KR101742079B1

KR101742079B1 - Mixture for manufacturing cokes and the method thereof

Info

Publication number: KR101742079B1
Application number: KR1020150105106A
Authority: KR
Inventors: 이상만; 김현용; 서영대; 백승열; 이상열
Original assignee: 주식회사 포스코
Priority date: 2015-07-24
Filing date: 2015-07-24
Publication date: 2017-05-31
Also published as: KR20170011809A

Abstract

The mixture for coke production according to the embodiment of the present invention and the method for producing coke using the same according to the present invention are characterized by containing ash by weight of less than 0.35% by weight of iron and less than 0% by weight of less than 0.35% by weight of alkali metal oxide A process of preparing a mixture by mixing raw charcoal and an additive, and a process of charging the mixture into a coke oven to produce a coke to produce a coke, so that the strength of the coke can be easily improved.

Description

TECHNICAL FIELD The present invention relates to a mixture for coke production and a method for manufacturing coke using the same.

The present invention relates to a coke-making mixture and a coke-making method using the same, and more particularly, to a coke-making mixture capable of improving the strength of coke and a coke making method using the same.

Generally, the coke used in the operation of a blast furnace of a steel mill is subjected to various steps in advance. For example, coke is charged into a carbonization chamber of a coke oven in a large amount (about 32 tons) of cokes, heated at a temperature of about 1200 ° C or higher for about 18 hours, extruded and cooled in a separate fire extinguishing facility The process of production.

In recent years, in line with efforts to reduce CO ₂ , which is a green house gas (GHG), the steel industry is also making efforts to reduce CO ₂ emissions. One of them is to reduce the ratio of the reducing agent to the energy source used in the blast furnace by using highly reactive coke with improved reactivity.

The highly reactive coke accelerates the gasification reaction that generates carbon monoxide (CO) in the low temperature region of the blast furnace to lower the temperature of the heat storage zone, thereby increasing the driving force required for reduction represented by the difference between the actual gas concentration and the reduction equilibrium gas concentration It has been reported that the efficiency is increased and the ratio of the reducing agent is decreased.

The gasification reactivity of the highly reactive coke can be improved by the promoter added in the preparation of the highly reactive coke, and accelerators such as alkali and iron series which can be used as the gasification reaction accelerator have been studied.

A highly reactive coke is prepared by spraying a liquid promoter to coke produced in a coke oven or by adding a post-promoter to make a coating film by immersing the coke in a promoter solution and by adding a promoter (alkali oxide, iron oxide) to the coke oven Can be prepared by a pre-accelerator addition method produced in a coke oven. However, when the reactivity of the coke is improved by using the accelerator as described above, the strength of the coke is lowered because locally promoted coke differentiation occurs in a region where the promoter is located in the coke matrix and the promoter activity is affected.

KR 10-1311955B GB 2012-36175A KR 10-1228599B

The present invention provides a coke-making mixture capable of improving the strength of coke and a method for producing coke using the same.

The coke making mixture according to an embodiment of the present invention comprises coking coal containing ash which is present in an amount of greater than 0 wt% to less than 0.35 wt% iron and greater than 0 wt% to 0.35 wt% % &Lt; / RTI > alkaline earth metal oxide.

The alkaline earth metal oxide may contain Ca.

The alkaline earth metal oxide may be CaO.

A method for producing coke according to an embodiment of the present invention comprises preparing a coking coal comprising by weight percent ash content of greater than 0 wt% to less than 0.35 wt% iron and greater than 0 wt% to less than 0.35 wt% alkaline earth metal oxide Mixing the coke oven and the additive to produce a mixture, and charging the mixture into a coke oven to produce a coke.

The alkaline earth metal oxide may include CaO.

The hot strength of the coke may be 63 to 65%.

The mixture for preparing coke and the method for producing coke using the same according to the embodiment of the present invention can suppress the decrease in the strength of coke by controlling the content of metal and metal oxide in the components contained in the ash in the coke.

In particular, the strength of the coke is improved by restricting the content of Fe in the metal contained in the ash and CaO as the alkaline earth metal oxide.

Therefore, it is possible to reduce the amount of high-quality coking coal used, thereby improving the competitiveness of the coke making process and reducing the manufacturing cost.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flowchart showing a method of manufacturing coke according to an embodiment of the present invention; FIG.
Fig. 2 is a process diagram of Fig.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be embodied in various different forms, and it is to be understood that these embodiments are merely illustrative of the principles of the invention and are not intended to limit the scope of the invention to those skilled in the art. It is provided to let you know completely.

