A high-strength adsorption type calcium silicate board and preparation method thereof

Abstract

The present invention relates to the technical field of calcium silicate boards, and discloses a high-strength adsorption type calcium silicate board and a preparation method thereof. First, fly ash, quicklime and lithium carbonate slag are mixed, and water is added to stir to form a slurry. Then, cotton pulp and modified activated carbon fiber are added to the slurry, and stirred evenly. After copying and forming, pre-curing treatment, autoclave curing and drying, a calcium silicate board is obtained. The present invention adds waste lithium carbonate slag to the calcium silicate board to achieve effective utilization of waste and reduce the production cost of the board. In addition, the calcium silicate board in the present invention can adsorb harmful gases such as methane in the air, thereby purifying indoor air.

Description

Technical Field

[0001] The invention relates to the technical field of plates, and in particular to a high-strength adsorption-type calcium silicate plate and a preparation method thereof. Background Art

[0002] Calcium silicate board is a new type of inorganic building material with excellent fire resistance, moisture resistance and sound insulation. Calcium silicate board can be used as thermal insulation material or decorative material. Calcium silicate board for thermal insulation is mainly used for exterior wall hanging board, exterior wall veneer, etc. Calcium silicate board for decoration is mainly used for suspended ceiling, ceiling, house partition wall, indoor floor, etc. With the continuous expansion of the market for thermal insulation decorative finished board, the demand for calcium silicate board is also increasing.

[0003] Lithium carbonate slag is the residue discharged after spodumene is calcined at 1150-1300℃ and then extracted by sulfuric acid method. my country is a country with large spodumene reserves in the world. In the process of using spodumene to produce lithium salt, about 8-10 tons of lithium slag are discharged for every ton of lithium salt produced. Based on the current lithium salt production, more than 4 million tons of lithium slag are produced each year. Lithium carbonate slag not only takes up space when it is piled up, but also if it is not properly stored, the alkali and acid-containing slag water will be lost, endangering farmland and polluting the environment. With the development of the lithium salt industry, the discharge of lithium slag is increasing day by day. Most of the waste generated is piled up and landfilled, resulting in waste of resources, pollution of the environment, and geological environmental risks, which has become an urgent problem to be solved.

[0004] Chinese patent publication number CN104926236 discloses a low-density fiber-reinforced calcium silicate fireproof board and its preparation method, the method comprising: step 1, mixing plant fiber, cement, and quartz stone to make pulp, wherein the calcium-silicon molar ratio is 0.80-0.82, and the mass of the plant fiber accounts for 8%-12% of the total raw material weight; step 2, blanking the board to prepare the blank; step 3, pre-reaction: placing the blank in a reactor, and at a pressure of 1.2±0.1Mpa in the reactor, from the time steam enters the reactor, steadily heating it to 250°C at a heating rate of 30°C / h, and then maintaining the temperature and pressure for not less than 24h; step 4, autoclaving and curing; step 5, demoulding, drying and sanding to obtain the low-density fiber-reinforced calcium silicate fireproof board. Chinese patent publication number CN115959867 discloses a method for preparing a modified oyster shell antibacterial calcium silicate board. The method comprises the following steps: immersing the biomass waste oyster shell in a Cu(NO3)2·3H2O solution, filtering and calcining the obtained solid to obtain CuO / CaO powder; then adding water to hydrate it to obtain CuO / Ca(OH)2 powder; mixing the powder with diatomaceous earth, adding fiber and ordinary silicate cement to obtain a mixed powder, and then adding water to stir to obtain a slurry; and performing compression molding and autoclaving to obtain a modified oyster shell antibacterial calcium silicate board. The strength of the calcium silicate board prepared in the above patent document is limited, and the mechanical strength of the calcium silicate board needs to be further improved. Summary of the invention

[0005] The present invention is to overcome the above-mentioned problems of the prior art and provide a high-strength adsorption type calcium silicate board and a preparation method thereof. The present invention adds waste lithium carbonate slag to the calcium silicate board to achieve effective utilization of waste and reduce the production cost of the board. In addition, the calcium silicate board of the present invention can adsorb harmful gases such as methane in the air, thereby purifying indoor air.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A high-strength adsorption-type calcium silicate board comprises the following components in parts by weight:

[0008] 30-45 parts fly ash

[0009] 10-15 parts quicklime

[0010] 20-25 parts of lithium carbonate slag

[0011] Modified activated carbon fiber 10-15 parts

[0012] 4-7 parts of cotton pulp.

[0013] The present invention adds waste lithium carbonate slag into the calcium silicate board to realize the recycling of waste materials and reduce the production cost of the board. The adsorption performance of activated carbon fiber is utilized to realize the adsorption of harmful gases in the air, which plays a role in indoor air purification. In addition, the modified activated carbon fiber can act as a material skeleton to improve the strength of the calcium silicate board.

