CN117003523A - Fluorite tailing slag calcium silicate board and preparation method thereof - Google Patents

Abstract

The invention relates to the technical field of plates, and discloses a fluorite tailings slag calcium silicate plate and a preparation method thereof. It includes quartz sand, cement, fluorite tailings, paper pulp and glass fiber. In the present invention, each component is first added to water, stirred and mixed to form a mixed slurry, and then the mixed slurry is sequentially subjected to extraction and molding, pre-curing treatment, autoclaved curing and Dry to obtain calcium silicate plate. By doping a large amount of fluorite tailings slag into the calcium silicate plate, the present invention not only realizes the waste utilization of fluorite tailing slag and reduces the production cost of the plate, but also improves the thermal insulation of the calcium silicate plate compared with the traditional calcium silicate plate. performance and mechanical strength.

Description

A kind of fluorite tailings slag calcium silicate plate and its preparation method

Technical field

The present invention relates to the technical field of plates, and in particular to a fluorite tailings slag calcium silicate plate and a preparation method thereof.

Background technique

The main chemical component of fluorite is calcium fluoride, which appears as a transparent rock in various colors such as white, red, blue, green, and purple. Most fluorite found in nature is mixed with silicon oxide, calcium carbonate, iron oxide and aluminum oxide. Its melting point is 1230°C, it has a strong fluxing effect and is a flux raw material in glaze. The chemical composition of fluorite slag formed by fluorite mining and processing is silica 42.76%, aluminum oxide 7.58%, iron oxide 1.02%, calcium oxide 38.97%, magnesium oxide 2.82%, potassium oxide 1.10%, sodium oxide 0.44 %, phosphorus pentoxide 51.69%, sulfur trioxide 0.2%, titanium oxide 0.12%, fluorine 2.00%, ignition loss 1.36%. From the chemical composition point of view, the main component of fluorite slag is calcium silicate. For a long time, the comprehensive utilization of fluorite slag has been a global problem. Although a lot of research has been conducted on the comprehensive utilization of fluorite slag at home and abroad, due to technical Due to various reasons both physically and economically, most of them have not been implemented in industry. Calcium silicate boards can be used as insulation materials or decorative materials. Calcium silicate boards for thermal insulation are mainly used for exterior wall hanging boards, exterior wall veneers, etc. Decorative calcium silicate boards are mainly used for suspended ceilings, ceilings, house partitions, indoor floors, etc. As the market for finished thermal insulation decorative boards continues to expand, the demand for calcium silicate boards has also increased.

Chinese Patent Publication No. CN104926236 discloses a low-density fiber-reinforced calcium silicate fireproof board and its preparation method. The method includes: step 1, mix plant fiber, cement, and quartz stone to make a pulp, wherein the calcium-silicon molar ratio is 0.80- 0.82, the mass of plant fiber accounts for 8%-12% of the total raw material weight; step 2, the plate is formed into a blank, and the blank is prepared; step 3, pre-reaction: place the blank in the reaction kettle, and the pressure in the reaction kettle is 1.2± Under 0.1Mpa, since the steam enters the reactor, the temperature is steadily raised to 250°C at a heating rate of 30°C/h, and then maintained at a constant temperature and pressure for not less than 24h; step 4, autoclave curing; step 5, demoulding and drying The edges are dried and sanded to prepare the low-density fiber-reinforced calcium silicate fireproof board. Chinese Patent Publication No. CN115959867 discloses a method for preparing modified oyster shell antibacterial calcium silicate boards. This method involves immersing biomass waste oyster shells in a Cu(NO3)2·3H2O solution, filtering and calcining the resulting solid to obtain CuO/CaO powder; adding water to hydrate it to obtain CuO/Ca(OH) 2 powder; mix it with diatomaceous earth, then add fiber and ordinary Portland cement to obtain a mixed powder, then add water and stir to obtain a slurry; after molding and autoclaving, the modified sea oyster is obtained Shell antibacterial calcium silicate board. The strength of the calcium silicate plate prepared in the above-mentioned patent documents is limited, and the mechanical strength of the calcium silicate plate needs to be further improved.

Contents of the invention

In order to overcome the above existing technical problems, the present invention provides a fluorite tailings slag calcium silicate plate and a preparation method thereof. By doping a large amount of fluorite tailings slag into calcium silicate plates, the invention not only realizes the waste utilization of fluorite tailings slag and reduces the production cost of the plates, but also improves the thermal insulation performance of the calcium silicate plates compared with traditional calcium silicate plates. and mechanical strength.

