CN102976771A - High temperature resistant lightweight heat insulation castables - Google Patents

Abstract

A high-temperature-resistant lightweight heat-insulating castable, the base material and its weight percentage are: main base material particles: average particle size ≤ 7mm, 53-60%; main base material fine powder: able to pass through a sieve of no less than 200 meshes, 25 ~32%; superfine powder: average particle size ≤ 10μm, 5~10%; aluminate cement: 6~7%; the sum of the weight of the above base materials is a whole, and compounding is required in addition to the above base materials Water reducing agent, the weight is 0.1~1% of the overall weight; polystyrene balls should be added in addition to the above base materials, the average particle size is 1~0.5mm, and the weight is 1~3% of the overall weight; This castable can be used as a thermal kiln working lining without contact with molten liquid. The operating temperature is from 1250 to 1650°C depending on the main base material. By adding different amounts of burnt matter, the volume density of this high-temperature-resistant lightweight heat-insulating castable can be increased. It is 1.2~1.7g/cm ³ .

Description

A high-temperature-resistant lightweight heat-insulating castable

technical field

The invention relates to the technical field of refractory materials, in particular to a high-temperature-resistant heat-insulating castable with added burnt matter.

Background technique

Generally, lightweight thermal insulation castables use lightweight aggregate as the aggregate of the castable, and use aluminate cement as the binder. Lightweight aggregates include waste lightweight brick sand, ceramsite, perlite and alumina hollow balls, among which waste lightweight brick sand, ceramsite, and perlite light-weight heat-insulating castables can be prepared according to the working conditions by adjusting the production method. Castables of various bulk densities are widely used in thermal furnace linings with low temperatures, such as petrochemical refinery lining materials, but they cannot be used as working linings in thermal equipment with high temperatures (>1250°C). This is because it is difficult to meet the requirements of such materials as a heat insulation layer on thermal equipment with high temperature, such as metal smelting equipment. Alumina hollow spheres are used as lightweight heat-insulating castables for lightweight aggregates, and the bulk density can be controlled at 1.5~1.7g/cm ³ , which can be used in thermal equipment at relatively high temperatures. The seismic stability is poor, the thermal conductivity is difficult to meet the requirements, the construction performance is poor, and the price is expensive.

The use of burn-out method to produce shaped heat-insulating materials has been mastered very early, such as polyhydrogen mullite heat-insulating refractory bricks with a bulk density of 0.5-1.5g/cm ³ and a refractory temperature of 1250-1650°C, and lightweight corundum made of petroleum coke. Zhuan et al., but the use of the loss-on-burn method to produce high-temperature-resistant lightweight heat-insulating castables has not been mentioned.

Contents of the invention

In view of the above-mentioned problems in the prior art, the applicant provides a high-temperature-resistant lightweight heat-insulating castable. This castable can be used as a thermal kiln working lining without contact with molten liquid. The operating temperature is from 1250 to 1650°C depending on the main base material. By adding different amounts of burnt matter, the volume density of this high-temperature-resistant lightweight heat-insulating castable can be increased. It is 1.2~1.7g/cm ³ .

Technical scheme of the present invention is as follows:

A high-temperature-resistant lightweight heat-insulating castable, the base material and its weight percentage are:

Main substrate particles: average particle size ≤7mm, 53~60%;

Fine powder of the main base material: can pass through a sieve of not less than 200 meshes, 25~32%;

Ultrafine powder: average particle size ≤10μm, 5~10%;

Aluminate cement: 6~7%;

The sum of the weights of the above-mentioned substrate materials is a whole, and a composite water reducer should be added in addition to the above-mentioned substrate materials, and the weight is 0.1~1% of the overall weight; polystyrene should be added in addition to the above-mentioned substrate materials Balls, with an average particle size of 1-0.5mm and a weight of 1-3% of said overall weight;

The main substrate can be at least one of pyrogem, kyanite, bauxite clinker, mullite or corundum;

The ultrafine powder is activated alumina micropowder or activated microsilica powder.

The specific preparation method of the high-temperature-resistant lightweight heat-insulating castable is to mix the above-mentioned raw materials together and stir evenly. The aluminate cement is selected from high alumina cement or calcium aluminate cement.

The beneficial technical effects of the present invention are:

The present invention uses the loss-on-burn method to produce high-temperature-resistant light-weight heat-insulating castables. The basic principle is to adjust the particle gradation in various refractory castables with mature formulas, and add a certain amount of lost-on-burn (polystyrene balls), By adjusting the amount of lost matter added, the construction performance can be satisfied on the basis of ensuring the fluidity of the original formula castable, and light-weight heat-insulating castables with different bulk densities and heat-insulating properties can be formed. After the castable is poured and molded, the burnt matter will be burnt out in the oven, resulting in porosity. Except for the decrease in volume density, other basic properties of the material remain unchanged.

When the service temperature of the castable is not higher than 1350°C, the main base material can be burnt gemstone and ordinary bauxite clinker; when the use temperature of the castable is higher than 1350°C, the main base material can be special grade bauxite clinker, Mullite or corundum.

Detailed ways

Example 1

Manufacture a furnace lid working lining (ρ=1.3g/cm ³ ) for an aluminum melting furnace of an aluminum product company. The long-term working temperature of the furnace lid fluctuates between 1000~1300°C. The raw materials used and the weight of each raw material are listed in Table 1. As indicated, just mix the ingredients in the table together.

Table 1

Example 2

Manufacture a high-aluminum lightweight heat-insulating castable (ρ=1.5g/cm ³ ) for the cupola front furnace cover of a foundry company. The long-term working temperature of the furnace cover is stable at 1450°C. The raw materials used and the weight of each raw material are As shown in Table 2, the raw materials in the table can be mixed together.

Table 2

Example 3

Manufacture a corundum lightweight heat _- insulating castable (ρ=1.2g/cm ³ ) for an ethylene cracking furnace of a petrochemical company. Its long-term working temperature is stable at 1350°C. The weight of the raw materials is shown in Table 3, just mix the raw materials in the table together.

table 3

Claims (3)

1. the adiabatic mould material of a heat-resistant light, it is characterized in that: base material raw material and weight percent thereof are:

Main substrate particles: mean particle size≤7mm, 53 ~ 60%;

Main base material fine powder: can cross and be not less than 200 purpose screen clothes, 25 ~ 32%;

Ultrafine powder: mean particle size≤10 μ m, 5 ~ 10%;

Aluminate cement: 6 ~ 7%;

The weight sum of above-mentioned base material raw material is as a whole, will add composite water-reducing agent outside above-mentioned base material raw material, and weight is 0.1 ~ 1% of described overall weight; Will add the polystyrene ball outside above-mentioned base material raw material, mean particle size is 1 ~ 0.5mm, and weight is 1 ~ 3% of described overall weight;

Described main base material can be for flint clay, kyanite, bauxitic clay grog, mullite or corundum at least a;

Described ultrafine powder is Reactive alumina or active SILICA FUME.

2. the adiabatic mould material of heat-resistant light according to claim 1 is characterized in that concrete preparation method mixes above-mentioned each raw material to stir.

3. the adiabatic mould material of heat-resistant light according to claim 1 is characterized in that described aluminate cement selects high-alumina cement or aluminous cement.