CN111499400A

CN111499400A - High-strength low-rebound fireproof spray coating and preparation method thereof

Info

Publication number: CN111499400A
Application number: CN202010342258.5A
Authority: CN
Inventors: 何贯通; 郭宏相; 李放; 万俊; 张群英; 石立光
Original assignee: HENAN HONGDA FURNACE INDUSTRIAL CO LTD
Current assignee: HENAN HONGDA FURNACE INDUSTRIAL CO LTD
Priority date: 2020-04-27
Filing date: 2020-04-27
Publication date: 2020-08-07
Anticipated expiration: 2040-04-27
Also published as: CN111499400B

Abstract

The invention discloses a high-strength low-rebound fireproof spray coating and a preparation method thereof, relates to the technical field of fireproof materials, solves the problems of low strength and high rebound rate of the existing light-weight spray coating, adopts the scheme that 30-35% of flint clay, 20-25% of porous mullite, 6-8% of expanded vermiculite, 5-6% of floating beads and 28.5-32% of composite bonding agent are adopted, firstly, silicate cement, CA-60 aluminate cement, CA-80 aluminate cement and active SiO are mixed, and the mixture is subjected to mixing and stirring₂Preparing the micro powder, the 200-mesh raw argil powder, NaOH and triethanolamine into a composite binder by adopting a horizontal dry-process ball mill; then mixing the composite binder with the expanded vermiculite and the floating beads by adopting a planetary mixer; finally adding flint clay and porous mullite and then carrying out planetary stirring to obtain a finished product; the compactness of the spray coating is effectively enhanced, the adhesion and the sintering property of the whole binding agent are good, the strength of the spray coating is high, and the rebound rate is low; during preparation, the horizontal dry ball mill and the planetary stirrer are mixed in three steps, and the uniformity and the activity of the spray coating are high.

Description

High-strength low-rebound fireproof spray coating and preparation method thereof

Technical Field

The invention relates to the technical field of refractory materials, in particular to a high-strength low-rebound refractory spray coating and a preparation method thereof.

Background

The refractory spray coating is an unshaped refractory constructed by utilizing a pneumatic tool and a mechanical spraying method, is a bulk material prepared by taking clay clinker as a raw material, is an important branch of the unshaped refractory, has good high-temperature performance and construction performance, has high construction efficiency when being applied to a lining of a high-temperature industrial furnace, can effectively shorten the construction time, and is widely applied to refractory linings of high-temperature industrial furnaces such as ferrous metallurgy, building materials and the like.

The spray coating is generally composed of aggregate, powder, a bonding agent and an additive, and is constructed by a dry method or a semi-dry method by a spraying machine. Mainly comprises heavy spray paint and light spray paint, and the volume density of the light spray paint is generally lower than 1.8g/cm³. The light spraying paint mainly adopts raw materials such as clay, ceramsite, perlite and the like, and although the light spraying paint has good heat insulation performance, the light spraying paint has lower strength compared with a heavy spraying paint, and the application range of the light spraying paint is limited. And when the light spray coating is constructed, the rebound rate is high and can reach 30 percent, and the loss is large. Therefore, it is required to improve the strength of the light-weight spray paint and reduce the construction rebound rate.

Disclosure of Invention

The invention aims to: the invention provides a high-strength low-rebound fireproof spray coating and a preparation method thereof, aiming at solving the problems of low strength and high rebound rate of the existing light spray coating.

The invention specifically adopts the following technical scheme for realizing the purpose: a high-strength low-rebound fireproof spray coating is characterized by comprising flint clay, porous mullite, expanded vermiculite, floating beads and a composite bonding agent in percentage by weight as follows:

30-35% of flint clay, 20-25% of porous mullite, 6-8% of expanded vermiculite, 5-6% of floating bead and 28.5-32% of composite bonding agent;

the composite binder comprises the following components: 20 to 25 percent of Portland cement, 30 to 35 percent of CA-60 aluminate cement, 20 to 24 percent of CA-80 aluminate cement, and active SiO₂8-12% of micro powder, 8-15% of 200-mesh raw pottery clay powder, 1-2% of NaOH and 1-2% of triethanolamine.

