RU2813865C1 - Refractory mixture for lining and repair works of thermal units - Google Patents

Abstract

FIELD: refractory mixtures.

SUBSTANCE: invention relates to production of refractory mixture, which can be used as masonry mortar and for coating during lining and repair works of thermal units. Refractory mixture contains chromite ore, iron oxide, magnesium sulphate or aluminium sulphate, periclase, as well as aluminium or an alloy of aluminium and silicon, and additionally contains a silicate lump used as flux, in the following ratio, wt.%: chromite ore 44.0–66.4, iron oxide 10.0–21.0, aluminium or aluminium and silicon alloy 9.0–15.0, periclase 5.0–10.0, magnesium sulphate or aluminium sulphate 7.0–15.0, silicate lump 0.5–1.0.

EFFECT: obtained mixture composition enables to reduce ignition temperature to values of 710–750 °C and has refractoriness of 1,680–1,770 °C.

1 cl, 2 tbl

Description

The invention relates to the production of refractory mixtures, which can be used as masonry mortar and for coating during lining and repair work of thermal units.

A refractory mass is known from the prior art, which can be used for lining thermal units [invention patent RU 2605567 C1. IPC C04B 35/105. Application No. 2015156075/03 dated December 25, 2015. Published on December 20, 2016 in Bulletin. No. 35]. The refractory mass contains, wt.%: chromite ore 60.0-64.0; magnesite 22.0-27.0; sodium hexametaphosphate 2.2-2.1; corundum 10.8-11.5.

A fire-resistant mixture is also known [patent for invention RU 2211200 C1. IPC C04B 35/65, C04B 35/185, C04B 35/66. Application No. 2002104347/03 dated 02/20/2002. Published on August 27, 2003 in Bulletin. No. 24], used in lining and repair work in high-temperature thermal units in ferrous and non-ferrous metallurgy, the chemical and coke-chemical industries, and the construction industry. This refractory mixture contains, wt.%: silicon dioxide 32-45, aluminum 29-35, VGTs grade cement 10-20, fly ash 0-16, aluminum oxide 0-10, fireclay powder 0-18.

The closest to the prior art is a refractory mixture, which includes, in wt.%: chromite ore 40 - 65, iron oxide 9 - 22, magnesium sulfate 8 - 14, aluminum or an alloy of aluminum and silicon 10 - 14, superplasticizer C-3 at based on the sodium salt of the condensation product of naphthalene sulfonic acid with formaldehyde 0 - 11.9, initiator - ammonium chloride or a mixture of ammonium-containing component from the group: ammonium sulfate, ammonium phosphate, urea, formamide with metal halide in a stoichiometric ratio of 0.1 - 0.9, modifier from groups: kyanite, sillimanite or their mixture 2 - 20.0. The composition makes it possible to reduce the porosity of the material to 8.7 - 12.5%, ignition temperature 820 - 890°C, fire resistance 1720 - 1800°C [patent RU 2138464 C1. Fireproof mixture "Gamma-ZHP". MPK S04V 35/65, 35/12, 35/66. Application No. 99103361/03 dated February 26, 1999, publ. 09/27/1999 in Bull. No. 27].

The disadvantages of the above technical solutions are the high ignition temperature (when starting self-propagating high-temperature synthesis (SHS) in combustion mode).

The technical result of the proposed invention is to reduce the ignition temperature when starting self-propagating high-temperature synthesis (SHS) in combustion mode.

The technical result is achieved by the fact that the refractory mixture, including chromite ore, iron oxide, magnesium sulfate or aluminum sulfate, periclase and aluminum or an alloy of aluminum and silicon, additionally contains a silicate block used as flux, in the following ratio, in wt. %:

chromite ore 44.0÷66.4 iron oxide 10.0÷21.0 aluminum or aluminum-silicon alloy (aluminium-containing component) 9.0÷15.0 periclase (thinning agent) 5.0÷10.0 magnesium sulfate or aluminum sulfate (sulfate binder) 7.0÷15.0 silicate block (flux) 0.5÷1.0.

The refractory mixture is prepared as follows.

In the mixing container, per 100 kg of output product, 60 kg of ground chromite ore, 10 kg of iron oxide, 9 kg of aluminum or an alloy of aluminum and silicon, 10 kg are sequentially poured using automatic dispensers or manually, weighing on scales in the required proportions. periclase, 10 kg of magnesium or aluminum sulfate and 1 kg of flux - ground silicate block. Then 12-15 liters of water are added to the mixing container and mixed until a thick paste-like masonry mortar is obtained, the consistency of which is sufficient to spread on the brick without spreading.

Table 1 presents examples of the composition of the claimed refractory mixture.

The properties of the resulting mixture are shown in Table 2.

The claimed composition makes it possible to reduce the ignition temperature to values of 710÷750°C, fire resistance 1680÷1770°C, shear strength 7.7÷15.0 MPa. The masonry mortar obtained in this way is used for lining cement kilns, sintering kilns, calcination kilns, etc.

Table 1

Composition, wt.% Components Chromite Ore Iron oxide Aluminum component Periclase protectant Sulfate binder Silicate block (flux) Fe2O3 Fe3O4 Al powder Al and Si alloy (silumin) _MgSO4 Al ₂ (SO ₄ ) ₃ 1 51.5 13.0 - - 15.0 5.0 15.0 - 0.5 2 66.4 - 10.0 11.0 - 5.0 7.0 - 0.6 3 65.2 10.0 - 9.0 - 8.0 - 7.0 0.8 4 44.0 - 21.0 9.0 - 10.0 15.0 - 1.0 5 47.2 21.0 - 15.0 - 5.0 11.0 - 0.8 6 52.0 - 15.0 - 9.0 8.0 - 15.0 1.0 7 52.5 15.0 - - 11.0 10.0 - 11.0 0.5

table 2

Properties of the resulting mixture Compositions 1 2 3 4 5 6 7 Shear strength, MPa 7.7 8.3 12.0 15.0 11.0 7.9 8.0 Ignition temperature, ^o C 750 740 720 710 711 740 710 Fire resistance, ^about C 1770 1740 1700 1680 1760 1710 1730

Claims (2)

A refractory mixture including chromite ore, iron oxide, sulfate binder, as well as aluminum or an alloy of aluminum and silicon, characterized in that it additionally contains periclase and silicate block used as flux, and magnesium sulfate or aluminum sulfate as a sulfate binder , in the following ratio, wt.%: chromite ore 44.0-66.4 iron oxide 10.0-21.0 aluminum or aluminum-silicon alloy 9.0-15.0 periclase 5.0-10.0 magnesium sulfate or aluminum sulfate 7.0-15.0 silicate block 0.5-1.0