A method for manufacturing coke according to an embodiment of the present invention includes preparing a mixture for producing coke, charging the mixture into a coke oven, and producing the coke by dry distillation. The coke making mixture according to an embodiment of the present invention comprises coking coal containing ash, the coking coal being used in an amount of more than 0 wt% to less than 0.35 wt% of iron based on the total weight of the ash and more than 0 wt% % &Lt; / RTI > alkaline earth metal oxide. That is, the method for producing coke according to the embodiment of the present invention comprises the steps of: preparing a coke comprising ash containing 0% by weight to less than 0.35% by weight of iron and an alkaline earth metal oxide, Mixing the mixture to prepare a mixture, and charging the mixture into a coke oven to produce a coke. At this time, the alkaline earth metal oxide may contain Ca, and the Ca-containing alkaline earth metal oxide may be CaO. The hot strength of the cose produced by the above-mentioned production method can exhibit a value of 63 to 65. [

Various factors affecting the strength of coke are known, such as mixing of raw materials, method of carbonizing coking coal, and method of extinguishing produced coke. The Basicity Index (BI), which is the content ratio of the alkali metal oxide contained in the ash (ASH) contained in the coke making mixture, that is, the blend, is the CSR (Coke Strength after Reaction) And is calculated as the content of the following components.

BI (basicity) = (Fe ₂ O ₃ + CaO + MgO + Na ₂ O + K ₂ O) / (Al ₂ O ₃ + SiO ₂ )

These alkali metal oxides act as catalysts in the process of reacting and differentiating iron and coke as transition metals in the blast furnace with carbon dioxide (CO2). As a result, the strength of the basicity (B.I.) and the coke have a correlation in inverse proportion to each other. Therefore, when the compounding coal for coke production is prepared, the basicity is minimized to suppress the strength of the coke.

Also, in order to more accurately predict the correlation with the coke oven strength index (CSR) of the blast furnace in consideration of the reactivity of the alkali metal oxide, the influence of each component of the alkali metal oxide may be separately derived to manage the coke strength.

MBI = (a * Fe ₂ O ₃ + b * CaO + c * MgO + d * Na ₂ O + e * K ₂ O)

Accordingly, if the influence of the coke strength on various alkali metal oxide components can be accurately known, it is possible to know the correlation of the coke strength, which is more compatible with the basicity index used in the past, and a new formulation method for improving the coke strength can be proposed have.

In the examples of the present invention, the influence of the iron oxide and the alkali metal oxide in the various components contained in the coke oven to the strength of the coke was grasped and it was found that it was economically feasible to comply with the existing high- It is possible to derive a blending standard for improving the quality of phosphorus coke.

1 and 2 are flowcharts and process diagrams illustrating a process for producing a coke using a mixture for coke production according to an embodiment of the present invention.

First, in general, the coking coal (coal) essentially contains volatile matter (wt%), ash (wt%) and fixed carbon (wt%) in a predetermined range and depends on the environment in which the coking coal is extrapolated and the type of coking coal Water can be extrapolated. The ash is composed of silicon dioxide (SiO ₂ ), calcium oxide (CaO), magnesium oxide (MgO), magnesium oxide (MgO), and the like. Such as aluminum oxide (Al ₃ O ₃ ), manganese oxide (MnO), titanium dioxide (TiO ₂ ), tritium oxide (Na ₂ O), potassium oxide (K ₂ O), phosphoric acid (P ₂ O ₅ ) Component, and it is preferable that the component constituting the coal acts as a harmful component and is contained in a small amount. Fixed carbon is a major component that induces combustion of coal. It means the amount of carbon except volatile matter, ash and moisture in the raw coal.

Here, in the present invention, coking coal containing iron and alkali metal oxide in an amount of more than 0 wt% to less than 0.35 wt% is selected for the total weight of the ash contained in the coking coal which may contain the above components. That is, among various kinds of coking coal loaded in the yard, iron and alkali metal oxides contained in the ash are selected in the range of the above range (S100). Thereafter, the selected coke is crushed to a size of 10 mm or less from the crusher and stored in the storage hopper. The particle size of the crushed coke is generally 80 to 90% or less and the water content is 7 to 11% so that the particle size is 3 mm or less so that the coke has the characteristics of the coke used in the coke making process. At this time, when the content of iron oxide and alkali metal oxide contained in the coke is in the range of 0.35% by weight or more based on the total weight of the ash, the coke strength is decreased, so that the content of iron and alkali metal oxide is within the range Value.

