CN106220210B - Fibrous ceramic insulation and preparation method thereof based on polyaluminium chloride waste residue - Google Patents

Abstract

The invention relates to a ceramic fiber thermal insulation material based on polyaluminum chloride waste residue and a preparation method thereof. The technical scheme is: mixing polyaluminum chloride waste residue, aluminum-containing raw materials and additives, adding water to stir, and filtering to obtain the filter material. The filter material, municipal sludge and surfactant are mixed, shaped, heat treated in a reducing atmosphere, ground, and sieved to obtain material A and material B. Material A, material B, silicon-containing raw material and aluminum-containing raw material are mixed, granulated, heat treated in a reducing atmosphere, and then heat treated in a neutral atmosphere to obtain material C and material D. Mix material A, material C, material D, ceramic fibers, binders, inorganic thickeners and organic thickeners, add water and stir, and shape; dry and heat treat to obtain ceramic fiber separators based on polyaluminum chloride waste residue hot material. The invention has the characteristics of wide source of raw materials and low production cost; the prepared ceramic fiber thermal insulation material based on polyaluminum chloride waste slag has small volume density and low thermal conductivity.

Description

Ceramic fiber thermal insulation material based on polyaluminum chloride waste slag and preparation method thereof

technical field

The invention belongs to the technical field of ceramic fiber thermal insulation materials. In particular, it relates to a ceramic fiber thermal insulation material based on polyaluminum chloride waste slag and a preparation method thereof.

Background technique

Polyaluminum chloride waste slag is the waste slag formed by the residual solid after bauxite and calcium aluminate powder react with hydrochloric acid or mixed acid under certain conditions to obtain liquid polyaluminum chloride (PAC). my country produces 400kt of liquid PAC annually, and every 1t of liquid PAC containing 10% alumina will produce 150kg of waste residue, and 60kt of solid waste residue will be generated every year. This kind of waste residue is viscous and weakly acidic, which is extremely harmful to the environment.

At present, the main treatment methods for PAC waste residue at home and abroad are landfill, dumping, brick making or fertilizer production. Landfilling, dumping and other methods have high processing costs, pollute the environment, and occupy land resources. "A burn-free brick with polyaluminum chloride waste slag and red mud as main materials and its preparation method" (ZL 201310486365.5) patented technology, using red mud, polyaluminum chloride waste slag, active mineral materials, lime and gypsum as raw materials , After adding water and mixing, pressing and molding, and watering and curing, the burn-free bricks are obtained. "A polyaluminum chloride filter residue recycling process" (CN 201410572881.4) patented technology uses polyaluminum chloride filter residue as raw material and reuses it in the polyaluminum chloride production system, reducing the discharge of filter residue. However, the existing technology does not make full use of the characteristics of PAC waste residue, nor does it carry out comprehensive development and utilization.

Contents of the invention

The present invention aims to overcome the deficiencies of the prior art, and the purpose is to provide a method for preparing a ceramic fiber thermal insulation material based on polyaluminum chloride waste slag with a wide range of raw material sources and low production cost; The waste ceramic fiber insulation material has small bulk density and low thermal conductivity.

In order to achieve the above object, the concrete steps of the technical solution adopted in the present invention are:

The first step is to mix 20~50wt% polyaluminum chloride waste residue, 40~70wt% aluminum-containing raw materials and 0.1~10wt% additives to obtain the mixture I; add 8~15 times the mass of the mixture I water, stirred at 50-90°C for 3-6 hours, allowed to stand, and filtered to obtain the filter material.

In the second step, 60~80wt% of the filter material, 10~30wt% of urban sludge and 0.1~10wt% of surfactant are mixed uniformly, and pressed and formed under the condition of 50~100MPa; in reducing atmosphere and 600~ Heat treatment at 900°C for 3-6 hours, crush, grind, and sieve to obtain material A with a particle size of less than 0.088mm and material B with a particle size of 0.088-1mm.

