Coal blend using Mongolia coking coal and 1 / 3 coking coal as coking main framework coal and coal blending method

Abstract

The invention provides a coal blending method using Mongolian coking coal and 1 / 3 coking coal as coking main framework coal. The coal blending method comprises the following steps: blending the following raw materials in parts by weight: 20-30 parts of Mongolian coking coal, 40-60 parts of 1 / 3 coking coal, 12-25 parts of first auxiliary coal and 5-12 parts of second auxiliary coal; wherein the first auxiliary coal is selected from at least one of anthracite, weakly caking coal and meager lean coal; the second auxiliary coal is selected from fat coal and / or gas coal. The invention also provides the blended coal obtained by the coal blending method and application of the blended coal in coal coking. The obtained coke has good abrasive resistance, crushing strength and post-thermal-reaction strength. According to the invention, coal resources for coking can be expanded, high-quality coking coal resources in China are saved, the coal blending cost is reduced, and the capabilities of reducing cost, increasing benefits and resisting operation risks of enterprises are enhanced.

Description

Technical Field

[0001] The invention relates to the field of coal blending for coking, and in particular to a blended coal and a coal blending method using Mongolian coking coal and 1 / 3 coking coal as main framework coal for coking. Background Art

[0002] In the coal coking industry, the main framework coal for coking is the main type of coal for coking blending. It can also be understood as the coal with the largest consumption among the same types of coal. The industry usually uses at least one of main coking coal, 1 / 3 coking coal, gas coal and fat coal as the main framework coal for coking.

[0003] However, the distribution and characteristics of my country's coal resources present distinct characteristics. According to statistics, coking coal accounts for about 27.65% of my country's total coal reserves, of which high-quality coking coal, especially coking coal with stable indicators, accounts for even less. At the same time, my country's high-quality coking coal is mainly concentrated in Shanxi, Hebei and other places, resulting in most domestic coking enterprises to bear high procurement and transportation costs when refining high-quality coke. In addition, overcapacity and weakening demand in the steel industry have put many coking enterprises under operating pressure.

[0004] In this context, the search for alternative coal types has become a consensus in the coking industry. Mongolia has abundant coking coal resources, and the coking coal it produces is of stable quality and has excellent physical and chemical indicators, especially its high cohesiveness and thick colloid layer, making it a potential high-quality coal type. In addition, the price of imported coking coal in Mongolia is relatively low, and its geographical location is close to my country, so large quantities of imports can be achieved through border ports, and the transportation cost is low.

[0005] On the other hand, domestic 1 / 3 coking coal has relatively large reserves, is widely distributed, and is moderately priced, making it an important resource for coking. Although the mechanical strength of coke produced from 1 / 3 coking coal is insufficient due to its high volatile content, and its reactivity and post-thermal strength (CSR) are unstable, its price advantage cannot be ignored. In recent years, the price trends of Mongolian imported coking coal and domestic 1 / 3 coking coal also reflect this market change. This price trend further highlights the importance and urgency of studying the coking scheme of Mongolian coking coal and my country's 1 / 3 coking coal.

[0006] In summary, combining the complementary advantages of Mongolian coking coal and one-third of my country's coking coal, conducting relevant research and exploring reasonable coal blending and coking schemes are of great significance for saving my country's main coking coal resources, reducing coking costs and enhancing the competitiveness of the coking industry. Summary of the invention

[0007] The purpose of the present invention is to provide an innovative method for coking coal blending, which uses imported Mongolian coking coal and domestic 1 / 3 coking coal as main framework coal for coking.

[0008] Traditionally, when using Mongolian coking coal alone for coal blending, due to its relatively high volatile content and average caking property, it may lead to a decrease in the caking property and coking property of coke, thereby affecting the overall strength of coke, especially the shatter strength. To solve this problem, domestic coking enterprises usually blend in high-quality primary coking coal to balance relevant indicators. However, with the downward trend in the coke market and the continuous increase in the price of high-quality primary coking coal, this traditional method has brought significant cost pressure to coking enterprises.

[0009] To solve the above problems, the present invention proposes a brand-new coal blending strategy: combining Mongolian coking coal with 1 / 3 coking coal with rich domestic reserves, and supplementing with a first auxiliary coal and a second auxiliary coal. This combination can not only effectively control the adverse effects of the high volatile content of Mongolian coking coal and 1 / 3 coking coal on coke quality, but also avoid over-reliance on high-quality primary coking coal, thereby reducing production costs. At the same time, through precise proportioning, the present invention also ensures the stability of coke quality, especially its overall strength and shatter strength.

[0010] Specifically, in the first aspect of the present invention, there is provided a coal blending method using Mongolian coking coal and 1 / 3 coking coal as the main framework coals for coking. The coal blending method is carried out by blending the following raw materials in parts by weight:

[0011] 20 - 30 parts of Mongolian coking coal;

[0012] 40 - 60 parts of 1 / 3 coking coal;

[0013] 12 - 25 parts of a first auxiliary coal;

[0014] 5 - 12 parts of a second auxiliary coal;

[0015] The first auxiliary coal is selected from at least one of weakly caking coal, anthracite, and lean coal;

[0016] The second auxiliary coal is selected from fat coal and / or gas coal.

