High-alkalinity tundish covering agent

Abstract

The invention relates to relates to auxiliary materials for steelmaking continuous casting operation. A high-alkalinity tundish covering agent comprises, by weight, 80 to 91% of melt materials and additional auxiliary materials, wherein the additional auxiliary materials comprise, by weight, 1 to 6% of magnesia, 1 to 7% of fluorite, 1 to 5% of bauxite, 2 to 6% of binding agent namely methyl cellulose and 1 to 10 % of other lightweight materials; the melt materials comprise, 48 to 55% of calcium oxide, 1 to 5% of silicon dioxide, 34 to 40% of aluminum oxide, 0.5 to 2% of ferric oxide and 9.6 to 55% of calcium silicate; the lightweight materials comprise calcium carbonate; the melting temperature of the covering agent is 12000 to 14000 DEG C and the viscosity of the covering agent is 0.1 to 2 Pa.S; the granularity of more than 95% of the covering agent is 1 to 5 mm and the bulk density of the covering agent is smaller than 1.2 g every cm<3>. According to the high-alkalinity tundish covering agent, the erosion on tundish refractory materials is small, the inclusion adsorption capability is strong, and the production requirements of ultra-low carbon steel can be met.

Description

technical field [0001] The invention relates to an auxiliary material for steelmaking and continuous casting operations, in particular to a high-alkalinity tundish covering agent. Background technique [0002] The tundish covering agent in the steelmaking and continuous casting operation is an auxiliary material for continuous casting added to the tundish. The tundish covering agent is mainly composed of CaO, SiO 2 、Al 2 o 3 , MgO and other components of mineral raw materials are added with an appropriate amount of flux and processed through crushing, grinding, mixing, granulating, packaging and other processes. The tundish covering agent added to the surface of molten steel has the functions of heat insulation, reducing heat loss of molten steel surface; isolating air, preventing secondary oxidation of molten steel; dissolving non-metallic inclusions floating to the surface of molten steel, purifying molten steel, etc. According to the classification of alkalinity, t...

AI Technical Summary

Problems solved by technology

The melting point of common high-alkalinity covering agents is generally greater than 1400°C, which is close to or higher than the liquidus temperature of poured steel. In this case, it is difficult to form a slag layer or the slag layer is relatively thin, and the effect of isolating air is relatively weak. Poor, molten steel is prone to secondary oxidation, which is not conducive to the production of high-grade pure steel. In addition, the usual tundish covering agent is easy to increase carbon on ultra-low carbon steel, which affects product quality