In the third step, 20-40wt% of the A material, 10-20wt% of the B material, 10-20wt% of the silicon-containing raw material and 20-40wt% of the aluminum-containing raw material are mixed uniformly and granulated. Screening; heat treatment in a reducing atmosphere at 400-800°C for 3-6 hours, and then in a neutral atmosphere at 1000-1300°C for 3-6 hours to obtain C materials with a particle size of less than 0.25mm and a particle size of 0.25mm ~1.5mm of D material.

In the fourth step, 10~20wt% of the A material, 10~20wt% of the C material, 10~20wt% of the D material, 30~50wt% of the ceramic fiber, 10~20wt% of the binder , 1~10wt% of inorganic thickener and 1~10wt% of organic thickener are mixed uniformly to obtain mixture II; add 10~30wt% water of said mixture II, stir, and extrude; Dry at 80°C for 12-24 hours, and then heat-treat at 900-1100°C for 3-6 hours to prepare ceramic fiber heat insulation material based on polyaluminum chloride waste residue.

The water content of the polyaluminum chloride waste residue is less than 30wt%, the Al content in the polyaluminum chloride waste residue is greater than 18wt%, and the particle size of the polyaluminum chloride waste residue is less than 0.088mm.

The aluminum-containing raw material is aluminum hydroxide or alumina micropowder, the content of Al(OH) in the aluminum hydroxide is greater than 99wt%, the content _{of Al2O3} in the alumina micropowder is greater _than 99wt%, and the The particle size of the aluminum-containing raw material is less than 0.088mm.

The water content of the municipal sludge is less than 10wt%, the _SiO2 content in the municipal sludge is greater than 30wt%, the _Fe2O3 content is less _than 6wt%, the _Al2O3 content is greater _than 10wt%, and the particle size of the municipal sludge is Less than 0.088mm.

The silicon-containing raw material is quartz sand or fused quartz, the content of SiO ₂ in the silicon-containing raw material is greater than 98wt%, and the particle size of the silicon-containing raw material is less than 0.088mm.

The additive is sorbitol or hydroxystearin.

The surfactant is coconut acid diethanolamide or alkyl glucoside.

The reducing atmosphere is a hydrogen atmosphere or a carbon monoxide atmosphere.

The neutral atmosphere is a nitrogen atmosphere or an argon atmosphere.

The ceramic fiber is aluminum silicate ceramic fiber or magnesium silicate ceramic fiber.

The binder is water glass or silica sol, the modulus of the water glass is 1.5-2, and the content of _SiO2 in the silica sol is 25-30wt%.

The inorganic thickener is diatomaceous earth or spherical clay.

The organic thickener is hydroxyethyl cellulose or modified starch.

Owing to adopting above-mentioned technical scheme, the present invention has following positive effect compared with prior art:

The raw materials used in the present invention have a wide range of sources and low production costs; the present invention is beneficial to the homogenization of different raw material particles and the separation between various raw material particles through strict control of the atmosphere, particle size, molding and heat treatment processes in each step. The close contact also provides a reasonable space for the formation of microstructures, so the prepared ceramic fiber insulation material based on polyaluminum chloride waste slag has low volume density and low thermal conductivity.

The ceramic fiber thermal insulation material prepared by the invention based on polyaluminum chloride waste slag is tested: the bulk density is less than 0.35g/cm ³ ; the thermal conductivity at 200-1200°C is 0.05-0.12w/(m·K).

Therefore, the invention has the characteristics of wide source of raw materials and low production cost; the prepared ceramic fiber thermal insulation material based on polyaluminum chloride waste slag has small volume density and low thermal conductivity.

Detailed ways

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

In order to avoid duplication, the materials involved in this specific embodiment are first described in a unified manner as follows, and will not be repeated in the embodiments:

The water content of the polyaluminum chloride waste residue is less than 30wt%, the Al content in the polyaluminum chloride waste residue is greater than 18wt%, and the particle size of the polyaluminum chloride waste residue is less than 0.088mm.

The content of Al(OH) ₃ in the aluminum hydroxide is greater than 99wt%, the content of _Al2O3 in the alumina micropowder is greater _than 99wt%, and the particle size of the aluminum-containing raw material is less than 0.088mm.

