A us gas coal participating in coking blending coal

Abstract

This invention discloses a coking blend containing US gas-rich coal, belonging to the field of metallurgical coke preparation technology. The blend consists of the following individual coking coals in the following mass percentages: US gas-rich coal 2%–8%, coking coal 40%–45%, coking coal 16%–21%, 1 / 3 coking coal 20%–25%, and lean coal 7%–14%. The blend has a caking index (G) of 77–83, a maximum plastic layer thickness (Y) of 14 mm–19 mm, and a volatile matter (Vdaf) of 27%–30%. The US gas-rich coal has a volatile matter (Vdaf) of 40%–43%, a caking index (G) greater than 95, a plastic layer thickness (Y) greater than 20, and a maximum vitrinite reflectance of 0.75–0.85. This invention utilizes a specific proportion of US gas-rich coal to replace part of the high-priced prime coking coal and coking coal. Without the need for tamping or briquetting processes, the coke cake is produced through high-temperature dry distillation in a 7.1-meter top-loading coke oven, with the center temperature controlled at 1000±50℃. The resulting coke exhibits stable and compliant cold and hot strength indicators, which can reduce coal blending costs and diversify coal blending resources, thus ensuring supply chain security.

Description

Technical Field

[0001] This invention relates to the field of coking coal blending technology involving US gas-rich coal, specifically to a coking coal blending technology involving US gas-rich coal. Background Technology

[0002] Coking is a crucial upstream process in the steel industry. Its core objective is to convert a blend of various single types of coal, prepared in specific proportions, into high-quality coke that meets the requirements of blast furnace smelting through high-temperature dry distillation in a coke oven. In the blast furnace, coke serves as fuel, reducing agent, and the structural support for the burden column. Its cold strength, hot strength, and reactivity directly affect the smooth operation of the blast furnace, energy consumption, and the quality of pig iron. Therefore, the design of the blended coal formulation is the core of coking technology.

[0003] Currently, the coking industry generally faces the following challenges in terms of coal blending structure: (1) Traditional high-quality coking coal, especially strong caking prime coking coal and fat coal, is an indispensable component for the production of high-strength coke. However, these resources are unevenly distributed globally. With long-term high-intensity mining, the reserves of high-quality coking coal in China have decreased sharply and prices have continued to rise, which has seriously restricted the cost control and supply chain security of steel enterprises.

[0004] (2) For a long time, coal blending schemes have relied heavily on prime coking coal and fat coal from specific production areas as the main components. This single-source resource dependence model is not only uneconomical, but also has weak risk resistance. Once the supply or transportation in the main production areas fluctuates, it will directly affect the stability of production.

[0005] (3) To make up for the resource gap, my country imports a large amount of coking coal every year, with the United States, Canada, Russia, and Mongolia being the main sources. However, the current application of these imported coals is mostly limited to simple substitution or supplementation, lacking in-depth research on their coal quality characteristics and systematic coal blending optimization. For example, the United States has a wealth of gas-rich coal resources with strong caking properties and low ash content. This type of coal has both good fluidity and caking ability, and theoretically is a coking coal component with great potential. However, in practical applications, if it is directly and in large quantities replaced by traditional prime coking coal, it often leads to problems such as unstable coke quality (especially CSR) and increased difficulty in coke oven operation, which limits its large-scale and efficient application. Summary of the Invention

[0006] (a) Technical problems to be solved

[0007] The technical problem to be solved by this invention is to provide a new coking coal blending system with US gas-rich coal as the core functional component, so as to achieve stable and controllable coke quality and significant optimization of coal blending costs.

[0008] (II) Technical Solution

[0009] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows: a coking blend containing US gas-rich coal, comprising the following mass percentages of individual coking coals: 2%–8% coking blend containing US gas-rich coal; 40%–45% coking coal; and one type of US gas-rich coal. The coking coal blends involved include: 16%–21% coking coal (containing US gas-rich coal); 20%–25% coking coal (containing US gas-rich coal); and 7%–14% lean coal (containing US gas-rich coal).

[0010] As an improvement, the caking index G of the blended coal is 77-83, the maximum thickness Y of the plastic layer is 14mm-19mm, and the volatile matter Vdaf is 27%-30%.

[0011] As an improvement, the coal quality characteristics of the US gas-rich coal are as follows: volatile matter (Vdaf) between 40% and 43%, caking index (G) greater than 95, plastic layer thickness (Y) greater than 20, and maximum vitrinite reflectance between 0.75 and 0.85.

[0012] A method for coking using the aforementioned coking blend coal, characterized by the following steps: A coking blend coal containing US gas-rich coal is prepared by inspecting each individual coking coal, proportioning them according to the stated mass percentage, mixing them evenly, and then pulverizing them to obtain the blend coal; the blend coal is then loaded into the coking oven carbonization chamber via a coal loading car for high-temperature dry distillation coking, wherein the coke cake center temperature is controlled at 1000±50℃.

[0013] As an improvement, the coke oven carbonization chamber is a 7.1-meter top-loading coke oven carbonization chamber.

[0014] As an improvement, the coking process employs dry quenching.

[0015] (III) Beneficial Effects

[0016] The advantages of this invention compared to the prior art are: (1) The relatively low-priced US gas-rich coal has successfully replaced some of the high-priced domestic coking coal and fat coal, which can reduce the cost of coal blending by 10 to 30 yuan / ton. This has fundamentally changed the situation of over-reliance on a few high-quality domestic coal types, and built a diversified and flexible supply system of "domestic high-quality coal + imported functional coal", which has enhanced the company's ability to cope with market fluctuations, policy regulation and natural risks.

