CS240459B1 - Method of high-compact basic refractory building materials - Google Patents

Abstract

The invention is in the field of refractory production materials and addresses acquisition issues high-density basic refractory building materials. Proceeding so that the cold pressed magnesite, magnesite, and the chromosmagnesite is heated to temperature 1700 to 2200 ° C heating speed · 30 to 300 ° C. h_1 for max. 8 hours, then is pressed at this temperature with a pressure of 10 to 200 MPa and the molding is further tempered at for 4 hours and then cooled at 20 to 300 ° C. h_1 a the cooled molded part is sized to required dimension by mechanical processing.

Description

The invention relates to a process for the production of high-density basic refractory magnesite, magnesio-chromite, chromium-magnesite, or other construction materials, the principal component of which is magnesium oxide.

Basic refractory building materials, the principal component of which is magnesium oxide, are produced by pressing granulometrically modified magnesite clinker mixtures with or without the addition of granulometrically modified refractory chrome ore containing small amounts of generally organic binders. The compacts are then dried and baked at a temperature of 1600 to 1850 °.

Basic refractory building materials for particularly demanding conditions of use at high temperatures, pressure changes, corrosion effects of molten metals and slags are produced or cut from castings of remelted magnesite clinkers to which chromium ore has been added, or are extruded from remelted granulometrically processed material moldings at high temperatures.

Refractory basic building materials carved from fused cast blocks have very good service life, but their production is very energy intensive, around 80 GJ. . t ^_1 . The lifetime of these building materials is reduced by the occurrence of large quantities of macropores, which is difficult to limit by melt chemistry and melting and casting technology.

High quality refractory basic building materials made of fused grain are also of high quality. However, the energy consumption in their production is also very high and is given by the most energy consumed when remelting the magnesite stalk or its mixture with chrome ore, the durability of the thus-made building materials depends on the quality of the fused grain and achievement of appropriate porosity and bulk density parameters.

The aforementioned shortcomings of the production technologies of the highest qualities of basic refractory construction materials, namely the high energy consumption in their production and the limited service life due to the relatively high porosity of these construction materials are eliminated by the invention. composition. The molding is heated to a firing temperature of 1700 to 2200 ° C at a heating rate of 30 to 300 ° C. . h ' ¹ for a maximum of 8 hours at o. 100 to 150 ° C higher than the start-up temperature, the glowing molding is compressed at a pressure of 10 to 200 MPa. The pressed compact is then held at the softening temperature for 4 hours to remove internal stresses and subjected to cooling at a rate of 20 to 300 ° C. tr ¹ , corresponding to the chemistry of the material to be treated. Chilled moldings are dimensioned by milling and grinding.

The high-mass magnesite, magnesic-chromium, chromium-magnesite refractory building material produced by the process of the present invention is characterized by having an apparent porosity 0.5 to 6% lower than a building material of the same chemical composition produced by the classical process, i. j. cold pressing and firing of pressings at temperatures up to 1 800 ° C without hot pressing.

EXAMPLE:

The cold-pressed unburned maghezitchrom brick was heated to 1800 ° C at a heating rate of 150 ° C. ^h1 , then compressed at 83 MPa and cooled after compression at 60 ° C. h “ ¹ . The cooled molding had a bulk density of 3.21 g. cm * ³ and an apparent porosity of 13.8%.

Example 1:

Cold-pressed unfired brick magnezitchrómová is heated to a temperature of 1950 ° C at a heating rate of 150 "Ch ^1, and then pressed pressure of 166 MPa. After compression, it was cooled at 60 ° C. h ^_1 . The resulting molding had a bulk density of 3.28 g. cm ³ and apparent porosity 12.6%>.

Claims (1)

SUBJECT Process for producing high-density basic refractory magnesite, magnesic-chromite, chromium-magnesite, or other construction materials whose principal component is magnesium oxide, characterized in that the cold compact is heated to a temperature of 1,700 to 2,200 ° C at a heating rate of 30 to 300 ° C . h ^_1 up to doYNÁLEZU either 8 hours, then, at this temperature, compressing pressure of 10 to 200 MPa and the green compact was further conditioned at a softening temperature for 4 hours and then cooled at a rate of 20 to 300 ° Ch ¹ and the cooled molding is dimensionally adjusted to size mechanical processing.