RU2294906C2 - Formulation for preparing light-weight unfired refractory - Google Patents

Abstract

FIELD: refractories.

SUBSTANCE: invention relates to formulations suitable for preparing unfired refractories and can be used for manufacturing heat-insulation layer of lining structure not being in direct contact with furnace medium. Formulation comprising cement, filler, foaming agent, and water has: as cement, high-alumina cement; as filler, chamotte filler, in particular finely ground broken refractory chamotte brick; as foaming agent, foam-forming surfactant PO-6K; and additionally aluminosilicate aggregate, namely naturally occurring kaolinite Al₂O₃•2SiO₂•2H₂O, and polymer additive: phenol-formaldehyde resin and polyvinylacetate dispersion in 1:1 proportion. Final proportions are as follows, wt %: high-alumina cement 10-16, chamotte filler 5.0-6.0, surfactant 0.4-0.5, filler 32-34, polymer additives 1.4-1.6, and water - the balance.

EFFECT: reduced average density and coefficient of heat-conductivity of material while maintained strength high enough for transportation, mounting, and functioning of light-weight material in heat-defense structures of heating assemblies.

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Description

The invention relates to compositions for the production of lightweight non-fired refractory materials and can be used as a material for the manufacture of a heat-insulating layer of the structure of linings not directly in contact with the furnace medium.

The known composition of light heat-resistant concrete with a cellular structure / 1 /, containing, wt.%:

Alumina cement 12 ... 16 Spent Sulfur Catalyst 7 ... 8 Pyrite cinder 2.5 ... 3.5 Expanded clay dust 20 ... 24 Foaming agent "Unipor" 1.5 ... 2.5 Water Rest

The disadvantage of this composition is a fairly high average density and a high coefficient of thermal conductivity of the material.

This disadvantage is eliminated by reducing the average density and thermal conductivity of the material while ensuring strength sufficient for transportation, installation and operation of lightweight in heat-shielding structures of thermal units.

This effect is achieved by the fact that the composition for the manufacture of lightweight non-fired refractory contains in certain quantities cement, filler, foaming agent and water. As cement it contains high-alumina cement (VHC 1 GOST 969-91), as a filler - chamotte filler - finely ground fire of refractory fireclay bricks, as a foaming agent - foaming surfactant surfactant - "PO-6K" and additionally aluminosilicate aggregate - natural kaolinite Al ₂ O ₃ • 2SiO ₂ • 2H ₂ O and polymer additives - phenol-formaldehyde resin and polyvinyl acetate dispersion in a ratio of 1: 1.

The ratio of the components is the following, wt.%:

High Alumina Cement 10 ... 16 Specified fireclay filler 5.0 ... 6.0 Specified Surfactant 0.4 ... 0.5 Specified Placeholder 32 ... 34 Specified Polymer Additives 1.4 ... 1.6 Water Rest

The material was prepared in two stages. At the first stage, the required amount of water was mixed with polymer additives and a solution of a foaming surfactant. After mixing the above components, the solution was foamed by increasing the rotor speed to 800 ... 1000 rpm. At the second stage, without stopping mixing, mineral components were introduced into the foam mass: binder, aluminosilicate and chamotte fillers.

The samples were kept for three days under natural hardening conditions until the strength set and partial evaporation of excess water. The increase in the gained strength was achieved by first heating the material to a temperature of 1250-1300 ° C.

The use of high-alumina cement in combination with natural aluminosilicates and foam mass made by mixing synthetic surfactants with water-diluted polymers made it possible to ensure sufficient strength and stability of the material structure at a minimum density.

Examples of compositions for the manufacture of lightweight non-fired refractory and properties of finished products are given in table 1 and table 2.

Table 1 Component The compositions of the proposed composition, wt.% Prototype ^* one 2 Alumina cement - - 12 ... 6 High Alumina Cement 12.0 16,0 - Spent Sulfur Catalyst - - 7 ... 8 Pyrite cinder - - 2.5 ... 3.5 Expanded clay dust - 20 ... 24 Specified Aluminosilicate Aggregate 34.0 32,0 - Specified fireclay filler 5,0 6.0 - Specified Polymer Additive 1.4 1,6 - Foaming agent 0.5 0.4 1.5 ... 2.5 Water 47.1 44 Rest Note * - composition of light heat-resistant concrete with a cellular structure [1].

table 2 Structure Average density
kg / m ³ The coefficient of thermal conductivity, W / (m · ° C) The limit of compressive strength, kgf / cm ² Before firing Proposed composition No. 1 450 0.09 6 Number 2 500 0.10 8 After firing Proposed composition No. 1 350 0.08 10 Number 2 450 0.09 12 Prototype 450 ... 600 0.14 ... 0.18 140 ... 162

Literature (prototype):

1. Gorin V.M., Sukhov V.Yu., Nechaev P.F., Khlystov A.I., Riyazov R.T. Light heat-resistant concrete with a cellular structure // Building materials. 2003. No8. S.17-19.

Claims (1)

Composition for the manufacture of lightweight non-fired refractory material, including cement, filler, foaming agent and water, characterized in that it contains high-alumina cement as a cement, chamotte filler - a finely ground fireclay chamotte brick as a filler, and a foaming surfactant as a foaming agent (SAS) software-6K, aluminosilicate and optional filler - natural kaolinite Al ₂ O ₃ · 2SiO ₂ · 2H ₂ O and polymer additives - phenol-formaldehyde resin and polyvinyl acetate di Persia in the ratio 1: 1, with the following component ratio, wt.%: High Alumina Cement 10 - 16 Specified fireclay filler 5.0 - 6.0 Specified Surfactant 0.4 - 0.5 Specified Placeholder 32 - 34 Specified Polymer Additives 1.4 - 1.6 Water Rest