Further, the volume density of the flint clay is more than 2.3g/cm³1.2-3 mm grain size, Al in flint clay₂O₃The content is 35 to 40 percent; the bulk density of the porous mullite is 1.0-1.2 g/cm³Porous mullite Al with particle size of 0.3-1.2 mm₂O₃The content is 36 to 40 percent; calcining the expanded vermiculite at 850-880 ℃ with the volume weight of 120-160 kg/mm³,Al₂O₃The content is 40-42%, and the grain diameter is less than 0.3 mm; the particle size of the floating bead is less than 200 mu m, and Al in the floating bead₂O₃35 to 40 percent of SiO₂50-61% of Fe₂O₃Content 1.5% -3.5%, R₂The content of O is 0.4 to 1.6 percent.

Further, the active SiO₂The pH value of the micro powder is 9.3 to 9.5, and the surface area is 15 to 17m².g^-1,SiO₂The content is 87-90 percent.

A preparation method of a high-strength low-rebound fireproof spray coating is characterized by comprising the following steps:

(1) mixing Portland cement, CA-60 aluminate cement, CA-80 aluminate cement and active SiO₂Mixing the micro powder, 200-mesh raw pottery clay powder, NaOH and triethanolamine, and grinding for 10-15 minutes by using a horizontal dry ball mill to prepare a composite binder;

(2) stirring and mixing the composite bonding agent prepared in the step 1, expanded vermiculite and floating beads for 2-5 minutes by using a planetary stirrer;

(3) adding flint clay and porous mullite into the planetary stirrer in the step 2, and continuously stirring for 3-5 minutes to prepare a high-strength low-rebound fireproof spray coating;

(4) and packaging the mixture according to the industry standard of refractory materials.

The invention has the following beneficial effects:

1. according to the invention, the flint clay, the porous mullite, the expanded vermiculite and the floating beads are mixed, the component contents of all the components are reasonably controlled, the particle size of all the components is optimized, the critical granularity of the aggregate is effectively reduced, the compactness of the spray coating is effectively enhanced, and the strength of the whole spray coating is effectively improved;

2. in the binding agent, silicate cement, aluminate cement and CA-80 aluminate cement are optimally combined, so that the binding property is effectively improved, the adhesion and high-temperature sintering property are effectively improved by adding the active SiO2 micro powder and the clay powder with excellent amount, NaOH and triethanolamine are added according to the optimal proportion, so that the spray coating has good coagulability and strength development, and the fineness of the binding agent is effectively increased and the uniformity of the binding agent is enhanced by ball milling after mixing; the whole bonding agent has the advantages of short solidification time, good adhesiveness and sintering property, effective improvement of the strength of the spray coating, good construction performance and low rebound rate;

3. the preparation method of the invention further effectively improves the uniformity and activity of the spray coating, improves the strength and reduces the rebound rate by three-step mixing of the horizontal dry ball mill and the planetary stirrer.

4. By adopting the technical scheme of the invention, the construction rebound rate is effectively reduced to below 6 percent from the original 15 percent, and the indexes are as follows:

Detailed Description

Example 1

A high-strength low-rebound fireproof spray coating is prepared from the following raw materials in percentage by weight: 35% of flint clay, 20% of porous mullite, 8% of expanded vermiculite, 5% of floating beads and 32% of composite bonding agent.

Flint clay Al₂O₃The content is 40 percent, and the volume density is 2.32g/cm³And the particle size is 3-1.2 mm.

Porous mullite Al₂O₃The content is 40 percent, and the bulk density is 1.2g/cm³And the particle size is 1.2-0.3 mm.

Calcining the expanded vermiculite at 850-880 ℃ with the volume weight of 160kg/m³,Al₂O₃Content is 42%, and particle diameter is less than 0.3 mm.

Floating bead Al₂O₃40% of SiO₂55% of Fe₂O₃Content 2.5%, R₂The O content is 1.2 percent, and the grain diameter is less than 200 mu m.

The composite binder adopts 20 percent of Portland cement, 30 percent of CA-60 aluminate cement, 20 percent of CA-80 aluminate cement and 12 percent of active SiO₂The micro powder, 15 percent of 200-mesh raw pottery clay powder, 1.5 percent of NaOH and 1.5 percent of triethanolamine are co-ground for 15 minutes by a horizontal dry ball mill. Wherein, active SiO₂The pH value of the micro powder is 9.3, and the specific surface area is 15m².g^-1,SiO₂The content is 87%.

