SU697452A1 - Raw mixture for preparing heat-resistant concrete - Google Patents

Description

The invention relates to the building materials industry and can be used by factories that manufacture products from refractory concrete-phosphate hardening. The known refractory mass, including electrocorundum, refractory clay and aluminum-chromophosphate binder ij. The disadvantage of it is low heat resistance. Closest to the invention is a refractory mixture, including chamotte powder 40-60, clay refractory 15-40, orthophosphoric acid 7-5 and waste of the abrasive industry (sludge) 2. The disadvantage of this mixture is low strength, as well as a high solidification temperature. The purpose of the invention is to increase the strength at high temperatures, as well as lowering the solidification temperature. This is achieved by the fact that the raw mix for the preparation of heat-resistant concrete, including orthophosphoric acid, high-alumina filler and electrocorundum sludge, contains additionally hydrated trivalent chromium compounds at the following component ratio, by weight,%: chromium1-13 High-alumina filler Else. As a hydrated trivalent chromium compound, the raw material mixture contains chromium hydroxide or chromic nitrate or chromium oxychloride. Alternatives to using hydrated trivalent chromium compounds as an additive to the aluminophosphate-heat-resistant, concrete is added to the raw material mixture of chromium hydroxide Cr (OH) nitric acid, nitrogen-resistant, nitrogen-treated, nitrogen-treated, chromium hydroxide Cr (OH), nitrogen-resistant, nitrogen-resistant, nitrogen-resistant, nitrogen-impregnated Cr (OH 3) (NOj) o, chromium oxychloride Cg (OH) 2CE. The advantage of the proposed combination is limited. and distinctive features is that the introduction of the addition of hydrated trivalent chromium compounds to the aluminophosphate raw material mixture significantly reduces the hardening temperature of the concrete as a result of the high reactivity of the chromium-containing ingredient. In addition, the strength of concrete is enhanced at high temperatures. This is a consequence of the fact that the material, having a certain high-tech and phase composition, acquires new physicomechanical properties.

The substance has the following basic properties:

Bulk weight, kg / m

Compressive strength, kgf / cm Deformation temperature (4%), ° С Heat resistance (air heat exchanges)

The process of preparation of the proposed substances. is as follows.

Weights of raw materials (high-alumina filler, electrocorundum sludge and hydrated trivalent chromium compounds), taken in powder form, are mixed in a forced mixing mixer. Then the dry mixture is closed with a calculated amount of orthophosphoric acid and placed in molds. The raw mixture in the forms is subjected to heat treatment at 160-200 C for 5 hours

However, one of the expedient fields of application of the proposed substance is the production of products with high physicomechanical and heat-resistant / and properties for lining high-temperature thermal units.

Pr and measures. Physical and heat-resistant properties were determined for formulations that include optimal and boundary values of ingredients. In tab. 1 shows the composition of the raw material mixtures, in table. 2 properties of concrete.

Table 1

I view it as an oily filler (chamotte fraction .5-0 mm),

Sludge electrocorundum

Phosphoric acid

Hydrated Compounds, Trivalent Chromium

In the first composition, as a hydrated compound, the mixture contains chromium hydroxide, in the second composition - chromium nitrate and in the third composition - chromium oxychloride.

kgf / cm 295

under 1580

85 s

1700

35

40 35 18 25 27

13

T a

faces

2050

1855

1550 210 165

1560

1560

75

Claims (2)

60 1700 1700 Expected technical and economic efficiency, t from replacement of magnesite and chrome-magnesite refractory bricks with heat-resistant concrete from the proposed raw mix ranges from 120 to 255 rubles / ton. . Claim 1, Raw mix for preparing refractory concrete, including orthophosphoric acid, high-alumina filler and electrocorundum sludge, which in order to increase strength at high temperatures, as well as lower the solidification temperature, it contains additionally hydrated trivalent chromium compounds in components, wt.%: Orthophosphoric dislot 14-27 Sludge electrocorundum25-35 Hydrated compound of trivalent chromium1-13 Vyyokoglyuminisyuministy Italic 2. A mixture according to l. 1 g, characterized in that it contains chromium hydroxide or chromium nitrate or chromium oxychloride as a hydrated trivalent chromium compound. Sources of information taken into account during the examination 1. USSR author's certificate No. 369109, cl. From 04 to 35/10, -1971. 2. USSR author's certificate number 5224779, cl. From 04 To 29/02 ,. 1974 (prototype).