Preparation method of lightweight micro-expansion ceramsite

Abstract

The invention discloses a preparation method of lightweight micro-expansion ceramsite. The lightweight micro-expansion ceramsite is prepared from the following raw materials: 30-90 parts of lightweight clay clinker powder, 5-50 parts of quartz tailing powder, 1-10 parts of an expanding agent, 5-15 parts of a binding agent and 0-10 parts of a reinforcing agent. The preparation method comprises the following steps: uniformly mixing the light clay clinker powder, the quartz tailing powder, the expanding agent, the binding agent and the reinforcing agent in a double-shaft stirrer, and then adding the mixture into a pelletizing disc for pelletizing or adding the mixture into an extruder for extruding and pelletizing. The mass of the used water is 15-30% of the mass of the whole solid material. And putting the ceramsite blank granulated in the step into a curing kiln for curing or naturally curing for more than or equal to 8 hours. And carrying out heat treatment on the ceramsite cured in the previous step at the treatment temperature of normal temperature to 700 DEG C to ensure that the water content is less than 1.5%, thereby obtaining the light micro-expansion ceramsite. The lightweight micro-expansion ceramsite prepared by the invention has excellent micro-expansion characteristic at high temperature, has the characteristics of heat insulation, heat preservation, low preparation cost by utilizing industrial solid waste and the like, and is a preferred raw material for preparing lightweight heat-insulation castable or lightweight heat-insulation bricks.

Description

Technical Field

[0001] The invention belongs to the field of refractory materials and relates to a preparation method of lightweight micro-expanded ceramsite, which is widely used as a raw material in heat-insulating castables or heat-insulating refractory brick products in the refractory industry. Background Art

[0002] Insulating castables or insulating refractory brick products are widely used in the insulating lining of various thermal furnaces to play a role in heat preservation and energy saving. However, in long-term use, insulating castables or insulating refractory brick products often shrink and cause damage. When preparing insulating castables or insulating refractory brick products, the grade of the material has to be improved to reduce the shrinkage during use, which increases the cost and even affects the thermal insulation performance of the material. For this reason, a ceramsite with micro-expansion properties is invented to be added to insulating castables or insulating refractory brick products, which can prevent or offset their shrinkage, thereby extending the service life of insulating castables or insulating refractory brick products. Summary of the invention

[0003] The purpose of the present invention is to provide a heat insulating castable or heat insulating refractory brick product with a bulk density of 800 to 1100 kg / m 3 Within this range, lightweight ceramsite with high strength and micro-expansion performance can be used as a raw material (or filler) for preparing insulating castables or insulating refractory bricks, which can prevent or offset their shrinkage, thereby extending the service life of the insulating castables or insulating refractory brick products.

[0004] In order to achieve the above object, the measures taken by the present invention are:

[0005] The present invention first discloses a light-weight slightly expanded ceramsite, comprising:

[0006] 30-90 parts of light clay clinker powder, 5-50 parts of quartz tailings powder, 1-10 parts of expander, 5-15 parts of binder, and 0-10 parts of enhancer.

[0007] Furthermore, the light clay clinker powder 60 parts, quartz tailings powder 25 parts, expansion agent 5 parts, binder 10 parts, reinforcing agent 5 parts

[0008] Furthermore, the light clay clinker powder is selected from:

[0009] One or more of sepiolite clay clinker powder, Hangmian Banner lightweight clay clinker powder, and high-aluminum fly ash collected from dust removal after combustion in power plant boilers.

[0010] Furthermore, the light clay clinker powder has an aluminum oxide content greater than 40% and an iron oxide content less than 2.5%; the light clay clinker powder passes through a 180-mesh sieve, and the sieve residue is ≤10%.

[0011] Furthermore, the total content of silicon dioxide and aluminum oxide in the quartz tailings powder is greater than 95%, and the content of iron oxide is less than 1%; the quartz tailings powder is sieved through a 180-mesh sieve, and the sieve residue is ≤5%.