The water content of the municipal sludge is less than 10wt%, the _SiO2 content in the municipal sludge is greater than 30wt%, the _Fe2O3 content is less _than 6wt%, the _Al2O3 content is greater _than 10wt%, and the particle size of the municipal sludge is Less than 0.088mm.

The content of SiO ₂ in the silicon-containing raw material is greater than 98wt%, and the particle size of the silicon-containing raw material is less than 0.088mm.

The modulus of the water glass is 1.5-2, and the content of _SiO2 in the silica sol is 25-30wt%.

Example 1

A ceramic fiber thermal insulation material based on polyaluminum chloride waste slag and a preparation method thereof. The preparation method described in this embodiment is:

The first step is to mix 20~35wt% polyaluminum chloride waste residue, 55~70wt% aluminum-containing raw materials and 0.1~10wt% additives to obtain the mixture I; add 8~13 times the mass of the mixture I water, stirred at 50-80°C for 3-6 hours, allowed to stand, and filtered to obtain the filter material.

In the second step, 60~70wt% of the filter material, 20~30wt% of municipal sludge and 0.1~10wt% of surfactant are mixed uniformly, and pressed and formed under the condition of 50~100MPa; in reducing atmosphere and 600~ Heat treatment at 800°C for 3-6 hours, crush, grind, and sieve to obtain material A with a particle size of less than 0.088mm and material B with a particle size of 0.088-1mm.

In the third step, 20~30wt% of the A material, 10~20wt% of the B material, 10~20wt% of the silicon-containing raw material and 30~40wt% of the described aluminum-containing raw material are mixed uniformly and granulated. Screening; heat treatment in a reducing atmosphere at 400-700°C for 3-6 hours, and then in a neutral atmosphere at 1000-1200°C for 3-6 hours to obtain C materials with a particle size of less than 0.25mm and a particle size of 0.25mm ~1.5mm of D material.

In the fourth step, 10~15wt% of the A material, 15~20wt% of the C material, 10~15wt% of the D material, 40~50wt% of the ceramic fiber, 10~15wt% of the binder , 5~10wt% of inorganic thickener and 1~6wt% of organic thickener are mixed evenly to obtain mixture II; add 10~25wt% water of the mixture II, stir, and extrude; Dry at 70°C for 12-24 hours, and then heat-treat at 900-1100°C for 3-6 hours to prepare ceramic fiber heat insulation material based on polyaluminum chloride waste residue.

In this example:

The aluminum-containing raw material is aluminum hydroxide;

The silicon-containing raw material is quartz sand;

The additive is sorbitol;

Described tensio-active agent is coconut oil diethanolamide;

The reducing atmosphere is a hydrogen atmosphere;

The neutral atmosphere is a nitrogen atmosphere;

The ceramic fiber is an aluminum silicate ceramic fiber;

The binding agent is water glass;

The inorganic thickener is diatomaceous earth;

The organic thickener is hydroxyethyl cellulose.

Example 2

A ceramic fiber thermal insulation material based on polyaluminum chloride waste slag and a preparation method thereof. Present embodiment except following material all the other are with embodiment 1:

The aluminum-containing raw material is alumina micropowder;

The silicon-containing raw material is fused silica;

The additive is hydroxystearin;

The surfactant is an alkyl glycoside;

The reducing atmosphere is a carbon monoxide atmosphere;

The neutral atmosphere is an argon atmosphere;

The ceramic fibers are magnesium silicate ceramic fibers;

The binding agent is silica sol;

The inorganic thickener is spherical clay;

The organic thickener is modified starch.

Example 3

A ceramic fiber thermal insulation material based on polyaluminum chloride waste slag and a preparation method thereof. The preparation method described in this embodiment is:

The first step is to mix 35~50wt% of polyaluminum chloride waste residue, 40~55wt% of aluminum-containing raw materials and 0.1~10wt% of additives to obtain the mixture I; add 10~15 times the mass of the mixture I water, stirred at 60-90°C for 3-6 hours, allowed to stand, and filtered to obtain the filter material.