[0014] Preferably, the method for preparing the modified activated carbon fiber comprises the following steps:

[0015] 1) preparing a carboxymethyl chitosan aqueous solution;

[0016] 2) mixing the activated carbon fiber with the carboxymethyl chitosan aqueous solution, and adding a cross-linking agent to carry out a cross-linking reaction;

[0017] 3) The activated carbon fibers after the reaction are heat treated to obtain the obtained carbon fibers.

[0018] Activated carbon fiber is directly added to the calcium silicate board. Since the interface bonding force between activated carbon fiber and other components is poor, the strength of the calcium silicate board is affected. Therefore, the present invention performs a modification treatment on the calcium silicate board. Carboxymethyl chitosan is used to generate a cross-linking reaction on the surface of the activated carbon fiber under the action of a cross-linking agent, so that the carboxymethyl chitosan is combined with the activated carbon fiber. The quicklime, a component of the calcium silicate board, generates calcium hydroxide when it meets water. The complexation of carboxymethyl chitosan and calcium hydroxide is used to improve the interface bonding force between the activated carbon fiber and other components in the calcium silicate board, thereby significantly improving the mechanical strength of the calcium silicate board.

[0019] Preferably, the concentration of the carboxymethyl chitosan aqueous solution in step 1) is 0.05-1.0%.

[0020] Preferably, in step 2), the cross-linking agent is glutaraldehyde.

[0021] Preferably, the heat treatment temperature in step 3) is 50-70°C.

[0022] A method for preparing a high-strength adsorption-type calcium silicate board comprises the following steps:

[0023] a) mixing fly ash, quicklime and lithium carbonate slag, adding water and stirring into slurry;

[0024] b) adding cotton pulp and modified activated carbon fiber to the slurry and stirring evenly;

[0025] c) After forming by copying, pre-curing, autoclaving and drying, a calcium silicate board is obtained.

[0026] The present invention has the following beneficial effects:

[0027] (1) The present invention adds waste lithium carbonate slag into the calcium silicate board to achieve the recycling of waste materials and reduce the production cost of the board;

[0028] (2) Utilize the adsorption properties of activated carbon fibers to adsorb harmful gases in the air and purify the indoor air;

[0029] (3) Carboxymethyl chitosan is cross-linked on the surface of activated carbon fibers under the action of a cross-linking agent, thereby combining carboxymethyl chitosan with the activated carbon fibers. The quicklime component of the calcium silicate board generates calcium hydroxide when it meets water. The complexation of carboxymethyl chitosan and calcium hydroxide is utilized to improve the interfacial bonding force between the activated carbon fibers and other components in the calcium silicate board, thereby significantly improving the mechanical strength of the calcium silicate board. DETAILED DESCRIPTION

[0030] The technical scheme of the present invention is further described below through specific examples. Unless otherwise specified in the present invention, the raw materials and equipment used can be purchased from the market or are commonly used in the art, and the methods in the embodiments are conventional methods in the art unless otherwise specified.

[0031] Example 1

[0032] The preparation method of modified activated carbon fiber comprises the following steps:

[0033] 1) adding carboxymethyl chitosan into water and stirring to dissolve to prepare a carboxymethyl chitosan aqueous solution with a mass concentration of 0.5%;

[0034] 2) mixing activated carbon fiber with carboxymethyl chitosan aqueous solution, wherein the mass ratio of activated carbon fiber to carboxymethyl chitosan is 1:0.5, adding glutaraldehyde crosslinking agent for crosslinking reaction, wherein the amount of glutaraldehyde added is 0.5% of the mass of carboxymethyl chitosan;

[0035] 3) The activated carbon fibers after the reaction are placed in an oven for heat treatment at a temperature of 60° C. for 30 min to obtain the obtained carbon fibers.

[0036] A high-strength adsorption-type calcium silicate board comprises the following components in parts by weight:

[0037] 40 parts fly ash

[0038] 12 parts quicklime

[0039] 23 parts of lithium carbonate slag

[0040] Modified activated carbon fiber 12 parts

[0041] 5 parts of cotton pulp.

[0042] A method for preparing a high-strength adsorption-type calcium silicate board comprises the following steps:

[0043] a) mixing fly ash, quicklime and lithium carbonate slag, adding water and stirring into slurry;

[0044] b) adding cotton pulp and modified activated carbon fiber to the slurry and stirring evenly;

[0045] c) After forming by copying, pre-curing, autoclaving and drying, the pre-curing temperature is 90°C for 16 hours, the autoclaving temperature is 170°C for 20 hours, and a calcium silicate board is obtained.

[0046] Example 2

[0047] The preparation method of modified activated carbon fiber comprises the following steps:

[0048] 1) adding carboxymethyl chitosan into water and stirring to dissolve to prepare a carboxymethyl chitosan aqueous solution with a mass concentration of 1.0%;

[0049] 2) mixing activated carbon fiber with carboxymethyl chitosan aqueous solution, wherein the mass ratio of activated carbon fiber to carboxymethyl chitosan is 1:0.5, adding glutaraldehyde crosslinking agent for crosslinking reaction, wherein the amount of glutaraldehyde added is 0.5% of the mass of carboxymethyl chitosan;

[0050] 3) The activated carbon fiber after the reaction is placed in an oven for heat treatment at a temperature of 70° C. for 30 min to obtain the obtained carbon fiber.

