Carbon Agglomerate Solid-Phase Sintering
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Solution Overview
Problem
The depletion of caking coal and the need to utilize carbonaceous materials with poor softening and melting properties for carbon agglomerate production poses challenges in achieving high-strength carbon agglomerate suitable for blast furnaces, as conventional liquid-phase sintering methods are inadequate.
Innovation Solution
A method involving pressure molding of carbonaceous powder with controlled volatile content, O/C ratio, and particle size, at elevated temperatures in an oxygen-excluded environment to induce solid-phase sintering, forming high-strength carbon agglomerate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional liquid-phase sintering methods are used to produce carbon agglomerate, then high strength can be achieved, but the method requires caking coal with softening and melting properties which is becoming depleted
Solution Approach 1:
The invention changes the fundamental parameter of sintering mechanism from liquid-phase to solid-phase sintering. By controlling particle size distribution (maximum 300 μm with specific proportions) and applying solid-phase sintering conditions, the method enables production of high-strength carbon agglomerate using non-caking coal that cannot be processed by conventional liquid-phase methods
Solution Approach 2:
The invention substitutes the chemical-mechanical bonding mechanism (liquid-phase sintering requiring softening and melting) with a purely mechanical bonding mechanism (solid-phase sintering through particle compression and deformation). This replacement allows use of raw materials that lack the necessary chemical properties for liquid-phase sintering
2Adaptability or versatility
If carbonaceous materials with poor softening and melting property are used, then raw material availability increases, but conventional liquid-phase sintering cannot achieve sufficient bonding
Solution Approach 1:
The invention changes the bonding mechanism parameter from liquid-phase to solid-phase sintering, which fundamentally alters how particles bond together. This parameter change enables effective bonding of carbonaceous materials that lack softening and melting properties, thereby achieving both raw material versatility and product strength
Solution Approach 2:
The invention applies local quality control through specific particle size distribution requirements (maximum 300 μm with defined proportions of different size ranges). This local control of particle characteristics ensures adequate bonding in solid-phase sintering while maintaining the ability to use diverse non-caking coal types
3Strength
If caking coal is extensively ground to achieve fine particle size for good bonding, then particle bonding improves, but plasticity decreases making the process inappropriate
Solution Approach 1:
The invention replaces the liquid-phase bonding mechanism (which requires plastic deformation and softening) with solid-phase sintering. This substitution eliminates the need for excessive particle size reduction and plasticity, as solid-phase sintering achieves bonding through mechanical compression and deformation at particle contact points rather than requiring bulk material plasticity
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 approach enables the production of high-strength carbon agglomerate capable of withstanding blast furnace conditions, even with increased use of materials with poor softening and melting properties, without relying on liquid-phase components.
Implementation Method 1
the particles of the carbonaceous powder are bonded to each other by a solid-phase sintering phenomenon
Implementation Method 2
by pressure molding a defined carbonaceous powder while heating at a temperature range of 600 °C or more
Data Source
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AI summary
A method of producing carbon agglomerate is provided, capable of producing carbon agglomerate having high strength capable of withstanding use in a blast furnace even when a usage amount of carbonaceous raw material that has poor softening and melting property is increased. The method includes: a powder preparation process of preparing a carbonaceous powder having a volatile content of 6 wt% D.B. or more and less than 20 wt% D.B., an O/C ratio representing an atomic ratio of O atoms to C atoms of 0.040 or more, and a maximum particle size of 300 µm or less; and a hot pressing process of pressure molding the carbonaceous powder under a set of conditions including a maximum arrival temperature of 600 °C to 1250 °C in an oxygen-excluded environment to obtain the carbon agglomerate.