Repair material for molten iron desulfurization stirring paddle

Abstract

The invention discloses a repair material for a molten iron desulfurization stirring paddle, which is prepared by mixing a base material and a proper amount of additives. The base material is prepared from the following components in percentage by weight: 45-65% of common bauxite, 3-8% of flint clay, 10-20% of andalusite, 20-28% of fireclay and 1-5% of pure calcium aluminate cement. The additives are sodium tripolyphosphate or melamine, and aluminum silicate fiber crushed cotton or organic fiber; on the basis of the total weight of the base material of the repair material (100%), the sodium tripolyphosphate or melamine accounts for at most 0.5%, and the aluminum silicate fiber crushed cotton or organic fiber accounts for at most 0.5%; and the two additives are matched, and the addition amount can not be zero. In order to overcome the defects in the prior art, the invention provides a repair material for a molten iron desulfurization stirring paddle, which has the advantages of wide raw material sources, low cost and excellent properties. The repair material can repair the stirring paddle, and can prolong the average service life of the KR desulfurization stirring paddle by more than 30 times.

Description

technical field [0001] The invention belongs to the field of refractory materials for molten iron pretreatment before converter steelmaking, and in particular relates to a repairing material for molten iron desulfurization stirring paddles. Background technique [0002] At present, when domestic and foreign metallurgical enterprises carry out stirring desulfurization of molten iron before converter steelmaking, most of the large and medium-sized steelmaking enterprises use KR stirring paddles for desulfurization, and most of the repair materials used for online maintenance are refractory materials mainly made of coke gemstones . [0003] Take the repair material for KR stirring paddle used in steel mills as an example. Its main raw material is coke gemstones, and its main ingredients are calculated by weight percentage AI 2 o 3 ≥55%, SiO 2 ≥20%, its physical and chemical indicators: compressive strength (110℃×24h) ≥20Mpa, compressive strength (1500℃×3h) ≥58Mpa; bulk densi...

AI Technical Summary

Problems solved by technology

[0004] Through the on-site investigation of the above-mentioned KR molten iron stirring desulfurization and the inspection of the damage condition of the stirring paddle repair material, it is found that the main forms of repair material damage are erosion, cracking, thermal spalling, etc. Good sintering cannot be carried out under temperature conditions, resulting in loose lining structure and low bonding strength, which will bring disadvantages to the maintenance of the service life of the stirring blade

Statistical data show that the KR stirring paddle repair material of Laiwu Iron and Steel Steelmaking Plant falls off after being used for 3 to 4 times, which seriously affects the service life of the stirring paddle

On the other hand, the use of coke gem raw materials also greatly increases the later maintenance cost of the stirring paddle and increases the material cost of the supplier