[0051] A high-strength adsorption-type calcium silicate board comprises the following components in parts by weight:

[0052] 45 parts fly ash

[0053] 15 parts quicklime

[0054] 25 parts of lithium carbonate slag

[0055] Modified activated carbon fiber 15 parts

[0056] 7 parts of cotton pulp.

[0057] A method for preparing a high-strength adsorption-type calcium silicate board comprises the following steps:

[0058] a) mixing fly ash, quicklime and lithium carbonate slag, adding water and stirring into slurry;

[0059] b) adding cotton pulp and modified activated carbon fiber to the slurry and stirring evenly;

[0060] c) After forming by copying, pre-curing, autoclaving and drying, the pre-curing temperature is 90°C for 16 hours, the autoclaving temperature is 170°C for 20 hours, and a calcium silicate board is obtained.

[0061] Example 3

[0062] The preparation method of modified activated carbon fiber comprises the following steps:

[0063] 1) adding carboxymethyl chitosan into water and stirring to dissolve to prepare a carboxymethyl chitosan aqueous solution with a mass concentration of 0.05%;

[0064] 2) mixing activated carbon fiber with carboxymethyl chitosan aqueous solution, wherein the mass ratio of activated carbon fiber to carboxymethyl chitosan is 1:0.5, adding glutaraldehyde crosslinking agent for crosslinking reaction, wherein the amount of glutaraldehyde added is 0.5% of the mass of carboxymethyl chitosan;

[0065] 3) The activated carbon fiber after the reaction is placed in an oven for heat treatment at a temperature of 50° C. and a heat treatment time of 30 min to obtain the obtained carbon fiber.

[0066] A high-strength adsorption-type calcium silicate board comprises the following components in parts by weight:

[0067] 30 parts fly ash

[0068] 10 parts quicklime

[0069] 20 parts of lithium carbonate slag

[0070] Modified activated carbon fiber 10 parts

[0071] 4 parts cotton pulp.

[0072] A method for preparing a high-strength adsorption-type calcium silicate board comprises the following steps:

[0073] a) mixing fly ash, quicklime and lithium carbonate slag, adding water and stirring into slurry;

[0074] b) adding cotton pulp and modified activated carbon fiber to the slurry and stirring evenly;

[0075] c) After forming by copying, pre-curing, autoclaving and drying, the pre-curing temperature is 90°C for 16 hours, the autoclaving temperature is 170°C for 20 hours, and a calcium silicate board is obtained.

[0076] Comparative Example 1

[0077] The difference between Comparative Example 1 and Example 1 is that no modified activated carbon fiber is added.

[0078] Comparative Example 2

[0079] The difference between Comparative Example 2 and Example 1 is that the activated carbon fiber is replaced by ordinary activated carbon fiber.

[0080] Performance Testing

[0081] The strength of calcium silicate board is tested according to CB / T8040, and the test results are as follows:

[0082]

[0083] The test data of Comparative Examples 1 and 2 show that adding ordinary activated carbon fibers to calcium silicate boards will reduce the flexural strength of the calcium silicate boards. This is because the interfacial interaction between the activated carbon fibers and other components is weak, which reduces the strength of the calcium silicate boards.

[0084] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modify the above-disclosed technical contents into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A high-strength adsorption-type calcium silicate board, characterized in that: It comprises the following components by weight: 30-45 parts fly ash 10-15 parts quicklime 20-25 parts of lithium carbonate slag Modified activated carbon fiber 10-15 parts 4-7 parts of cotton pulp; The preparation method of the modified activated carbon fiber comprises the following steps: 1) Prepare carboxymethyl chitosan aqueous solution; 2) Mixing the activated carbon fiber with the carboxymethyl chitosan aqueous solution and adding a cross-linking agent to carry out a cross-linking reaction; 3) The activated carbon fiber after the reaction is heat treated to obtain.

2. The high-strength adsorption-type calcium silicate board according to claim 1, characterized in that: The mass concentration of the carboxymethyl chitosan aqueous solution in step 1) is 0.05-1.0%.

3. The high-strength adsorption-type calcium silicate board according to claim 1, characterized in that: In the step 2), the cross-linking agent is glutaraldehyde.

4. The high-strength adsorption-type calcium silicate board according to claim 1, characterized in that: The heat treatment temperature in step 3) is 50-70°C.

5. A method for preparing a high-strength adsorption-type calcium silicate board according to any one of claims 1 to 4, characterized in that: The following steps are involved: a) Mix fly ash, quicklime and lithium carbonate slag, add water and stir to form slurry; b) adding cotton pulp and modified activated carbon fiber into the slurry and stirring evenly; c) After forming, pre-curing, autoclaving and drying, the calcium silicate board is obtained.

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