phenolic - 3.42; carbonyl - 2.75;

The difference in the group compositions of the proposed binder and prototype is that they have almost the same content of the β fraction (carbenes), but differ in the yields of asphaltenes and maltens. Moreover, the yield of asphaltenes in the proposed binder is 10.4% higher than that of the prototype.

It is known that the sintering ability of binders correlates with the content of £ ₂ and β fractions in them. The increased content of the? -Fraction in the binder contributes to greater shrinkage of the charge during coking. The content of the £ ₂ fraction in the proposed binder is 9.2 wt.%, And the prototype is 8.1-8.2 wt.%.

The heat treatment of the initial heavy brown coal resin of high-speed brown coal pyrolysis consists in heating it in a metal reactor at a rate of 5.7 ° C / min to such a maximum temperature at which the proportion of distillation of liquid light fractions is 3 wt.%.

At the same time, 2.1 wt.% Of vaporous products are also removed from the resin (the total weight loss during heat treatment is 5.1 wt.%). After this treatment, the heating of the reactor is switched off and the resin is discharged through the lower nozzle. The heat-treated brown coal resin has a boiling point of 270 ° C.

The initial humic acids (HA) were isolated by treating finely divided brown coals with 10% NaOH for 2 hours, followed by decantation and centrifugation of sodium humate, followed by acidification with 5% HCl, filtering off the acid precipitate, washing it three times with water and drying at 60 ° C. The yield of HA from the oxidized coals of the Berezovsky deposit reached 82.6 wt.%. The output of HA from the oxidized coals of the Baganuurskoye and Tugrugnuurskoye deposits is 59.5 wt.% And 43.8 wt.%, Respectively.

For coking, a charge was used that was previously tested on an industrial scale on factory coking ovens (gas coal (G6) - 40%; fat coal (G25) - 30%; coke coal (K) 14-15%; lean sintering coal (OS ) - fifteen%). As claimed, the charges were tested (Table 1), containing in their composition an increase in the amount of coals of grades G, OS, heat-treated HA in the amount of 5-10% of the un briquetted load, consisting of a mixture of 60% carbon briquettes and 40% of the charge. The base shaft was briquetted (G6 - 40%; Ж25 - 30%; K 14-15%; OS - 15%).

An example implementation of the method.

Used in the inventive method, the binder is obtained by mixing the components at 110-115 ° C for 3-5 minutes. The mixture is heated to 30 ° C., The heated binder is introduced into it in the amounts shown in table 1, and pressed on a press at a pressure of 250 kg / cm ² . The briquettes were in the form of cylinders with a diameter of 10 mm and a height of 6 mm. Heat-treated HAs were added to the blends, the compositions of which are given in Table 1, they were thoroughly mixed with the components of the coal charge (Table 1), and placed in a coking chamber. The latter is a chamber with dimensions 10 × 150 × 180 mm, having a top removable lid with a metal tube for removal of chemical coking products and two pockets for thermocouples located along the axis of the chambers. Tightness is ensured by installing asbestos gaskets and tightening the bolts of the flange connection of the cover. The coking chamber is placed in a muffle furnace heated to 950 ° C. After the coke reaches a temperature of 950 ° C along the axis of the chamber, it is aged for another 2 hours. Then the coke is cooled without access of air (a gas outlet pipe is connected to a gas seal). The obtained coke is tested for structural strength according to the method of N.S. Gryaznov (GOST 9521-74). The test results are shown in table 1, from which it can be seen that the use of a modified binder and additives in the mixture of heat-treated HA in an amount of 2-4 wt.% On coked mass gives a positive effect.

The positive effect of the invention is achieved through a combination of a number of factors:

a) the use of a binder component for the preparation of coal briquettes of heat-treated resin high-speed pyrolysis of brown coal;

b) the use of heat-treated low-ash humic acids, previously isolated from brown coal, as a component of the coking charge;

c) exclusion from the composition of the binder deficient medium temperature pitch;

d) the use in coking charges of a high content of gas and low-sintering coals while reducing the amount of fat and coke coals.

The structural strength of the obtained coke is higher than that of the prototype on all compositions of coked partially briquetted blends. Thus, the combination of the claimed methods (modification of the binder and the addition of heat-treated HA) allows to increase the amount of G6 grade non-deficient coals in batch up to 10 wt.%, Reduce the content of Zh25 grade scarce coal in the charge to 16 wt.% (Vary within a wide range the content in the charge coals of grades OS and K14), increase the content of coal grade OS in the mixes (up to 10 wt.%).

Table 1 The compositions of the charges for layer coking (% wt.) And structural strength according to the method of N. S. Gryaznova No. p / p The coal content by brand and binder in coal briquettes,% HA content per total charge,% Structural strength of bulk coke,% G6 W 25 K 14 OS Binder one 40 thirty fifteen fifteen 0 0 84.5 2 40 27 fifteen fifteen 3 2 85.6 3 45 17 fifteen twenty 3 2 86.5 four 45 fifteen fifteen twenty 5 four 89.7 5 fifty 16 fifteen fifteen four four 87.3 6 fifty fourteen 10 twenty 6 four 86.1 7 40 twenty twenty twenty 0 - 78.5 8 40 10 10 thirty 10 four 86.5 9 45 10 10 25 10 four 87.2 10 40 twenty 10 10 10 four 89.8 eleven fifty twenty 10 10 10 four 87.1

According to the prototype, the structural strength of coke is 84.4-86.1%.

Claims (3)

1. A method of preparing for charge coking, including the preparation of a binder by mixing high-temperature coking coal tar tar coking coal mixture, crude anthracene and heat-treated brown coal brown coal high-speed pyrolysis resin, processing the charge with a binder in an amount of 3-10 wt.% For partial briquetting of the charge and partially introducing briquetted charge of heat-treated humic acids extracted from brown coals in the amount of 2-4% by weight of the coked coal of the charge and binder. 2. The method according to claim 1, characterized in that for the briquetting of the charge using a binder of the following composition, wt.%: Coal tar - 43; heat-treated brown coal pyrolysis resin - 43; crude anthracene - 14. 3. The method according to claim 1, characterized in that the mixture prepared for coking consists of 40% of the non-briquetted part and 60% of the briquetted part.