SU777011A1 - Composition for making light refractory articles - Google Patents

Description

one

The invention relates to the production of lightweight refractories.

The known raw mix for the production of a light heat resistant bead, including, and phosphate binder, kaolin, sh-5 mot, a surfactant, expanded clay gravel and steel fiber ij.

The disadvantage of it is low refractoriness and high apparent density.

Also known is the raw material mixture for the preparation of lightweight refractory products, including, by weight. %: high-alumina component 15-40, orthophosphoric acid ei-45, aluminum-chromium filler 20-36, dispersed aluminum and water - the rest 2.

This mixture is the closest to the described invention.

Its disadvantage is the apparent apparent density, the lack of low splash rate and the high cost are not high enough.

The purpose of the invention is to reduce the apparent density, increase refractoriness and

reduction in the cost of products.

This is achieved by the fact that the composition for iz- ;. 5 preparation of lightweight refractory products, including orthophosphoric acid, kaolin, aluminum powder, filler and water, contains as filler alumina and additionally wood 30

Opilkn prn the following ratios of components, weight. %

Kaolin15-25

Orthophosphoric acid5-15

Aluminum powder 0.2-1.5 Alumina10-25

Wood sawdust5-10

WaterEverything

A decrease in the apparent density is achieved by incorporating sawdust into the composition, which is a reinforcement, unrochny; it receives the mass and (1) ixides the resulting porous structure. Due to this, the gas-holding mass drift increases and its sedimentation is prevented after expansion. In the firing process, wood blinds burn out, due to which the porosity of the material is further increased. The apparent density also contributes to the introduction of a small amount of aluminum powder (but compared with known compounds), which form heavy alumina during calcination.

An increase in the refractoriness of products is achieved due to the introduction of alumina with high refractoriness into the composition, as well as the use of a small amount (in comparison with the existing compositions) of orthophosphoric acid, which forms compounds with a low refractoriness.

Cheaper composition is achieved by reducing the consumption of the most expensive component - aluminum powder.

The composition is made according to the following technology.

Dry components are mixed (preferably with joint grinding in a ball mill). To the resulting mixture with continuous stirring, pre-mixed water and phosphoric acid are added. After 6-10 minutes of continuous stirring, the resulting mass is laid out in forms where it swells. The product together with the form is dried in air for 1 day, and then in a drying chamber with a gradual rise in temperature to 200 ° C at a rate of 5 deg / h. After drying, the product is freed from the forms and subjected to firing according to the mode: temperature rise to 300 ° C at a speed of 50 deg / h, holding at 300 ° C for 3 h, heating to 800 ° C with a speed of 50 deg / h, heating to 1450 ° C at a rate of 100 degrees / hour, holding at 1450 ° C for 2 hours, cooling together with a furnace.

Targeted changes in the properties of products obtained from this composition, for example, an increase in heat resistance, are made by varying the technological parameters, for example, by changing the temperature of the water introduced into the mass, within the range of 20-90 ° C, using during the swelling period

vibration by changing the oscillation frequency

vibration platforms ranging from 2 to 20000

periods in s and amplitudes of fluctuations from 0.1

up to 2 mm.

In tab. 1 and 2 shows the content of the obtained compositions and their properties.

T a b l II c a 1

Water

Claims (2)

Invention Formula A composition for the manufacture of lightweight refractory products, including orthophosphoric acid, kaolin, aluminum powder, filler and water, characterized in that, in order to reduce the apparent density, increase refractoriness and reduce the cost, it contains alumina as a filler and additionally table 2 Properties of the resulting compounds spring sawdust in the following ratio of components, weight. %: Kaolin15-25 Orthophosphoric acid5-15 Aluminum mink 0.2-1.5 Alumina10-25 Sawdust5-10 WaterEverything Sources of information taken into account in the examination 5 1. USSR Copyright Certificate № 619466, cl. From 04B to 29/02, 1977. 6 2. Application N ° 2646130 / 29-33, 1978, according to which a positive decision was made (prototype).