SU1689359A1 - Mass for producing refractory quartzite products not requiring firing - Google Patents

Abstract

The invention relates to the building materials industry and may be used in the manufacture of refractories for bucket lining. The aim of the invention is to increase volume and strength at operating temperature. The mass for the manufacture of quartzite refractory unburned products contains, wt%: co-milled mixture of quartzite and powder of ferrophosphoric iron in the ratio

Description

The invention relates to the building materials industry and can be used in the manufacture of refractories for lining ladles.

The aim of the invention is to increase the volume and strength at service temperature.

Example. Liquid glass with a silicate module 2.96, a density of 1.31 0.02 g / cm, ferrochromic slag of the following composition, wt.%: CaO 46-55; Si02 24-32; A1203 4-8; MDO 7-16, quartzite crystalline fraction 0-3 mm as a filler, fractions 2-7 mm - for grinding, powder

ferrophosphoric cast iron, crushed ferrophosphoric cast iron of blast-furnace production (TU 325-121-87) with a particle size of more than 5 mm, of the following composition, wt.%: Fe base, P 10-16; Mp 4; SlЈ2; .five.

In the process of joint grinding, the ferrophosphoric powder has a dispersing effect on the particles of ground quartzite, as a result of which the resulting silica-containing additive has a large specific surface. The presence in the refractory mass of a finely dispersed material with a high specific surface makes it possible to improve the mass cementing.

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in the presence of a liquid glass binder, increase the density and strength of the products after they are pressed.

The formation of the structure of unbaked products is carried out during operation. Due to the mineralizing effect of the ferrophosphor powder, the polymorphic transformations of SI02 in the cementing component of the refractory material occur in the liquid phase during heating, which prevents the structure from loosening. At the same time, tridymite splices are formed in the refractory matrix, reinforcing its structure. The absence of loosening and increase in the density of products provide an increase in their slag resistance.

An increase in the share of ferrophosphoric powder in the silica-containing cement (more than 10 wt.%) Reduces the refractoriness of the products. By reducing the content of the powder (less than 5 wt.%), There is no noticeable increase in the density and strength of the products at service temperatures.

The choice of the limits of content in the refractory mass of the product of joint grinding is due to the following. With an excess of this product (more than 17% by weight), the processability of the mass deteriorates, which leads to repressing cracks in the raw material. When the content is less than 10.8 wt.%, The optimum particle size distribution of the mass is disturbed, the quality of the light-shaped products decreases, and in the heating process, the strength decreases below the required values.

The refractory mass is prepared according to the following technology.

A joint grinding of a quartzite fraction of 7–2 mm and a ferrophosphoric powder was carried out. Grinding is carried out in a continuous tube mill to obtain a finely ground product with a particle size of less than 0.09 mm and a specific surface area of 2500 cm2 / g. The grinding product is mixed with a quartzite filler, after which ferrochrome slag and water glass are introduced into the mixture and mixed again.

Samples of various configurations are pressed from the obtained refractory mass: for determining linear changes, strength characteristics and density — in the form of cylinders, whose diameter and height is 50 mm, for determining slag resistance — in the form of crucibles. Samples incubated in air for 4 h, then subjected to drying at 120 ° C to a residual moisture content of not more than 0.8%. Manufactured by

According to this technology, quartzite products are ready for operation.

To characterize unburned quartzite products at service temperatures in steel split racks, part

The samples are fired at 1350 ° С (at a given temperature, it is customary to evaluate the thermomechanical properties of refractory concretes that characterize their behavior during operation).

Quartzite refractory compounds

masses and properties of samples from the proposed and known masses are given in the table.

The table shows that the proposed refractory mass provides a higher density of products at 1350 ° C, the strength at this temperature increases 1.4-3.2 times, the volume condition increases by 20-60%, the area of corroded and impregnated slag in cross section the crucible is reduced in optimal variants by 2 times.

Tests of products from the proposed mass (experiment 3) in the lining of steel-wall walls show an increase in durability by 35% compared with products of known mass (experiment 10).

The higher properties of unburned quartzite products allow the use of this type of refractories for the lining of the slag shell.

Claims (1)

Invention Formula A mass for the manufacture of quartzite refractory unburned products, including quartzite aggregate, fine ground silica containing additive, liquid glass and ferrochromic slag, characterized in that, in order to increase volume and strength at service temperature, it contains, as a quartzite-containing additive, co-milled mixture of quartzite and ferrophosphoric iron powder in a ratio of 90: 10-95: 5 in the following ratio of components , wt.%: Mixed hammer mixture 10.8-17.7 Liquid glass7.4 10.6 Ferrochrome slag 0.5-0.9 Quartzite fillerEstal Unarcytic filler81, 0 2.17 Fine ground quartzite france less 0.09 mp11.0 Tedious glass7,4 Slag fvrrohromovyyS, 5 13.1 25.6 15.9 7.3 +9.3 6.7 1690 22 Primcania. Test data on steel-shafts with a capacity of 160 tons. In compositions 1-3.10 and 11 gd of Savpvstnogo gtzmol willow and powder of farofpsfornogo pig iron in the ratio of 90:10, in compositions 4-6 - 95: 5; and compositions 7-3 - 02: 3.