[0017] Preferably, the Mongolian coking coal has the following parameters: ash content ≤ 12Ad%, volatile content ≤ 24 - 28Vdaf%, sulfur content ≤ 0.7St%, caking index ≥ 70, and plastic layer thickness ≥ 15 mm. More preferably, the particle size D of the Mongolian coking coal 85 ≤ 3 mm.

[0018] Preferably, the 1 / 3 coking coal has the following parameters: ash content ≤ 12Ad%, volatile content of 33 - 35Vdaf%, sulfur content ≤ 0.7 - 0.9St%, caking index of 75 - 85, and plastic layer thickness of 15 - 17 mm. More preferably, the particle size D of the 1 / 3 coking coal 85 ≤ 3 mm.

[0019] Preferably, the first auxiliary coal has the following parameters: for the weakly caking coal, the ash content is 3.5 - 4.5 Ad%, the volatile matter content is 33 - 35 Vdaf%, and the sulfur content is 0.3 - 0.5 St%; for the anthracite, the ash content is 4 - 8 Ad%, the volatile matter content is 8 - 12 Vdaf%, and the sulfur content is 0.3 - 0.5 St%; for the lean and meager coal, the ash content is 9 - 11 Ad%, the volatile matter content is 14 - 16 Vdaf%, and the sulfur content is 0.7 - 0.9 St%.

[0020] More preferably, in the first auxiliary coal, the dosage ratio of the weakly caking coal, anthracite and lean and meager coal is (17 - 20):(2 - 4):(0 - 2). More preferably, the particle size D of the anthracite 90 ≤1 mm, the particle size D of the weakly caking coal 90 ≤1 mm, and the particle size D of the lean and meager coal 85 ≤3 mm.

[0021] Preferably, the second auxiliary coal has the following parameters: for the fat coal, the ash content ≤10 Ad%, the volatile matter content is 30 - 35 Vdaf%, the sulfur content is 2.0 - 3.0 St%, the caking index ≥80, and the plastic layer thickness ≥18 mm; for the gas coal, the ash content ≤6 Ad%, the volatile matter content is 38 - 42 Vdaf%, the sulfur content is 0.25 - 0.5 St%, the caking index ≥80, and the plastic layer thickness ≥10 mm.

[0022] More preferably, in the second auxiliary coal, the dosage ratio of the fat coal and gas coal is (6 - 8):(0 - 4). More preferably, the particle size D of the second auxiliary coal 85 ≤3 mm.

[0023] The second aspect of the present invention provides a blended coal obtained according to the above coal blending method.

[0024] Preferably, the blended coal has the following parameters: the ash content ≤10.0 Ad%, the volatile matter content is 27 - 32 Vdaf%, the sulfur content ≤0.84 St%, the caking index is 70 - 80, and the plastic layer thickness is 10 - 16 mm.

[0025] The third aspect of the present invention provides the use of the blended coal in the production of coke.

[0026] Preferably, the coke obtained by stamp charging coking of the blended coal has the following parameters: the ash content ≤13 Ad%, the volatile matter content is 1.5 - 1.6 Vdaf%, and the sulfur content is 0.6 - 0.7 St%.

[0027] Preferably, the coke obtained by coking the blended coal has good cold properties (crushing strength, abrasion resistance) and hot properties (strength after thermal reaction); among them, the crushing strength value M 40 = 80 - 83%, M 25 = 90 - 92%; the abrasion resistance value M 10 = 6 - 7%; the strength value CSR after thermal reaction = 59 - 63%.

[0028] The beneficial effects of the present invention are as follows:

[0029] (1) In the present invention, only a small amount (or no use at all) of high - value and high - quality coal types (such as prime coking coal, fat coal) is used. Instead, Mongolian coking coal (low - quality imported coking coal) and domestic 1 / 3 coking coal are used as the main framework coals for coking, replacing domestic high - quality prime coking coal, which expands the applicable range of coking coal resources and significantly reduces the dependence on scarce domestic prime coking coal.

[0030] (2) The present invention opens up a new idea for coking coal blending. By successfully using high - volatile Mongolian coking coal and 1 / 3 coking coal, through fine proportioning and the addition of auxiliary coal types, the quality of coke is effectively controlled, ensuring the strength and stability of coke. At the same time, the diversity of the main framework coals for coking is realized, enhancing the production flexibility.

[0031] (3) In the present invention, as much as possible of the first auxiliary coal is incorporated into the blended coal. On the premise of ensuring the stable quality of coke, the goal of cost reduction and efficiency increase is achieved. Taking the purchase price of raw coal for Guoneng Mengxi Coal Coking as an example, the average purchase price of domestic prime coking coal in 2023 was about 2200 yuan, the average purchase price of weakly caking coal was 780 yuan, and the average purchase price of anthracite was 1700 yuan.

[0032] In summary, the present invention not only optimizes the coking coal blending scheme, expands the coking coal resources, reduces the cost, but also ensures the quality of coke, providing strong support for the sustainable development of the coking industry. Specific Embodiments

[0033] The technical solutions and their effects of the present invention are further described below in combination with specific embodiments / examples. The following embodiments / examples are only used to illustrate the content of the present invention, and the invention is not limited to the following embodiments or examples. Simple changes made to the present invention using the concept of the present invention are within the scope of protection required by the present invention.

