CN101713235B - A kind of forsterite lightweight brick and its preparation method - Google Patents

Abstract

The invention relates to a forsterite light brick and a preparation method thereof. The method adopts the following technical scheme: mixing 60 to 95 weight percent of forsterite raw material and 5 to 40 weight percent of magnesium oxide; adding 25 to 45 weight percent of water, 0.05 to 0.5 weight percent of bonding agent, 0.1 to 0.5 weight percent of water reducer and 0 to 0.5 weight percent of mineralizer and uniformly mixing the mixture; adding foam made of 0.5 to 2 weight percent of foaming agent into the mixture; casting the mixture after uniformly stirring; naturally drying the mixture; baking the mixture at low temperature; and sintering the mixture at the temperature of between 1,300 and 1,550 DEG C, and preserving the heat for 2.5 to 12 hours. The forsterite light brick prepared by the invention has excellent compression strength, lower volume density and heat conductivity, and can be used in production of furnace construction insulating materials in steel, ceramic and other industries after being subjected to heat treatment at the temperature of between 1,300 and 1,550 DEG C; and the used forsterite raw material is forsterite tailings with few utilization value at present, which not only reduces production cost, but also can realize good economic and social benefit.

Description

A kind of forsterite lightweight brick and its preparation method

technical field

The invention belongs to the technical field of lightweight bricks, and in particular relates to a forsterite lightweight brick and a preparation method thereof.

Background technique

Energy conservation is one of the important measures to maintain sustainable economic development, and thermal insulation is one of the important measures for energy conservation. Therefore, lightweight thermal insulation materials with micro-nano pores play an important role in the field of thermal insulation. High-quality lightweight refractory products require good high-temperature performance, high strength at room temperature, low thermal conductivity, and good thermal insulation performance; thus, higher requirements are put forward for the preparation method of lightweight materials.

Forsterite lightweight thermal insulation material has a series of advantages such as high compressive strength, low bulk density, good thermal insulation performance and excellent high temperature thermal stability. It is a new type of high-strength light-weight heat insulation material for high-temperature industries, especially iron and steel smelting, ceramics and cement production equipment. At present, the production of forsterite lightweight materials mainly includes gas generation method and porous material method. The gas generation method cannot guarantee the uniformity of the pores and is unstable, resulting in poor slag resistance of the product. For example, the in-situ decomposition method is used in the gas generation method (Hu Limin, Li Nan. In-situ decomposition to prepare high-strength light forsterite material. Refractory Materials. 2005, 39[4]: 283-285) prepared forsterite insulation materials, on the one hand, did not directly use forsterite tailings raw materials, which is not conducive to resource utilization; on the other hand, the uniformity of pores generated by in-situ decomposition It cannot be guaranteed and the pores are irregular, so the strength and heat insulation effect of the product cannot be guaranteed. The scope of application of the porous material method is limited, and the energy consumption is high; as a method for preparing forsterite light materials with carbonate powder, chloride salt and talc raw ore powder (Deng Chengji, Zhu Hongxi, etc. A kind of forsterite light Materials and their preparation method, 200910060878.3); method for preparing forsterite thermal insulation material with chloride salt, carbonate and forsterite ore powder as raw materials (Deng Chengji, Zhu Hongxi, etc. A kind of forsterite thermal insulation material and its preparation method, 200910060879.8); and a method for preparing forsterite light material with chloride salt and forsterite raw ore powder (Deng Chengji, Zhu Hongxi, etc. A kind of high thermal resistance forsterite light material and its preparation method, 200910060875.X ) The main defects of this series of methods are as follows: (1) the production process is complicated, and multiple processes are needed to complete; (2) the pores of the product are not uniform and most of them are open pores, which will affect the heat insulation effect of the product; (3) ) soaking in water will cause serious waste of water resources and increase production costs; (4) the chlorine gas produced in the firing process will directly enter the air and pollute the environment; (4) soaking is difficult to clean the residual chloride, and the melting point of chloride Lower, which will seriously affect the high temperature performance of the product. Or forsterite light materials prepared by other methods either have a higher bulk density or a lower use temperature.

Contents of the invention

The invention aims to overcome the defects of the prior art, and aims to provide a method for preparing a forsterite lightweight brick with simple manufacturing process, energy saving and environmental protection, and excellent performance. The prepared forsterite lightweight brick has high strength, low bulk density and thermal conductivity.

