A method for preparing magnesium oxychloride lightweight partition board from activated regenerated micropowder

Abstract

The present invention provides a method for preparing a magnesium oxychloride lightweight partition board from activated regenerated micropowder, belonging to the technical field of partition board preparation. The present invention crushes, calcines, and ball-mills waste concrete to obtain regenerated micropowder, adds an alkaline activator for activation, then adds light-burned magnesium oxide and magnesium chloride, water, and boric acid, mixes with foam, and then adds chopped vinylon engineering fiber to obtain a slurry. The slurry is then used to prepare a core board together with expanded perlite, and the slurry is then added and naturally cured to obtain a lightweight partition board. The present invention uses a specific activation process to increase the activity of the regenerated micropowder, enabling it to effectively react with the magnesium oxychloride gelling material to form a lightweight partition board with good physical properties and chemical stability.

Description

Technical Field

[0001] The invention relates to the technical field of partition board preparation, in particular to a method for preparing a magnesium oxychloride lightweight partition board by using activated regenerated micropowder. Background Art

[0002] With the acceleration of urbanization, the construction industry has developed rapidly, and with it comes the generation of a large amount of construction waste. If these wastes are not effectively treated, they will not only occupy land resources, but may also cause serious pollution to the environment. On the other hand, the production of traditional building materials often relies on large-scale exploitation of natural resources, which not only aggravates resource depletion but also has an adverse impact on the ecological environment. The resource utilization of construction waste has become an urgent problem to be solved. In particular, the recycled micropowder of building materials in construction waste has certain potential activity due to its small particle size and large specific surface area. It can be converted into a material with cementitious properties through appropriate activation treatment, which can be used to replace part of the cement and prepare new building materials.

[0003] Magnesium oxychloride cement is a pneumatic cement characterized by high temperature resistance, high strength, good wear resistance, and low density. Solid waste is often used as an admixture in its production. This is due to its high strength, allowing it to meet strength requirements even with the addition of large amounts of solid waste, with a maximum admixture of up to 60%. While this is a key advantage of magnesium oxychloride cement, it also has significant drawbacks: poor water resistance. Its hardened form gradually loses 60-80% of its strength in water, limiting its application. Summary of the Invention

[0004] In light of this, the present invention provides a method for preparing lightweight magnesium oxychloride partition boards from activated regenerated micropowder. This method utilizes a specific activation process to enhance the activity of the regenerated micropowder, enabling it to effectively react with the magnesium oxychloride gelling material to form lightweight partition boards with excellent physical properties and chemical stability. This method not only achieves high-value utilization of construction waste, reduces material costs, but also minimizes environmental impact, thus possessing significant economic and social value.

[0005] The method for preparing a lightweight magnesium oxychloride partition board from activated regenerated micropowder of the present invention comprises the following steps:

[0006] A method for preparing a magnesium oxychloride lightweight partition board from activated regenerated micropowder, the method comprising the following steps:

[0007] S1: Preliminary crushing of waste concrete, screening of particles with a diameter of less than 40 mm, and calcination of the obtained particles to obtain particles A;

[0008] S2: Ball milling particle A for 2-3 hours to obtain regenerated micropowder B;

[0009] S3: calcining the regenerated micropowder B, and then mixing the regenerated micropowder with 0.1-5% by weight of an alkaline activator to obtain activated regenerated micropowder C;

[0010] S4: adding light-burned magnesium oxide and magnesium chloride to the activated regenerated micropowder C obtained in step S3, continuously stirring, then mixing with water, adding boric acid, and stirring homogenously to obtain slurry D;

[0011] S5: mixing a foaming agent, a foam stabilizer, and water to obtain foam, and then uniformly mixing slurry D and the foam to obtain slurry E;

[0012] S6: adding engineering fiber to the slurry E obtained in step S5, stirring and homogenizing to obtain slurry F;

[0013] S7: Lay a glass fiber mesh in the mold, pour the slurry F obtained in step S6 into it, then add expanded perlite, stir and homogenize, lay another layer of glass fiber mesh on the shallow surface of the slurry F, and complete natural curing to obtain the core board G;

[0014] S8: Lay the glass fiber mesh cloth flat in the mold, pour the slurry F obtained in step S6 with a thickness of 5-10mm, place the core board G obtained in step S5 in the center of the surface of the bottom slurry F, pour the slurry F obtained in step S6 around and on the surface of the core board G, the thickness of the slurry on the core board surface is equal to the thickness of the bottom slurry, and complete natural curing to obtain a lightweight partition board.

[0015] Preferably, the calcination temperature in step S1 is 300-500° C., and the calcination time is 2-3 hours.