Next, the coke can be mixed with the additive to facilitate the production of the coke as coke. That is, an additive for improving the cohesiveness of the coke can be mixed with the coke to control the degree of cohesion of the coke used to produce the coke. At this time, various additives capable of imparting cohesion can be used. For example, a vegetable additive or a petroleum additive can be used. The amount of the additive to be used is not limited, but can be suitably used within a range that can realize the effect of improving the reactivity of the coke with respect to the total weight of the mixture for coke production.

The mixture prepared by mixing the coking coal and the additive uniformly is charged into a coke oven (S200), and is dried at a temperature of about 1100 ° C or higher to produce a coke (S300). The resulting coke is heated (S400) to finally complete the coke production (S500).

Hereinafter, the mixture for coke production and the method for producing coke according to the embodiment of the present invention will be described in detail through the examples shown in [Table 1] to [Table 5].

First, in order to understand the effect of the iron oxide and the alkali metal oxide contained in the coke making mixture on the coke, a mixture for preparing coke containing iron and an alkali metal oxide in different contents is made to be as close as possible to the manufacturing conditions of the coke, , That is, a specimen was prepared.

That is, in the following, the sample 1 and the sample 2 are taken as examples, and the preparation of the sample 1 and the sample 2, and the coke making conditions are as follows. The raw coke was prepared so as to have a particle size of 3 mm or less at 85% and a water content of 8%. The coke was sufficiently mixed according to the mixing ratio shown in Table 1, and then charged to a dry basis at a constant loading density of 750 kg / m 3. In the coke test, a heater was installed so that heat is transferred from both walls in the same manner as a commercial coke oven. After the sample 1 and the sample 2 were respectively charged into the test furnace heated to 700 캜, the heating wall temperature was raised to 950 캜 at a heating rate of 2.7 캜 / min. When the oven central temperature reached 1000 캜, Time was maintained and extruded, and the extruded glow coke was extinguished in a fire extinguishing facility under a nitrogen atmosphere.

The cooled coke samples were mixed with each other at an appropriate ratio by particle size, and 200g of the sample was put into a reaction furnace and reacted with CO ₂ at a high temperature (1100 ° C) for 120 minutes. Thereafter, the weight loss of the sample after cooling was measured, and the weight of 10 mm after 600 rotations in the I-type stiffness machine was obtained. The hot strength of the coke sheath (specimen 1 and specimen 2) Respectively. Then, we analyzed the properties of the samples and specimens used in the experiments.

Bullet
Formulation ratio (%) Industrial analysis Sample 1 Sample 2 ASH VM Variable gun A 0 10 7.59 35.26 B 15 5 7.75 33.76 Basic shot C 8 9.95 29.5 D 15 8.43 21.59 E 15 10.33 19.05 F 10 9.34 21.96 G 15 8.01 33.42 H 15 10.94 22.73 I 7 8.18 18.54

In Table 1, VM (Volatile Matter) means volatile content and ASH means batch. In addition, the basic coal refers to coking coal using the same mixing ratio, and the variable carbon refers to coking coal containing different contents of iron oxide and alkali metal oxide. That is, the basic carbon was prepared in the same manner as the raw carbon having the same content of catalyst components (including iron oxide and alkali metal oxide) in the coke.

The carbonaceous material A and the carbonaceous material B contained ash (ASH) in an amount of about 7 to 8 wt% (7.59 wt%, 7.75 wt%) based on the total weight of the raw material coke. Industrial analysis of the coke according to the blending ratio of each coking coal, And the composition results are shown in Table 2 below.

Bullet Component analysis (wt%) TS C H N A 0.72 85.73 5.52 2.78 B 0.55 85.18 5.53 2.85

Bullet Industrial analysis (wt%) Batch analysis (wt% in ASH) ASH Fe ₂ O ₃ CaO Na ₂ O K ₂ O A 7.78 10.79 12.19 0.79 0.94 B 7.45 7.89 6.61 1.62 1.97

Table 2 and Table 3 show that the carbonaceous material A and the carbonaceous material B have different amounts of ash contained in the coke-making blend, but the amount of iron (Fe) or alkali metal (Na, K) oxide Or alkaline earth metal (Ca) oxide. That is, it can be seen that the content of Fe and Ca in the carbonaceous material A is larger than that of the carbonaceous material B, and the content of Na and K in the carbonaceous material B is larger than that of the carbonaceous material A.

