Graphite Bodies from Anthracite and Binder Coke Precursor
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Solution Overview
Problem
The high cost and limited availability of high-quality needle cokes for producing graphite bodies, such as electrodes and nipples, lead to increased production costs due to the need for precise process curves to manage irreversible thermal volume expansion, resulting in higher defect rates and operational issues in steel mills.
Innovation Solution
A method using high-temperature treated anthracite with a high vitrinite content and a binder coke precursor is employed to create graphite bodies, which are carbonized and graphitized, offering comparable properties to needle cokes at a lower cost, with a coefficient of thermal expansion (CTE) of less than 0.5 μm/mK, improving thermal shock resistance and mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high-quality needle cokes are used to produce graphite bodies, then the coefficient of thermal expansion is reduced and thermal shock resistance is improved, but production costs increase and availability is limited
Solution Approach 1:
The patent replaces expensive needle cokes with cheaper anthracite coal as the base material for producing graphite electrodes. By using anthracite with specific properties (low CTE, high carbon content) and optimizing the graphitization process, the invention achieves comparable thermal shock resistance and electrical properties at lower production cost, effectively substituting a costly material with a more economical alternative
Solution Approach 2:
The patent changes the material parameters by using anthracite coal with specific characteristics (low coefficient of thermal expansion, high carbon content, low sulfur content) instead of conventional needle cokes. The graphitization process parameters are also optimized to transform the anthracite into graphite with desired properties, thereby achieving the required performance at lower cost
2Reliability
If precise process curves are applied during graphitizing of premium cokes, then defect rate is reduced and service behavior is improved, but production costs increase
Solution Approach 1:
The patent performs preliminary selection and preparation of anthracite coal with specific properties (low CTE, high carbon content, low impurities) before the graphitization process. By pre-screening the raw material to match the required specifications, the need for complex process curve adjustments and defect management during graphitization is reduced, thereby lowering production costs while maintaining high reliability
Solution Approach 2:
The patent changes the approach by selecting anthracite coal with inherently favorable parameters (low coefficient of thermal expansion, high carbon content) that require less precise process control during graphitization compared to needle cokes. This material parameter change simplifies the manufacturing process and reduces the need for expensive process optimization
3Manufacturing precision
If needle cokes with low CTE are used, then linear expansion of graphite electrode is reduced, but material availability is limited and cost increases
Solution Approach 1:
The patent substitutes scarce and expensive needle cokes with abundant and cheaper anthracite coal. By selecting anthracite with naturally low coefficient of thermal expansion and optimizing the graphitization process, the invention achieves comparable linear expansion control while accessing a much larger and more economical material supply
Solution Approach 2:
The patent changes the material base from needle cokes to anthracite coal with specific parameters (low CTE, high carbon content, low sulfur). This parameter change enables access to abundant domestic anthracite resources while maintaining the required linear expansion control through proper material selection and process optimization
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
The method produces graphite bodies with comparable properties to high-quality needle cokes but at a lower cost, reducing production expenses and defect rates, while maintaining exceptional service behavior in electric arc furnaces with minimal material tears.
Implementation Method 1
carbonizing and graphitizing the green body from step b)
Implementation Method 2
The material to be graphitized is heated as an ohmic resistance in the direct passage of current to above 2200° C. to 3000° C.
Implementation Method 3
the relevant graphite electrode has a low coefficient of thermal expansion... the lower the CTE of the needle coke, the less will be the linear expansion of the graphite electrode produced with this needle coke when used in the electric arc furnace
Implementation Method 4
The material to be graphitized is heated as an ohmic resistance in the direct passage of current to above 2200° C. to 3000° C.
Data Source
AI summary
A method for the production of graphite bodies, including the step of provisioning a mixture including a high-temperature treated anthracite having a high vitrinite content and provisioning at least one binder coke precursor. The method also includes the steps of forming a green body from the mixture provided in the provisioning step, and carbonizing and graphitizing the green body.