[0016] Preferably, the regenerated fine powder B in step S2 has a diameter of 5-80 microns and a pass rate of not less than 75% through a 75-micron sieve. The diameter of the regenerated fine powder has a significant impact on the activation effect. Regenerated fine powder with a smaller diameter has a larger specific surface area and can react more effectively with the magnesium oxychloride cement raw material, thereby increasing its activity.

[0017] Preferably, the alkaline activator in step S3 is one or more of CaO, CaCl2 or Ca(OH)2.

[0018] Preferably, the calcination process in step S3 is: first calcining at a temperature of 700-800° C. for 1-3 hours, then heating to 900-1000° C. for 1-2 hours.

[0019] The calcination temperature in steps S1 and S3 has a significant impact on the activation of the regenerated micropowder. High-temperature thermal activation can change the mineral structure of the regenerated micropowder, promote the chemical bond breakage of the active components SiO2 and Al2O3, and generate hydration products with rehydration and gelation capabilities, such as CSH gel.

[0020] Preferably, the mass ratio of light-burned magnesium oxide, magnesium chloride, activated regenerated micropowder C, water, and boric acid in step S4 is 120-150:30-60:80-120:100-200:5-10. Boric acid plays a retarding role, and the addition of boric acid can react with Mg in the hydration process of magnesium oxychloride cement. 2+ The ions react to form stable hydration products, which help improve the stability and strength of cement in humid environments.

[0021] Preferably, the foaming agent in step S5 is a protein foaming agent and a physical foaming agent;

[0022] The foam stabilizer is fatty acid methanol amide;

[0023] The mass ratio of the foaming agent to the foam stabilizer is 200 to 1000: 1. By adding the foam stabilizer, the foam in the lightweight partition board can be made more stable, more dispersed and more uniform in the partition board, thereby improving the strength of the partition board.

[0024] More preferably, the foaming agent is any one of rosin acid soap foaming agents, sodium lauryl sulfate, sodium dodecylbenzene sulfonate, and a composite foaming agent.

[0025] Preferably, the volume ratio of the slurry D to the foam in step S5 is 1-4:1-6.

[0026] Preferably, the engineering fiber in step S6 is chopped polyvinyl alcohol fiber with a fiber length of 5-10 mm; and the mass ratio of the slurry E to the chopped polyvinyl alcohol fiber is 300-3000:1.

[0027] Preferably, the mass ratio of the slurry F to the expanded perlite in step S7 is 3.5 to 5:1.

[0028] During the curing process, Ca(OH)2 and phosphoric acid in the regenerated micropowder and alkaline activator form hydroxyapatite with high waterproof performance. The silicon and aluminum in the metastable material are dissolved and polymerized through the bridging effect of sodium ions to form Si-Al-O chain polymers, forming a low-polymer gel with mechanical strength.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The present invention first calcines the regenerated micropowder, adds an alkaline activator to activate the regenerated micropowder, and then adds light-burned magnesium oxide and magnesium chloride to further treat the slurry. Since magnesium oxychloride cement is an air-hardening cement with high temperature resistance, high strength, good wear resistance and low density, it can improve the strength and high temperature resistance of the partition board. Boric acid is added to reduce the setting time of the magnesium oxychloride cement, and phosphoric acid is added to participate in the generation of a compound with waterproof performance to improve the waterproof performance. Then, foam, expanded perlite and fiber mesh are added to improve the integrity of the finally formed partition board and reduce the overall density of the partition board. Finally, a composite lightweight partition board with excellent performance can be produced, and the light weight and surface density can reach 65-90 kg / m 2 , with good fireproof performance, the present invention adopts expanded perlite, and the recycled micropowder and magnesium oxychloride cement used are all non-combustible and have good flame retardancy. The present invention is a magnesium oxychloride cement foamed hollow product with a large number of closed tiny pores inside, which has good sound absorption and heat preservation effects, and the ultimate compressive strength is 5.0-10.0MPa, the bending load is 2-5 times, the impact resistance is greater than 5 times, and the single-point hanging force is 900-1200N. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the composition of a magnesium oxychloride lightweight partition board material prepared from activated regenerated micropowder according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The present invention will be further described below with reference to the embodiments.