[0012] Furthermore, the expansion agent is low-grade kyanite ore, the aluminum oxide content of which is greater than 45%, and the iron oxide content is less than 2%; the particle size of the expansion agent is 40 mesh to 100 mesh.

[0013] Furthermore, the binder is high alumina cement, the alumina content of which is greater than 50% and the specific surface area is greater than or equal to 3000 cm 2 / g.

[0014] Furthermore, the reinforcing agent is selected from: any one or two of silica fume and used low-aluminum mullite fibers.

[0015] The present invention also discloses a method for preparing any of the above-mentioned lightweight slightly expanded ceramsite, comprising:

[0016] First, light clay clinker powder, quartz tailings powder, expander, binder and enhancer are put into a double-shaft mixer and mixed evenly, and then added into a ball-forming plate for ball granulation, or extruded into an extruder for granulation, and 15-30% of the total weight of the solid material is added with water to meet the granulation molding;

[0017] Put the granulated ceramsite into the curing kiln for curing or natural curing, and the curing time is ≥8h;

[0018] The cured ceramsite is heat treated at room temperature to 700° C. to make the moisture content less than 1.5%, thereby obtaining light and slightly expanded ceramsite.

[0019] The present invention also discloses a light-weight slightly expanded ceramsite prepared according to the above preparation method, wherein:

[0020] The cylinder pressure strength of the lightweight slightly expanded ceramsite is ≥5MPa and the density is 800-1100kg / m 3 ;Refractory ≥1750℃;

[0021] The re-burning linear change rate of the lightweight slightly expanded ceramsite is 0-0.2% when the temperature is kept at 1000°C for 3 hours, and the linear change rate is 0-0.4% when the temperature is kept at 1200°C for 3 hours.

[0022] The beneficial effects of the present invention are:

[0023] The lightweight micro-expanded ceramsite has excellent micro-expansion properties at high temperatures, is light, heat-insulating, and thermally insulating, and is prepared at low cost using industrial solid waste, and is a preferred raw material for preparing lightweight thermal insulation castables or lightweight thermal insulation bricks. DETAILED DESCRIPTION

[0024] The technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] The invention discloses a light-weight slightly expanded ceramsite, comprising:

[0026] 30-90 parts of light clay clinker powder, 5-50 parts of quartz tailings powder, 1-10 parts of expander, 5-15 parts of binder, 0-10 parts of enhancer; among which:

[0027] The light clay clinker powder is selected from one or more of: sepiolite clay clinker powder, Hangmian Banner light clay clinker powder, and high-aluminum fly ash collected by dust removal after combustion in power plant boilers;

[0028] The light clay clinker powder has an aluminum oxide content of more than 40% and an iron oxide content of less than 2.5%; the light clay clinker powder is sieved through a 180-mesh sieve, and the sieve residue is ≤10%;

[0029] The total content of silicon dioxide and aluminum oxide in the quartz tailings powder is greater than 95%, and the content of iron oxide is less than 1%; the quartz tailings powder is sieved through a 180-mesh sieve, and the sieve residue is ≤5%;

[0030] The expansion agent is low-grade kyanite ore, with an aluminum oxide content of more than 45% and an iron oxide content of less than 2%; the particle size of the expansion agent is 40 mesh to 100 mesh;

[0031] The binder is high alumina cement, with an alumina content of >50% and a specific surface area of ​​≥3000cm 2 / g;

[0032] The reinforcing agent is selected from any one or two of silica fume and used low-aluminum mullite fibers.

[0033] The present invention also discloses a method for preparing light-weight slightly expanded ceramsite, comprising:

[0034] First, light clay clinker powder, quartz tailings powder, expander, binder and enhancer are put into a double-shaft mixer and mixed evenly, and then 15-30% of the total weight of solid materials is added with water for granulation;

[0035] Put the granulated ceramsite into the curing kiln for curing or natural curing, and the curing time is ≥8h;

[0036] The cured ceramsite is heat treated at room temperature to 700°C to make the moisture content less than 1.5%, thereby obtaining light and slightly expanded ceramsite;

[0037] The cylinder pressure strength of the lightweight slightly expanded ceramsite is ≥5MPa and the density is 800-1100kg / m 3 ;Refractory ≥1750℃;

[0038] The re-burning linear change rate of the lightweight slightly expanded ceramsite is 0-0.2% when the temperature is kept at 1000°C for 3 hours, and the linear change rate is 0-0.4% when the temperature is kept at 1200°C for 3 hours.