In the second step, 70~80wt% of the filter material, 10~20wt% of municipal sludge and 0.1~10wt% of surfactant are mixed uniformly, and pressed under the condition of 50~100MPa; in reducing atmosphere and 700~ Heat treatment at 900°C for 3-6 hours, crush, grind, and sieve to obtain material A with a particle size of less than 0.088mm and material B with a particle size of 0.088-1mm.

In the third step, 30-40wt% of the A material, 10-20wt% of the B material, 10-20wt% of the silicon-containing raw material and 20-30wt% of the aluminum-containing raw material are mixed uniformly and granulated. Screening; heat treatment in a reducing atmosphere at 500-800°C for 3-6 hours, and then in a neutral atmosphere at 1100-1300°C for 3-6 hours to obtain C materials with a particle size of less than 0.25mm and a particle size of 0.25mm ~1.5mm of D material.

In the fourth step, 15~20wt% of the A material, 10~15wt% of the C material, 15~20wt% of the D material, 30~40wt% of the ceramic fiber, 15~20wt% of the binder , 1~6wt% of inorganic thickener and 5~10wt% of organic thickener are mixed uniformly to obtain mixture II; add 15~30wt% water of said mixture II, stir, and extrude; Dry at 80°C for 12-24 hours, and then heat-treat at 900-1100°C for 3-6 hours to prepare ceramic fiber heat insulation material based on polyaluminum chloride waste residue.

In this example:

The aluminum-containing raw material is aluminum hydroxide;

The silicon-containing raw material is quartz sand;

The additive is sorbitol;

Described tensio-active agent is coconut oil diethanolamide;

The reducing atmosphere is a hydrogen atmosphere;

The neutral atmosphere is a nitrogen atmosphere;

The ceramic fiber is an aluminum silicate ceramic fiber;

The binding agent is water glass;

The inorganic thickener is diatomaceous earth;

The organic thickener is hydroxyethyl cellulose.

Example 4

A ceramic fiber thermal insulation material based on polyaluminum chloride waste slag and a preparation method thereof. Present embodiment is all the same as embodiment 3 except following material:

The aluminum-containing raw material is alumina micropowder;

The silicon-containing raw material is fused silica;

The additive is hydroxystearin;

The surfactant is an alkyl glycoside;

The reducing atmosphere is a carbon monoxide atmosphere;

The neutral atmosphere is an argon atmosphere;

The ceramic fibers are magnesium silicate ceramic fibers;

The binding agent is silica sol;

The inorganic thickener is spherical clay;

The organic thickener is modified starch.

Compared with the prior art, this specific embodiment has the following positive effects:

The source of raw materials used in this specific embodiment is wide, and the production cost is low; this specific embodiment is beneficial to the homogenization of different raw material particles and various The close contact between raw material particles also provides a reasonable space for the formation of microstructures, so the prepared ceramic fiber insulation material based on polyaluminum chloride waste slag has low volume density and low thermal conductivity.

The ceramic fiber insulation material based on polyaluminum chloride waste slag prepared in this specific embodiment is tested: the bulk density is less than 0.35g/cm ³ ; the thermal conductivity at 200-1200°C is 0.05-0.12w/(m·K).

Therefore, this specific embodiment has the characteristics of wide source of raw materials and low production cost; the prepared ceramic fiber thermal insulation material based on polyaluminum chloride waste slag has small volume density and low thermal conductivity.

Claims (9)

