Problems with coking coal blending

The blending of coals for coking is primarily done by determining the appropriate parameters for the blended coal based on the required quality specifications for coke, such as ash content, sulfur content, G and Y values, reactivity, and strength after reaction. For the parameters of ash content, sulfur content, and volatile matter in the blended coal, these values are additive; they can be calculated from the individual values of each type of coal. However, the GY value is not additive and must be determined through experiments (using empirical data)

Different coke ovens have varying requirements regarding the quality of blended coal; the key parameters are basically those mentioned on the second floor. There are documents on the forum related to the quality of blended coal and coke, as well as predictions for the yield of chemical products – the poster can go and look for them.

The ash content should not exceed 12%, the sulfur content should not be more than 1.0–1.2%, and the moisture content should not be more than 10%. In addition, there are stricter requirements for compaction and briquetting.

Take a look at the references for educational design

This question has been asked many times already. :lol :lol :lol :handshake

What was said on the fifth floor is incorrect; the calculation should be done based on the product requirements and your type of furnace. What was said on the second floor is correct. For example, the calculation of the coal blending ratio for ramming coking is carried out in accordance with the provisions of YB9069-96 \"Technical Specifications for Coking Process Design\". The quality requirements for the coal used in ramming coke ovens are as follows: moisture content (Mt) of 10%–12%, and bonding index G = 55–65. When determining the coal blending ratio, it is necessary to take into account factors such as the quality of each individual coal type, its inventory and supply, the daily coal demand for coke oven production, the quality of the coke, as well as customer requirements, in order to formulate an appropriate coal blending plan. The quality indicators of blended coal mainly refer to its ash content, sulfur content, volatile matter, bonding index, moisture, fineness, etc. It can be calculated based on the quality parameters and proportions of individual coal types, using the principle of \"additivity\". Furthermore, the quality of the laboratory analysis of the blended coal is used to verify the standardization of coal blending operations and management. Factors such as minimizing the cost of coal feedstock while ensuring coke quality should also be taken into consideration. For a certain company, 1/3 of the coal used in slot No. 1 is coking coal (JM); the quality parameters as determined by laboratory analysis are: ash content Ad=8.78%, volatile matter Vdaf=33.70%, and sulfur content Std=0.52% ； G=70. The single coal type in Slot 2 is gas coal (QM); the quality parameters from analytical testing are: ash content Ad=8.65% ； Volatiles Vdaf=37.20% ； Sulfur content Std=0.62% ； G=78. The coal in slot No. 3 is fat coal (FM); the quality parameters as determined by analytical testing are: ash content Ad=9.12% ； Volatiles Vdaf=34.50% ； Sulfur content Std=1.90% ； G=98. The coal in slot No. 4 is poor-quality coal (PSM); the quality parameters from analytical testing are: ash content Ad=9.20% ； Volatiles Vdaf=14.70% ； Sulfur content Std=0.38% ； G=12. Let’s assume the coal blending ratio (%): 1/3JM : QM : FM : PSM = 40:15:20:25. The calculated values for the quality parameters of this blended coal are as follows: G = 70×0.40 + 78×0.15 + 98×0.20 + 12×0.25 = 62; Ad = 8.78×0.4 + 8.65×0.15 + 9.12×0.2 + 9.20×0.25 = 8.93%; Vdaf = 33.70×0.4 + 37.2×0.15 + 34.50×0.20 + 14.70×0.25 = 29.64%; Std = 0.52×0.40 + 0.62×0.15 + 1.90×0.20 + 0.38×0.25 = 0.78%

The principle for formulating coal blends should be to first, based on experiments in small coke ovens, ensure that the blend has sufficient cohesiveness without being too rich in certain components; at the same time, attention must also be paid to the quality issues related to the generation of waste gas

The particle size of coal is also a significant factor; it can certainly be adjusted. Orthogonal experiments can be conducted first, using the formulas mentioned above to determine the optimal ratio. Subsequent tests can then be carried out in smaller experimental coke ovens, with adjustments made until the optimal ratio is achieved – this process requires a great deal of technical expertise

(1) Ensure that the quality of coke meets the requirements； (2) In coke oven production, care should be taken to avoid excessive expansion pressure; sufficient contraction should occur toward the end of coking to prevent difficulties in pushing out the coke and damage to the oven structure ； (3) Make full use of the local coal resources, ensure reasonable transportation, minimize the average distance to coal sources, and reduce production costs ； (4) Where possible, use an appropriate amount more coal with high volatility in order to increase the yield of chemical products ； (5) While ensuring the quality of coke, more weakly caking coals such as gas coal should be used, and high-quality coking coal should be utilized as little as possible, in order to make rational use of China’s coal resources.

Generally, a basic coal blending ratio is determined based on local conditions (geographical location, transportation costs, quality requirements, coal storage areas, etc.), and then adjustments are made according to the amount of coal stored, quality requirements, and cost considerations. Generally, bituminous coal is used less, while coals with high ash and sulfur content and low caking strength are used more often.

One can refer to what others are doing, but the most important thing is to explore, summarize, and develop one’s own set of prediction methods based on the actual conditions of one’s own factory! Try hard! We’ll help you!