[0039] Example 1

[0040] 65 parts of lightweight clay clinker powder (including 30 parts of Hangmian Banner lightweight clay clinker powder, 35 parts of high-aluminum fly ash collected from power plant boiler combustion), 20 parts of quartz tailings powder, 5 parts of expander, 3 parts of reinforcing agent silica fume, and 7 parts of binder. The above raw materials are mixed and stirred evenly, pelletized in a ball plate, naturally cured for 24 hours, and heat treated at 110℃x48 hours to obtain lightweight micro-expanded ceramsite.

[0041] Example 2

[0042] 50 parts of light clay clinker powder (including 25 parts of sepiolite light clay clinker powder, 25 parts of high-aluminum fly ash collected from dust removal after combustion in power plant boilers), 35 parts of quartz tailings powder, 3 parts of expander, 2 parts of low-aluminum mullite fiber after use as reinforcing agent, and 10 parts of binder. The above raw materials are mixed and stirred evenly, pelletized by balling plate, naturally cured for 24 hours, and heat treated at 200℃x24 hours to obtain light micro-expanded ceramsite.

[0043] Example 3

[0044] 40 parts of lightweight clay clinker powder (including 10 parts of sepiolite lightweight clay clinker powder, 30 parts of high-aluminum fly ash collected from dust removal after combustion in power plant boilers), 30 parts of quartz tailings powder, 10 parts of expander, 5 parts of reinforcing agent (2.5 parts each of silica fume and used low-aluminum mullite fiber), and 15 parts of binder. The above raw materials are mixed and stirred evenly, pelletized in a balling plate, naturally cured for 24 hours, and heat treated at 500℃x8h to obtain lightweight micro-expanded ceramsite.

[0045] Example 4

[0046] 80 parts of light clay clinker powder (including 20 parts of sepiolite light clay clinker powder, 20 parts of Hangmian Banner light clay clinker powder, 40 parts of high-aluminum fly ash collected from power plant boiler combustion dust removal), 5 parts of quartz tailings powder, 5 parts of expander, 1 part of reinforcing agent silica fume, and 9 parts of binder. The above raw materials are mixed and stirred evenly, balled and granulated, naturally cured for 24 hours, and heat treated at 150℃x48 hours to obtain light micro-expanded ceramsite.

[0047] Example 5

[0048] 30 parts of light clay clinker powder (including 5 parts of sepiolite light clay clinker powder, 25 parts of high-aluminum fly ash collected from dust removal after combustion in power plant boilers), 45 parts of quartz tailings powder, 1 part of expander, 9 parts of enhancer, and 15 parts of binder. The above raw materials are mixed and stirred evenly, extruded and granulated by a mud extruder, naturally cured for 24 hours, and heat treated at a temperature of 110℃x48 hours to obtain light micro-expanded ceramsite.

[0049] Example 6

[0050] 40 parts of lightweight clay clinker powder (including 30 parts of Hangmian Banner lightweight clay clinker powder, 10 parts of high-aluminum fly ash collected from dust removal after combustion in power plant boilers), 40 parts of quartz tailings powder, 2 parts of expander, 3 parts of enhancer (including 1 part of silica fume, 2 parts of used low-aluminum mullite fiber each), 15 parts of binder. The above raw materials are mixed and stirred evenly, extruded and granulated by a mud extruder, naturally cured for 7 days, and heat treated at 110℃x8h to obtain lightweight micro-expanded ceramsite.

