DE1220776B - Process for the production of hydration-resistant, refractory, magnesia-containing stones and masses - Google Patents

Description

Process for the production of hydration-resistant, refractory, magnesia-containing Stones and Masses It is known to have porous building materials and materials, such as masses on the Based on cement, gypsum, magnesia cement or other binders, as well as porous, to impregnate organic or natural building and construction materials with synthetic resin in order to their water permeability, water sensitivity, chemical resistance and mechanical Increase strength and resilience. Also dolomite stones are made with tar impregnated to ensure their storage stability, i.e. their resistance to weathering, to increase. It is known for sheet metal-coated dolomite stones that are not covered with sheet metal to cover covered parts with synthetic resin.

The invention relates to a method for producing hydration-resistant, refractory bricks and masses containing magnesia. Impregnating such stones using tar or synthetic resin to protect them from the elements is not required because they are only attacked by the weather for very long periods of time will.

From the German Auslegeschrift 1056 038 it is known that magnesite and forsterite stones to be impregnated with synthetic resins in order to heat them up with to protect them from the effects of hot steam. However, this requires a special process for curing the synthetic resins.

From German patents 1043 913, 961697 and 968 586 is it is known to burn stones containing magnesia with salt solutions and organic acids or acid vapors to treat the active, hydration-sensitive areas to saturate the magnesia. Will such stones over long periods of exposure exposed to hot water vapor, they tend to hydrate despite the treatment, as the pores are not closed by the treatment, hot steam so can penetrate into the stone and also fully crystalline periclase from hot Attacked water vapor, especially in the temperature range from about 60 to 100 ° C will.

It has also been proposed to use water glass as a binder for To use magnesia-containing stones and masses, in particular magnesite stones. Here However, several percent of water glass is required, based on the refractory material. With these amounts of water glass, the fire resistance of the products becomes considerable reduced.

According to the invention it is now proposed that the magnesia-containing, fired To soak stones with water glass and then to dry them. Through the watering and the subsequent air drying, the pores of the stone are closed so that no Water vapor can penetrate more into the stone. A special treatment for curing as with synthetic resins is unnecessary.

Potash and / or soda water glass with a is expedient for impregnation Density of about 40 Be, preferably about 15 Be, is used. The stones are soaked easiest by diving. They should expediently at least 15 seconds be covered on all sides by water glass. A dive time of 60 seconds is generally completely adequate.

The stones or grains are dried in the air, with two Days are sufficient throughout. In rainy and cool weather it is possible that To dry stones in dry and, if necessary, heated rooms.

Exemplary embodiment Magnesite bricks were placed in soda water glass for 15 seconds a density of 15 Be and then immersed for two days in a closed room at room temperature dried. After a water vapor treatment in an autoclave at 6.6 atmospheres and 170 ° C No hydration could be observed for 4 hours.

Claims (1)

Claim: Method of preventing hydration of refractory Magnesia-containing stones and masses through hot water vapor, especially in the temperature range from 60 to 100 ° C, d u r c h marked that the stones or masses according to soaked, brushed, sprayed or sprinkled and then with water glass before firing to be dried. Documents considered: German patent application A 14823 VIb / SOb (published on April 7, 1955).