[0033] Example 1

[0034] A method for preparing a lightweight magnesium oxychloride partition board from activated regenerated micropowder, comprising the following steps:

[0035] S1: The waste concrete was preliminarily crushed by a universal crusher, and particles with a diameter of less than 40 mm were screened. The obtained particles were calcined at 300°C for 2 hours to obtain particles A;

[0036] S2: ball milling the particles A for 2 hours using a planetary ball mill to obtain regenerated micropowder B with a diameter of 5-80 μm and a passing rate of not less than 75% through a 75 μm sieve;

[0037] S3: After calcining the regenerated micropowder B at 700°C for 1 hour, the temperature was raised to 900°C and calcined for 1 hour, and then the regenerated micropowder was thoroughly mixed with 5% by weight of an alkaline activator Ca(OH)2 to obtain activated regenerated micropowder C.

[0038] S4: 120 parts by mass of light-burned magnesium oxide and 30 parts by mass of magnesium chloride were added to 80 parts by mass of activated regenerated micropowder C, and the mixture was continuously stirred. The mixture was then mixed with 100 parts by mass of water, and 5 parts by mass of boric acid was added and stirred to obtain slurry D.

[0039] S5: A foaming agent (sodium dodecylbenzenesulfonate) and a foam stabilizer (fatty acid methanol amide) are mixed in a mass ratio of 500:1, and then 10 times the amount of water is added to dilute the mixture. Foam is obtained by a foaming machine, and slurry D and the foam are evenly mixed in a ratio of 4:1 to obtain slurry E.

[0040] S6: adding 1 part by mass of chopped polyvinyl alcohol fibers having a fiber length of 5-10 mm to 350 parts by mass of the slurry E obtained in step S5, and stirring and homogenizing to obtain slurry F;

[0041] S7: Lay a glass fiber mesh in a partition board mold, pour the slurry F obtained in step S6, and then add expanded perlite. The mass ratio of slurry F to expanded perlite is 4:1. Lay another layer of glass fiber mesh on the shallow surface of slurry F. After natural curing, a core board G is obtained. The core board has a thickness of 60 to 80 mm (the same below) and is set aside.

[0042] S8: Lay glass fiber mesh cloth flat in the partition board mold, pour in the slurry F obtained in step S6 with a thickness of 5-10 mm, place the core board G obtained in step S5 in the center of the surface of the bottom slurry F, pour the slurry F obtained in step S6 around and on the surface of the core board G, the thickness of the slurry on the core board surface is equal to the thickness of the bottom slurry, and complete natural curing to obtain a lightweight partition board.

[0043] The core material and core board of the lightweight partition board prepared by the present invention generate micro powder hydration products and bubbles due to the reaction, which are evenly distributed in the core material and the core board. The structure of the lightweight partition board is as follows: Figure 1 .

[0044] Example 2

[0045] A method for preparing a lightweight magnesium oxychloride partition board from activated regenerated micropowder, comprising the following steps:

[0046] S1: The waste concrete was preliminarily crushed by a universal crusher, and particles with a diameter of less than 40 mm were screened. The obtained particles were calcined at 500°C for 3 hours to obtain particles A;

[0047] S2: ball milling the particles A for 2 hours using a planetary ball mill to obtain regenerated micropowder B with a diameter of 5-80 μm and a passing rate of not less than 75% through a 75 μm sieve;

[0048] S3: After calcining the regenerated micropowder B at 800°C for 2 hours, the temperature was raised to 900°C and calcined for 2 hours. The regenerated micropowder was then thoroughly mixed with 5% by weight of an alkaline activator Ca(OH)2 to obtain activated regenerated micropowder C.

[0049] S4: 150 parts by mass of light-burned magnesium oxide and 60 parts by mass of magnesium chloride were added to 120 parts by mass of activated regenerated micropowder C, and the mixture was continuously stirred. The mixture was then mixed with 200 parts by mass of water, and 8 parts by mass of boric acid was added and stirred to obtain slurry D.

[0050] S5: A foaming agent (sodium dodecylbenzenesulfonate) and a foam stabilizer (fatty acid methanol amide) were mixed in a mass ratio of 500:1, and then 10 times water was added to dilute the mixture. Foam was obtained by a foaming machine. Slurry D and the foam were evenly mixed in a ratio of 1:5 to obtain slurry E.

[0051] S6: adding 1 part by mass of chopped polyvinyl alcohol fibers having a fiber length of 5-10 mm to 550 parts by mass of the slurry E obtained in step S5, and stirring and homogenizing to obtain slurry F;

[0052] S7: Lay a glass fiber mesh in a partition board mold, pour the slurry F obtained in step S6, and then add expanded perlite, the mass ratio of slurry F to expanded perlite is 4:1, and lay another layer of glass fiber mesh on the shallow surface of slurry F. After natural curing is completed, a core board G is obtained and set aside;

[0053] S8: Lay glass fiber mesh cloth flat in the partition board mold, pour in the slurry F obtained in step S6 with a thickness of 5-10 mm, place the core board G obtained in step S5 in the center of the surface of the bottom slurry F, pour the slurry F obtained in step S6 around and on the surface of the core board G, the thickness of the slurry on the core board surface is equal to the thickness of the bottom slurry, and complete natural curing to obtain a lightweight partition board.

