CN-122012859-A - Process control method for improving temperature rising efficiency of LF furnace electrode

Abstract

The invention discloses a process control method for improving the heating efficiency of an LF furnace electrode, and belongs to the technical field of metallurgy. The method comprises the steps of implementing a pre-slag making system in the converter tapping process, adding aluminum products and lime to form reducing top slag, recovering the surplus of the hot refining slag of the previous converter, further improving the top slag reducibility, forming high-reducibility (FeO+MnO is less than or equal to 1%) top slag before the LF furnace enters a station, controlling low-gas-volume bottom blowing in the front stage of the LF furnace in cooperation with a ladle bottom blowing three-stage control system, prohibiting the addition of slag making materials and alloys, achieving good submerged arc effect in the power transmission process, and ensuring stable output of electric arcs. Through the measures, the rapid temperature rise in the power transmission process of the LF furnace is realized, the electrode temperature rise efficiency is improved by more than 15%, the power consumption is obviously reduced, the refining efficiency and the molten steel cleanliness are improved, and the method has good industrial application prospect.

Inventors

• JIA GUOXIANG
• GAO FUBIN
• YAN LONGGE
• SHI JINQIANG
• DAI HONGXING
• ZHANG TAO
• ZHANG YANLONG
• CHEN XIAOLI

Assignees

• 邯郸钢铁集团有限责任公司
• 河钢股份有限公司邯郸分公司

Dates

Publication Date

20260512

Application Date

20260226

Claims (6)

1. 1. A process control method for improving the electrode heating efficiency of an LF furnace is characterized by comprising the following control steps of a converter tapping pre-slag making system, a hot liquid refining slag pouring and surplus recycling system and LF furnace refining; The converter tapping pre-slag-making system is characterized in that a reasonable pre-slag-making system is implemented in the converter tapping process, the ladle bottom blowing high flow before tapping is 700-1000NL/min, aluminum products and lime are sequentially added after tapping is 1/5-1/4, the ladle bottom blowing low flow is 100-400NL/min, the aluminum products and the lime are completely melted by utilizing the heat of molten steel and the impact stirring of steel flow, the top slag is reduced slag, and the ladle bottom blowing flow after tapping is 400-700NL/min; The hot liquid refining slag casting residue recovery system is characterized in that hot liquid refining slag casting residue after continuous casting of the previous furnace is added into a steel ladle after converter tapping, the ladle bottom blowing flow is 100-400NL/min, and FeO+MnO in top slag is less than or equal to 1%.
2. 2. The process control method for improving the electrode heating efficiency of the LF furnace is characterized by further comprising a ladle bottom blowing system, wherein ladle bottom blowing is of a double-air brick design, when the ladle bottom blowing flow is controlled, the flow of a single-side air brick is independently regulated, the flow range is 0-1000NL/min, ladle bottom blowing three-level control is implemented, the ladle bottom blowing three-level control system comprises a small air volume control stage, the bottom blowing air volume is 100-400NL/min, a medium air volume control stage, the bottom blowing air volume is 400-700NL/min, and the large air volume control stage, and the bottom blowing air volume is 700-1000NL/min.
3. 3. The process control method for improving the heating efficiency of the LF furnace electrode according to claim 1, wherein the converter tapping pre-slag system comprises 2.2-2.3kg/t steel of aluminum products, the aluminum products are one or a combination of more of aluminum blocks, aluminum particles or aluminum-iron alloy, and the lime addition amount is 5.7-5.8kg/t steel.
4. 4. The process control method for improving the heating efficiency of the LF furnace electrode according to claim 1, wherein the hot liquid refining slag pouring and recycling system is characterized in that the temperature of the hot liquid refining slag pouring and recycling system is 1540-1560 ℃, and the slag comprises 50-60% of CaO, 3-7% of Al 2 O 3 ：25-35%,SiO 2 , 6-8% of MgO and less than or equal to 1% of FeO+MnO by weight.
5. 5. The process control method for improving the heating efficiency of the LF furnace electrode according to any one of claims 1 to 4, wherein the hot liquid refining slag surplus recovery system is characterized in that the adding amount of the hot liquid refining slag surplus is 8-11kg/t steel.
6. 6. The process control method for improving the heating efficiency of the LF furnace electrode according to any one of claims 1-4, wherein the hot liquid refining slag pouring surplus recovery system is used for controlling the ladle bottom blowing small gas amount in the early power transmission after the LF furnace enters a station, the gas amount is 100-400NL/min, the addition of slag forming materials and alloy is forbidden before the electricity is finished, a good submerged arc effect is realized, a stable resistance layer is formed, and stable output of electric arcs is ensured.