[0034] The first aspect of the present invention provides a coal blending method using Mongolian coking coal and 1 / 3 coking coal as the main framework coals for coking. The coal blending method is carried out by blending Mongolian coking coal, 1 / 3 coking coal, the first auxiliary coal and the second auxiliary coal as raw materials.

[0035] In the present invention, by weight, the content of the Mongolian coking coal is 20 - 30 parts, for example, it can be 20, 20.5, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 and any value within this range.

[0036] The inventor of the present invention has found that the addition of Mongolian coking coal can effectively reduce the volatile matter of the blended coal and the cost of coal blending, and the coke obtained after coking the blended coal has good structure and strength (such as shatter strength and abrasion strength).

[0037] The inventor of the present invention has found that: in the coking coal blending system, the adjustment of the blending ratio of the Mongolian coking coal and the 1 / 3 coking coal has a significant impact on the quality of the blended coal and the properties of the coke. Specifically, through the analysis of the properties of single coals, it can be known that the volatile matter of the Mongolian coking coal is about 4 - 7 percentage points lower than that of the 1 / 3 coking coal, but the strength after thermal reaction is about 4 - 5 percentage points lower than that of the latter. Those skilled in the art understand that when the volatile matter of the blended coal is high, it has a great impact on the mechanical strength and the strength after thermal reaction of the coke. The amount of gas generated during coking of high-volatile coal increases, resulting in an increase in the porosity inside the coke, a loose structure, and a decrease in shatter strength (M 40 ) and abrasion strength (M 10 ). The carbon structure remaining after coking of high-volatile coal is more active, resulting in an increase in the coke reactivity index (CRI) and a decrease in the strength after thermal reaction (CSR), affecting the permeability and slag erosion resistance of blast furnace ironmaking. When the blending ratio of the Mongolian coking coal (by weight of the blended coal) is increased from 20% to 30%, the blending ratio of the 1 / 3 coking coal in the blended coal needs to be correspondingly reduced. During this process, the G value of the blended coal will decrease by 4 - 5 percentage points, and the Audibert-Arnu dilatation will shrink from 125% to 98%, resulting in a decreasing trend of the strength after thermal reaction of the coke at a rate of 0.8 - 1.2 percentage points / 5% (that is, based on the share of Mongolian coal in the total ratio, for every 5% increase, the strength after thermal reaction of the coke decreases by 0.8 - 1.2 percentage points).

[0038] The inventor of the present invention has also found that when the content of the Mongolian coking coal is too high, it will lead to a decrease in the coke strength, and when the content of the Mongolian coking coal is too low, the volatile matter of the blended coal will be unbalanced, resulting in the need to add high-quality domestic prime coking coal to balance the coke quality.

[0039] In some embodiments, in the Mongolian coking coal, the ash content ≤ 12 Ad%, for example, it can be 11 Ad%, 10 Ad% and 9.5 Ad% and any value within this range.

[0040] In some embodiments, in the Mongolia coking coal, the volatile matter content is 24 - 28 Vdaf%, for example, it can be 28 Vdaf%, 27.5 Vdaf%, 27 Vdaf%, 26.5 Vdaf%, 26 Vdaf%, 25.5 Vdaf%, 25 Vdaf%, 24.5 Vdaf%, 24 Vdaf% and any value within this range.

[0041] In some embodiments, in the Mongolia coking coal, the sulfur content is ≤ 0.7 St%, for example, it can be 0.65 St%, 0.6 St% and 0.55 St%.

[0042] In some embodiments, in the Mongolia coking coal, the caking index is ≥ 70, for example, it can be 72, 75, 78, 79, 80, 81, 82, 83 and 85.

[0043] In some embodiments, in the Mongolia coking coal, the plastic layer thickness is ≥ 15 mm, for example, it can be 15.5 mm, 17 mm, 18 mm, 19.5 mm.

[0044] In some embodiments, before coal blending, the Mongolia coking coal is crushed to a particle size of D 85 ≤ 3 mm, for example, it can be 2.9, 2.8, 2.5, 2.

[0045] In the present invention, by weight, the content of the 1 / 3 coking coal is 40 - 60 parts. For example, it can be 41, 42, 44, 45, 46, 48, 50, 52, 54, 56, 57, 58, 59 and 60 and any value within this range.

[0046] The inventors of the present invention also found that when the content of the 1 / 3 coking coal is too high, the volatile matter of the blended coal will be too high, affecting the mechanical strength and post - thermal reaction strength of the coke. When the content of the 1 / 3 coking coal is too low, the caking index of the blended coal will be directly reduced, resulting in insufficient post - thermal reaction strength of the coke.

[0047] In some embodiments, in the 1 / 3 coking coal, the ash content is ≤ 12 Ad%. Those skilled in the art know that the lower the ash content of the coal used for coking, the more beneficial it is. For example, it can be 10.7 Ad%, 11 Ad%, 11.2 Ad%, 11.5 Ad% and 11.7 Ad%.

[0048] In some embodiments, in the 1 / 3 coking coal, the volatile matter content is 33 - 35 Vdaf%, for example, it can be 33.5 Vdaf%, 34 Vdaf% and 34.5 Vdaf% and any value within this range.