[0054] Example 3

[0055] A method for preparing a lightweight magnesium oxychloride partition board from activated regenerated micropowder, comprising the following steps:

[0056] S1: The waste concrete was preliminarily crushed by a universal crusher, and particles with a diameter of less than 40 mm were screened. The obtained particles were calcined at 500°C for 3 hours to obtain particles A;

[0057] S2: ball milling the particles A for 2 hours using a planetary ball mill to obtain regenerated micropowder B with a diameter of 5-80 μm and a passing rate of not less than 75% through a 75 μm sieve;

[0058] S3: After calcining the regenerated micropowder B at 800° C. for 2 h, the temperature was raised to 900° C. and calcined for 2 h. The regenerated micropowder was then thoroughly mixed with 5% by weight of an alkaline activator, CaCl 2 , to obtain activated regenerated micropowder C.

[0059] S4: 150 parts by mass of light-burned magnesium oxide and 60 parts by mass of magnesium chloride were added to 120 parts by mass of activated regenerated micropowder C, and the mixture was continuously stirred. The mixture was then mixed with 200 parts by mass of water, and 8 parts by mass of boric acid was added and stirred to obtain slurry D.

[0060] S5: A foaming agent (sodium dodecylbenzenesulfonate) and a foam stabilizer (fatty acid methanol amide) were mixed in a mass ratio of 500:1, and then 10 times water was added to dilute the mixture. Foam was obtained by a foaming machine. Slurry D and the foam were evenly mixed in a ratio of 1:6 to obtain slurry E.

[0061] S6: adding 1 part by mass of chopped polyvinyl alcohol fibers having a fiber length of 5-10 mm to 550 parts by mass of the slurry E obtained in step S5, and stirring and homogenizing to obtain slurry F;

[0062] S7: Lay a glass fiber mesh in a partition board mold, pour the slurry F obtained in step S6, and then add expanded perlite, the mass ratio of slurry F to expanded perlite is 4:1, and lay another layer of glass fiber mesh on the shallow surface of slurry F. After natural curing is completed, a core board G is obtained and set aside;

[0063] S8: Lay glass fiber mesh cloth flat in the partition board mold, pour in the slurry F obtained in step S6 with a thickness of 5-10 mm, place the core board G obtained in step S5 in the center of the surface of the bottom slurry F, pour the slurry F obtained in step S6 around and on the surface of the core board G, the thickness of the slurry on the core board surface is equal to the thickness of the bottom slurry, and complete natural curing to obtain a lightweight partition board.

[0064] Example 4

[0065] A method for preparing a lightweight magnesium oxychloride partition board from activated regenerated micropowder, comprising the following steps:

[0066] S1: The waste concrete was preliminarily crushed by a universal crusher, and particles with a diameter of less than 40 mm were screened. The obtained particles were calcined at 500°C for 3 hours to obtain particles A;

[0067] S2: ball milling the particles A for 2 hours using a planetary ball mill to obtain regenerated micropowder B with a diameter of 5-80 μm and a passing rate of not less than 75% through a 75 μm sieve;

[0068] S3: After calcining the regenerated micropowder B at 800°C for 2 hours, the temperature was raised to 900°C and calcined for 2 hours. The regenerated micropowder was then thoroughly mixed with 5% by weight of an alkaline activator Ca(OH)2 to obtain activated regenerated micropowder C.

[0069] S4: 120 parts by mass of light-burned magnesium oxide and 30 parts by mass of magnesium chloride were added to 120 parts by mass of activated regenerated micropowder C, and the mixture was continuously stirred. The mixture was then mixed with 200 parts by mass of water, and 8 parts by mass of boric acid was added and stirred to obtain slurry D.

[0070] S5: A foaming agent (sodium dodecylbenzenesulfonate) and a foam stabilizer (fatty acid methanol amide) were mixed in a mass ratio of 500:1, and then 10 times water was added to dilute the mixture. Foam was obtained by a foaming machine. Slurry D and the foam were evenly mixed in a ratio of 1:6 to obtain slurry E.