In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

A kind of fluorite tailings calcium silicate plate, including the following components in dry weight by weight:

Quartz sand 35-45 parts

25-30 parts of cement

20-30 parts of fluorite tailings slag

4-8 parts of pulp.

In the prior art, the main components of calcium silicate boards are cement, quartz sand and pulp. The present invention not only realizes the waste utilization of fluorite tailings slag but also reduces the production of boards by doping a large amount of fluorite tailings slag into the calcium silicate boards. Compared with traditional calcium silicate boards, it also improves the thermal insulation performance and mechanical strength of calcium silicate boards.

Preferably, the calcium silicate board also includes glass fiber.

In the existing technology, the strength of calcium silicate boards is usually enhanced by adding a single pulp. However, the improvement in the strength of calcium silicate boards by adding cotton pulp alone is limited. In the present invention, cotton pulp fiber and glass fiber are mixed and added to the calcium silicate board, and the synergistic effect of the two further improves the mechanical strength of the calcium silicate board.

Preferably, the mass ratio of glass fiber to pulp is 1:1-5.

Preferably, the glass fiber is modified, and the modification method includes the following steps:

1) Add γ-glycidoxypropyltrimethoxysilane to the mixed solution of ethanol and water, heat, stir and dissolve to obtain a silane coupling agent solution. Add glass fiber to the silane coupling agent solution for reaction and separation. , dry to obtain coupling agent modified glass fiber;

2) Add sodium alginate to water, stir and dissolve, add sodium hydroxide catalyst, then add coupling agent to modify glass fiber for reaction, and obtain after separation and drying.

Through experiments, it was found that it is difficult to achieve uniform dispersion of glass fibers when ordinary glass fibers are added to the calcium silicate board components, and glass fibers and paper pulp cannot form an interwoven three-dimensional network structure. In the present invention, by further modifying the glass fibers, First, the surface of the glass fiber is grafted with epoxy groups through a silicic acid coupling agent, and then the sodium alginate is grafted onto the surface of the glass fiber through a ring-opening reaction between the epoxy group and the hydroxyl group on the sodium alginate. The surface of the glass fiber is loaded with COO ^- . Under the action of electrostatic repulsion, the glass fiber can be fully dispersed in the components. At the same time, the hydroxyl groups on the sodium alginate molecules that did not participate in the reaction form a hydrogen bonding force with the hydroxyl groups on the surface of the pulp fiber. The two The combination forms an intertwined three-dimensional network, thereby significantly further improving the mechanical strength of calcium silicate sheets.

Preferably, the heating temperature in step 1) is 40-60°C.

Preferably, the mass ratio of the reacted glass fiber to the silane coupling agent in step 1) is 1:0.2-0.6.

Preferably, the reaction time in step 1) is 3-5h.

Preferably, the mass ratio of coupling agent-modified glass fiber and sodium alginate in step 2) is less than 1:0.5.

When the mass ratio of coupling agent-modified glass fiber to sodium alginate is greater than 1:0.5, there will be an excess of epoxy groups on the surface of the coupling agent-modified glass fiber, and the hydroxyl groups on the sodium alginate will interact with the epoxy groups on the surface of the glass fiber. Full reaction results in the lack of hydroxyl groups on the surface of the final glass fiber and the inability to form hydrogen bonds with the hydroxyl groups on the pulp fibers, thus affecting the further improvement of the strength of the calcium silicate board. Therefore, the present invention controls the mass ratio of coupling agent-modified glass fiber to sodium alginate to be less than 1:0.5.

Preferably, the reaction time in step 3) is 30-60 min.

A method for preparing fluorite tailings calcium silicate plates, including the following steps:

1) Crush the fluorite tailings slag into granules, then mix it with quartz sand and cement, add water and stir to form a slurry;

2) Add paper pulp or paper pulp and glass fiber or add paper pulp and modified glass fiber to the slurry, and continue to stir evenly to obtain a mixed slurry;

3) The mixed slurry is sequentially subjected to copy molding, pre-curing treatment, autoclaved curing and drying to obtain calcium silicate sheets.

The invention has the following beneficial effects:

1) By doping a large amount of fluorite tailings slag into calcium silicate plates, the present invention not only realizes the waste utilization of fluorite tailings slag and reduces the production cost of the plates, but also improves the thermal insulation of the calcium silicate plates compared with traditional calcium silicate plates. Thermal insulation performance and mechanical strength;

2) In the present invention, cotton pulp fiber and glass fiber are mixed and added to the calcium silicate board, and the synergistic effect of the two further improves the mechanical strength of the calcium silicate board;

3) The modified glass fiber can be fully dispersed in the components, and the modified glass fiber and pulp fiber combine to form an interwoven three-dimensional network, thereby significantly further improving the mechanical strength of the calcium silicate board.