The C, H, N, and S elements in the specimen 1 and the specimen 2 made of the specimen 1 and the specimen 2, the specimen 1 and the specimen 2 produced by mixing the above-mentioned carbonaceous material A and the carbonaceous material B in the blending ratios shown in Table 1 The contents, volatile matter, ash content and compositional analysis results are shown in Tables 4 and 5 below.

T-Fe CaO Sample 1 0.347 0.346 Sample 2 0.367 0.377

division Ash content Batch analysis (wt% in ASH) T-Fe CaO Na ₂ O K ₂ O Psalm 1 11.8 2.95 2.94 0.81 1.06 Psalm 2 12.0 3.06 3.14 0.73 0.99

As shown in Table 4, the contents of T-Fe and CaO in the sample 1 and the sample 2 in which the carbonaceous material A and the carbonaceous material B were mixed at different mixing ratios were examined. As a result, the sample 1 was found to contain the T- And CaO content, and sample 2 contains T-Fe and CaO content values exceeding 0.35.

This is because, as shown in Table 5, when the ash analysis results of the specimen were examined, the ash contents in Specimen 1 and Specimen 2 are respectively 11.8% by weight and 12.0% by weight and 0.2% by weight, respectively. However, the ash content of ash was higher than that of sample 1 in Fe ₂ O ₃ and CaO contents of sample 2, which was 10% more mixed with Fe ₂ O ₃ and CaO. On the other hand, it can be seen that the specimen 1 containing 15% of the carbonaceous material B contains a larger amount of Na ₂ O and K ₂ O than the specimen 2.

division Coke Hot Strength (CSR) Psalm 1 63.19 Psalm 2 61.69

Therefore, as shown in Table 5, the hot strength of the specimen 1 and the specimen 2 was determined as follows. As described above, 200 g of the fired sample was charged into the reaction furnace and reacted with CO2 for 120 minutes at high temperature. The weight (Y) of the sample 10 mm or more after 600 rotations in the I-type stiffness machine was measured and the hot strength was measured as a percentage of the weight (X) after the reaction. At this time, it can be confirmed that the hot strength value of the test piece 1 is 1.5 higher than the hot strength value of the test piece 2. This is because the content of Fe and CaO contained in the sample 1 is smaller than the content of Fe and CaO contained in the sample 2. That is, according to the result of the hot strength of the specimen 1 and the specimen 2, it can be understood that Fe and Ca contained in the specimen are more affected by reducing the hot strength of the specimen than components such as Na and K. Therefore, it can be seen that the hot strength of the specimen can be sufficiently controlled by controlling only the contents of Fe and Ca components in the specimen.

As described above, according to the coke making mixture and the coke making method using the same according to the embodiment of the present invention, the content of T-Fe and CaO in the coke contained in the coke making up the coke making mixture can be adjusted, Can be increased. That is, by adjusting the amounts of T-Fe and CaO to be added in an amount of more than 0 wt% to less than 0.35 wt% based on the total amount of the ash contained in the coking coal, a coke having a high hot strength can be obtained even by using a similar carbonaceous material.

Claims

As a mixture for producing coke,
A coking coal containing ash,
Wherein the ash comprises greater than 0 wt% to less than 0.35 wt% iron and greater than 0 wt% to less than 0.35 wt% alkaline earth metal oxide, based on the total weight of the ash,
The alkaline earth metal oxide is CaO Mixtures for the production of coke.

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Preparing a coking coal containing ash;
Preparing a mixture by mixing the coke and the additive; And
Charging the mixture into a coke oven to produce a coke;
In preparing the coke containing the ash,
Wherein the ash comprises greater than 0 wt% to less than 0.35 wt% iron and greater than 0 wt% to less than 0.35 wt% alkaline earth metal oxide, based on the total weight of the ash,
The alkaline earth metal oxide is CaO Method of manufacturing coke.

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The method of claim 4,
Wherein the hot strength of the coke is 63 to 65%.