[0071] S6: adding 1 part by mass of chopped polyvinyl alcohol fibers having a fiber length of 5-10 mm to 500 parts by mass of the slurry E obtained in step S5, and stirring and homogenizing to obtain slurry F;

[0072] S7: Lay a glass fiber mesh in a partition board mold, pour the slurry F obtained in step S6, and then add expanded perlite, the mass ratio of slurry F to expanded perlite is 4:1, and lay another layer of glass fiber mesh on the shallow surface of slurry F. After natural curing is completed, a core board G is obtained and set aside;

[0073] S8: Lay glass fiber mesh cloth flat in the partition board mold, pour in the slurry F obtained in step S6 with a thickness of 5-10 mm, place the core board G obtained in step S5 in the center of the surface of the bottom slurry F, pour the slurry F obtained in step S6 around and on the surface of the core board G, the thickness of the slurry on the core board surface is equal to the thickness of the bottom slurry, and complete natural curing to obtain a lightweight partition board.

[0074] Example 5

[0075] A method for preparing a lightweight magnesium oxychloride partition board from activated regenerated micropowder, comprising the following steps:

[0076] S1: The waste concrete was preliminarily crushed by a universal crusher, and particles with a diameter of less than 40 mm were screened. The obtained particles were calcined at 500°C for 3 hours to obtain particles A;

[0077] S2: ball milling the particles A for 2 hours using a planetary ball mill to obtain regenerated micropowder B with a diameter of 5-80 μm and a passing rate of not less than 75% through a 75 μm sieve;

[0078] S3: After calcining the regenerated micropowder B at 800°C for 2 hours, the temperature was raised to 900°C and calcined for 2 hours. The regenerated micropowder was then thoroughly mixed with 5% by weight of an alkaline activator Ca(OH)2 to obtain activated regenerated micropowder C.

[0079] S4: 120 parts by mass of light-burned magnesium oxide and 60 parts by mass of magnesium chloride were added to 120 parts by mass of activated regenerated micropowder C, and the mixture was continuously stirred. The mixture was then mixed with 200 parts by mass of water, and 8 parts by mass of boric acid was added and stirred to obtain slurry D.

[0080] S5: A foaming agent (sodium dodecylbenzenesulfonate) and a foam stabilizer (fatty acid methanol amide) were mixed in a mass ratio of 500:1, and then 10 times water was added to dilute the mixture. Foam was obtained by a foaming machine. Slurry D and the foam were evenly mixed in a ratio of 1:6 to obtain slurry E.

[0081] S6: adding 1 part by mass of chopped polyvinyl alcohol fibers having a fiber length of 5-10 mm to 520 parts by mass of the slurry E obtained in step S5, and stirring and homogenizing to obtain slurry F;

[0082] S7: Lay a glass fiber mesh in a partition board mold, pour the slurry F obtained in step S6, and then add expanded perlite, the mass ratio of slurry F to expanded perlite is 4:1, and lay another layer of glass fiber mesh on the shallow surface of slurry F. After natural curing is completed, a core board G is obtained and set aside;

[0083] S8: Lay glass fiber mesh cloth flat in the partition board mold, pour in the slurry F obtained in step S6 with a thickness of 5-10 mm, place the core board G obtained in step S5 in the center of the surface of the bottom slurry F, pour the slurry F obtained in step S6 around and on the surface of the core board G, the thickness of the slurry on the core board surface is equal to the thickness of the bottom slurry, and complete natural curing to obtain a lightweight partition board.

[0084] Comparative Example 1

[0085] A method for preparing a lightweight magnesium oxychloride partition board from activated regenerated micropowder, comprising the following steps:

[0086] S1: Use a universal crusher to preliminarily crush the waste concrete and screen out particles with a diameter of less than 40 mm to obtain particles A;

[0087] S2: ball milling the particles A for 2 hours using a planetary ball mill to obtain regenerated micropowder B with a diameter of 5-80 μm and a passing rate of not less than 75% through a 75 μm sieve;

[0088] S3: After calcining the regenerated micropowder B at 800°C for 2 hours, the temperature was raised to 900°C and calcined for 2 hours. The regenerated micropowder was then thoroughly mixed with 5% by weight of an alkaline activator Ca(OH)2 to obtain activated regenerated micropowder C.

[0089] S4: 120 parts by mass of light-burned magnesium oxide and 60 parts by mass of magnesium chloride were added to 120 parts by mass of activated regenerated micropowder C, and the mixture was continuously stirred. The mixture was then mixed with 200 parts by mass of water, and 8 parts by mass of boric acid was added and stirred to obtain slurry D.

[0090] S5: A foaming agent (sodium dodecylbenzenesulfonate) and a foam stabilizer (fatty acid methanol amide) were mixed in a mass ratio of 500:1, and then 10 times water was added to dilute the mixture. Foam was obtained by a foaming machine. Slurry D and the foam were evenly mixed in a ratio of 1:6 to obtain slurry E.

