How does the LF ladle refining furnace perform secondary refining treatment on scrap steel

China produces about 200 million tons of iron and steel waste (such as trimming, trimming, scrapped machinery, household waste, etc.) every year. The LF ladle refining furnace is a kind of molten steel refining treatment device built after the primary furnace (converter, electric furnace). The LF principle uses electrode arc heating to heat up the molten steel instead of the primary furnace for the reduction period operation, while heating and deoxidizing the molten steel. , Desulfurization, degassing, alloying, argon blowing and stirring to improve the quality of molten steel.

A large amount of scrap steel resources are produced in China every year, and the LF ladle refining furnace is a kind of molten steel refining device built after the primary furnace. A set of scrap preheating system can be added to the LF furnace, and the gas produced by the blast furnace or converter can be used for scrap steel. Preheat to 450～600℃, continuously add to LF, add high-temperature scrap steel to 1500℃ molten steel in LF furnace, plus LF's own electric arc heating function, the scrap will melt quickly and be carried out in LF furnace Refining treatment, qualified molten steel meeting process requirements.

Each refining furnace can add 10%-20% of scrap steel during each refining period, which can increase the output of molten steel by 10%-20% per day. It is characterized by the recycling and reuse of iron and steel elements in waste. From the perspective of sustainable development, this scrap steel smelting process is a recycling economy process that relies on waste recycling.

Using the molten steel temperature of the LF furnace itself and the arc heating function of the LF furnace, the blast furnace or converter gas as the baking heat source can greatly reduce the waste of resources, greatly reduce the production cost per ton of steel, save the production cost of the enterprise, and improve the economic efficiency of the enterprise. 

Technical characteristics of LF ladle refining furnace:

The scrap steel preheating feeding system is a mechatronics multi-station special equipment for baking and heating the crushed steel scrap materials. The size of the scrap steel materials is controlled at 50-100mm. The scrap steel materials are baked and heated to the required process temperature in the furnace. , Generally the temperature is controlled at 450℃～600℃ to meet the requirements of steelmaking production. The scrap steel preheating and charging system adopts a steel structure furnace body with refractory materials inside the furnace body. Each system can be equipped with 1 to 4 stations and the furnace body is installed on the steel structure frame. A single preheating furnace body can preheat the amount of scrap steel per hour from 5t to 10t.

The scrap steel is loaded into the bottom opening tank in the raw material storage yard, and the crane in the workshop is used to lift the material tank to add cold material into the scrap preheating furnace. The upper part of the preheating furnace body is the feeding bin. The feed port is equipped with a pneumatic gate valve; the middle and lower part is a scrap steel baking chamber, and the lower part uses a vibrating continuous feeding device to continuously transport the baked high temperature scrap to the chute below the vibrating feeder and add it to the LF furnace; There is a weighing device on the preheating furnace body, which can accurately control the feeding amount; the vibrating feeder adopts frequency conversion control, and the feeding speed can be adjusted.