[0049] In some embodiments, in the 1 / 3 coking coal, the sulfur content is ≤0.9St%, preferably 0.7-0.9St%, for example, it can be 0.75St%, 0.8St%, 0.85St%, and any value within this range.

[0050] In some embodiments, in the 1 / 3 coking coal, the caking index is 75-85, for example, it can be 76, 77, 78, 79, 80, 81, 82, 83, and 84, and any value within this range.

[0051] In some embodiments, in the 1 / 3 coking coal, the plastic layer thickness is 15-17mm, for example, it can be 15.5mm, 16mm, and 16.5mm, and any value within this range.

[0052] In some embodiments, the 1 / 3 coking coal is crushed to a particle size of D 85 ≤3mm, for example, it can be 2.9, 2.8, 2.5, 2, and any value within this range.

[0053] In the present invention, the first auxiliary coal is selected from at least one of anthracite, weakly caking coal, and lean coal. By weight, the content of the first auxiliary coal is 12-25 parts. For example, it can be 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, and 24, and any value within this range.

[0054] In some embodiments, the dosage ratio of the weakly caking coal, anthracite, and lean coal can be (17-20):(2-4):(0-2), for example, (17-20):(2-4):(0.1-2), (17-20):(2-4):(1-2), and also for example, 17:4:0, 17:4:1, 17:4:2, 17:3:2, 18:4:0, 18:4:2, 19:4:0, 19:4:2, 20:4:0, 20:4:2, and any ratio within this range.

[0055] The inventors of the present invention found that: when the content of the first auxiliary coal is too high (i.e., exceeding 25% of the total weight of the blended coal), the porosity of the obtained coke will increase from 38.5% to 42.3%, and the decline rate of the post-heat reaction strength value reaches 1.5-2.0 percentage points. Especially under the conditions of the stamping coking process (bulk density ≥0.85t / m 3) For every 1 percentage point increase in the blending ratio of the first auxiliary coal, the post-reaction strength of the coke will be additionally reduced by 0.35 - 0.5 percentage points. At this time, the content of the Mongolian coking coal and 1 / 3 coking coal decreases relatively, and the decrease in the post-thermal reaction strength of the coke is even greater in actual operation. Therefore, generally, without the blending of extremely high-quality primary coking coal, the blending ratio of the first auxiliary coal type generally does not exceed 22%, otherwise it is impossible to ensure the stable qualification of the coke quality. The present invention has stably increased the blending amount of the first auxiliary coal type in actual application and reduced the coal blending cost. However, according to the coal blending coking theory applicable to the present invention, the content of the first auxiliary coal in industrial production needs to be strictly controlled within 25% of the total weight of the blended coal to ensure the quality stability of the coke obtained after coking.

[0056] The inventor also found that: the weakly caking coal has the characteristics of low ash content and low sulfur, the anthracite has the characteristics of low sulfur and low volatility, and the lean coal has the characteristics of slimming. Through the optimized application of the first auxiliary coal type, the volatile content of the blended coal can be reduced, the ash content and sulfur content of the coke produced from the blended coal can be effectively adjusted, and at the same time, the optical texture morphology of the coke obtained by coking can be improved. At the same time, because the price of the first auxiliary coal is relatively low, it can also help to reduce the coal blending cost of coking.

[0057] In some embodiments, in the first auxiliary coal, the ash content of the weakly caking coal is 3.5 - 4.5 Ad%, the volatile content is 33 - 35 Vdaf%, and the sulfur content is 0.3 - 0.5 St%.

[0058] In some embodiments, in the first auxiliary coal, the ash content of the anthracite is 4 - 8 Ad%, the volatile content is 8 - 12 Vdaf%, and the sulfur content is 0.3 - 0.5 St%.

[0059] In some embodiments, in the first auxiliary coal, the ash content of the lean coal is 9 - 11 Ad%, the volatile content is 14 - 16 Vdaf%, and the sulfur content is 0.7 - 0.9 St%.

[0060] Those skilled in the art can understand that both the weakly caking coal and the lean coal in the first auxiliary coal have a certain amount of caking index and plastic layer thickness. However, due to their too low index values (for example, both are less than 1) and the characteristics of the coal type itself, the influence of these two values on the coke strength is almost zero, so they are not considered.

[0061] In some embodiments, the anthracite in the first auxiliary coal is crushed to a particle size of D 90 ≤1 mm before coal blending, and can be, for example, 0.9 mm, 0.8 mm, 0.5 mm, 0.2 mm and any value within this range.

[0062] In some embodiments, the weakly caking coal in the first auxiliary coal is crushed to a particle size of D 90 ≤1 mm before coal blending, and can be, for example, 0.9 mm, 0.8 mm, 0.5 mm, 0.2 mm, and any value within this range.

[0063] In some embodiments, the lean and meager coal in the first auxiliary coal is crushed to a particle size of D 85 ≤3 mm before coal blending, and can be, for example, 2.9 mm, 2.8 mm, 2.5 mm, 2 mm, and any value within this range.

