Out-of-furnace dephosphorizing method for electric-arc furnace molten steel

Abstract

The invention relates to the technical field of molten steel dephosphorizing, in particular to an out-of-furnace dephosphorizing method for electric-arc furnace molten steel. Primary smelting molten steel of an electric-arc furnace is rapidly dephosphorized outside the electric-arc furnace through a dephosphorizing agent and a fluxing agent. The dephosphorizing agent comprises iron oxide powder, calcium oxide, magnesium oxide and aluminium oxide, wherein the weight of the magnesium oxide and the weight of the aluminium oxide are smaller than 10% of the weight of the iron oxide powder; the weight of the calcium oxide is 0.5-5 times as high as the weight of the iron oxide powder; the carbon content is not higher than 0.2 wt%, the silicon content is not higher than 0.1 wt%; and the manganese content is not higher than 0.5 wt%. When chromium-containing low alloy steel is dephosphorized, the carbon content of the primary smelting molten steel takes the upper limit. By controlling the molten steel oxidizing condition and controlling the using amount of the added dephosphorizing agent to be within 0.5-3 wt% of the steel tapping amount, the primary smelting molten steel and the chromium-contained low alloy steel can be rapidly dephosphorized. According to the method, it is beneficial to reducing the production cost of electric-arc furnace smelting and beneficial for energy saving and emission reduction in steel production, and the out-of-furnace dephosphorizing method for the electric-arc furnace molten steel is simple and practical.

Description

technical field [0001] The invention relates to the technical field of molten steel dephosphorization, in particular to an out-of-furnace dephosphorization method for electric arc furnace molten steel. Background technique [0002] Phosphorus is a harmful element in steel, and high phosphorus content can cause material embrittlement. Therefore, high-quality castings and steel ingots have clear requirements for the impurity element phosphorus, and the phosphorus content is generally required to be below 0.02wt%. As a molten steel smelting equipment, the electric arc furnace has a strong dephosphorization ability, but the dephosphorization operation of the electric arc furnace is carried out under high temperature conditions, which will generate a large amount of waste slag and waste gas, and the alloy will be burned. In order to promote energy saving and emission reduction in the iron and steel smelting process, a simple and fast method for dephosphorization of electric arc ...

AI Technical Summary

Problems solved by technology

[0003] Aiming at a series of problems exposed in the existing electric arc furnace dephosphorization technology, such as long dephosphorization time, large alloy burning loss, and large waste slag and exhaust gas emissions, the purpose of the present invention is to provide an external dephosphorization method for electric arc furnace molten steel , based on the principle of molten steel dephosphorization, this method solves the problem of low dephosphorization rate of molten steel outside the electric arc furnace, and develops a practical dephosphorization method that adds high-efficiency dephosphorization agents to molten steel in batches and stages , control the dephosphorization rate of molten steel above 30wt%, and realize rapid dephosphorization of molten steel