Rapid-Heating Coking Coal for Blast Furnace Coke Strength
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge is to enhance the operational efficiency and productivity of blast furnaces while increasing the use of non- or slightly-coking coals while maintaining or exceeding conventional coke strength, as existing methods are inefficient and require multiple steps.
Innovation Solution
A method involving rapid-heating of blended coals in a fluidized-bed to a temperature range between 300° C. and the softening point, followed by classification and forming of fine-size coal, which is then blended with coarse-size coal and carbonized, eliminating the need for pre-classification of non- or slightly-coking coals from strongly-coking coals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional methods are used to maintain coke strength with depleting high-quality coal resources, then coke strength is maintained, but productivity and operational efficiency deteriorate due to inability to use low-quality coals
Solution Approach 1:
The invention changes the thermal parameters by applying rapid heating (heating rate of 100-1000°C/sec) to non- or slightly-coking coals, transforming their physical and chemical properties to achieve caking behavior similar to high-quality coals, thereby enabling their use in metallurgical coke-making while maintaining coke strength
Solution Approach 2:
The invention performs preliminary classification of coals into size fractions before heating, and conducts rapid heating and agglomeration operations before carbonization, preparing the low-quality coals in advance to acquire caking properties needed for strong coke production
2Stability of the object's composition
If multiple classification and treatment steps are applied to improve caking properties of low-quality coals, then caking properties are enhanced, but device complexity and operational complexity increase
Solution Approach 1:
The invention merges the classification and heating operations into an integrated process where coals are classified by size and then rapidly heated in sequence, combining multiple functions into a streamlined workflow that reduces the number of separate equipment units and operational steps required
Solution Approach 2:
The invention segments the coal charge by particle size (fine coal not more than 0.3 mm and coarse coal over 0.3 mm) to apply appropriate heating and treatment conditions to each fraction, enabling effective improvement of caking properties through targeted processing
3Stability of the object's composition
If rapid-heating is applied to improve caking properties of non- or slightly-coking coals, then caking properties are enhanced, but energy consumption increases due to high heating rates required
Solution Approach 1:
The invention applies rapid heating specifically to the fine coal fraction (not more than 0.3 mm) which requires the most intensive treatment to develop caking properties, while the coarse coal fraction is preheated at a moderate rate, optimizing energy distribution across different size fractions based on their specific needs
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 allows for the production of high-strength coke using large quantities of non- or slightly-coking coals, enhancing caking properties without classification, thereby increasing operational efficiency and reducing production costs.
Implementation Method 1
rapid-heating said coking coal in a fluidized-bed to a temperature range between not lower than 300° C. and not higher than the temperature at which the coking coal begins to soften
Implementation Method 2
rapid-heating of blended coals in a fluidized-bed to a temperature range between 300° C. and the softening point
Implementation Method 3
rapid-heating said fine-size coal and coarse-size coal individually in a pneumatic preheater to a temperature range between not lower than 300° C. and not higher than the temperature at which the coking coal begins to soften
Implementation Method 4
rapid-heating said fine-size coal and coarse-size coal individually in a pneumatic preheater at a rate of 103 to 105° C./min.
Implementation Method 5
classifying the rapid-heated coking coal to fine-size coal and coarse-size coal
Implementation Method 6
forming said fine-size coal
Data Source
AI summary
Methods for pretreating and improving coking coal quality for producing blast-furnace coke by: (a) rapid-heating the coal charge in a fluidized-bed to a temperature range between not lower than 300° C. and not higher than the temperature at which the coal charge begins to soften, at a rate of 30 to 103 ° C./min., (b) classifying the rapid-heated coal charge to fine- and coarse-size coal, and then (c-1) briquetting the fine-size coal or (c-2) rapid-heating the fine- and coarse-size coal individually in a pneumatic preheater to a temperature range between not lower than 300° C. and not higher than the temperature at which the coal charge begins to soften, at a rate of 103 to 105 ° C./min., and (d) forming the fine-size coal.