Coking coal additive as well as preparation method and application thereof

Abstract

The invention provides a coking coal additive as well as a preparation method and application thereof. The coking coal additive comprises organic extracts of asphalt, titanium dioxide, kaolin, diboron trioxide and lignite. Through research, the coking coal additive provided by the invention is used for coal blending and coking, can be used for improving the strength of coke after reaction, or increasing the ratio of weak caking property or non-coking coal resources, reducing the cost and expanding the coking coal source under the condition that the strength of the coke after reaction is not changed, and has a good popularization and application prospect in the coking industry.

Description

Technical Field

[0001] The invention belongs to the field of iron and steel metallurgy, and in particular relates to a coking coal additive and a preparation method and application thereof. Background Art

[0002] Coke is an indispensable fuel in blast furnace smelting, and the strength of coke after reaction is the most core indicator of coke. In the long-term industry background of large-scale consumption of coking coal, the supply of coking coal resources is becoming increasingly tight and deteriorating. At present, the quality of coke is the key to the stable operation of blast furnaces and the improvement of technical and economic indicators of blast furnace smelting, among which the strength of coke after reaction is the most core. Generally, the quality of coke is determined by the quality of coking coal. If high coke quality is required, it must be supported by a high proportion of high-quality coking coal. High-quality coking coal resources are scarce resources, not only in short supply, but also in high price. Summary of the invention

[0003] In view of this, the object of the present invention is to provide a coking coal additive and its preparation method and application. The coking coal additive can improve the strength of coke after reaction or reduce the cost of coking coal blending.

[0004] To achieve this object, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a coking coal additive comprising asphalt, titanium dioxide, boron trioxide and an organic extract of lignite.

[0005] Preferably, the asphalt is preferably high temperature asphalt. The high temperature asphalt is a special term in this field.

[0006] Preferably, the organic extract of lignite includes any one or more of an acetone extract of lignite, a tetrahydrofuran extract of lignite or a cyclohexanone extract of lignite.

[0007] Preferably, the coking coal additive further comprises an auxiliary agent, which is used to help each component to be mixed evenly, and comprises kaolin and / or diatomaceous earth.

[0008] Preferably, the fineness of the auxiliary agent is ≤0.074 mm.

[0009] Preferably, the coking coal additive comprises, by weight: 30-50 parts of asphalt, 5-10 parts of titanium dioxide, 0-35 parts of auxiliary agent, and 5-10 parts of boron trioxide.

[0010] More preferably, the coking coal additive comprises, by weight: 35-45 parts of asphalt, 5-8 parts of titanium dioxide, 25-30 parts of auxiliary agent, and 5-8 parts of boron trioxide.

[0011] Preferably, based on the total mass of asphalt, titanium dioxide, optional additives and boron trioxide being 100 g, the amount of the organic extract of lignite is 30-50 mL / g.

[0012] More preferably, based on the total mass of asphalt, titanium dioxide, optional additives and boron trioxide being 100 g, the amount of the organic extract of lignite is 35-45 mL / g.

[0013] Preferably, the fineness of the asphalt is ≤2 mm, the fineness of titanium dioxide is ≤0.1 mm, the fineness of boron trioxide is ≤0.2 mm; and the fineness of lignite is ≤0.2 mm.

[0014] In a second aspect, the present invention provides a method for preparing the above-mentioned coking coal additive, comprising the following steps: S1: Evenly mix asphalt, titanium dioxide, optional additives, and boron trioxide to obtain a mixed material; S2: Evenly mix the mixed material and the organic extract of lignite, and dry them to obtain a coking coal additive.

[0015] In a third aspect, the present invention provides an application of the coking coal additive prepared by the above preparation method in coal blending and coking.

[0016] Preferably, the amount of the coking coal additive is 1-25 wt% of the amount of coal blended.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a coking coal additive, which includes asphalt, titanium dioxide, optional auxiliary agents, boron trioxide and an organic extract of lignite. Among them, the asphalt and the organic extract of lignite can play the role of bonding components in coal blending and coking, thereby improving the bonding ability of coking coal, that is, improving its ability to bond itself or added inert substances, improving the quality of coking coal, and having no side effects on coal or coke. Titanium dioxide, boron trioxide and other substances have a passivating effect (negative catalytic effect) on the thermal properties of coke after coal coking, thereby improving the post-reaction strength of coke, reducing the reactivity of coke, and better playing the role of coke in a blast furnace. In addition, the addition of auxiliary agents can make the various components in the coking coal additive better mixed, and better make the additive and coking coal mixed evenly.

