A primary metallurgical coke with zero addition of main coking coal and a preparation method thereof

Abstract

The application discloses a kind of zero addition main focus coal primary metallurgical coke and its preparation method, it is related to coal processing technical field.Primary metallurgical coke includes hydrogen donor and compound coal, compound coal is composed of 20wt%-50wt% lean coal and the rest coking coal, hydrogen donor includes the following weight parts components: 40 parts-60 parts tetrahydro naphthalene;20 parts-30 parts hydrogenated anthracene oil;2 parts-10 parts B 10 C3.By adding hydrogen donor, a large amount of free hydrogen can be provided in the plastic stage of high-volatility coking coal. The free radical fragments formed in the plastic stage of coking coal can still be stabilized in a large amount at the temperature of a large amount of pyrolysis and decomposition of lean coal, so that the plastic stage can be maintained for a long time, and finally the hot and cold strength of coke is significantly improved, so that it reaches the national first-class metallurgical coke standard. Moreover, the resource advantage of high-volatility coking coal can be fully utilized to promote the sustainable development of high-efficiency and low-cost coking industry.

Description

Technical Field

[0001] This invention relates to the field of coal processing technology, and in particular to a primary metallurgical coke of coking coal with zero additives and its preparation method. Background Technology

[0002] The functions of coke in blast furnace are as follows: (1) providing most of the heat required for blast furnace smelting; (2) providing the reducing agent required for blast furnace smelting; (3) coke is the skeleton of the blast furnace burden. In the lower part of the blast furnace, the ore and flux have all softened, slag-forming, and melted into liquid. Coke is the only material in the furnace that exists in solid form. It is the skeleton that supports the burden and also a highly permeable passage through which the gas generated in front of the tuyeres can flow smoothly from bottom to top; (4) the carbon source for carburization during the formation of pig iron. Among the above four functions, the role of coke as the burden is irreplaceable. Therefore, it is necessary to ensure that coke still has high strength at high temperatures in order to meet the stable production of the blast furnace. Usually, the composition of the coking coal determines the quality of coke and affects its reactivity and hot strength. In order to meet the needs of the current large-scale blast furnace, more than 50% of prime coking coal (fat coal and coking coal) is usually added in the coke production process to produce high-quality metallurgical coke with a post-reaction strength (CSR) greater than 55%. However, coking coal and coking coal in China are not only scarce, but also generally have high ash and sulfur content. In fact, the content of high-quality coking coal and coking coal accounts for only 3% and 6% of the coking coal reserves, respectively. Relying solely on domestically supplied high-quality primary coking coal to produce first-grade metallurgical coke is insufficient to sustain the sustainable development of the coking industry. At the same time, due to factors such as the international trade war, the import volume of high-quality primary coking coal has also been restricted, which has driven up the price of first-grade metallurgical coke in China and is not conducive to the sustainable development of the steel industry.

[0003] High-volatile gas coal, gas-rich coal, and 1 / 3 coking coal typically have low sulfur and ash content, with resource reserves approximately 55% of coking coal reserves. Their prices are significantly lower than prime coking coal, and they all form a considerable amount of plastic mass during coking. While lean coal with a higher degree of metamorphism forms less plastic mass during coking, its higher aromatic content makes it a good supporting coal for the coke skeleton. Generally, coke produced solely from high-volatile coking coal blended with lean coal is of poor quality, characterized by loose coke lumps, numerous pores, low mechanical strength, high reactivity, and low post-reaction strength, with a CSR of only around 40%, failing to meet the requirements of first-grade metallurgical coke. This is because high-volatile coking coal has a lower degree of metamorphism, with higher aliphatic and oxygen-containing functional group content. These groups rapidly decompose during the lower-temperature plasticization stage of carbonization, forming a large amount of liquid phase. For lean coal, due to its higher degree of metamorphism, the temperature at which the plasticization stage is formed during carbonization is significantly higher than that of high-volatile coking coal, and the resulting liquid phase is also higher. Therefore, when these two types of coal are directly blended without the addition of prime coking coal for coking, on the one hand, the liquid phase formed in the plastic stage of high-volatile coking coal will undergo violent condensation and cross-linking due to a lack of sufficient freely moving hydrogen, generating stable small-molecule solid substances and reducing the stabilization time of the colloid. On the other hand, lean coal has not yet had time to decompose in large quantities at the temperature corresponding to the plastic stage of high-volatile coking coal, and exists mostly as large-particle solid substances, which will increase the viscosity of the liquid phase formed in the plastic stage of high-volatile coking coal, which is not conducive to the growth of the mesophase. Under the combined influence of these two factors, the anisotropy of the microstructure of the produced coke will be low, resulting in poor coke quality.