A preparation method of a high-strength low-rebound fireproof spray coating comprises the following steps:

(1) mixing Portland cement, CA-60 aluminate cement, CA-80 aluminate cement and active SiO₂Mixing the micro powder, 200-mesh raw argil powder, NaOH and triethanolamine, and grinding for 15 minutes by using a horizontal dry-process ball mill to prepare a composite binder;

(2) stirring and mixing the composite bonding agent prepared in the step 1, expanded vermiculite and floating beads for 2 minutes by using a planetary stirrer;

(3) adding flint clay and porous mullite into the planetary stirrer in the step 2, and continuing stirring for 5 minutes to prepare a high-strength low-rebound fireproof spray coating;

(4) and packaging the mixture according to the industrial standard of the refractory material, and transporting the mixture to a site for spraying construction by using a spraying machine when in use.

The high strength, low bounce spray paint prepared using this example employed the following test indexes:

example 2

A high-strength low-rebound fireproof spray coating is prepared from the following raw materials in percentage by weight: 30% of flint clay, 25% of porous mullite, 7% of expanded vermiculite, 6% of floating beads and 32% of composite bonding agent.

Flint clay Al₂O₃The content is 36 percent, and the volume density is 2.35g/cm³And the particle size is 3-1.2 mm.

Porous mullite Al₂O₃Content 36% and a bulk density of 1.15g/cm³And the particle size is 1.2-0.3 mm.

Calcining the expanded vermiculite at 860-880 ℃ and obtaining the bulk density of 120kg/m³,Al₂O₃42 percent and the grain diameter is less than 0.3 mm.

Floating bead Al₂O₃35% of SiO₂60% of Fe₂O₃Content 3.5%, R₂The O content is 1.2 percent, and the grain diameter is less than 200 mu m.

The composite binder adopts 25 percent of Portland cement, 30 percent of CA-60 aluminate cement, 20 percent of CA-80 aluminate cement and 8 percent of active SiO₂The micro powder, 15 percent of 200-mesh raw pottery clay powder, 1.0 percent of NaOH and 1.0 percent of triethanolamine are milled for 12 minutes by a horizontal dry ball mill. Wherein, active SiO₂The pH value of the micro powder is 9.5, and the specific surface area is 17m².g^-1,SiO₂The content is 90 percent.

(1) mixing Portland cement, CA-60 aluminate cement, CA-80 aluminate cement and active SiO₂Mixing the micro powder, 200-mesh raw argil powder, NaOH and triethanolamine, and grinding for 12 minutes by using a horizontal dry-process ball mill to prepare a composite binder;

(3) adding flint clay and porous mullite into the planetary stirrer in the step 2, and continuously stirring for 3 minutes to prepare a high-strength low-rebound fireproof spray coating;

example 3

A high-strength low-rebound fireproof spray coating is prepared from the following raw materials in percentage by weight: 33% of flint clay, 23% of porous mullite, 8% of expanded vermiculite, 6% of floating beads and 30% of composite bonding agent.

Flint clay Al₂O₃The content is 38 percent, and the volume density is 2.31g/cm³And the particle size is 3-1.2 mm.

Porous mullite Al₂O₃The content is 38 percent, and the bulk density is 1.18g/cm³And the particle size is 1.2-0.3 mm.

Calcining the expanded vermiculite at 860-880 ℃ and obtaining the bulk density of 130kg/m³,Al₂O₃The content is 41 percent, and the grain diameter is less than 0.3 mm.

Floating bead Al₂O₃36% of SiO₂Content 57% Fe₂O₃Content 2.0%, R₂The O content is 1.0 percent, and the grain diameter is less than 200 mu m.

The composite binder adopts 22 percent of Portland cement, 31.6 percent of CA-60 aluminate cement, 21 percent of CA-80 aluminate cement and 8 percent of active SiO₂The micro powder, 15 percent of 200-mesh raw pottery clay powder, 1.2 percent of NaOH and 1.2 percent of triethanolamine are milled for 10 minutes by a horizontal dry ball mill. Wherein, active SiO₂The pH value of the micro powder is 9.5, and the specific surface area is 17m².g^-1,SiO₂The content is 90 percent.

(3) adding flint clay and porous mullite into the planetary stirrer in the step 2, and continuously stirring for 4 minutes to prepare a high-strength low-rebound fireproof spray coating;

example 4

A high-strength low-rebound fireproof spray coating is prepared from the following raw materials in percentage by weight: 35% of flint clay, 25% of porous mullite, 6% of expanded vermiculite, 5.5% of floating beads and 28.5% of composite bonding agent.