[0018] After research, the coking coal additive provided by the present invention is used for coal blending for coking, which can be used to improve the strength of coke after reaction, or to increase the proportion of weakly adhesive or non-coking coal resources without changing the strength of coke after reaction, thereby reducing costs and expanding the source of coking coal. It has good prospects for promotion and application in the coking industry. DETAILED DESCRIPTION

[0019] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] In view of the problem of scarcity and high price of high-quality coking coal resources in the prior art, the present invention provides a coking coal additive that can be added in the coal blending and coking process, comprising asphalt, titanium dioxide, optional auxiliary agents, boron trioxide and an organic extract of lignite.

[0021] In the present invention, the coking coal additive comprises, by weight, 30 to 50 parts of asphalt, preferably 35 to 45 parts. The asphalt of the present invention is preferably high-temperature asphalt, which can provide better adhesion compared to medium-temperature asphalt and low-temperature asphalt, thereby improving the quality of coking coal.

[0022] In the present invention, the coking coal additive includes, by weight, 5 to 10 parts of titanium dioxide, preferably 5 to 8 parts. The presence of titanium dioxide can passivate the thermal properties of coke (negative catalytic effect) when it is used for coking, thereby improving the post-reaction strength of coke, reducing the reactivity of coke, and better playing the role of coke in the blast furnace.

[0023] In the present invention, the coking coal additive comprises, by weight, 5 to 10 parts of diboron trioxide, preferably 5 to 8 parts. The effect of the diboron trioxide is consistent with that of titanium dioxide. By introducing the two into the coking coal additive at the same time, the post-reaction strength of the coke can be synergistically improved.

[0024] In the present invention, the coking coal additive includes 0 to 35 parts (optionally 0 parts) of an additive by weight, preferably 25 to 35 parts, and more preferably 25 to 30 parts. The additive includes kaolin and / or diatomaceous earth. The addition of the additive can make the components in the coking coal additive better mixed, and make the additive and the coking coal better mixed.

[0025] The present invention does not impose any particular limitation on the sources of the above-mentioned asphalt, titanium dioxide, additives and boron trioxide, and they may be common commercial products.

[0026] In some embodiments of the present invention, the fineness of the asphalt is ≤2 mm, preferably ≤1 mm; the fineness of the titanium dioxide is ≤0.1 mm, preferably ≤0.06 mm; the fineness of the boron trioxide is ≤0.2 mm, preferably ≤0.1 mm; the fineness of the additive is ≤0.074 mm, preferably ≤0.070 mm.

[0027] The present invention controls the particle sizes of the asphalt, titanium dioxide, additives and boron trioxide, so that different components can be fully mixed and each component can fully play its own role during coal blending and coking.

[0028] In the present invention, the coking coal additive also includes an organic extract of lignite. Based on the sum of the mass of (high-temperature) asphalt, titanium dioxide, kaolin and boron trioxide being 100 g, the amount of the organic extract of lignite is 30-50 mL / g, preferably 35-45 mL / g.

[0029] Compared with single lignite, the present invention uses an organic solvent to extract lignite to obtain an organic extract of lignite, which is beneficial to the coking property of coal.

[0030] In the present invention, the organic extract of lignite includes any one or more of an acetone extract of lignite, a tetrahydrofuran extract of lignite, and a cyclohexanone extract of lignite, and is preferably an acetone extract of lignite.

[0031] The acetone extract of lignite can be prepared according to a method well known to those skilled in the art, illustratively comprising the following steps: The dried lignite was mixed with acetone in a ratio of 1 g:10 mL and heated in a water bath at 40°C for 2 h. The solid and liquid were then separated by filtration. The resulting liquid phase was heated in a water bath at 60°C to evaporate and remove part of the acetone. The result was the acetone extract of lignite.

[0032] The parameters in the above method can be adjusted according to actual conditions and are not particularly limited in the present invention.