[0064] In the present invention, the second auxiliary coal is selected from fat coal (such as medium-sulfur fat coal, high-sulfur fat coal) and / or gas coal. Preferably, the second auxiliary coal is selected from fat coal. By weight, the content of the second auxiliary coal is 5 - 12 parts. It can be, for example, 6, 7, 8, 9, 10, 10.5, 11, and 11.5, and any value within this range.

[0065] In some embodiments, in the second auxiliary coal, the dosage ratio of fat coal to gas coal can be (6 - 8):(0 - 4), such as 6:0.5, 6:1, 6:2, 6:3, 6:4, 7:0.5, 7:1, 7:2, 7:3, 8:0.5, 8:1, 8:2, 8:3, 8:4, and any ratio within this range.

[0066] In some embodiments, the ash content of the fat coal ≤10 Ad%, the volatile matter content is 30 - 35 Vdaf%, the sulfur content can be 2.0 - 3.0 St%, the caking index ≥80, and the plastic layer thickness ≥18 mm.

[0067] In some embodiments, the ash content of the gas coal ≤6 Ad%, the volatile matter content is 38 - 42 Vdaf%, the sulfur content is 0.25 - 0.5 St%, the caking index ≥80, and the plastic layer thickness ≥10 mm.

[0068] In some embodiments, the second auxiliary coal is crushed to a uniform particle size of D 85 ≤3 mm before coal blending, and can be, for example, 2.9 mm, 2.8 mm, 2.5 mm, 2 mm, and any value within this range.

[0069] The inventors found that the prices of 1 / 3 coking coal, the first auxiliary coal, and the second auxiliary coal are low. When using Mongolian coking coal as the main framework coal for coking, the ratios of 1 / 3 coking coal, the first auxiliary coal, and the second auxiliary coal can be increased, thereby reducing the coal blending cost.

[0070] The inventor also found that although imported Mongolian coking coal and domestic 1 / 3 coking coal have relatively high caking indices and relatively thick plastic layers (as is well-known in the art: the caking index and plastic layer thickness of coking coal are the core indicators for measuring the caking property of coal, directly affecting the coking process and final quality of coke, and are the most direct indicators affecting the mechanical strength and post-reaction strength of coke), their volatile matter contents are relatively high. Those skilled in the art can understand that excessive volatile matter greatly affects the forming and strength indices during subsequent coking. At this time, it is necessary to precisely control the blending amounts of the first auxiliary coal and the second auxiliary coal, and utilize the characteristics of low ash, low sulfur, and low volatile matter of the auxiliary coal types to reduce the influence of the physical and chemical indices and volatile matter of the obtained blended coal on the mechanical strength and post-reaction strength of its coke, and ultimately improve the coke quality. Especially the proportion of fat coal. Fat coal usually has relatively high caking property and plastic layer thickness, and plays a crucial role in enhancing the strength indices of coke. At the same time, one of the main characteristics of gas coal is its relatively high volatile matter content. Blending it with 1 / 3 coking coal and Mongolian coking coal with high volatile matter will further increase the volatile matter content of the blended coal, thereby affecting the coke indices. Therefore, in the present invention, fat coal is more preferred than gas coal.

[0071] In addition, when the raw material indices of imported Mongolian coking coal and domestic 1 / 3 coking coal fluctuate or the coke oven production process fluctuates, resulting in unqualified or greatly fluctuating coke quality, the cold-state properties (such as abrasion resistance strength and shatter resistance strength) and hot-state properties (post-reaction strength) of coke can be effectively stabilized by finely adjusting the first physical and chemical indices (ash content, sulfur content), especially by finely adjusting the blending amount of fat coal in the second auxiliary coal.

[0072] The second aspect of the present invention provides a blended coal obtained according to the above coal blending method.

[0073] In some embodiments, in the blended coal, the ash content ≤ 10.0 Ad%, for example, it can be 9.5 Ad%, 9 Ad%, 8.5 Ad%, 8 Ad% and any value within this range.

[0074] In some embodiments, in the blended coal, the volatile matter content is 27 - 32 Vdaf%, for example, it can be 27.5 Vdaf%, 28 Vdaf%, 28.5 Vdaf%, 29 Vdaf%, 29.5 Vdaf%, 30 Vdaf%, 30.5 Vdaf%, 31 Vdaf% and 31.5 Vdaf% and any value within this range.

[0075] In some embodiments, in the blended coal, the sulfur content ≤ 0.84 Ad%, for example, it can be 0.82 St%, 0.81 St%, 0.80 St%, 0.75 St% and 0.70 St% and any value within this range.

[0076] In some embodiments, in the blended coal, the caking index is 70 - 80, for example, it can be 71, 72, 73, 74, 75, 76, 77, 78, 79, and any value within this range.

[0077] In some embodiments, in the blended coal, the plastic layer thickness is 10 - 16 mm, for example, it can be 10.5 mm, 11 mm, 11.5 mm, 12 mm, 12.5 mm, 13 mm, 13.5 mm, 14 mm, 14.5 mm, 15 mm, 15.5 mm, and any value within this range.

[0078] The third aspect of the present invention provides the use of the blended coal in the production of coke.

