Surface treatment method of aggregates for enhancing resistance of refractory concretes against the action of carbon extracted from a body

摘要

In the present invention, there is described a surface treatment method of aggregates for refractory concretes by a milk-of lime suspension prepared by the use of lime, magnesium lime or half-burnt magnesium lime (a mixture of MgO and CaCOi3). Through subsequent calcination at a temperature of at least 1100 degC for a period of at the most 2 hours a layer of a hard calcined lime is formed on the surface of the aggregate grain. An intermediate layer with a composition and thickness depending on the composition of aggregates, a lime used in the preparation of the milk-of lime suspension, temperature and time of calcination is created below the surface layer. Depending on chemical nature and thickness of the formed surface layer, aggregates treated by the method according to the present invention exhibit an enhanced resistance against the action of carbon and iron eutectic hot melts extracted from a body. Therefore, they can be used for the preparation of loose refractory building materials and mixtures thereof, shotcrete mixtures, repair mixtures, mortars and refractory monoliths.