[0033] In the present invention, the lignite is preferably crushed to a size of less than 0.2 mm before extraction, which is beneficial to improving the extraction efficiency.

[0034] The present invention also provides a method for preparing the above coking coal additive, comprising the following steps: S1: Mix solid (high temperature) asphalt, titanium dioxide, optional additives, and boron trioxide in a uniform ratio to obtain a solid mixed material; S2: The solid mixed material and the organic extract of lignite are mixed evenly according to a proportion, and dried to obtain a coking coal additive.

[0035] The drying is preferably carried out in an oven at a temperature not higher than 40°C.

[0036] The present invention also provides an application of the coking coal additive involved in the above technical solution in coal blending and coking.

[0037] The present invention does not limit the method of adding the coking coal additive to the coal blending coke oven, and it can be done in a manner well known to those skilled in the art, such as adding the coal in a coal blending trough, etc. Similarly, the present invention does not limit the method of coking, and it can be done in a manner well known to those skilled in the art.

[0038] According to research, the amount of the coking coal additive is 1-25 wt% of the amount of coal blended, preferably 5-25 wt%, and more preferably 10-25 wt%, which can better improve the strength of coke after reaction.

[0039] In order to further illustrate the present invention, the following examples are used to explain it in detail. The coking production blended coal used in the following examples of the present invention has the following quality indicators after chemical analysis: ash content 9.6%, dry basis volatile matter 22.6%, and bonding index 78. The coking production blended coal is divided into 11 equal parts according to the reduction method, and is used for the benchmark, example 1, example 2, example 3, and example 4, example 5, example 6, example 7, example 8, example 9, and example 10 of the examples.

[0040] The fineness requirements for the following raw materials are as follows: high-temperature asphalt ≤0.1 mm accounts for 60%, titanium dioxide ≤0.06 mm accounts for 70%, kaolin ≤0.074 mm and boron trioxide ≤0.1 mm accounts for 70%.

[0041] Preparation Example 1 - Preparation of acetone extract of lignite The dried lignite was crushed to less than 0.2 mm, and the lignite was mixed with acetone at a ratio of 1 g:10 mL, and heated in a 40°C water bath for 2 h. The solid-liquid separation was then performed by filtration, and the resulting liquid phase was the acetone extract of the lignite.

[0042] Preparation Example 2 - Preparation of coking coal additive Take 35 g, 5 g, 20 g and 5 g of high-temperature asphalt, titanium dioxide, kaolin and boron trioxide respectively and mix them evenly. Then mix the obtained mixture with the acetone extract of lignite obtained in Preparation Example 1 at a ratio of 100 g of the mixture plus 30 mL, dry it and obtain a coking coal additive.

[0043] Preparation Example 3 - Preparation of coking coal additive Take 40 g, 6 g, 25 g and 7 g of high-temperature asphalt, titanium dioxide, kaolin and boron trioxide respectively and mix them evenly. Then mix the obtained mixture with the acetone extract of lignite obtained in Preparation Example 1 at a ratio of 100 g of the mixture plus 35 mL, dry them and obtain a coking coal additive.

[0044] Preparation Example 4 - Preparation of coking coal additive Take 45 g, 8 g, 30 g and 8 g of high-temperature asphalt, titanium dioxide, kaolin and boron trioxide respectively and mix them evenly. Then mix the obtained mixture with the acetone extract of lignite obtained in Preparation Example 1 at a ratio of 100 g of the mixture plus 45 mL, dry them and obtain a coking coal additive.

[0045] Embodiment 1~5 As shown in Table 1, the blended coals of Examples 1 to 5 and the coking coal additive obtained in Preparation Example 2 were mixed, and a single blended coal was set as a benchmark: Table 1 The coking results are shown in Table 2: Table 2 It can be seen from Table 2 that after adding the coal blending additive, the cohesiveness of the coking coal is improved and the post-reaction strength of the coke is significantly improved, so the additive has a significant effect on improving the post-reaction strength of the coke.

[0046] Example 6

[0047] Refer to Example 1, the only difference is that the coking coal additive obtained in Preparation Example 2 is replaced by the coking coal additive obtained in Preparation Example 3 in equal amount, and the other parameters and steps are consistent with Example 1.