[0079] In some embodiments, the blended coal is subjected to stamp charging coking using two common methods in the art, namely a small coke oven and an iron box, and the obtained coke has excellent technical indicators, specifically: the ash content ≤ 13 Ad%, the volatile matter content is 1.5 - 1.6 Vdaf%, and the sulfur content is 0.6 - 0.7 St%. In addition, the obtained coke has excellent shatter strength, abrasion resistance strength, and strength after thermal reaction.

[0080] Those skilled in the art can understand that the shatter strength is an important indicator to measure the quality of coke, reflecting the ability of coke not to break along the cracks or defects of the structure when subjected to impact, and is represented by M 40 value and M 25 value. Among them, the M 40 value refers to the proportion of the oversize material sieved by a 40 - mm sieve finally (i.e., the proportion of the particle size exceeding 40 mm), and the M 25 value represents the proportion of the oversize material sieved by a 25 - mm sieve. In addition, the shatter strength M 40 value and M 25 value are affected by the crack degree of coke.

[0081] In some embodiments, the M 40 value is 80 - 83%, and the M 25 value is 90 - 92%.

[0082] Those skilled in the art can understand that the abrasion resistance strength refers to the ability of coke to resist external friction without generating surface glass to form debris or powder, and is represented by M 10 value. In addition, the abrasion resistance strength M 10 value is affected by the pore structure of coke.

[0083] In some embodiments, the M 10 value is 6 - 7%.

[0084] Those skilled in the art can understand that the post - thermal reaction strength (CSR) refers to the ability of coke to resist fragmentation and abrasion under the action of mechanical force and thermal stress. Among them,

[0085] In some embodiments, the CSR value is 59 - 63%.

[0086] As is well known to those skilled in the art, M 40 value, M 25 value, M 10 value is used to represent the cold - state performance of coke, and CSR is used to represent the hot - state performance of coke.

[0087] The present invention will be further described below through specific examples and comparative examples. Among them,

[0088] The sources and parameters of the raw materials used are as follows:

[0089] The main coking coal is produced in Shanxi and has the following parameters: ash content is 10.65Ad%, sulfur content is 0.77St%, volatile matter content is 23Vdaf%, caking index is 85, plastic layer thickness is 16.5mm, and post - thermal reaction strength is 66.4%;

[0090] The Mongolian coking coal is Mongolian No. 3 main coking coal, produced in the Mongolian region, and the manufacturer is the coal washing plant of Bayannur Company of National Energy Group Coking Company. It has the following parameters: ash content is 12Ad%, sulfur content is 0.7St%, volatile matter content is 27Vdaf%, caking index is 75, and plastic layer thickness is 16mm;

[0091] The 1 / 3 coking coal is produced in Qipanjing, Etuoke Banner, Ordos City, Inner Mongolia, and the manufacturer is the coal washing plant of Qipanjing of National Energy Group Coking Company. It has the following parameters: ash content is 10.5Ad%, sulfur content is 0.8St%, volatile matter content is 34Vdaf%, caking index is 85, and plastic layer thickness is 16mm;

[0092] The first auxiliary coal includes anthracite, weakly caking coal and lean - meager coal. Among them,

[0093] The anthracite is produced in Ningxia and has the following parameters: ash content is 8Ad%, sulfur content is 0.4St%, and volatile matter content is 10Vdaf%;

[0094] The weakly caking coal is produced in Ordos City and has the following parameters: ash content is 4Ad%, sulfur content is 0.4St%, and volatile matter content is 34Vdaf%;

[0095] The lean - meager coal is produced in Shanxi and has the following parameters: ash content is 10.5Ad%, sulfur content is 0.8St%, and volatile matter content is 15Vdaf%;

[0096] The second auxiliary coal includes medium-sulfur fat coal and gas coal, where

[0097] The manufacturer of the medium-sulfur fat coal is Wuhai Energy Company of National Energy Group, and it has the following parameters: ash content is 9Ad%, sulfur content is 2.5St%, volatile matter content is 30Vdaf%, caking index ≥ 80, and plastic layer thickness ≥ 18 mm;

[0098] The manufacturer of the gas coal is Xinjiang Jinxin Coal Preparation Plant, and it has the following parameters: ash content is 4.6Ad%, sulfur content is 0.28St%, volatile matter content is 39.02Vdaf%, caking index is 87, and plastic layer thickness is 11.5 cm;

[0099] The main coking coal, Mongolian coking coal, 1 / 3 coking coal, second auxiliary coal (medium-sulfur fat coal and gas coal), and lean-lean coal are crushed to a particle size D 85 ≤ 3 mm;

[0100] The anthracite and weakly caking coal are crushed to a particle size D 90 ≤ 1 mm.

[0101] Example 1 (IE1)

[0102] Mix the Mongolian coking coal, 1 / 3 coking coal, first auxiliary coal, and second auxiliary coal according to a weight ratio of 22:50:22:6 to obtain blended coal A1; where

[0103] The first auxiliary coal includes weakly caking coal and anthracite, and their weight ratio is 18:4;

[0104] The second auxiliary coal is medium-sulfur fat coal.

[0105] Example 2 (IE2)

[0106] Mix the Mongolian coking coal, 1 / 3 coking coal, first auxiliary coal, and second auxiliary coal according to a weight ratio of 25:47:22:6 to obtain blended coal A2; where

[0107] The first auxiliary coal includes weakly caking coal and anthracite, and their weight ratio is 18:4;

[0108] The second auxiliary coal is medium-sulfur fat coal.