[0091] S6: adding 1 part by mass of chopped polyvinyl alcohol fibers having a fiber length of 5-10 mm to 500 parts by mass of the slurry E obtained in step S5, and stirring and homogenizing to obtain slurry F;

[0092] S7: Lay a glass fiber mesh in a partition board mold, pour the slurry F obtained in step S6, and then add expanded perlite, the mass ratio of slurry F to expanded perlite is 4:1, and lay another layer of glass fiber mesh on the shallow surface of slurry F. After natural curing is completed, a core board G is obtained and set aside;

[0093] S8: Lay glass fiber mesh cloth flat in the partition board mold, pour in the slurry F obtained in step S6 with a thickness of 5-10 mm, place the core board G obtained in step S5 in the center of the surface of the bottom slurry F, pour the slurry F obtained in step S6 around and on the surface of the core board G, the thickness of the slurry on the core board surface is equal to the thickness of the bottom slurry, and complete natural curing to obtain a lightweight partition board.

[0094] Comparative Example 2

[0095] A method for preparing a lightweight magnesium oxychloride partition board from activated regenerated micropowder, comprising the following steps:

[0096] S1: The waste concrete was preliminarily crushed by a universal crusher, and particles with a diameter of less than 40 mm were screened. The obtained particles were calcined at 500°C for 3 hours to obtain particles A;

[0097] S2: ball milling the particles A for 2 hours using a planetary ball mill to obtain regenerated micropowder B with a diameter of 5-80 μm and a passing rate of not less than 75% through a 75 μm sieve;

[0098] S3: The regenerated micropowder is thoroughly mixed with 5% by weight of an alkaline activator Ca(OH)2 to obtain activated regenerated micropowder C.

[0099] S4: 150 parts by mass of light-burned magnesium oxide and 60 parts by mass of magnesium chloride were added to 120 parts by mass of activated regenerated micropowder C, and the mixture was continuously stirred. The mixture was then mixed with 200 parts by mass of water, and 8 parts by mass of boric acid was added and stirred to obtain slurry D.

[0100] S5: A foaming agent (sodium dodecylbenzenesulfonate) and a foam stabilizer (fatty acid methanol amide) were mixed in a mass ratio of 500:1, and then 10 times water was added to dilute the mixture. Foam was obtained by a foaming machine. Slurry D and the foam were evenly mixed in a ratio of 1:6 to obtain slurry E.

[0101] S6: adding 1 part by mass of chopped polyvinyl alcohol fibers having a fiber length of 5-10 mm to 550 parts by mass of the slurry E obtained in step S5, and stirring and homogenizing to obtain slurry F;

[0102] S7: Lay a glass fiber mesh in a partition board mold, pour the slurry F obtained in step S6, and then add expanded perlite, the mass ratio of slurry F to expanded perlite is 4:1, and lay another layer of glass fiber mesh on the shallow surface of slurry F. After natural curing is completed, a core board G is obtained and set aside;

[0103] S8: Lay glass fiber mesh cloth flat in the partition board mold, pour in the slurry F obtained in step S6 with a thickness of 5-10 mm, place the core board G obtained in step S5 in the center of the surface of the bottom slurry F, pour the slurry F obtained in step S6 around and on the surface of the core board G, the thickness of the slurry on the core board surface is equal to the thickness of the bottom slurry, and complete natural curing to obtain a lightweight partition board.

[0104] Comparative Example 3

[0105] A method for preparing a lightweight magnesium oxychloride partition board from activated regenerated micropowder, comprising the following steps:

[0106] S1: The waste concrete was preliminarily crushed by a universal crusher, and particles with a diameter of less than 40 mm were screened. The obtained particles were calcined at 500°C for 3 hours to obtain particles A;

[0107] S2: ball milling the particles A for 2 hours using a planetary ball mill to obtain regenerated micropowder B with a diameter of 5-80 μm and a passing rate of not less than 75% through a 75 μm sieve;

[0108] S3: After calcining the regenerated micropowder B at 800°C for 2 hours, the temperature was raised to 900°C and calcined for 2 hours. The regenerated micropowder was then thoroughly mixed with 5% by weight of an alkaline activator Ca(OH)2 to obtain activated regenerated micropowder C.

[0109] S4: 150 parts by mass of light-burned magnesium oxide and 60 parts by mass of magnesium chloride were added to 120 parts by mass of activated regenerated micropowder C, and the mixture was continuously stirred. The mixture was then mixed with 200 parts by mass of water, and 8 parts by mass of boric acid was added and stirred to obtain slurry D.

