Magnesium calcium RH varnished tube hot spray repair material for smelting silicon steel and formulating method thereof

Abstract

The invention relates to a calcium magnesium RH dip pipe hot spray repair material used for high-performance smelting silicon steel and a preparation method, and is characterized in that the invention adopts high-purity magnesium gravel and synthesis magnesium calcium as main components; more than one of organic addition agents of woodiness calcium sulphonate, modified starch ether, and the like are used in composite mode to substitute low-melting harmful plasticizers of soft clay, water glass, and the like used by conventional spray repair material to realize good spray repair adhesiveness and good high-temperature performance of the spray repair material. The invention uses two ultra fine powder of ultra fine MgO micro powder, SiO2 micro powder and calcium hydroxide micro powder in composite mode to act slushing enhancement effect, further improves adhesiveness and agglutinating property of the material, and enhances high temperature strength of the material. Provided spray repair material has high hot strength, good high-residue erosion resistance performance and good molten steel erosion resistance performance; spraying and repairing a dip pipe can make the service life be more than one furnace when a RH device smelts low sulphur special silicon steel, thus satisfying the requirements of the smelting of the special silicon steel.

Description

Technical field [0001] The invention relates to a high-performance magnesia-calcium RH dip tube hot gunning material for silicon steel smelting and a preparation method thereof. Specifically, the present invention is to improve the life of the RH dip tube in a silicon steel smelting and refining system, and provides a magnesium-calcium Hot gunning material. It belongs to the field of refractory materials. Background technique [0002] With the emergence of new smelting technologies, the production of pure steel has developed rapidly. The RH cycle degassing method is one of the refining methods outside the furnace. Its main principle is: insert the ascending pipe and descending pipe of the vacuum degassing cylinder into the molten steel at the same time, and blow argon gas into the lower end of the ascending pipe, so that the ascending pipe and the descending pipe will generate pressure drop each other, and the molten steel can pass The ascending pipe returns to the vacuum cyli...

AI Technical Summary

Problems solved by technology

However, with the increase of high-grade special steel varieties, especially the sharp increase in the demand for special silicon steel, harsh operating conditions such as high-alkaline slag lead to the loss of general magnesium gunning material when it is used for less than one furnace after gunning. No damage, which seriously threatens the life of magnesia-chrome bricks and affects the normal operation of the RH furnace

The reason for the analysis is that special silicon steel needs to add a large amount of CaF during refining due to its ultra-low sulfur requirements. 2 , CaO and other high-alkalinity desulfurizers, but the general magnesia gunning materials used today have poor resistance to high-alkalinity slag and low thermal strength, which in turn affects their resistance to the cyclic erosion of molten steel, and cannot maintain the smelting of a furnace of steel after use already exhausted

For this reason, refractory workers at home and abroad have tried to improve the purity of magnesium gunning materials or use high-purity magnesium-aluminum gunning materials, but they have not achieved satisfactory results.

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