FOAM CONCRETE CONTAINING MAGNESIA BINDER AND METHOD FOR ITS PRODUCTION Russian patent published in 1998 - IPC

FIELD: production of building materials. SUBSTANCE: foam concrete has the following composition powdery waste resulting from roasting magnesite rock, aqueous magnesium chloride solution, finely crushed broken ceramic bricks as filler, foam-forming agent and foam-stabilizing agent. Used as foam-forming agent is non-ionogenic surfactant SYNTHANOL, while methyl cellulose in the form of MTS adhesive is used as foam-stabilizing agent. Components are taken in the following ratio, parts by weight: powdery waste resulting from roasting magnesite mineral, 75-100; finely ground broken ceramic bricks, 5-25; aqueous magnesium chloride solution with density 1200 kg/cu. m, 66-144; SYNTHANOL surfactant, 0.11-1.2; adhesive MTS used for fixing wall paper, 0.11-1.2. In order to increase strength and water resistance of foam magnesite while keeping low its density (500-600 kg/cu.m), composition comprises specially pre-treated finely ground broken ceramic bricks (pre-treatment resides in implementing with magnesium solution and heat treating) and powdery waste resulting from roasting magnesite mineral 75 which is either pre-calcined at 400-420 C or additionally ground. Solution for producing foam containing foam-forming and foam-stabilizing agents is prepared not with water but with aqueous magnesium chloride solution, the latter serving at the same time as agent for slaking magnesia binder. Foam mineralization treatment is carried out by dry technique, by mixing foam with dense magnesia concrete mix. Foam production and foam mineralization, i. e. production of foam/concrete mix, is carried out in one and the same foam generating/mixing apparatus provided with special activator. After removing free magnesium chloride, ready-made foam concrete articles containing magnesia binder are held in water for 1-3 days and dried. As a result of drying, foam concrete articles acquire reinforced structure and their moisture content due to sorption is reduced in 2-3 times. EFFECT: improved quality and higher efficiency. 19 cl, 4 tbl