1. A preparation method based on polyaluminum chloride waste slag ceramic fiber insulation material, characterized in that the preparation method is: The first step is to mix 20-50wt% of polyaluminum chloride waste residue, 40-70wt% of aluminum-containing raw materials and 0.1-10wt% of additives to obtain the mixture I; add 8-15 times the mass of the mixture I water, stirred at 50-90°C for 3-6 hours, allowed to stand, and filtered to obtain the filter material; In the second step, 60-80wt% of the filter material, 10-30wt% of municipal sludge and 0.1-10wt% of surfactant are mixed evenly, and pressed under the condition of 50-100MPa; Heat treatment at 900°C for 3-6 hours, crushing, grinding, and sieving to obtain material A with a particle size of less than 0.088mm and material B with a particle size of 0.088-1mm; In the third step, 20-40wt% of the A material, 10-20wt% of the B material, 10-20wt% of the silicon-containing raw material and 20-40wt% of the aluminum-containing raw material are mixed uniformly, and granulated, Screening; heat treatment in a reducing atmosphere at 400-800°C for 3-6 hours, and then in a neutral atmosphere at 1000-1300°C for 3-6 hours to obtain C materials with a particle size of less than 0.25mm and a particle size of 0.25mm ~1.5mm D material; In the fourth step, 10-20wt% of the A material, 10-20wt% of the C material, 10-20wt% of the D material, 30-50wt% of the ceramic fiber, and 10-20wt% of the binder , 1-10wt% of inorganic thickener and 1-10wt% of organic thickener are mixed evenly to obtain mixture II; add 10-30wt% water of said mixture II, stir, and extrude; Drying at 80°C for 12 to 24 hours, and then heat treatment at 900 to 1100°C for 3 to 6 hours to prepare a ceramic fiber insulation material based on polyaluminum chloride waste residue; The water content of the polyaluminum chloride waste residue is less than 30wt%, the Al content in the polyaluminum chloride waste residue is greater than 18wt%, and the particle size of the polyaluminum chloride waste residue is less than 0.088mm; The aluminum-containing raw material is aluminum hydroxide or alumina micropowder, the content of Al(OH) ₃ in the aluminum hydroxide is greater than 99wt%, the content of _Al2O3 in the alumina micropowder is greater _than 99wt%, and the The particle size of aluminum-containing raw materials is less than 0.088mm; The water content of the municipal sludge is less than 10wt%, the _SiO2 content in the municipal sludge is greater than 30wt%, the _Fe2O3 content is less _than 6wt%, and the _Al2O3 content is greater _than 10wt%, and the particle size of the municipal sludge is Less than 0.088mm; The silicon-containing raw material is quartz sand or fused quartz, the content of _SiO2 in the silicon-containing raw material is greater than 98wt%, and the particle size of the silicon-containing raw material is less than 0.088mm; The additive is sorbitol or hydroxystearin. 2. according to the preparation method of the said polyaluminum chloride waste slag-based ceramic fiber thermal insulation material of claim 1, it is characterized in that said tensio-active agent is coconut oil diethanolamide or is alkyl glucoside. 3. The preparation method of the ceramic fiber thermal insulation material based on polyaluminum chloride waste slag according to claim 1, characterized in that the reducing atmosphere is a hydrogen atmosphere or a carbon monoxide atmosphere. 4. The preparation method of the ceramic fiber thermal insulation material based on polyaluminum chloride waste slag according to claim 1, characterized in that the neutral atmosphere is a nitrogen atmosphere or an argon atmosphere. 5. The preparation method of the ceramic fiber thermal insulation material based on polyaluminum chloride waste slag according to claim 1, characterized in that the ceramic fiber is aluminum silicate ceramic fiber or magnesium silicate ceramic fiber. 6. The preparation method of the ceramic fiber thermal insulation material based on polyaluminum chloride waste slag according to claim 1, characterized in that the binder is water glass or silica sol, and the modulus of the water glass is 1.5 to 2 , the content of SiO ₂ in the silica sol is 25-30wt%. 7. The preparation method of the ceramic fiber thermal insulation material based on polyaluminum chloride waste slag according to claim 1, characterized in that the inorganic thickener is diatomaceous earth or ball clay. 8. The preparation method of the ceramic fiber thermal insulation material based on polyaluminum chloride waste slag according to claim 1, characterized in that the organic thickener is hydroxyethyl cellulose or modified starch. 9. A ceramic fiber heat insulation material based on polyaluminum chloride waste residue, characterized in that the ceramic fiber heat insulation material based on polyaluminum chloride waste residue is based on polyaluminum chloride waste according to any one of claims 1 to 8. The preparation method of the ceramic fiber thermal insulation material based on aluminum chloride waste slag prepares the ceramic fiber thermal insulation material based on polyaluminum chloride waste slag.