Flint clay Al₂O₃Content 39%, volume density 2.32g/cm³And the particle size is 3-1.2 mm.

Porous mullite Al₂O₃Content 38%, bulk density 1.19g/cm³And the particle size is 1.2-0.3 mm.

Calcining expanded vermiculite at 860-880 ℃ and 140kg/m of bulk density³,Al₂O₃The content is 41.5 percent, and the grain diameter is less than 0.3 mm.

Floating bead Al₂O₃38% of SiO₂58% of Fe₂O₃Content 2.0%, R₂The O content is 1.0 percent, and the grain diameter is less than 200 mu m.

The composite binder adopts 20 percent of Portland cement, 35 percent of CA-60 aluminate cement, 24 percent of CA-80 aluminate cement and 10 percent of active SiO₂The micro powder, 8 percent of 200-mesh raw argil powder, 1.0 percent of NaOH and 2.0 percent of triethanolamine are jointly milled for 13 minutes by adopting a horizontal dry ball mill. Wherein, active SiO₂The pH value of the micro powder is 9.5, and the specific surface area is 17m².g^-1,SiO₂The content is 90 percent.

(1) mixing Portland cement, CA-60 aluminate cement, CA-80 aluminate cement and active SiO₂Mixing the micro powder, 200-mesh raw argil powder, NaOH and triethanolamine, and performing horizontal dry ball millingGrinding for 15 minutes to obtain a composite bonding agent;

(2) stirring and mixing the composite bonding agent prepared in the step 1, expanded vermiculite and floating beads for 5 minutes by using a planetary stirrer;

(3) adding flint clay and porous mullite into the planetary stirrer in the step 2, and continuously stirring for 3.5 minutes to prepare a high-strength low-rebound fireproof spray coating;

according to the invention, flint clay, porous mullite, expanded vermiculite and floating beads are mixed, the component content of each component is reasonably controlled, the particle size of each component is optimized, and the critical particle size of aggregate is effectively reduced, so that the compactness of a spray coating is effectively enhanced, portland cement, aluminate cement and CA-80 aluminate cement in a binding agent are optimally combined, the binding property is effectively improved, the adhesion and high-temperature sintering property are effectively improved by adding the active SiO2 micro powder and the argil powder, NaOH and triethanolamine are added according to the optimal proportion, so that the spray coating has good setting time and strength development, and the fineness of the binding agent can be effectively increased and the uniformity of the spray coating is enhanced by ball milling after mixing; according to the preparation method, the horizontal dry-process ball mill and the planetary stirrer are mixed in three steps, so that the uniformity and the activity of the spray paint are further effectively improved, the strength of the spray paint is improved, the rebound rate is reduced, in practical application, the rebound rate is effectively reduced to be below 6% from the original 15%, and the reduction effect of the rebound rate is remarkable.

Claims

1. A high-strength low-rebound fireproof spray coating is characterized by comprising flint clay, porous mullite, expanded vermiculite, floating beads and a composite bonding agent in percentage by weight as follows:

2. A high strength, low bounce refractory spray coating according to claim 1, wherein: the flint clay has a volume density of more than 2.3g/cm3 and a particle size of 1.2-3 mm, and Al in the flint clay₂O₃The content is 35 to 40 percent; the bulk density of the porous mullite is 1.0-1.2 g/cm³Porous mullite Al with particle size of 0.3-1.2 mm₂O₃The content is 36 to 40 percent; calcining the expanded vermiculite at 850-880 ℃ with the volume weight of 120-160 kg/mm³,Al₂O₃The content is 40-42%, and the grain diameter is less than 0.3 mm; the particle size of the floating bead is less than 200 mu m, and Al in the floating bead₂O₃35 to 40 percent of SiO₂50-61% of Fe₂O₃Content 1.5% -3.5%, R₂The content of O is 0.4 to 1.6 percent.

3. A high strength, low bounce refractory spray coating according to claim 1, wherein: the active SiO₂The pH value of the micro powder is 9.3 to 9.5, and the surface area is 15 to 17m².g^-1,SiO₂The content is 87-90 percent.

4. A method of making a high strength, low bounce refractory spray coating according to claim 1, comprising the steps of: