CN108395227B

CN108395227B - Lightweight refractory material and preparation method thereof

Info

Publication number: CN108395227B
Application number: CN201810382926.XA
Authority: CN
Inventors: 唐龙燕; 周文杰
Original assignee: SHANGHAI BAOMING REFRACTORY MATERIALS CO Ltd
Current assignee: SHANGHAI BAOMING REFRACTORY MATERIALS CO Ltd
Priority date: 2018-04-26
Filing date: 2018-04-26
Publication date: 2021-01-15
Anticipated expiration: 2038-04-26
Also published as: CN108395227A

Abstract

The invention provides a lightweight refractory material which is spherical particles, and comprises 2-10% by weight of 0.001-0.074 mm starch; 70-80% of 0.1-1.5 mm sawdust; 5-10% of 50-100 nano-scale alumina powder; 5-10% of 50-100 nano-scale fused spinel powder.

Description

Lightweight refractory material and preparation method thereof

Technical Field

The invention relates to a refractory material, in particular to a lightweight refractory material for producing a ladle permanent layer castable.

Background

The ladle permanent layer castable not only needs to resist high temperature in a ladle, but also has good heat preservation effect, so that a lightweight refractory material needs to be added in the production process of the ladle permanent layer castable, thereby reducing the volume density of the ladle permanent layer castable and playing a good heat preservation role.

In the prior art, the alumina hollow sphere is mainly added to realize the functions, and as the alumina hollow sphere particles are of a hollow structure, when the alumina hollow sphere particles are added into a ladle casting material for construction vibration, the hollow sphere particles are easy to float to the upper part of the casting material, so that the hollow sphere particles at the upper part and the lower part of the casting material are unevenly distributed, the thermal insulation performance difference of the ladle at different heights (the height of the ladle is 4-6 m) is caused, and the thermal insulation effect is influenced; in addition, the wall breaking phenomenon is easy to occur in the stirring process of producing the castable due to the thin wall of the alumina hollow ball, and the heat insulation performance of the castable is affected once the wall breaking occurs.

In the prior art, the material of the foam plastic particles is often added into the castable of the permanent layer of the steel ladle to replace the alumina hollow sphere particles, however, the foam plastic particles can form a large amount of toxic gas at high temperature, which causes great pollution to human bodies and the environment.

Disclosure of Invention

The invention aims to solve the technical problem of providing a lightweight refractory material which is spherical particles and is characterized by comprising 2-10% of 0.001-0.074 mm starch in percentage by weight; 70-80% of 0.1-1.5 mm sawdust; 5-10% of 50-100 nano-scale alumina powder; 5-10% of 50-100 nano-scale fused spinel powder.

The invention is further characterized in that:

the diameter of the particles is 0.5-5 mm, and the volume density is 1.5-1.0g/cm³。

In another aspect, the invention provides a preparation method of a lightweight refractory material, comprising the following steps:

(1) mixing the materials according to the proportion of the components in the claim 1, uniformly stirring the materials in a stirrer, adding water according to the proportion of adding 100 and 120 kilograms of water to every 1000 kilograms of the mixed materials, and stirring the materials again;

(2) adding water into the stirred material, and transferring the stirred material into a granulator for granulation and molding to obtain spherical particles with the particle diameter of 0.5-5 mm;

(3) and (3) baking the spherical particles obtained in the step (2) at the temperature of 90-120 ℃ for 20-30 hours, and removing moisture to obtain a finished product.

The invention has the beneficial effects that:

the invention contains sawdust and starch with higher specific gravity, and is baked at the temperature of 90-110 ℃, at the temperature, the sawdust does not reach the burning point, and the starch can play a role of structure reinforcement. However, when the temperature is high, particularly in the environment of more than 1000 ℃ in a steel ladle, sawdust and starch can be combusted and completely burned out, so that uniform micropores (generally 0.1-1.5 mm) are formed in particles, and the heat insulation performance of the castable of the steel ladle working layer in the using process can be effectively improved; in addition, the nano-scale fused spinel powder is added, so that the slag resistance at high temperature is greatly improved.

The specific implementation mode is as follows:

the following is a specific description of examples 1 to 5 of the present invention.

Example 1

The lightweight refractory material comprises the following components in percentage by weight: 2% of starch with the thickness of 0.001-0.074 mm; 80% of sawdust with the thickness of 0.1-1.5 mm; 10% of 50-100 nano-scale alumina powder; 50-100 nm fused spinel powder 8%, as shown in Table 1 below.

Mixing the components according to the proportion, uniformly stirring in a stirrer, adding water according to the proportion of adding 100-120 kg of water to every 1000 kg of the mixed materials, and stirring again; adding water into the stirred material, and transferring the stirred material into a granulator for granulation and molding to obtain spherical particles with the particle diameter of 0.5-5 mm; and (3) baking the obtained spherical particles at the temperature of 90-120 ℃ for 20-30 hours, and removing water to obtain a finished product.

The lightweight refractory material obtained by adopting the components and the process has the advantages that the thermal conductivity coefficient is 1.06 (w/m.k) when the lightweight refractory material is detected at 1000 ℃, and is obviously reduced compared with the thermal conductivity coefficient (1.15 (w/m.k)) of the alumina hollow sphere detected under the same condition, so that the heat insulation performance of the ladle permanent layer castable produced by the invention in the use process is greatly improved, as shown in the following table 2.

The specific components (in weight percent) of the other examples 2-5 are also shown in Table 1, and the properties tested are shown in Table 2.

TABLE 1 raw material composition (in weight percent) of the examples

Table 2 comparison table for detecting thermal conductivity of alumina hollow sphere in each embodiment and prior art

As can be seen from table 2 above, when the lightweight refractory material obtained by the present invention and the alumina hollow spheres of the prior art are tested at 1000 ℃, it is found that the lightweight refractory material of the present invention has a thermal conductivity of about 1.06 (w/m.k), and the alumina hollow spheres of the prior art have a thermal conductivity of about 1.15 (w/m.k), the lightweight refractory material of the present invention has a significantly lower thermal conductivity than the prior alumina hollow spheres, and the result proves that the thermal insulation performance of the steel ladle permanent layer castable produced by the present invention is greatly improved in the using process.

Although specific embodiments of the invention have been described herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all embodiments fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents. The protection scope of the invention is subject to the claims.

Claims

1. A lightweight refractory material is spherical particles and is characterized by comprising 2-10% by weight of 0.001-0.074 mm starch; 70-80% of 0.1-1.5 mm sawdust; 5-10% of 50-100 nano-scale alumina powder; 5-10% of 50-100 nano-scale fused spinel powder, and the preparation method of the lightweight refractory material comprises the following steps:

(1) mixing the components according to the proportion, uniformly stirring in a stirrer, adding water according to the proportion of 100-120 kg of water in every 1000 kg of mixed materials, and stirring again;

(2) adding water into the stirred material, and moving the stirred material into a granulator for granulation and forming to enable the particle diameter to be 0.5-5 mm;

(3) and (3) baking the spherical particles obtained in the step (2) at the temperature of 90-120 ℃ for 20-30 hours, and removing water to obtain a finished product.

2. The lightweight refractory according to claim 1, wherein the particle volume density is 1.5 to 1.0g/cm³。