[0109] Example 3 (IE3)

[0110] Mix the Mongolian coking coal, 1 / 3 coking coal, first auxiliary coal, and second auxiliary coal according to a weight ratio of 25:45:24:6 to obtain blended coal A3; where

[0111] The first auxiliary coal includes weakly caking coal, anthracite, and lean coal, and their weight ratio is 18:4:2;

[0112] The second auxiliary coal is medium-sulfur fat coal.

[0113] Example 4 (IE4)

[0114] Mix the Mongolian coking coal, 1 / 3 coking coal, the first auxiliary coal, and the second auxiliary coal according to a weight ratio of 30:40:23:7 to obtain blended coal A4; among them,

[0115] The first auxiliary coal includes weakly caking coal and anthracite, and their weight ratio is 19:4;

[0116] The second auxiliary coal is medium-sulfur fat coal.

[0117] Example 5 (IE5)

[0118] Mix the Mongolian coking coal, 1 / 3 coking coal, the first auxiliary coal, and the second auxiliary coal according to a weight ratio of 29:40:25:6 to obtain blended coal A5; among them,

[0119] The first auxiliary coal includes weakly caking coal, anthracite, and lean coal, and their weight ratio is 19:4:2;

[0120] The second auxiliary coal is medium-sulfur fat coal.

[0121] Example 6 (IE6)

[0122] Mix the Mongolian coking coal, 1 / 3 coking coal, the first auxiliary coal, and the second auxiliary coal according to a weight ratio of 26:40:22:12 to obtain blended coal A6; among them,

[0123] The first auxiliary coal includes weakly caking coal, anthracite, and lean coal, and their weight ratio is 18:4;

[0124] The second auxiliary coal includes medium-sulfur fat coal and gas coal, and their weight ratio is 8:4.

[0125] Comparative Example 1 (CE1)

[0126] Mix the Mongolian coking coal, 1 / 3 coking coal, the first auxiliary coal, and the second auxiliary coal according to a weight ratio of 35:37:22:6 to obtain blended coal A7; among them,

[0127] The first auxiliary coal includes weakly caking coal and anthracite, and their weight ratio is 18:4;

[0128] The second auxiliary coal is medium-sulfur fat coal.

[0129] Comparative Example 2 (CE8)

[0130] Mix the Mongolian coking coal, 1 / 3 coking coal, first auxiliary coal and second auxiliary coal according to a weight ratio of 30:38:26:6 to obtain blended coal A8; wherein,

[0131] The first auxiliary coal includes weakly caking coal, anthracite and lean coal, and their weight ratio is 20:4:2;

[0132] The second auxiliary coal is medium-sulfur fat coal.

[0133] Comparative Example 3 (CE9)

[0134] Mix the prime coking coal, 1 / 3 coking coal, first auxiliary coal and second auxiliary coal according to a weight ratio of 29:40:25:6 to obtain blended coal A9; wherein,

[0135] The first auxiliary coal includes weakly caking coal, anthracite and lean coal, and their weight ratio is 21:4;

[0136] The second auxiliary coal is medium-sulfur fat coal.

[0137] Stamping coking test (small coke oven test and iron box test)

[0138] Sample the blended coals A1 - A9 obtained in Examples 1 - 5 (IE1 - IE5) and Comparative Examples 1 - 3 (CE1 - CE3), and conduct stamping coking tests in two ways: a 40 kg small coke oven and a 40 kg iron box to obtain cokes B1 - B9. Among them, the key process parameters of the 40 kg small coke oven test are as follows: charging at 800 °C, heating and coking for 18 h, soaking for 4 h, and temperature control at 1050 °C; the key process parameters of the 40 kg iron box test are as follows: heating and coking in an industrial stamping coke oven, coking temperature 1050 °C, and coking time 23 h.

[0139] The results of the stamping coking are shown in Table 1 below.

[0140] Table 1:

[0141]

[0142] Note: In Table 1, M 40 refers to the shatter strength of the coke (the proportion of the material on the 40 mm sieve), M 25 refers to the shatter strength of the coke (the proportion of the material on the 25 mm sieve), M 10 refers to the abrasion resistance of the coke, and CSR refers to the strength after the thermal reaction of the coke.

[0143] According to the analysis of the test data in Table 1, the blended coal obtained by using the Mongolia coking coal, 1 / 3 coking coal, the first auxiliary coal and the second auxiliary coal in the present invention is then coked, and the obtained coke has lower sulfur content and volatile content, and at the same time has good crush strength, abrasion strength and strength after thermal reaction. Specifically:

[0144] It can be seen from the comparison between Example 1 and Comparative Example 1 that when the content of Mongolia coking coal in the blended coal is too high, the content of 1 / 3 coking coal is relatively low at this time, which will lead to a decrease in the abrasion strength and strength after thermal reaction of the coke.

[0145] It can be seen from the comparison between Example 3 and Comparative Example 2 that when the content of the first auxiliary coal type exceeds 25% of the total amount of the blended coal, the strength after thermal reaction of the coke decreases significantly. According to the blending principle, the addition of too much non-caking coal type leads to changes in coal melting, and high-quality structured coke cannot be formed after coking.

