SU990734A1 - Concrete mix - Google Patents

Description

(54) CONCRETE MIXTURE

one

The invention relates to compositions of refractory concretes and can be used in the manufacture of linings of electrode and gas suction ports of industrial furnaces.

A known concrete mixture comprising high alumina cement and aggregate of high alumina chamotte.

Closest to the proposed technical essence and the achieved result is a concrete mix consisting of finely dispersed sintered magnesite and a filler of scrap magnetitochromite or chromo magnesite products (7% by weight.%) And 30% by weight of high-alumina cement G2}.

The disadvantage of these mixtures is low heat resistance and high temperature.

The aim of the invention is to increase the heat resistance, the elimination of shrinkage.

This goal is achieved by the fact that a concrete mixture comprising finely sintered magnesite, a magnetically chromium scrap filling and binder filling unit, contains liquid glass as a binding agent and in addition finely sized corundum titanium waste with the following component ratio., Wt.%:

Fine sintered magnesite O-2O Liquid glass 8 -12

10 Fine-grained corundum titanium wastes 2O-ZO Aggregate from scrap metal-15 chromite products Else The composition of corundum titanium wastes is stable and is characterized by the presence of the following oxides,%: 86-94 ot And € 20z;

20 2-7 TiOj; I, 5r2.5 Rho; O, 9-1.9552; 0.3-1.0 CaO-; the rest is M p.

The combined presence of effective mineralizers, which is in the composition of liquid glass, and Ti02, which is in the corundum-titanium waste in the complex, is already a binder at relatively low heating temperatures of the concrete and then, up to expansive temperature, tells the mass the necessary mineralizing and sintering, promotes the active formation of crystalline neoplasms, which provide concrete with high heat resistance and constant volume. Such new formations include enlarged zermashpinel - MS, APgOj, surrounded by films of peritus of the whale - CaO, TCHO2, spinelic compound of complex composition, Fe. C ") 204" a small amount of forsterite - 2, 3i 0 and magnesium orthotitanate - 2 MejO Ti02. The above minerals were found in a petrographic study of samples of concrete manufactured under laboratory conditions, as well as after a test of 10O ton steelmaking furnace selected from the lining of the electrode rings. The introduction of less than 20% of corundum titanium wastes into the concrete does not provide the necessary TiO2 does not provide intensive sintering, the introduction of more than 30% reduces heat resistance. Change interval 8-12%; Liquid glass leads to the fact that less than 8% of liquid glass does not provide the strength properties of concrete at low temperatures, and more than 12% leads to a decrease in firing properties and the temperature at which deformation begins. Example. For the manufacture of concrete, crushed scrap of magnesite-chromite products with a grain size of from 0.1 to 12 mm, finely dispersed sintered magnesite fractions less than 0.088 mm, finely dispersed corundum titanium wastes containing 80-85% of fraction below O, O63 mm, 2O are used as a filler. -25% of the fraction below O, O88 mm with a specific surface of 380 O cm / g and liquid sodium glass with a density of 1.35-1.4 g / cm with MS 2.6-3.2. Initially prepared. To do this, liquid glass and finely dispersed corundum titanium waste are loaded into the concrete mixer in appropriate quantities, which are mixed for 7–10 minutes, after which the remaining components are loaded and mixed again for 1–15 minutes to obtain a homogeneous mass of thick consistency, from which samples are prepared by printed material at a force of 15 MPa in size OxlOxlO, see. Samples are dried at 80 ° C for 3 hours and burned at OOO ° C with an exposure of 3 hours. The thermal stability is determined in the samples in the form of a rectangular box with a square cross-section. th echeniem. For the purpose of the fullest ottazheni operational properties of concrete; The sample cross sections create a concentration of thermal ng stresses and are tested at maximum temperatures close to operational temperatures (160 ° C - air), the concentration of stresses is provided by preliminary cutting the specimen with two cuts paralle and symmetric one of the diagonals of the transverse specimen. The compositions of the proposed and known mixtures are given in table. 1. Physical and ceramic properties of refractory concrete are listed in Table. 2. As can be seen from the table. 2 magnitude thermo. the stability and exponential constancy of the volume of samples made using finely dispersed corundum titanium wastes and water glass as a binder significantly exceed those of samples made from a mixture of known composition. These properties allow to obtain refractory concrete with high performance properties. Table.

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Claims (2)

N cm with S Formula of the Invention A concrete mixture comprising finely dispersed sintered magnesite, a filler from scrap of magnesite and chromite isoelium, and a binder, characterized in that, in order to resist shrinkage, it contains liquid glass as a bonding agent and additional heat resistance. Corundant waste at the next ratio of components, wt.%:. Fine sintered magic nez1O - 20 Liquid glass 8-12 & 4 Fine-grained corundum titanium wastes 2O — ZO Aggregate for magnesito-chromite and other items of the rest. Others Sources of information taken into account during the examination 1. Zhikharev; S. S. A. et al. Og Eupo | concrete as an electrically insulating material for electrode coolers of arc steel melting furnaces. - Og yupory, 1959, hfe 7 p. 31. 2. Kaibicheva MN Lining electric furnaces. M., 1975, p. 41