[0110] S5: adding 1 part by mass of chopped polyvinyl alcohol fibers having a fiber length of 5-10 mm to 550 parts by mass of the slurry D obtained in step S4, and stirring and homogenizing to obtain slurry E;

[0111] S6: Lay a glass fiber mesh in a partition board mold, pour the slurry E obtained in step S5, and then add expanded perlite, the mass ratio of slurry E to expanded perlite is 4:1, and lay another layer of glass fiber mesh on the shallow surface of slurry E. After natural curing is completed, a core board F is obtained and set aside;

[0112] S7: Lay glass fiber mesh cloth flat in the partition board mold, pour in the slurry E obtained in step S5 with a thickness of 5-10 mm, place the core board G obtained in step S6 in the center of the surface of the bottom slurry E, pour the slurry E obtained in step S5 around and on the surface of the core board G, the thickness of the slurry on the core board surface is equal to the thickness of the bottom slurry, and complete natural curing to obtain a lightweight partition board.

[0113] Comparative Example 4

[0114] A method for preparing a lightweight magnesium oxychloride partition board from activated regenerated micropowder, comprising the following steps:

[0115] S1: The waste concrete was preliminarily crushed by a universal crusher, and particles with a diameter of less than 40 mm were screened. The obtained particles were calcined at 500°C for 3 hours to obtain particles A;

[0116] S2: ball milling the particles A for 2 hours using a planetary ball mill to obtain regenerated micropowder B with a diameter of 5-80 μm and a passing rate of not less than 75% through a 75 μm sieve;

[0117] S3: After calcining the regenerated micropowder B at 800°C for 2 hours, the temperature was raised to 900°C and calcined for 2 hours. The regenerated micropowder was then thoroughly mixed with 5% by weight of an alkaline activator Ca(OH)2 to obtain activated regenerated micropowder C.

[0118] S4: 150 parts by mass of light-burned magnesium oxide and 60 parts by mass of magnesium chloride were added to 120 parts by mass of activated regenerated micropowder C, and the mixture was continuously stirred. The mixture was then mixed with 200 parts by mass of water, and 8 parts by mass of boric acid was added and stirred to obtain slurry D.

[0119] S5: A foaming agent (sodium dodecylbenzenesulfonate) and a foam stabilizer (fatty acid methanol amide) were mixed in a mass ratio of 500:1, and then 10 times water was added to dilute the mixture. Foam was obtained by a foaming machine. Slurry D and the foam were evenly mixed in a ratio of 1:6 to obtain slurry E.

[0120] S6: Lay a glass fiber mesh in a partition board mold, pour the slurry E obtained in step S5, and then add expanded perlite, the mass ratio of slurry E to expanded perlite is 4:1, and lay another layer of glass fiber mesh on the shallow surface of slurry E. After natural curing is completed, a core board F is obtained and set aside;

[0121] S7: Lay glass fiber mesh cloth flat in the partition board mold, pour in the slurry E obtained in step S5 with a thickness of 5-10 mm, place the core board F obtained in step S6 in the center of the surface of the bottom slurry E, pour the slurry E obtained in step S6 around and on the surface of the core board F, the slurry thickness on the core board surface is equal to the thickness of the bottom slurry, and complete natural curing to obtain a lightweight partition board.

[0122] Comparative Example 5

[0123] A method for preparing a lightweight magnesium oxychloride partition board from activated regenerated micropowder, comprising the following steps:

[0124] S1: The waste concrete was preliminarily crushed by a universal crusher, and particles with a diameter of less than 40 mm were screened. The obtained particles were calcined at 500°C for 3 hours to obtain particles A;

[0125] S2: ball milling the particles A for 2 hours using a planetary ball mill to obtain regenerated micropowder B with a diameter of 5-80 μm and a passing rate of not less than 75% through a 75 μm sieve;

[0126] S3: After calcining the regenerated micropowder B at 800°C for 2 hours, the temperature was raised to 900°C and calcined for 2 hours. The regenerated micropowder was then thoroughly mixed with 5% by weight of an alkaline activator Ca(OH)2 to obtain activated regenerated micropowder C.

[0127] S4: 150 parts by mass of light-burned magnesium oxide and 60 parts by mass of magnesium chloride were added to 120 parts by mass of activated regenerated micropowder C, and the mixture was continuously stirred. The mixture was then mixed with 200 parts by mass of water, and 8 parts by mass of boric acid was added and stirred to obtain slurry D.

[0128] S5: A foaming agent (sodium dodecylbenzenesulfonate) and a foam stabilizer (fatty acid methanol amide) were mixed in a mass ratio of 500:1, and then 10 times water was added to dilute the mixture. Foam was obtained by a foaming machine. Slurry D and the foam were evenly mixed in a ratio of 1:6 to obtain slurry E.