[0004] In summary, exploring and developing methods for producing first-grade metallurgical coke from primary coking coal with zero additives is of great significance and can effectively solve the current problem of the scarcity of primary coking coal in China. Summary of the Invention

[0005] This invention provides a method for producing primary metallurgical coke from coking coal with zero additives and its preparation. It also develops a hydrogen donor capable of providing freely moving hydrogen to produce primary metallurgical coke from coking coal with zero additives, thereby reducing the price of primary metallurgical coke in China and promoting the sustainable development of the steel industry.

[0006] To address the aforementioned technical problems, one objective of this invention is to provide a hydrogen donor comprising the following components by weight: 40-60 parts of tetrahydronaphthalene; 20-30 parts of hydrogenated anthracene oil; and 2-10 parts of B... 10 C3.

[0007] As a preferred embodiment, it also includes 10 to 30 parts by weight of tetrahydrofuran.

[0008] As a preferred embodiment, it also includes 2 to 10 parts by weight of AlCl3.

[0009] To address the aforementioned technical problems, a second objective of this invention is to provide a primary metallurgical coke with zero additives, comprising a hydrogen donor and a blended coal, wherein the blended coal consists of 20wt%-50wt% lean coal and the remainder coking coal.

[0010] By adopting the above scheme, this application can provide a large amount of free-moving hydrogen in the plastic stage of high-volatile coking coal by adding a hydrogen donor. The free radical fragments formed in the plastic stage of coking coal can still be stabilized in large quantities at the temperature of large-scale pyrolysis and decomposition of lean coal, so as to ensure that its plastic stage can be maintained for a long time. Ultimately, it significantly improves the hot and cold strength of coke, enabling it to meet the national first-class metallurgical coke standard. Moreover, it can fully utilize the resource advantages of high-volatile coking coal and promote the efficient and low-cost sustainable development of the coking industry.

[0011] As a preferred embodiment, the mass fraction of the hydrogen donor added is 0.5wt%-10wt%.

[0012] As a preferred embodiment, the coking coal includes one or more of gas coal, gas-rich coal, and 1 / 3 coking coal.

[0013] As a preferred embodiment, the compounded coal is composed of gas coal or gas-rich coal, 1 / 3 coking coal, and lean coal in a mass ratio of 25:45:30.

[0014] As a preferred embodiment, the content of lean coal in the compound coal is 30wt%-50wt%, and the hydrogen donor also includes 2-10 parts by weight of AlCl3.

[0015] By adopting the above scheme, AlCl3 can promote the transport and transfer of free-moving hydrogen. When a large proportion of lean coal is added, the viscosity of the plastic body is relatively high. It is necessary to add AlCl3 to accelerate the thermal decomposition of lean coal, so that the thermal decomposition temperature of lean coal is advanced, improves the fluidity of the plastic body in the blended coal, promotes the efficient transfer of free-moving hydrogen, and ensures that its plastic stage can be maintained for a longer time, thereby improving the quality of coking coal.

[0016] As a preferred embodiment, the content of lean coal in the compounded coal is 20wt%-29wt%, and the hydrogen donor also includes 10-30 parts by weight of tetrahydrofuran.

[0017] By adopting the above scheme, tetrahydrofuran can thermally decompose at about 250°C to produce free-moving hydrogen, which can be used to stabilize the large number of free radical fragments that are formed prematurely when a large proportion of high-volatile coking coal is added, thereby promoting the directional arrangement of the mesophase to ensure that its plastic stage can be maintained for a longer time and improve the quality of coking coal.

[0018] To address the aforementioned technical problems, the third objective of this invention is to provide a method for preparing primary metallurgical coke from coking coal with zero additives, comprising the following steps: adding a hydrogen-donating agent to the blended coal and then producing coke in a coking oven using a conventional tamping coking method.

[0019] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0020] 1. This application, by adding a hydrogen donor, can provide a large amount of freely moving hydrogen during the plastic stage of high-volatile coking coal. The free radical fragments formed during the plastic stage of coking coal can remain largely stable even at the temperature of large-scale pyrolysis and decomposition of lean coal, thus ensuring that the plastic stage can be maintained for a longer period of time. Ultimately, this significantly improves the hot and cold strength of coke, enabling it to meet the national first-class metallurgical coke standard. Moreover, it can fully leverage the resource advantages of high-volatile coking coal and promote the efficient and low-cost sustainable development of the coking industry.

[0021] 2. This application can not only solve the problem of scarcity of prime coking coal, but also reduce coking costs and produce coke with low sulfur and low ash content, which is beneficial to the use of blast furnaces. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1

[0024] A primary metallurgical coke with zero additives from prime coking coal, comprising a blended coal and 2 wt% hydrogen donor. The blended coal consists of 40 kg of gas coal, 35 kg of 1 / 3 coking coal, and 25 kg of lean coal. The hydrogen donor consists of 60 g of tetrahydronaphthalene, 30 g of hydrogenated anthracene oil, and 10 g of B. 10 C3; after the hydrogen donor is evenly mixed with the compound coal, it is co-carbonized and coked using the conventional tamping coking method.

[0025] Example 2

[0026] A primary metallurgical coke with zero additives from prime coking coal, comprising a blended coal and 3 wt% hydrogen donor. The blended coal consists of 40 kg of gas-rich coal, 30 kg of 1 / 3 coking coal, and 30 kg of lean coal. The hydrogen donor consists of 55 g of tetrahydronaphthalene, 30 g of hydrogenated anthracene oil, 5 g of AlCl3, and 10 g of B. 10 C3; after the hydrogen donor is evenly mixed with the compound coal, it is co-carbonized and coked using the conventional tamping coking method.

[0027] Example 3

[0028] A primary metallurgical coke with zero additives from prime coking coal, comprising a blended coal and 5 wt% hydrogen donor. The blended coal comprises 10 kg of gas coal, 20 kg of gas-rich coal, 50 kg of 1 / 3 coking coal, and 20 kg of lean coal. The hydrogen donor comprises 50 g of tetrahydronaphthalene, 25 g of hydrogenated anthracene oil, 20 g of tetrahydrofuran, and 5 g of B. 10 C3; after the hydrogen donor is evenly mixed with the compound coal, it is co-carbonized and coked using the conventional tamping coking method.

[0029] Example 4

[0030] A primary metallurgical coke with zero additives from prime coking coal, comprising a blended coal and 3 wt% hydrogen donor. The blended coal consists of 25 kg of gas coal, 45 kg of 1 / 3 coking coal, and 30 kg of lean coal. The hydrogen donor consists of 55 g of tetrahydronaphthalene, 30 g of hydrogenated anthracene oil, 5 g of AlCl3, and 10 g of B. 10 C3; after the hydrogen donor is evenly mixed with the compound coal, it is co-carbonized and coked using the conventional tamping coking method.

[0031] Example 5

[0032] A primary metallurgical coke with zero additives from prime coking coal, comprising a blended coal and 3 wt% hydrogen donor. The blended coal consists of 25 kg of gas-rich coal, 45 kg of 1 / 3 coking coal, and 30 kg of lean coal. The hydrogen donor consists of 55 g of tetrahydronaphthalene, 30 g of hydrogenated anthracene oil, 5 g of AlCl3, and 10 g of B. 10 C3; after the hydrogen donor is evenly mixed with the compound coal, it is co-carbonized and coked using the conventional tamping coking method.

[0033] Example 6

[0034] A primary metallurgical coke with zero additives from prime coking coal, comprising a blended coal and 0.5 wt% hydrogen donor. The blended coal consists of 40 kg of gas-rich coal, 30 kg of 1 / 3 coking coal, and 30 kg of lean coal. The hydrogen donor consists of 55 g of tetrahydronaphthalene, 30 g of hydrogenated anthracene oil, 5 g of AlCl3, and 10 g of B. 10 C3; after the hydrogen donor is evenly mixed with the compound coal, it is co-carbonized and coked using the conventional tamping coking method.

