The present invention belongsrefractory materialThe field of preparation technology specifically relates to a refractory material and a preparation method and application thereof. Magnesium-calcium refractory is an alkaline refractory material, which has been used as a steel-making converter lining material since the early 1960 s, and has contributed to the development of China's converter steelmaking industry. By the end of the 1980 s, due to the promotion and application of magnesia-carbon bricks, the amount of magnesia-calcium refractories was drastically reduced and almost eliminated. Since the beginning of this century, with the rapid development of stainless steel and clean steel production in China, all kinds of magnesium calciumrefractory materialBecause of its unique performance (with the function of purifying molten steel), low price and environmental protection advantages, it has been valued again. At present, it has been widely used in the refining equipment of high-grade steel such as stainless steel and clean steel, and its development speed is relatively fast.

In the past 20 years, aod furnace has developed rapidly as an external refining method for refining high-quality steel such as stainless steel. The main processes of aod converter in stainless steel smelting are decarburization, chromium alloying, reduction and desulfurization. And the working conditions are relatively harsh, which is characterized by strong oxidizing atmosphere in the furnace, frequent mechanical impact of the alloy at the feeding point, large mixing kinetic energy of the blowing gas on the side of the eye area, serious chemical erosion of the slag line brick, large change range of furnace lining temperature cycle, high frequency, and high requirements on fire resistance. At present, mgo-cao bricks are used in the working lining of aod converter. The melting loss of magnesia-calcium brick is large in the initial and final refining stages, and the high temperature strength and thermal shock stability are low. The life of the AOD converter is about 100-120 furnaces. Therefore, how to improve the high temperature resistance of aod converter working furnace lining, reduce melting loss and prolong its service life has become one of the important research contents at present.

Therefore, the technical problem to be solved by the present invention is to overcome the defects of poor high temperature resistance, large melting loss, and low service life of the aod converter working furnace lining in the prior art, which affect the large production capacity of the aod converter, thereby providing a refractory Material and its preparation method and application. Therefore, the present invention provides the following technical solutions. The invention provides a.refractory material, Including the following parts by weight of raw materials: 95-98 parts of fused magnesia, 3-5 parts of antioxidant, 0.8-1.2 parts of sintering agent, 1-3 parts of graphite, 1-3 parts of phenolic resin. The mass fraction of magnesium oxide in fused magnesium calcium is not less than 98%. The antioxidant is at least one of aluminum, silicon, and boron carbide. The sintering agent is a rare earth metal oxide.

The invention also provides a method for preparing the refractory material, comprising the following steps: mixing all the raw materials, molding and firing to obtain the refractory material. The molding pressure is 15-25 MPa; the firing temperature is 345-355, and the firing time is 9-11 hours. In addition, the present invention also provides the use of the refractory material or the refractory material prepared by the preparation method in an AOD converter. The application includes the following steps: laying refractory materials on the eye area of the aod converter for pre-sintering; then building refractory materials on the working furnace lining of the aod converter and baking to obtain the aod converter.

The specific step of pre-sintering includes: sintering at 340-360 for not less than 2 hours, and then holding at 1600-1800 for at least 2 hours; preferably, the specific step of pre-sintering includes sintering at 340-360 for 10-15 hours, and then holding at 1600-1800 for 35-37 hours.

Baking includes the first firing and the second firing, the baking time is greater than 36h; the first firing temperature is 450-550, the time is not less than 10 hours; the second firing temperature is 1500-1700, the time is not less than 5h.

Stainless steels that can be smelted in aod converters include conventional stainless steels 304, 430 and SUS 410S; ultra-pure ferritic stainless steels suh409l, sus436l, 439, sus441, etc. Martensitic 3CR13, 4CR13; duplex stainless steel 2205.

The technical solution of the present invention has the following advantages: 1. Provided by the present inventionrefractory materialIncluding electrofused magnesium oxide dicalcium, antioxidant, sintering agent, graphite and phenolic resin, wherein the mass fraction of magnesium oxide in electrofused magnesium oxide dicalcium is not less than 98%, and the magnesium oxide with magnesium oxide content not less than 98% is compounded with antioxidant, which can make the refractory material have better high temperature resistance, mechanical strength and oxidation resistance.