Detailed ways

Unless otherwise specified, the raw materials and equipment used in the specific embodiments of the present invention can be purchased from the market or are commonly used in the field. Unless otherwise specified, the methods in the examples are conventional methods in the field.

Example 1

A fluorite tailings calcium silicate board includes the following components in dry weight by weight:

44 parts of quartz sand

28 parts of cement

Fluorite tailings slag 29 parts

7 parts of pulp.

A method for preparing fluorite tailings calcium silicate plates, including the following steps:

1) Crush the fluorite tailings slag into granules, then mix it with quartz sand and cement, add water and stir to form a slurry;

2) Add paper pulp to the slurry and continue stirring evenly to obtain a mixed slurry;

3) The mixed slurry is sequentially subjected to copy molding, pre-curing treatment, autoclaved curing and drying. The pre-curing treatment temperature is 60°C, the time is 8h, the pressure is 0.12MPa; the autoclaved curing temperature is 150°C, the time is The time is 18h, the pressure is 1.0MPa, and the calcium silicate plate is obtained.

Comparative example 1

The difference between Comparative Example 1 and Example 1 is that the fluorspar tailings slag is replaced by quartz sand.

Example 2

A fluorite tailings calcium silicate board includes the following components in dry weight by weight:

34 parts of quartz sand

26 parts of cement

25 parts of fluorite tailings slag

5 parts pulp

3 parts fiberglass.

A method for preparing fluorite tailings calcium silicate plates, including the following steps:

1) Crush the fluorite tailings slag into granules, then mix it with quartz sand and cement, add water and stir to form a slurry;

2) Add paper pulp and glass fiber to the slurry and continue to stir evenly to obtain a mixed slurry;

3) The mixed slurry is sequentially subjected to copy molding, pre-curing treatment, autoclaved curing and drying. The pre-curing treatment temperature is 60°C, the time is 9h, and the pressure is 0.13MPa; the autoclaved curing temperature is 155°C, the time is The time is 20h, the pressure is 1.2MPa, and the calcium silicate plate is obtained.

Example 3

A fluorite tailings calcium silicate board includes the following components in dry weight by weight:

45 parts of quartz sand

30 parts of cement

30 parts of fluorite tailings slag

8 parts pulp

8 parts modified glass fiber.

The preparation method of modified glass fiber includes the following steps:

1) Add γ-glycidoxypropyltrimethoxysilane to a mixed solution of ethanol and water mixed at a ratio of 5:1. γ-glycidyloxypropyltrimethoxysilane accounts for 5% of the mass of the mixed solution. Heat to 60°C, stir and dissolve to obtain a silane coupling agent solution, add glass fiber to the silane coupling agent solution and react for 5 hours. The mass ratio of glass fiber to silane coupling agent is 1:0.6; after separation and drying, Obtain coupling agent modified glass fiber;

2) Add sodium alginate to water, stir and dissolve to prepare a sodium alginate solution with a concentration of 0.5wt%, add a sodium hydroxide catalyst with a mass concentration of 0.1%, then add a coupling agent to modify the glass fiber and react for 60 minutes. The mass ratio of the joint agent modified glass fiber and sodium alginate is 1:0.5, which can be obtained after separation and drying.

A method for preparing fluorite tailings calcium silicate plates, including the following steps:

1) Crush the fluorite tailings slag into granules, then mix it with quartz sand and cement, add water and stir to form a slurry;

2) Add paper pulp and modified glass fiber to the slurry, and continue to stir evenly to obtain a mixed slurry;

3) The mixed slurry is sequentially subjected to copy molding, pre-curing treatment, autoclaved curing and drying. The pre-curing treatment temperature is 60°C, the time is 8h, the pressure is 0.10MPa; the autoclaved curing temperature is 160°C, the time is The time is 15h, the pressure is 1.0MPa, and the calcium silicate plate is obtained.

Comparative example 2

The difference between Comparative Example 2 and Implementation 3 is that the mass ratio of coupling agent-modified glass fiber and sodium alginate in the preparation process of modified glass fiber is 1:0.4.

Example 4

A fluorite tailings calcium silicate board includes the following components in dry weight by weight:

35 parts of quartz sand

25 parts of cement

20 parts of fluorite tailings slag

4 parts pulp

Modified glass fiber 0.8 parts.