[0035] Example 7

[0036] A primary metallurgical coke with zero additives from prime coking coal, comprising a blended coal and 10 wt% hydrogen donor. The blended coal consists of 40 kg of gas-rich coal, 30 kg of 1 / 3 coking coal, and 30 kg of lean coal. The hydrogen donor consists of 55 g of tetrahydronaphthalene, 30 g of hydrogenated anthracene oil, 5 g of AlCl3, and 10 g of B. 10 C3; after the hydrogen donor is evenly mixed with the compound coal, it is co-carbonized and coked using the conventional tamping coking method.

[0037] Example 8

[0038] A primary metallurgical coke with zero additives from prime coking coal, comprising a blended coal and 15 wt% hydrogen donor. The blended coal consists of 40 kg of gas-rich coal, 30 kg of 1 / 3 coking coal, and 30 kg of lean coal. The hydrogen donor consists of 55 g of tetrahydronaphthalene, 30 g of hydrogenated anthracene oil, 5 g of AlCl3, and 10 g of B. 10 C3; after the hydrogen donor is evenly mixed with the compound coal, it is co-carbonized and coked using the conventional tamping coking method.

[0039] Example 9

[0040] A primary metallurgical coke with zero additives, comprising a blended coal and 3 wt% hydrogen donor. The blended coal consists of 40 kg of gas-rich coal, 30 kg of 1 / 3 coking coal, and 30 kg of lean coal. The hydrogen donor consists of 55 g of tetrahydronaphthalene, 30 g of hydrogenated anthracene oil, and 10 g of B. 10 C3; after the hydrogen donor is evenly mixed with the compound coal, it is co-carbonized and coked using the conventional tamping coking method.

[0041] Example 10

[0042] A primary metallurgical coke with zero additives, comprising a blended coal and 5 wt% hydrogen donor. The blended coal consists of 10 kg of gas coal, 20 kg of gas-rich coal, 50 kg of 1 / 3 coking coal, and 20 kg of lean coal. The hydrogen donor consists of 50 g of tetrahydronaphthalene, 25 g of hydrogenated anthracene oil, and 5 g of B. 10 C3; after the hydrogen donor is evenly mixed with the compound coal, it is co-carbonized and coked using the conventional tamping coking method.

[0043] Comparative Example 1

[0044] A primary metallurgical coke with zero additives, comprising a blended coal, which includes 40 kg of gas coal, 35 kg of 1 / 3 coking coal, and 25 kg of lean coal. The blended coal is co-carbonized and coked using conventional compaction coking methods.

[0045] Comparative Example 2

[0046] A primary metallurgical coke with zero additives, comprising a blended coal, which includes 40 kg of gas-rich coal, 30 kg of 1 / 3 coking coal, and 30 kg of lean coal. The blended coal is co-carbonized and coked using conventional compaction coking methods.

[0047] Comparative Example 3

[0048] A primary metallurgical coke with zero additives from prime coking coal includes a blended coal, comprising 10 kg of gas coal, 20 kg of gas-rich coal, 50 kg of 1 / 3 coking coal, and 20 kg of lean coal. The blended coal is co-carbonized and coked using conventional compaction coking methods.

[0049] Performance testing

[0050] Currently, the national standard for first-grade metallurgical coke is A. d <12.0%, S t,d <0.6%, M 10 <7.0%, M 25 >92.0%, CRI<30.0%, CSR>55.0%; The method used for the coke quality analysis results involved in the examples and comparative examples in Table 1 of this application is as follows:

[0051] 1. The standard GB / T 1996-2017 for total sulfur analysis of coke is used to detect the sulfur content (S) in coke. t,d );

[0052] 2. The analytical standard GB / T 2001-2013 for coke industry is used to determine the ash content (A) in coke. d );

[0053] 3. The standard GB / T 2006-2008 for mechanical strength analysis of coke is used to test the cold strength (M) of coke. 25 and M 10 );

[0054] 4. The standard GB / T 2286-2017 for analyzing the hot strength of coke is used to test the hot strength (CRI and CSR) of coke.

