Continuous casting tundish magnesia coating

Abstract

The invention provides two proposals for a continuous casting tundish magnesia coating. In the first proposal, the magnesia coating consists of the following raw materials in weight percentage: 85 to 95 percent of intermediate-range magnesia, 2 to 6 percent of soft clay, 2 to 6 percent of sodium hexametahposphate, 0.4 to 2.5 percent of active lime powder, 0.4 to 0.8 percent of paper fiber and 0.1 to 0.2 percent of explosion-proof fiber. In the second proposal, the magnesia coating consists of the following raw materials in weight percentage: 85 to 94 percent of intermediate-range magnesia, 2 to 6 percent of soft clay, 2 to 6 percent of sodium hexametahposphate, 0.5 to 2.5 percent of active lime powder, 1 to 1.5 percent of aluminum silicate fiber and 0.1 to 0.2 percent of explosion-proof fiber. The two proposals of the invention both adopt the soft clay and the sodium hexametahposphateas as bonding agents so as to adapt to the low-carbon or carbon-free tundish coating. Low carbon content or no carbon in the coating can ensure steel pouring quality, improve the finished product rate of steel, improve the erosion resistance and permeability of tundish simultaneously, and provide reliable guarantee for smooth production.

Description

technical field [0001] The invention relates to a low-carbon and carbon-free tundish coating, in particular to a refractory coating used for the working lining of a continuous casting tundish, and belongs to the field of unshaped refractory materials. Background technique [0002] With the rapid development of modern steelmaking and continuous casting technology, the quality and smelting process of continuous casting billets have been gradually improved, and the level of continuous casting has been greatly improved. Now many steel mills have begun to use tundish dry materials as working linings. In order to increase the service life of the tundish, reduce the cost, and reduce the accident rate, the requirements for the tundish coating for continuous casting are getting higher and higher. [0003] At present, the working lining of the continuous casting tundish mainly adopts magnesia smear material, among which, mid-grade magnesia is used as the main raw material, silicon mic...

AI Technical Summary

Problems solved by technology

In practical application, since 1.5~2% of paper fibers are added to the paint, the coating layer has a high porosity and poor penetration resistance; especially in the slag line, the penetration and erosion of the slag are particularly serious, resulting in The tundish cannot be automatically turned over due to sintering with the permanent layer, which brings certain difficulties to the production organization; in addition, because the paper fiber contains a certain amount of carbon, it will cause carbon backflow during the steel pouring process, which has a negative impact on the quality of the steel. Great side effects; especially have a great impact on the quality of silicon steel

[0004] As we all know, to solve the problem of high carbon content in existing magnesia coatings, it is necessary to reduce the content of paper fibers. However, after reducing the content of paper fibers, the viscosity of the slurry is low, which in turn leads to a gap between the working lining and the permanent layer. The problem of poor adhesion