The preparation method of modified glass fiber includes the following steps:

1) Add γ-glycidoxypropyltrimethoxysilane to a mixed solution of ethanol and water mixed at a ratio of 5:1. γ-glycidyloxypropyltrimethoxysilane accounts for 5% of the mass of the mixed solution. Heat to 40°C, stir and dissolve to obtain a silane coupling agent solution, add glass fiber to the silane coupling agent solution and react for 3 hours. The mass ratio of glass fiber to silane coupling agent is 1:0.2; after separation and drying, Obtain coupling agent modified glass fiber;

2) Add sodium alginate to water, stir and dissolve to prepare a sodium alginate solution with a concentration of 0.5wt%, add a sodium hydroxide catalyst with a mass concentration of 0.1%, then add a coupling agent to modify the glass fiber and react for 30 minutes. The mass ratio of the joint agent modified glass fiber and sodium alginate is 1:0.6, which can be obtained after separation and drying.

A method for preparing fluorite tailings calcium silicate plates, including the following steps:

1) Crush the fluorite tailings slag into granules, then mix it with quartz sand and cement, add water and stir to form a slurry;

2) Add paper pulp and modified glass fiber to the slurry, and continue to stir evenly to obtain a mixed slurry;

3) The mixed slurry is sequentially subjected to copy molding, pre-curing treatment, autoclaved curing and drying. The pre-curing treatment temperature is 70°C, the time is 12h, and the pressure is 0.10MPa; the autoclaved curing temperature is 180°C, the time is was 13h, the pressure was 1.0MPa, and the calcium silicate plate was obtained.

Performance Testing

The strength of calcium silicate sheets was tested in accordance with CB/T8040, and the thermal conductivity was tested in accordance with GB/T10294. The test results are as follows:

The above are only preferred embodiments of the present invention and are not intended to limit the present invention in any form. Although the present invention has been disclosed above with preferred embodiments, they are not intended to limit the present invention. Anyone familiar with this field will Skilled persons can make some changes or modifications to equivalent embodiments with equivalent changes using the above disclosed technical content without departing from the scope of the technical solution of the present invention. Technical Essence Any simple modifications, equivalent changes and modifications made to the above embodiments still fall within the scope of the technical solution of the present invention.

Claims (10)

1. A fluorite tailings calcium silicate plate, characterized in that it includes the following components in parts by weight on a dry basis: Quartz sand 35-45 parts 25-30 parts of cement 20-30 parts of fluorite tailings slag 4-8 parts of pulp. 2. A fluorite tailings slag calcium silicate plate according to claim 1, characterized in that the calcium silicate plate further includes glass fiber. 3. A fluorite tailings slag calcium silicate board according to claim 1, characterized in that the mass ratio of the glass fiber to the pulp is 1:1-5. 4. A kind of fluorite tailings slag calcium silicate board according to claim 3, characterized in that the glass fiber is modified, and the modification method includes the following steps: Add γ-glycidoxypropyltrimethoxysilane to a mixed solution of ethanol and water, heat, stir and dissolve to obtain a silane coupling agent solution. Add glass fiber to the silane coupling agent solution for reaction, then separate and dry , obtain coupling agent modified glass fiber; Add sodium alginate to water, stir and dissolve, add sodium hydroxide catalyst, then add coupling agent to modify glass fiber for reaction, and obtain it after separation and drying. 5. A fluorite tailings slag calcium silicate plate according to claim 4, characterized in that the heating temperature in step 1) is 40-60°C. 6. A fluorite tailings slag calcium silicate board according to claim 4, characterized in that the mass ratio of the reaction glass fiber and the silane coupling agent in step 1) is 1:0.2-0.6. 7. A fluorite tailings slag calcium silicate plate according to claim 4, characterized in that the reaction time in step 1) is 3-5h. 8. A fluorite tailings slag calcium silicate board according to claim 4, characterized in that the mass ratio of coupling agent modified glass fiber and sodium alginate in step 2) is less than 1:0.5. 9. A fluorite tailings slag calcium silicate plate according to claim 4, characterized in that the reaction time in step 3) is 30-60 minutes. 10. A method for preparing the fluorite tailings slag calcium silicate plate according to any one of claims 1 to 9, characterized by comprising the following steps: Crush the fluorite tailings slag into granules, then mix it with quartz sand and cement, add water and stir to form a slurry; Add paper pulp or paper pulp and glass fiber or add paper pulp and modified glass fiber to the slurry, and continue to stir evenly to obtain a mixed slurry; The mixed slurry is sequentially subjected to copy molding, pre-curing treatment, autoclaved curing and drying to obtain calcium silicate sheets.