[0055] Table 1 - Results of coke quality analysis in the embodiments and comparative examples of this application

[0056]

[0057] Based on the performance test results of Examples 1-3 and Comparative Examples 1-3 in Table 1, it can be seen that although the blank coke in Comparative Examples 1-3 has low sulfur and ash content, comparable to hydrogen-donating coke, its hot and cold strength indicators are significantly worse, making it unsuitable for use in 1000m... 3 The above are large and medium-sized blast furnaces. In Examples 1-3 of this application, under the action of the hydrogen-supplying agent, the hot and cold strength of the hydrogen-supplying coke is significantly improved, M 10 Decrease of 5%-7%, M 25 The CRI (Concentration Intake) increased by 16%-17%, the CSR (Concentration Ratio) decreased by 26%-31%, and the CSR (Concentration Satisfaction Rate) increased by 24%-31%. All of these indicators meet the first-grade metallurgical coke standard.

[0058] Based on the performance test results of Examples 2 and 4-5 in Table 1, it can be seen that by limiting the composition and proportion of the blended coal, the quality of coke is further improved after the blended coal is made of gas coal or gas-rich coal, 45% 1 / 3 coking coal, and 30% lean coal in a ratio of 25:45:30.

[0059] Based on the performance test results of Examples 2 and 6-8 in Table 1, it can be seen that when the amount of hydrogen donor added is in the range of 0.5wt%-10wt%, the quality of coke is relatively high. However, if the content of hydrogen donor additive is too high, it will cause excessive development of isotropic structure in coke, significantly reduce the hot strength of coke, and reduce the quality of coke.

[0060] Based on the performance test results of Examples 2 and 9 in Table 1, it can be seen that AlCl3 has the effect of promoting the transport and transfer of free-moving hydrogen. When a large proportion of lean coal is added, the viscosity of the plastic body is relatively high. It is necessary to add AlCl3 to accelerate the thermal decomposition of lean coal, so that the thermal decomposition temperature of lean coal is advanced, improve the fluidity of the plastic body in the blended coal, promote the efficient transfer of free-moving hydrogen, so as to ensure that its plastic stage can be maintained for a longer time and improve the quality of the blended coal.

[0061] Based on the performance test results of Examples 3 and 10 in Table 1, it can be seen that tetrahydrofuran can thermally decompose at about 250°C to produce free-moving hydrogen, which can be used to stabilize the large number of free radical fragments formed prematurely when a large proportion of high-volatile coking coal is added, thereby promoting the directional arrangement of the mesophase to ensure that its plastic stage can be maintained for a longer time and improve the quality of the blended coal.

[0062] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention for those skilled in the art.

Claims

1. A hydrogen donor, characterized in that, Composed of the following components in parts by weight: 40-60 parts of tetrahydronaphthalene; 20-30 parts of hydrogenated anthracene oil; 2-10 parts of B 10 C3; 10-30 parts tetrahydrofuran; 2-10 parts AlCl3.

2. A method for preparing primary metallurgical coke from zero-additive prime coking coal, characterized in that, Includes the following steps: After adding a hydrogen supply agent to the blended coal, coke is produced in a coking oven using a conventional tamping coking method; the hydrogen supply agent is the hydrogen supply agent as described in claim 1, and the blended coal consists of 20wt%-50wt% lean coal and the balance coking coal. The mass fraction of the hydrogen donor added is 0.5wt%-10wt%; The coking coal is one or more of gas coal, gas-rich coal, and 1 / 3 coking coal.

3. The method for preparing primary metallurgical coke from zero-additive prime coking coal as described in claim 2, characterized in that, The blended coal is composed of gas coal or gas-rich coal, 1 / 3 coking coal, and lean coal in a mass ratio of 25:45:

30.

4. The method for preparing primary metallurgical coke from zero-additive prime coking coal as described in claim 2, characterized in that, The content of lean coal in the compounded coal is 30wt%-50wt%.

5. The method for preparing primary metallurgical coke from zero-additive prime coking coal as described in claim 2, characterized in that, The content of lean coal in the compounded coal is 20wt%-29wt%.

Images