Blast Furnace Coke Production via Coal Classification and Hot Pressing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for producing blast furnace coke struggle to achieve high strength and productivity while using a large amount of non- or slightly-caking coal, as they face issues with dust production, coke strength, and increased costs due to complex equipment and processes.
Innovation Solution
A method involving drying and classifying mixed coal, adding a caking additive like heavy distillate of tar, soft pitch, or petroleum pitch to fine-grained coal, and agglomerating by hot pressing before carbonizing with coarse-grained coal in a coke oven, optimizing the interaction of vitrinite and caking ingredients for improved coke strength and expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the moisture content in coking coal is reduced to 5% or less or near 0% through drying or preheating, then coke productivity and coke strength are improved, but fine-grained coal easily produces dust during transport and charging
Solution Approach 1:
The patent applies preliminary action by classifying the coal into fine-grained and coarse-grained fractions before drying. This allows the fine-grained coal to be dried to low moisture content (improving productivity and strength) while the classification prevents dust generation during subsequent handling. The classification step prepares the material in advance to avoid the harmful dust effect during transport and charging operations.
2Ease of manufacture
If the ratio of non- or slightly-caking coal in mixed coal is increased to improve cost efficiency, then production cost is reduced, but coke strength deteriorates due to poor caking ability
Solution Approach 1:
The patent applies local quality by treating the fine-grained fraction differently from the coarse-grained fraction. The fine-grained coal, which contains the caking ingredients (vitrinite), is dried to low moisture content to enhance its caking ability, while the coarse-grained non-caking coal is handled separately. This localized treatment of different particle size fractions allows the use of high ratios of inexpensive non-caking coal while maintaining coke strength through the optimized fine-grained fraction.
3Strength
If fine-grained coal is dried to low moisture content and then classified, then coke strength is improved, but the fine-grained coal crumbles during transport due to reduced adhered moisture
Solution Approach 1:
The patent performs classification into fine-grained and coarse-grained fractions before the drying process. By separating the fine-grained coal that will be dried to low moisture content from other fractions in advance, the system prevents the crumbling problem during transport. The preliminary classification ensures that only the intended fine-grained fraction undergoes extensive drying, while maintaining its integrity through proper handling of the classified material.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method enables the production of high strength coke at high productivity with reduced costs by enhancing the expansion rate and caking ability of briquettes, effectively handling a large proportion of non- or slightly-caking coal.
Implementation Method 1
drying mixed coal
Implementation Method 2
classifying it into fine-grained coal and coarse-grained coal
Implementation Method 3
agglomerating by hot pressing
Implementation Method 4
adding to the fine-grained coal at a temperature of 80 to 350°C
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method of production of blast furnace coke comprising drying mixed coal, then, or simultaneously with the drying, classifying it to fine-grained coal and coarse-grained coal, then adding to the fine-grained coal at a temperature of 80 to 350°C a caking additive comprising one or more of a heavy distillate of tar, soft pitch, and petroleum pitch, agglomerating it by hot pressing, then mixing the clumps of coal and the coarse-grained coal and charging and carbonizing the mixture in a coke oven.