In order to achieve the above purpose, the technical solution adopted in the present invention is: first mix 60-95wt% of forsterite raw material and 5-40wt% magnesium oxide, add 25-45wt% of water, 0.05-0.5wt% of binder , 0.1-0.5wt% water-reducing agent and 0-0.5% mineralizer are mixed evenly, and the foam made by adding 0.5-2wt% foaming agent is added, stirred evenly, casted, dried naturally, and baked at low temperature. Fire at 1300-1550°C and keep warm for 2.5-12 hours.

Among them: the particle size of forsterite raw material is less than 200 mesh; magnesia is one of light-burned magnesia, sintered magnesia, and fused magnesia, and the particle size is all less than 180 mesh; the binder is carboxymethyl cellulose, One of silica sol and phenolic resin; water reducer is more than one of sodium tripolyphosphate, sodium hexametaphosphate, sodium lignosulfonate; mineralizer or MgCl ₂ or NH ₄ OH.

Due to the adoption of the above-mentioned technical scheme, the main raw material forsterite used in the present invention is forsterite tailings raw material with little value at present, and the cost is relatively low; the production process is also very simple, and it can be casted after casting It is used in the production of furnace insulation materials in various industries such as steel and ceramics; at the same time, the whole process will not produce harmful gases, and it also plays a certain role in protecting the environment. The forsterite lightweight brick prepared by the foam method in the present invention has a large number of closed and uniform tiny pores formed inside the material, which is conducive to improving the heat insulation effect and mechanical properties of the material, and the prepared forsterite lightweight brick has a volume density of 0.6 ～1.2g/cm ³ , thermal conductivity 0.2～0.60w/(mk), compressive strength 3.0～11.5MPa, which can well meet the current production requirements of thermal industry.

Therefore, the present invention has the advantages of low production cost, simple process, energy saving and environmental protection, and easy large-scale production, and the produced lightweight brick products also have higher strength, lower bulk density and thermal conductivity. Has a wide range of social and economic value.

Detailed ways

The present invention will be further described below in combination with specific embodiments, which are not intended to limit the protection scope of the present invention.

In this specific embodiment, the parameters to be involved are uniformly described as follows: the particle size of the forsterite raw material is less than 200 mesh; the particle size of light-burned magnesia, sintered magnesia and fused magnesia is all less than 180 mesh. It will not be described in detail in the embodiments.

Example 1:

A forsterite lightweight brick and a preparation method thereof. First mix 60-70wt% forsterite raw material and 30-40wt% light-burned magnesia, add 38-45wt% water, 0.05-0.2wt% carboxymethyl cellulose and 0.1-0.3wt% three Mix sodium polyphosphate evenly, add 0.5~0.8wt% foaming agent to make foam, stir evenly, cast into shape, dry naturally, bake at low temperature, burn at 1450~1550℃, keep warm for 2.5~ 6 hours.

The bulk density of the forsterite lightweight brick prepared in Example 1 is 0.9-1.2 g/cm ³ , the thermal conductivity is 0.30-0.60 w/(mk), and the compressive strength reaches 3.0-10.8 MPa.

Example 2

A forsterite lightweight brick and a preparation method thereof. First mix 70-75wt% forsterite raw material and 25-30wt% light-burned magnesia, add 35-42wt% water, 0.1-0.4wt% phenolic resin, 0.2-0.5wt% lignosulfonic acid Sodium and 0.1-0.5wt% MgCl ₂ are mixed evenly, and the foam made by adding 0.8-2wt% foaming agent is added, stirred evenly, poured, dried naturally, baked at low temperature, under the condition of 1400-1500°C Firing and heat preservation for 6.0 to 10 hours.

The bulk density of the forsterite lightweight brick prepared in Example 2 is 0.8-1.1 g/cm ³ , the thermal conductivity is 0.30-0.50 w/(mk), and the compressive strength reaches 3.4-10.4 MPa.

Example 3

A forsterite lightweight brick and a preparation method thereof. First mix 75-80wt% forsterite raw material and 20-25wt% light-burned magnesia, add 30-40wt% water, 0.3-0.5wt% silica sol, 0.1-0.2wt% sodium tripolyphosphate , 0.05-0.3wt% sodium lignosulfonate and 0.1-0.4% MgCl ₂ are mixed evenly, and the foam made by adding 0.8-1.5wt% foaming agent is added, and the foam is poured after being stirred evenly, naturally dried, and low temperature Baking, firing under the condition of 1300-1500 ℃, heat preservation for 8.0-12 hours.

The bulk density of the forsterite lightweight brick prepared in Example 3 is 0.7-1.0 g/cm ³ , the thermal conductivity is 0.20-0.50 w/(mk), and the compressive strength reaches 3.2-9.4 MPa.