[0146] It can be seen from the comparison between Example 4 and Example 6 that although the use of gas coal can effectively and stably control the physical and chemical indexes of coke, its too high volatile content will cause great influence on the strength after thermal reaction of coke and the cold state properties such as M 40 value, M 25 value, M 10 value, etc., and it can be used as an alternative coal when the supply of raw coal is abnormal.

[0147] It can be seen from the comparison between Examples 1-6 and Comparative Example 3 that the present invention can realize that the Mongolia coking coal with poor quality indexes can be used to replace the domestic high-quality prime coking coal as the main framework coal, and the obtained coke also has better hot state properties and cold state properties.

Claims

1. A coal blending method using Mongolian coking coal and 1 / 3 coking coal as the main framework coal for coking, characterized in that: The coal blending method uses the following raw materials in parts by weight for blending: Mongolian coking coal 20-30 parts; 1 / 3 coking coal 40-60 parts; 12-25 parts of first auxiliary coal; 5-12 parts of the second auxiliary coal; The first auxiliary coal is selected from at least one of anthracite, weakly caking coal and lean coal; The second auxiliary coal is selected from fat coal and / or gas coal.

2. The coal blending method according to claim 1, characterized in that: In the first auxiliary coal, the ratio of the weakly sticky coal, anthracite and lean coal is (17-20):(2-4):(0-2); and / or In the second auxiliary coal, the usage ratio of fat coal to gas coal is (6-8):(0-4).

3. The coal blending method according to claim 1 or 2, characterized in that: The ash content of the Mongolian coking coal is ≤12Ad%; and / or The volatile matter content of the Mongolian coking coal is ≤24-28Vdaf%; and / or The sulfur content of the Mongolian coking coal is ≤ 0.7 St%; and / or The Mongolian coking coal has a caking index of ≥ 70; and / or The thickness of the colloidal layer of the Mongolian coking coal is ≥15 mm.

4. The coal blending method according to any one of claims 1 to 3, characterized in that: The ash content of the 1 / 3 coking coal is ≤12Ad%; and / or The volatile matter content of the 1 / 3 coking coal is 33-35Vdaf%; and / or The sulfur content of the 1 / 3 coking coal is 0.7-0.9 St%; and / or The caking index of the 1 / 3 coking coal is 75-85; and / or The thickness of the gelatinous layer of the 1 / 3 coking coal is 15-17 mm.

5. The coal blending method according to any one of claims 1 to 4, characterized in that: In the first auxiliary coal, The weakly caking coal has an ash content of 3.5-4.5Ad%, a volatile matter content of 33-35Vdaf%, and a sulfur content of 0.3-0.5St%; and / or The anthracite has an ash content of 4-8Ad%, a volatile content of 8-12Vdaf%, and a sulfur content of 0.3-0.5St%; and / or The lean coal has an ash content of 9-11 Ad%, a volatile matter content of 14-16 Vdaf%, and a sulfur content of 0.7-0.9 St%.

6. The coal blending method according to any one of claims 1 to 5, characterized in that: In the second auxiliary coal, The fat coal has an ash content of ≤10Ad%, a volatile content of 30-35Vdaf%, a sulfur content of 2.0-3.0St%, a bonding index of ≥80, and a gelatinous layer thickness of ≥18mm; and / or The gas coal has an ash content of ≤6Ad%, a volatile content of 38-42Vdaf%, a sulfur content of 0.25-0.5St%, a bonding index of ≥80, and a gelatin layer thickness of ≥10mm.

7. The coal blending method according to any one of claims 1 to 6, characterized in that: The particle size D of the Mongolian coking coal 85 ≤3mm; and / or The particle size D of the 1 / 3 coking coal 85 ≤3mm; and / or The particle size D of the second auxiliary coal 85 ≤3mm.

8. The coal blending method according to any one of claims 1 to 7, characterized in that: In the first auxiliary coal, The particle size D of the anthracite 90 ≤1mm; and / or The particle size D of the weakly caking coal 90 ≤1mm; and / or The particle size D of the lean coal 85 ≤3mm.

9. A blended coal obtained by the coal blending method according to any one of claims 1 to 8; Preferably, the ash content of the blended coal is ≤10.0Ad%; and / or The volatile matter content of the blended coal is 27-32 Vdaf%; and / or The sulfur content of the blended coal is ≤ 0.84 St%; and / or The bonding index of the blended coal is 70-80; and / or The thickness of the colloidal layer of the blended coal is 10-16 mm.

10. Use of the blended coal obtained by the coal blending method according to any one of claims 1 to 7 or the blended coal according to claim 8 or 9 for coking; Preferably, the coke obtained by ramming coking of the blended coal has the following parameters: ash content ≤ 13Ad%, volatile matter content 1.5-1.6Vdaf%, sulfur content 0.6-0.7St%; Preferably, the crushing strength value M of the coke obtained by tamping coking of the blended coal is 40 80-83%, crushing strength value M 25 90-92%, wear resistance value M 10 It is 6-7%, and the strength value CSR after thermal reaction is 59-63%.

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