SU101886A1 - Method for the production of high density magnesite brick - Google Patents

Description

Methods are known for producing highly dense magnesite bricks with an apparent porosity of about 10-14%) from metallurgical magnesite powder.

The described method for producing high-density magnesite bricks makes it possible to produce bricks with an apparent porosity below B%.

The differences I have with this method are that in order to increase the density of the brick (obtaining porosity below 8%), the powder introduced into the brick building brick consists of 97-99% magnesite and 1-3% titanium dioxide or ilmenite concentrate, 8-10% of a sieve of 10,000 holes / cm, ground to a sieve residue together, with 50-70% of this powder being precompressed into briquettes at a pressure of at least 800 kg / cm, which are roasted at a temperature of 1200-1300 ° and ground to a grain size 3 mm, including grain diameter up to 0.2 m was dissolved meiee 15%.

The mixture for making bricks according to this method is prepared as follows.

Metallurgical mine or

Tubular magnesite in the amount of 97-99% and 1-3% of titanium dioxide or ilmenite concentrate, enhancing the degree of sintering, are mixed and grinded together to a fineness of about 60 microi, determined by a residue of not more than 8-10% at a distance of 10,000 holes / cm.

The resulting powder is moistened with a 5-6% solution of sulfite-alcohol bards with a density of 1.15-1.20 and pressed into briquettes under a pressure not lower than 800 kg / mm, which, after drying to a residual moisture of 0.2%, are burned at a temperature of 1200-1300. After that, the briquettes are milled to obtain grain with a grain size of up to 3 mm, and moreover grain with a grain size of less than 0.2 mm should be more than 10-15%.

The obtained grains are mixed with the powder from which the briquettes were made, in the ratio of 50-70% of the grain and 30-50% of the fine powder and moistened with a solution of sulfite activated bards.

Before pressing, the mass is cured for 2–3 days and subjected to repeated mixing.

The products are pressed on hydraulic presses with a specific pressure not lower than 800 / cg / cu2.

The compressed raw material is dried at a residual moisture content of 0.15-0.20%.

Brick baking is carried out at a temperature of 1650 ° with an exposure at this temperature for 4-6 hours. Since the raw material during firing gives 9-10% shrinkage, it is fired in the upper row of the furnace using a metallurgical powder.

The brick can also be produced from the mixture without caking, their additions are titanium dioxide and ilmenite, but then the magnesite powder should have a calcium oxide content of more than 3%, and silica more than 3.5%, and the magnesium oxide in the product x should be at least 89 %

Studies of the properties of magnesite kirnich obtained by this method showed high slag resistance and deformation temperature under the load (see table).

Prevention Invention

Claims (2)

1. Method for the production of high-density magnesite brick from metallurgical magnesite powder with additives of titanium dioxide or fine ground ilmenite, with wetting sulphite-alcohol barda and using a specific pressure of 800 kg / cm and higher for pressing brick and firing it at temperatures up to 1650 °, In order to increase brick density (obtaining porosity below 8%), the powder introduced into the charge for making bricks contains 97-99% of magpesite and I-3% titanium dioxide. or ilmeiitovogo concentration co-waste to a sieve residue of 8–10% on a sieve of 10,000 holes / cm, with 50–70% of this powder being precompressed into briquettes under a pressure not lower than 800 kg / cm, which are burned at a temperature of 1200–1300 and ground to a grain size of 3 mm in diameter, which number of grains with a diameter up to 0,2 AiM should not be more than 15%. 2. A modification of the method according to claim 1, such that, in order to eliminate sintering additives, magnesite powder for preparation of the charge is taken with a calcium oxide content above 3% and silica above 3.5% , moreover, the content of magnesium oxide in the products to be at least 89%.