Example 4

A forsterite lightweight brick and a preparation method thereof. First mix 80-90wt% forsterite raw material and 10-20wt% light-burned magnesia, add 25-40wt% water, 0.05-0.4wt% carboxymethyl cellulose, 0.1-0.3wt% hexa Sodium metaphosphate and 0.05-0.4% MgCl ₂ are mixed evenly, and the foam made by adding 1.0-2.0wt% foaming agent is added, stirred evenly, poured, dried naturally, baked at low temperature, at 1350-1500 ° C Firing under conditions, heat preservation for 2.5 to 10 hours.

The volume density of the forsterite lightweight brick prepared in Example 4 is 0.6-0.9 g/cm ³ , the thermal conductivity is 0.20-0.50 w/(mk), and the compressive strength reaches 3.6-11.5 MPa.

Example 5

A forsterite lightweight brick and a preparation method thereof. First mix 80-85wt% forsterite raw material and 15-20wt% light-burned magnesia, add 28-40wt% water, 0.05-0.3wt% carboxymethyl cellulose, 0.05-0.15wt% six Sodium metaphosphate and 0.1-0.2wt% sodium tripolyphosphate are mixed evenly, and the foam made by adding 0.5-1.0wt% foaming agent is added, stirred evenly, poured, dried naturally, baked at low temperature, at 1450~ Firing at 1550°C, heat preservation for 6.0 to 10 hours.

The bulk density of the forsterite lightweight brick prepared in Example 5 is 0.7-0.9 g/cm ³ , the thermal conductivity is 0.20-0.50 w/(mk), and the compressive strength reaches 3.6-10.8 MPa.

Example 6

A forsterite lightweight brick and a preparation method thereof. First mix 85-90wt% forsterite raw material and 10-15wt% light-burned magnesia, add 25-35wt% water, 0.05-0.2wt% carboxymethyl cellulose, 0.1-0.3wt% hexa Mix sodium metaphosphate and 0.05-0.2wt% MgCl ₂ evenly, add 0.5-1.2wt% foaming agent to form a foam, stir it evenly, cast it, dry it naturally, bake it at low temperature, at 1350-1450℃ Firing under certain conditions, heat preservation for 2.5 to 8.0 hours.

The bulk density of the forsterite lightweight brick prepared in Example 6 is 0.6-0.8 g/cm ³ , the thermal conductivity is 0.20-0.40 w/(mk), and the compressive strength reaches 4.0-11.5 MPa.

Example 7

A forsterite lightweight brick and a preparation method thereof. First mix 90-95wt% forsterite raw material with 5-10wt% sintered magnesia, add 25-32wt% water, 0.2-0.3wt% silica sol, 0.05-0.2wt% sodium hexametaphosphate, 0.05-0.1wt% sodium lignosulfonate and 0.05-0.3wt% MgCl ₂ are mixed evenly, and the foam made by adding 0.8-1.8wt% foaming agent is added, stirred evenly and casted, naturally dried, low temperature Baking, firing under the condition of 1400-1500 ℃, heat preservation for 8.0-12 hours.

The bulk density of the forsterite lightweight brick prepared in Example 7 is 0.7-1.1 g/cm ³ , the thermal conductivity is 0.30-0.50 w/(mk), and the compressive strength reaches 3.5-10.6 MPa.

Example 8

A forsterite lightweight brick and a preparation method thereof. First mix 60-75wt% forsterite raw material and 25-40wt% fused magnesia, add 35-45wt% water, 0.15-0.35wt% carboxymethyl cellulose, 0.1-0.35wt% wood Mix sodium sulfonate and 0.2-0.5wt% MgCl ₂ evenly, and then add 0.8-1.5wt% foaming agent to form a foam, stir it evenly, cast it, dry it naturally, bake it at low temperature, at 1400-1500 Firing under the condition of ℃, heat preservation for 8.0 to 12 hours.

The volume density of the forsterite lightweight brick prepared in Example 8 is 1.0-1.2 g/cm ³ , the thermal conductivity is 0.40-0.60 w/(mk), and the compressive strength reaches 3.4-10.0 MPa.

Example 9

A forsterite lightweight brick and a preparation method thereof. First mix 75-85wt% forsterite raw material and 15-25wt% fused magnesia, add 32-40wt% water, 0.05-0.25wt% phenolic resin, 0.1-0.15wt% sodium hexametaphosphate , 0.1-0.2wt% sodium tripolyphosphate, 0.05-0.15wt% sodium lignosulfonate and 0.1-0.5wt% MgCl ₂ are mixed evenly, and then 0.5-1.0wt% foaming agent is added The foam is stirred evenly and cast into shape, dried naturally, baked at low temperature, fired at 1350-1450°C, and kept for 6.0-10 hours.

