CS240633B1 - Lightweight insulating material, especially for gunning - Google Patents

Abstract

Lightweight insulating material, especially for shotcrete, solves the issue of adhesion, strength and increased productivity when applying porous insulating material. The essence is that it consists of 20 to 60% by weight of lightweight aggregate and 40 to 80% by weight of water glass.

Description

The invention relates to a lightweight insulating material, in particular for shotcreting. It can be used especially for light parts of linings of industrial furnaces and similar equipment and their repairs.

Currently, cement-bonded hydraulic bonding materials are used to make lightweight linings and repair them. The disadvantages of these compositions are their relatively high cost and short shelf life of the premixed compositions. Further disadvantages are in particular in the reduction of the strength of the mass during the first heating by the dehydration of cements, the low adhesion of the mass to the substrate, which has a very negative effect especially during the spraying of these masses. These compositions also require a relatively long setting and setting time, which results in time losses in operation, in particular for repairs. The sprayed masses should also be treated with dampening to ensure hydration and hence strength.

These disadvantages are overcome by a lightweight insulating material, in particular for shotcreting, which consists of the aggregate according to the invention. The essence of the invention is that the mass consists of 20 to 60% by weight. % of lightweight aggregate and 40 to 80 wt. water glass. The waterglass may preferably be of a sodium density of 30-36 ° Be. The lightweight aggregate may consist of 10 to 95 wt. expanded perlite and at least one other component. This component then comprises at least one of a group of substances of a maximum of 70% by weight. ceramite with a particle size of 0.2 to 4 mm, a maximum of 70 Ϊ wt. % of a ceramite having a particle size of 0.2 to 4 mm, a maximum of 25 wt. and a maximum of 95 wt. foam grit with a particle size of 0.2 to 4 mm.

The aggregate composition chosen in this way guarantees low waste by reflection during shotcreting. It also guarantees the binding of the alkali contained in the water glass, which allows a higher temperature of use. At lower deposition temperatures, the composition may preferably further comprise from 0.8 to 8% by weight. sodium fluorosilicate.

The advantage of the lightweight insulating material according to the invention, whose porosity is above 45%, is in particular its relatively low purchase price and high adhesion of this material to virtually all base materials. This grip is increased by firing. Also firing increases the strength. Another advantage is that the material does not need to be treated during solidification. The shelf life of the pre-mixed mixtures is practically unlimited. A very important advantage, which significantly accelerates repairs of heat aggregates, is the possibility to apply these materials even at higher temperatures. In this case, the lining can be dried and fired immediately without delaying the temperature to achieve the required strength. Another advantage is the lower waste during spraying.

The invention is further described by way of example.

Example 1

The gunning compound consists of 50% by weight. Foam-grit chippings with a particle size of 0.2 to 8 mm

4.5 i wt. % expanded perlite, 3.5 wt. silica drift and 42 wt. of sodium water glass with a density of 1 290 kg.m. The temperature of use of the mass is maximum 950 ° C.

Tests revealed the following mechanical properties:

Order no. weight after drying 1 100 kg.m Compressive strength after drying 3 MPa after firing at 800 ° C / 4 hours 3 MPa Length changes after firing to 800 ° C / 4 hours - o, , 6%

Resistance to deformation in heat under load of 0.05 MPa

T 06 900 C T 20 980 ° C

Example 2

The tortering composition consists of 40% by weight. keramsite having a particle size of 0.2 to 4 mm; % expanded perlite, 50 wt. of sodium water glass with a density of 1 290 kg.m ^-3 .

The temperature of use of this material is 1000 ° C. The following mechanical properties were found by testing the samples of this mass.

Bulk density after drying Compressive strength after drying after firing at 800 ° C / 4 hours Length changes after firing at 800 ° C / 4 hours Deformation resistance. in the heat at a load of 0.05 MPa

Example 3

150 kg.m 4 MPa 3 MPa

- 0,1

T 06 T 20 1

960 ° C 050 ° C

The gunning compound consists of 20 wt. % expanded perlite 2 wt. % of silica drift and 78 wt. of sodium water glass with a density of 1 290 kg.m. The temperature of use of this material is maximum 850 ° C. Tests of this material showed the following mechanical properties:

Bulk density after drying 900 kg.m

Compressive strength after drying 1.5 MPa after firing at 800 ° C / 4 hours 1 MPa

Remote changes after firing at 800 ° C / 4 hours -0.8%

Claims (2)

A lightweight insulating material, in particular for shotcreting, consisting of aggregates, characterized in that it consists of 20 to 60% by weight. % of lightweight aggregate containing 10 to 95 wt. % of expanded perlite and at most 70 wt. % of a ceramite having a particle size of 0.2 to 4 mm, and / or a maximum of 25 wt. % siliceous drift and / or at most 95 wt. % of granulated crumb having a particle size of 0.2 to 8 mm and 40 to 80 wt. water glass, preferably sodium. 2. The composition of claim 1, further comprising from about 0.8% to about 8% by weight of the composition. sodium fluorosilicate.