Stainless steel smelting method for improving content of MgO in slag of gas oxygen refining converter and LF (ladle furnace)

Abstract

The invention discloses a stainless steel smelting method for improving the content of MgO in slag of a gas oxygen refining converter and an LF (ladle furnace). The method comprises the following steps: a, preparing a magnesium-calcium refractory material with particle size of 3-15mm and a magnesium-calcium refractory material with the particle size less than 3mm; b, adding the magnesium-calcium refractory material with the particle size of 3-15mm into the gas oxygen refining converter to serve as a bottom magnesium-calcium refractory material; adding the magnesium-calcium refractory material with the particle size of 3-15mm once more during the converting period I, so as to keep the content of MgO in the slag within 9-11%; c, during the smelting and slagging process of the refining LF, adding lime, a slagging agent and the magnesium-calcium refractory material with the particle size less than 3mm together, so as to control the content of MgO in the slag within 7-9%; and d, proceeding to the continuous casting procedure. The method disclosed by the invention can improve the content of MgO in the slag, at the same time, improves the content of CaO, reduces erosion to the furnace lining, and prolongs the furnace life of the converter as well as the ladle life of the LF. The method disclosed by the invention has low requirements on a crushing appliance, lowers the production cost, and has higher economic and social benefits.

Description

technical field [0001] The invention belongs to the technical field of metallurgical solid waste reuse, and in particular relates to a stainless steel smelting method for increasing the MgO content of gas-oxygen refining converters and LF slags. Background technique [0002] At present, more than 80% of stainless steel smelting at home and abroad adopt converter gas-oxygen refining processes such as AOD, GOR, CLU, K-OBM, MRP, etc. Among them, K-OBM and MRP are used in the intermediate links of three-step smelting, and the furnace shell is made of magnesium. Carbon brick masonry and the furnace age is 800 to 1000 furnace times, AOD, GOR, CLU and other furnace types are almost all built with magnesia-calcium bricks, and the furnace age is only 50-230 furnace times. Among them, AOD, GOR, CLU and other furnace types account for more than 90% of the stainless steel converter gas-oxygen refining process, and the entire industry produces a large amount of waste magnesia-calcium bri...

AI Technical Summary

Problems solved by technology

[0006] In addition, the slag used in traditional stainless steel smelting LF is mainly composed of 50%~80%CaO, 20~40%SiO2, less than 15%Al 2 o 3 Composition, and MgO is often brought by the residual slag of the gas-oxygen refining furnace in the previous link, and the residual slag brings MgO to less than 2% after adding lime to create new slag diluted by LF

The MgO saturation concentration of LF stainless steel refining slag is about 8%. If there is no external addition, the MgO in the ladle slag wire refractory material containing more than 80% MgO will melt into the slag, which will affect the refractory life of the stainless steel refining ladle.