[0017] (2) This invention can directly coke without the need for processes such as compaction and coal briquetting, while ensuring that the quality of the produced coke meets the requirements of industrial production such as blast furnace ironmaking. This reduces production costs and provides an economical, efficient, stable and reliable coking solution for the coking industry. Detailed Implementation

[0018] The technical solution of the present invention will be further described in detail below with reference to specific embodiments.

[0019] Example 1

[0020] A coking coal blend has a caking index (G) of 77–83, a maximum plastic layer thickness (Y) of 14 mm–19 mm, and a volatile matter (Vdaf) of 27%–30%. It is composed of the following individual coking coals by mass percentage: 45% coking coal, 21% fat coal, 4% US gas-rich fat coal, 23% 1 / 3 coking coal, and 7% lean coal.

[0021] Each type of coking coal was tested, and the qualified coking coal was sent to the hopper for later use. According to the coal blending plan, the corresponding amount of each type of coking coal was first taken from the hopper, then mixed evenly in the blending trough, and then crushed by a crusher before being transported to the coal tower for storage. The blended coal in the coal tower was then transported to the carbonization chamber of a 7.1-meter top-loading coke oven via a coal loading car for high-temperature dry distillation and coking. The center temperature of the coke cake was controlled at 1000±50℃. The blended coal underwent thermal decomposition and coking processes to become coke, which was then dry-quenched.

[0022] The quality indicators of the coke obtained in this embodiment are as follows: crush resistance strength M40 is 90.8%, abrasion resistance strength M10 is 4.3%, coke reactivity CRI is 20.2%, and post-reaction strength CSR is 71.7%.

[0023] Example 2

[0024] A coking coal blend has a caking index (G) of 77–83, a maximum plastic layer thickness (Y) of 14 mm–19 mm, and a volatile matter (Vdaf) of 27%–30%. It is composed of the following individual coking coals by mass percentage: 43% coking coal, 16% fat coal, 6% US gas-rich fat coal, 23% 1 / 3 coking coal, and 12% lean coal.

[0025] The preparation method is the same as in Example 1.

[0026] The quality indicators of the coke obtained in this embodiment are as follows: crush resistance strength M40 is 90.1%, abrasion resistance strength M10 is 5.1%, coke reactivity CRI is 20.3%, and post-reaction strength CSR is 71.3%.

[0027] Example 3

[0028] A coking coal blend has a caking index (G) of 77–83, a maximum plastic layer thickness (Y) of 14 mm–19 mm, and a volatile matter (Vdaf) of 27%–30%. It is composed of the following individual coking coals by mass percentage: 40% coking coal, 16% fat coal, 8% US gas-rich fat coal, 23% 1 / 3 coking coal, and 13% lean coal.

[0029] The preparation method is the same as in Example 1.

[0030] The quality indicators of the coke obtained in this embodiment are as follows: crush resistance strength M40 is 89.3%, abrasion resistance strength M10 is 5.6%, coke reactivity CRI is 20.6%, and post-reaction strength CSR is 71.7%.

[0031] As can be seen from Examples 1 to 3, as the proportion of high-priced coking coal and fat coal gradually decreases, while the proportion of low-priced US gas-rich fat coal and lean coal gradually increases, the coal blending cost is significantly reduced. Meanwhile, the cold strength indices M40 and M10, and the hot strength indices CRI and CSR of the resulting coke remain within the acceptable range, indicating stable coke quality. This demonstrates that the technical solution of this invention can effectively reduce dependence on high-quality prime coking coal and fat coal while ensuring that the coke quality meets the requirements of industrial production, thereby significantly optimizing coal blending costs.

[0032] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A coking coal blend containing US gas-rich coal, characterized in that, It consists of the following percentages of individual coking coals by mass: 2%–8% U.S. gas-rich coal; 40%–45% coking coal; 16%–21% fat coal; 20%–25% 1 / 3 coking coal; and 7%–14% lean coal.

2. The coking coal blend containing US gas-rich coal as described in claim 1, characterized in that, The blended coal has a caking index G of 77-83, a maximum plastic layer thickness Y of 14mm-19mm, and a volatile matter Vdaf of 27%-30%.

3. The coking coal blend containing US gas-rich coal as described in claim 1, characterized in that, The coal quality characteristics of the aforementioned US gas-rich coal are as follows: volatile matter (Vdaf) between 40% and 43%, caking index (G) greater than 95, plastic layer thickness (Y) greater than 20, and maximum vitrinite reflectance between 0.75 and 0.

85.

4. A method for coking using the coking coal according to any one of claims 1 to 3, characterized in that, The process includes the following steps: each type of coking coal is inspected, proportioned according to the stated mass percentage, and then pulverized to obtain a blended coal; the blended coal is loaded into the coke oven carbonization chamber via a coal loading car for high-temperature dry distillation and coking, wherein the center temperature of the coke cake is controlled at 1000±50℃.

5. The coking coal blend containing US gas-rich coal as described in claim 4, characterized in that, The coke oven carbonization chamber is a 7.1-meter top-loading coke oven carbonization chamber.

6. The coking coal blend containing US gas-rich coal as described in claim 4, characterized in that, The coking process employs dry quenching.