[0048] Example 7

[0049] Refer to Example 1, the only difference is that the coking coal additive obtained in Preparation Example 2 is replaced by an equal amount of the coking coal additive obtained in Preparation Example 4, and the other parameters and steps are consistent with Example 1.

[0050] Embodiments 8 to 10 As shown in Table 3, the blended coal, the coking coal additive obtained in Preparation Example 2, and the weakly caking coal were mixed, and a single blended coal was set as a benchmark: Table 3 The coking results are shown in Table 4: Table 4 It can be seen from Table 4 that after adding a large proportion of weakly coking coal and adding a certain amount of coking coal additive, the post-reaction strength of coke has no obvious change, indicating that this coal blending additive can be used to reduce the cost of coking coal blending, expand the source of coking coal, and is conducive to the sustainable development of the coking industry.

[0051] Comparative Examples 1 to 3 The additive components in Preparation Example 3 were adjusted to ① lack of high temperature asphalt, that is, the composition is: 6 g of titanium dioxide, 25 g of kaolin, and 7 g of diboron trioxide; ② lack of titanium dioxide, that is, the composition is: 40 g of high temperature asphalt, 25 g of kaolin, and 7 g of diboron trioxide; ③ lack of diboron trioxide, that is, the composition is: 40 g of high temperature asphalt, 6 g of titanium dioxide, and 25 g of kaolin. Under the condition of the same amount of lignite extract, the grouping is shown in Table 5, and the results are shown in Table 6.

[0052] Table 5 Table 6 It can be seen from Table 6 that although the additive is increased by 8%, the effect of the additive is not obvious or basically ineffective because the added formula lacks a certain effective component of the coking coal additive provided by the present invention.

[0053] In summary, the present invention can achieve the purpose of improving the strength of coke after reaction or increasing the coking efficiency of weakly adhesive coal by adding the coking coal additive to the coking process of blended coal, and has significant direct economic and social benefits.

[0054] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A coking coal additive, characterized in that: Includes bitumen, titanium dioxide, boron trioxide and organic extracts from lignite.

2. The coking coal additive according to claim 1, characterized in that The asphalt is high temperature asphalt; The organic extract of lignite includes any one or more of an acetone extract of lignite, a tetrahydrofuran extract of lignite or a cyclohexanone extract of lignite.

3. The coking coal additive according to claim 1 or 2, characterized in that: The coking coal additive also includes an auxiliary agent, and the auxiliary agent includes kaolin and / or diatomaceous earth; The fineness of the auxiliary agent is ≤0.074 mm.

4. The coking coal additive according to any one of claims 1 to 3, characterized in that The coking coal additive comprises, by weight: 30-50 parts of asphalt, 5-10 parts of titanium dioxide, 0-35 parts of additives, and 5-10 parts of boron trioxide; Wherein, based on the total mass of asphalt, titanium dioxide, optional additives and boron trioxide being 100 g, the amount of the organic extract of lignite is 30-50 mL / g.

5. The coking coal additive according to any one of claims 1 to 4, characterized in that Based on the total mass of asphalt, titanium dioxide, optional additives and boron trioxide being 100 g, the amount of the organic extract of lignite used is 35-45 mL / g.

6. The coking coal additive according to any one of claims 1 to 5, characterized in that The fineness of the lignite is ≤0.2 mm.

7. The coking coal additive according to any one of claims 1 to 6, characterized in that The fineness of the asphalt is ≤2 mm, the fineness of titanium dioxide is ≤0.1 mm, and the fineness of boron trioxide is ≤0.2 mm.

8. A method for preparing a coking coal additive as claimed in any one of claims 1 to 7, characterized in that: The following steps are involved: S1: Evenly mix asphalt, titanium dioxide, optional additives, and boron trioxide to obtain a mixed material; S2: Evenly mix the mixed material and the organic extract of lignite, and dry them to obtain a coking coal additive.

9. Use of the coking coal additive according to any one of claims 1 to 7 or the coking coal additive prepared by the preparation method according to claim 8 in coal blending and coking.

10. The use according to claim 9, characterized in that: The amount of the coking coal additive is 1-25 wt% of the amount of coal blended.

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