Description

Process control method for improving temperature rising efficiency of LF furnace electrode Technical Field The invention belongs to the technical field of metallurgy, and particularly relates to a process control method for improving the heating efficiency of an LF furnace electrode. Background The ladle refining furnace (LADLE REFINING furnace) has the heating refining function of the steelmaking furnace, is used for refining molten steel in a primary refining furnace (an electric arc furnace, an open hearth furnace and a revolving furnace), can adjust the temperature of the molten steel, has process buffering, meets the requirements of important metallurgical equipment of continuous casting and continuous rolling, and is one of main equipment of external refining. The heating system mainly comprises a transformer, a high-voltage control system, a water-cooling cable, a conductive cross arm, an electrode holder and a graphite electrode, wherein the electric system is used for controlling the electrode current and the voltage and the distance between the graphite electrode and the surface of molten steel in the heating process, so that a high-temperature electric arc is generated between the graphite electrode and the molten steel, and the molten steel is heated by utilizing the heat transfer among the electric arc, steel slag and the molten steel. The patent of publication number 202110405981.8 discloses a method for recycling refining slag and molten steel casting residue, recovering the refining slag and molten steel casting residue in an empty ladle, reacting with molten steel in the tapping process of a converter, and having a sufficient liquid slag layer when LF refining is in place, thereby shortening the time for making white slag, saving slag making material consumption, reducing the melting consumption heat of slag, saving electric energy and not improving the electrode heating efficiency; the patent with the application number of 202411500867.3 discloses a method for determining the voltage and current gear parameters of an LF furnace for reducing the power consumption, and the economic current and the fastest heating speed current under each voltage gear are obtained by utilizing a database technology, so that a reasonable power supply system is realized, and the heating efficiency of an electrode is improved on a process path of the LF furnace; The patent with the application number of 202311180681.X discloses a method for controlling the temperature of molten steel by heating an LF electrode, which effectively improves the once heating temperature achievement rate of the LF electrode by reasonably calculating the heating time of the LF electrode, thereby reducing the LF treatment period; The patent with the application number of 202411317449.0 discloses a refining process for quickly heating LF, wherein an LF furnace utilizes the characteristic of quick fluorite slag formation to quickly form white slag, shortens the earlier-stage smelting time and improves the heating efficiency; The electrode heating efficiency is related to the stability of an electric arc in the electrode heating process, the stability of the electric arc depends on the resistance of current passing through refining slag and the stability of the liquid level of molten steel, the refining white slag is high in alkalinity and high in reducibility (characteristics in slag, good in submerged arc effect and heat insulation, high in alkalinity and good in fluidity, so that the slag can be better covered on the surface of the molten steel to form a compact protective layer, the molten steel is prevented from being contacted with air, heat loss is reduced, the high reducibility slag (the mass fraction of FeO+MnO in the slag is less than 1%) can absorb free electrons in the electric arc, the electric arc is enabled to be more stable, the exposure of the electric arc can be effectively reduced, the fluctuation of the electric arc is reduced, the electrode heating efficiency is improved, the ladle bottom blowing air quantity control system is optimized, and the electrode heating efficiency is improved on the premise of meeting the uniform molten steel temperature. At present, the electrode temperature rising efficiency of an LF furnace is unstable, and the dual tasks of electrode power transmission process temperature rising and slag melting exist at the early stage, so that the temperature rising efficiency is low, slag is continuously regulated according to the condition of refined slag at the middle stage, refined white slag cannot be quickly and stably manufactured, so that how to promote the process is to realize that ladle top slag becomes high-alkalinity and high-reducibility slag before the LF furnace enters a station, the good submerged arc effect in the power transmission process is achieved, stable output of electric arc is realized, and the electrode temperature rising efficiency is improved. Disclosure of Invention The i