Method for lowering chrome oxide in arc furnace slag in stainless steel smelting process

Abstract

The invention relates to a method for lowering chrome oxide in arc furnace slag in a stainless steel smelting process, which comprises the following steps: when the power supply amount reaches 53-55% of the total power supply amount, blowing oxygen for fluxing; (2) when the molten steel temperature reaches the tapping temperature after the scrap steel in the arc furnace is molten down, stopping blowing the oxygen, and blowing 100-200kg of silicon iron powder to the molten steel; blowing nitrogen at the rate of 1800 Nm<3>/h for stirring; (3) adding silicon iron and fluorite into the furnace to perform reduction while continuing blowing nitrogen at the rate of 1800 Nm<3>/h for stirring; (4) continuing power supply in the reduction process, and stopping power supply when the power supply amount reaches 2.5-3% of the total power supply amount; blowing nitrogen for stirring for more than 4 minutes, stopping the nitrogen stirring, shaking the furnace, and tapping; and (5) adding lime for slagging in the smelting process so that the alkalinity of the final arc furnace slag after reduction is 1.20-1.35. The method can lower the chrome oxide in the stainless steel arc furnace slag, enhance the recovery rate of chrome and lower the smelting cost.

Description

technical field [0001] The invention belongs to the field of metallurgy; it is a technique in the process of smelting stainless steel, and in particular relates to a method for reducing chromium oxide in electric arc furnace slag in the stainless steel smelting process. Background technique [0002] In the process of smelting all-scrap stainless steel, the electric arc furnace is mixed with raw materials such as high-carbon ferrochromium, returned scrap steel containing chromium and nickel, and nickel alloys to smelt crude steel liquid close to the finished stainless steel product. The crude molten steel produced by the electric arc furnace is continuously cast into steel billets after being refined outside the furnace to fine-tune the composition. [0003] During the smelting process of stainless steel, due to the characteristics of easy oxidation of chromium, it has a high affinity with oxygen and can be oxidized even when the partial pressure of oxygen is relatively low. ...

AI Technical Summary

Problems solved by technology

[0004] Because the electric arc furnace needs to pursue high-efficiency production, it often cannot consume a long time to reduce the chromium metal in the slag. In addition, the dynamic conditions of the electric arc furnace are poor. Usually, the chromium content in the slag is as high as about 9%, and the reduction effect is poor. The chromium metal serious loss