[0051] Comparative Example

[0052] An expanded porous lightweight ceramsite and its preparation method and application (application number 202311593253.X)

[0053] Although the expanded ceramsite trial in this method is also mainly prepared from solid waste, its preparation process requires expansion at a temperature above 1100°C, and its refractoriness must be lower than 1690°C. It is usually used at room temperature, and its use temperature does not exceed 1000°C. It will inevitably shrink after reburning.

[0054] Test Example 1

[0055] The performance of the lightweight slightly expanded ceramsite prepared in various embodiments of the present invention was tested, and the specific results are as follows:

[0056] The performance indexes of the light-weight slightly expanded ceramsite prepared according to the present invention are shown in Table 1 below:

[0057]

[0058]

[0059] The above embodiments are only for the purpose of illustrating the method of the present invention. Without departing from the spirit and scope of the present invention, the present invention may be subject to various changes and modifications, which are all within the scope of the present invention to be protected. The scope of the present invention to be protected is defined by the attached claims and their equivalents.

Claims

1. A lightweight slightly expanded ceramsite, comprising: 30-90 parts of light clay clinker powder, 5-50 parts of quartz tailings powder, 1-10 parts of expander, 5-15 parts of binder, and 0-10 parts of enhancer.

2. The light slightly expanded ceramsite according to claim 1, wherein: The light clay clinker powder comprises 60 parts, quartz tailings powder 25 parts, expansion agent 5 parts, binder 10 parts and reinforcing agent 5 parts.

3. The light slightly expanded ceramsite according to claim 1 or 2, wherein: The light clay clinker powder is selected from: Two or three of the following: sepiolite clay clinker powder, Hangmian Banner lightweight clay clinker powder, and high-aluminum fly ash collected from dust removal after combustion in power plant boilers.

4. The light slightly expanded ceramsite according to claim 1 or 2, wherein: The light clay clinker powder has an aluminum oxide content of more than 40% and an iron oxide content of less than 2.5%; The light clay clinker powder is passed through a 180-mesh sieve, and the sieve residue is ≤10%.

5. The light slightly expanded ceramsite according to claim 1 or 2, wherein: The total content of silicon dioxide and aluminum oxide in the quartz tailings powder is greater than 95%, and the content of iron oxide is less than 1%; The quartz tailing powder is sieved through a 180-mesh sieve, and the sieve residue is ≤5%.

6. The light slightly expanded ceramsite according to claim 1 or 2, wherein: The expansion agent is low-grade kyanite ore, with an aluminum oxide content greater than 45% and an iron oxide content less than 2%; the particle size of the expansion agent is 40-100 meshes.

7. The light slightly expanded ceramsite according to claim 1 or 2, wherein: The binder is high alumina cement, with an alumina content of >50% and a specific surface area of ​​≥3000cm 2 / g.

8. The light slightly expanded ceramsite according to claim 1 or 2, wherein: The reinforcing agent is selected from any one or two of silica fume and used low-aluminum mullite fibers.

9. A method for preparing the lightweight slightly expanded ceramsite according to any one of claims 1 to 8, comprising: First, light clay clinker powder, quartz tailings powder, expander, binder and enhancer are put into a double-shaft mixer and mixed evenly, and then 15-30% of the total weight of solid materials is added with water to form granules; Put the granulated ceramsite into the curing kiln for curing or natural curing, and the curing time is ≥8h; The cured ceramsite is heat treated at room temperature to 700° C. to make the moisture content less than 1.5%, thereby obtaining light and slightly expanded ceramsite.

10. A light-weight slightly expanded ceramsite prepared according to the preparation method of claim 9, wherein: The cylinder pressure strength of the lightweight slightly expanded ceramsite is ≥5MPa and the density is 800-1100kg / m 3 ;Refractory ≥1750℃; The re-burning linear change rate of the lightweight slightly expanded ceramsite is 0-0.2% when the temperature is kept at 1000°C for 3 hours, and the linear change rate is 0-0.4% when the temperature is kept at 1200°C for 3 hours.

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