The bulk density of the forsterite lightweight brick prepared in Example 9 is 0.9-1.2 g/cm ³ , the thermal conductivity is 0.30-0.60 w/(mk), and the compressive strength reaches 3.2-9.3 MPa.

Example 10

A forsterite lightweight brick and a preparation method thereof. First mix 85-90wt% of forsterite raw material and 10-15wt% of fused magnesia, add 30-40wt% of water, 0.1-0.2wt% of carboxymethyl cellulose, 0.1-0.3wt% of six Sodium metaphosphate and 0.05-0.2wt% NH ₄ OH are mixed evenly, and the foam made by adding 0.8-2wt% foaming agent is added, stirred evenly, poured, dried naturally, baked at low temperature, at 1450-1550°C Firing under certain conditions, heat preservation for 6.0 to 10 hours.

The volume density of the forsterite lightweight brick prepared in Example 10 is 0.7-1.0 g/cm ³ , the thermal conductivity is 0.20-0.50 w/(mk), and the compressive strength reaches 3.0-8.2 MPa.

Example 11

A forsterite lightweight brick and a preparation method thereof. First mix 90-95wt% of forsterite raw material and 5-10wt% of sintered magnesia, add 25-35wt% of water, 0.2-0.5wt% of silica sol, 0.1-0.4wt% of sodium hexametaphosphate and Mix 0.1~0.3wt% NH ₄ OH evenly, add 0.6~1.8wt% foaming agent to make foam, stir evenly, pour into molding, dry naturally, bake at low temperature, under the condition of 1350~1450℃ Firing and heat preservation for 8.0 to 12 hours.

The bulk density of the forsterite lightweight brick prepared in Example 11 is 0.8-1.1 g/cm ³ , the thermal conductivity is 0.30-0.50 w/(mk), and the compressive strength reaches 3.2-8.8 MPa.

The main raw material used in this specific embodiment is forsterite tailings raw material with little utilization value at present, and the cost is relatively low; the production process is also very simple. It can be put into steel, ceramics after being fired by casting. It is used in the production of furnace insulation materials in various industries; at the same time, the whole process will not produce harmful gases, and it also plays a certain role in protecting the environment. The forsterite lightweight brick prepared by the foam method in the present invention has a large number of closed and uniform tiny pores formed inside the material, which is conducive to improving the heat insulation effect and mechanical properties of the material, and the prepared forsterite lightweight brick has a volume density of 0.6 ～1.2g/cm ³ , thermal conductivity 0.2～0.60w/(mk), compressive strength 3.0～11.5MPa, which can well meet the current production requirements of thermal industry.

Therefore, this specific embodiment has the advantages of low production cost, simple process, energy saving and environmental protection, and easy large-scale production, and the produced lightweight brick products also have higher strength, lower bulk density and thermal conductivity. Has a wide range of social and economic value.

Claims (7)

1. A preparation method for forsterite lightweight brick, characterized in that 60-95wt% forsterite raw material and 5-40wt% magnesia are mixed, and 25-45wt% water, 0.05-0.5wt% The binder, 0.1-0.5wt% water-reducing agent and 0-0.5wt% mineralizer are mixed evenly, and then the foam made by adding 0.5-2wt% foaming agent is mixed evenly, poured and molded, and dried naturally , baked at low temperature, fired at 1300-1550°C, and kept warm for 2.5-12 hours. 2. The preparation method of the forsterite lightweight brick according to claim 1, characterized in that the particle size of the forsterite raw material is less than 200 mesh. 3. The preparation method of forsterite lightweight brick according to claim 1, characterized in that the magnesia is one of light-burned magnesia, sintered magnesia, and fused magnesia, and the particle size is less than 180 mesh. 4. The preparation method of forsterite lightweight brick according to claim 1, characterized in that said binding agent is one of carboxymethyl cellulose, silica sol, and phenolic resin. 5. The preparation method of forsterite lightweight brick according to claim 1, characterized in that said water reducer is more than one of sodium tripolyphosphate, sodium hexametaphosphate and sodium lignosulfonate. 6. The preparation method of forsterite lightweight brick according to claim 1, characterized in that the mineralizer is MgCl ₂ or NH ₄ OH. 7. The forsterite lightweight brick prepared by the method for preparing the forsterite lightweight brick according to any one of claims 1-6.