Main Factors Influencing Graphite Electrode Consumption in EAF SteelmakingAuthor : Hani Time : 2020/06/10
The consumption of graphite electrode in EAF steelmaking runs through the whole smelting process, and its consumption is affected by many factors, which is only analyzed for the operation of smelting process.
1. The poor quality of scrap or the improper ratio of scrap lead to the poor slag forming effect and prolong the smelting time; the increase of the number of charging and well penetration increases the damage and fracture probability of the electrode bottom; the increase of smelting time is the direct factor leading to the increase of power consumption and electrode consumption and loss.
2. Electric furnace power supply equipment does not match with electrode specification
Electric arc furnace power transmission is a high current and low pressure operation. If the capacity of the power supply equipment is too large to exceed the limit load of the electrode, the inner electrode of 5-10min arc starting will turn red from the bottom to the top, and the boundary line of the connection is very obvious and most of them will break; if the current is too high or the fluctuation is too large, the breaking frequency of the connection type will increase and the consumption of the bottom will be cone-shaped. If the power supply capacity is low, the furnace temperature cannot meet the process requirements within the effective medium heat time, the operation will be delayed. The loss and consumption of graphite electrode are the biggest in overload and overtime operation.
3. Forced increase of chemical energy and smelting strength in oxidation period
In smelting, it is necessary to increase oxygen blowing (generally less than 45m3 / T) to achieve rapid melting and increase furnace temperature, which is easy to make furnace condition bad and rich in furnace and on furnace, so that each phase of electrode is in high temperature flame. When the electrode is in this kind of furnace condition, there are many serious phenomena such as delamination and surface oxidation.
4. Configuration of electric furnace and technicality of operation
There are essential differences between modern EAF and traditional EAF. The appearance of UHP large-scale EAF and hot charging steelmaking process improves the smelting strength and production capacity, and puts forward higher technical requirements for the quality of graphite electrode. In operation, the selection of power transmission curve and gear, the control of arc starting and arc stabilizing voltage and current, the cooperation of long, medium and short arcs, the configuration and application of water-cooling system, etc. all play a key role in the service life and consumption of electrodes.
5. Quality of graphite electrode
At present, the smelting and process of EAF have more and more strong requirements on the oxidation resistance and thermal shock resistance of graphite electrode, and the high consumption caused by the quality fluctuation has attracted the great attention of the direct users. So the balance and stability of graphite electrode quality is the most important factor to determine the consumption.
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