High-basicity refining slag for slag washing of revolving furnace steel-making

Abstract

The invention relates to a high-alkalinity refining slag and a preparing method for the slag for scrubbing slag of a converter, which comprises active lime, fluorspar and industrial pure alkaline that are mixed evenly in a disk mixer. The chemical components of the slag by weight are: 70.0%<=CaO<= 88%, 0<SiO2<=3.0%, 0<Al2O3<=4.5%, 2.0%<=Na2O<=4.1%, 8.0%<=CaF2<=13.3%, 0<MgO<= 5.2% and the remainder are igloss elements and trace foreign matters such as P and S, etc., the binary alkalinity CaO / SiO2>=23.3. When the high-alkalinity refining slag is used for scrubbing slag when tapping in the converter, the melting is fast, and no splashing will occur, the desulfurization efficiency is high and steady, and can meet the requirements for refining, deoxidizing and removing non-metallic foreign matters.

Description

technical field [0001] The invention relates to a high-alkalinity refining slag, in particular to a high-alkalinity refining slag for washing converter steelmaking slag and a preparation method thereof, belonging to the technical field of iron and steel metallurgy. Background technique [0002] With the development of society and economy, users have higher and higher requirements on the quality of steel. High-quality steel has strict requirements on the content of sulfur, oxygen and non-metallic inclusions. For example, high-grade pipeline steel requires S≤0.005% in steel, gears Steel requires total oxygen (T[O])≤0.0015% in steel, but the molten steel smelted by ordinary steelmaking furnace is difficult to meet such quality requirements. On the other hand, in order to improve production efficiency and shorten the smelting time, it is also hoped that some tasks of the steelmaking furnace can be transferred to the outside of the furnace. Therefore, people pay more and more at...

AI Technical Summary

Problems solved by technology

[0005] 1. The low alkalinity is not conducive to the subsequent refining desulfurization, deoxidation and removal of non-metallic inclusions of aluminum deoxidized steel

If only active lime is used as refining slag, although the alkalinity of the ladle slag formed in the tapping process can be significantly increased, the melting point of active lime is high, and the heating and melting time required for the refining process is long, which adversely affects the production rhythm;

[0006] 2. The desulfurization rate is low, usually around 30%, which cannot meet the production requirements of some low-sulfur and ultra-low-sulfur steels;

[0007] 3. Contains CaC 2 The synthetic slag will produce CO, CO 2 Gas and ladle slag are prone to splashing, posing safety hazards