[0129] S6: adding 1 part by mass of chopped polyvinyl alcohol fibers having a fiber length of 5-10 mm to 550 parts by mass of the slurry E obtained in step S5, and stirring and homogenizing to obtain slurry F;

[0130] S7: Laying a glass fiber mesh in a partition board mold, pouring the slurry F obtained in step S6, laying another layer of glass fiber mesh on the shallow surface of the slurry F, and completing natural curing to obtain a core board G for standby use;

[0131] S8: Lay glass fiber mesh cloth flat in the partition board mold, pour in the slurry F obtained in step S6 with a thickness of 5-10 mm, place the core board G obtained in step S5 in the center of the surface of the bottom slurry F, pour the slurry F obtained in step S6 around and on the surface of the core board G, the thickness of the slurry on the core board surface is equal to the thickness of the bottom slurry, and complete natural curing to obtain a lightweight partition board.

[0132] The performance tests of the partition boards prepared in the examples and comparative examples were carried out, and the results are shown in Table 1:

[0133] Table 1

[0134]

[0135]

[0136] From Table 1 we can see that:

[0137] Analysis of the experimental results of Examples 1-2, 4-5 and Comparative Example 1 shows that in the lightweight partition board of the present invention, the recycled micropowder needs to be pre-treated by calcination at 300-500°C, and when the calcination time is between 2-3h, the performance of the lightweight partition board is significantly higher.

[0138] From the analysis of the experimental results of Examples 1-3 and Comparative Example 2, it can be seen that in the lightweight partition boards of the present invention, the regenerated micropowder needs to be calcined again after ball milling to improve its activity. The calcination temperature is 700-800°C, the calcination time is 1-3h, and then the temperature is raised to 900-1000°C and calcined for 1-2h, which can significantly improve the performance of the lightweight partition boards.

[0139] From the analysis of the experimental results of Examples 1-4 and Comparative Examples 3 and 4, it can be seen that the addition of foam and expanded perlite to the lightweight partition boards of the present invention can effectively reduce the surface density of the lightweight partition boards without significantly affecting the performance of the lightweight partition boards, and reduce the raw material cost of the lightweight partition boards, which has better practicality and is more conducive to the large-scale application of lightweight partition boards.

[0140] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing magnesium oxychloride lightweight partition board from activated regenerated micropowder, characterized in that: The method comprises the following steps: S1: Preliminary crushing of waste concrete, screening of particles with a diameter of less than 40 mm, and calcination of the obtained particles to obtain particles A; S2: Ball milling particle A for 2-3 hours to obtain regenerated micropowder B; S3: calcining the regenerated micropowder B, and then mixing the regenerated micropowder with 0.1-5% by weight of an alkaline activator to obtain activated regenerated micropowder C; S4: adding light-burned magnesium oxide and magnesium chloride to the activated regenerated micropowder C obtained in step S3, continuously stirring, then mixing with water, adding boric acid, and stirring homogenously to obtain slurry D; S5: mixing a foaming agent, a foam stabilizer, and water to obtain foam, and then uniformly mixing slurry D and the foam to obtain slurry E; S6: adding engineering fiber to the slurry E obtained in step S5, stirring and homogenizing to obtain slurry F; S7: Lay a glass fiber mesh in the mold, pour the slurry F obtained in step S6 into it, then add expanded perlite, stir and homogenize, lay another layer of glass fiber mesh on the shallow surface of the slurry F, and complete natural curing to obtain the core board G; S8: Lay the glass fiber mesh cloth flat in the mold, pour the slurry F obtained in step S6 with a thickness of 5-10mm, place the core board G obtained in step S5 in the center of the surface of the bottom slurry F, pour the slurry F obtained in step S6 around and on the surface of the core board G, the thickness of the slurry on the core board surface is equal to the thickness of the bottom slurry, and complete natural curing to obtain a lightweight partition board.

2. The method for preparing a lightweight partition board of magnesium oxychloride from activated regenerated micropowder according to claim 1, characterized in that: The calcination temperature in step S1 is 300-500° C., and the calcination time is 2-3 hours.

3. The method for preparing a lightweight partition board of magnesium oxychloride from activated regenerated micropowder according to claim 1, characterized in that: The diameter of the regenerated micropowder B in step S2 is 5-80 microns, and the passing rate of the 75-micron sieve is not less than 75%.

4. The method for preparing a lightweight partition board of magnesium oxychloride from activated regenerated micropowder according to claim 1, characterized in that: The alkaline activator described in step S3 is one or more of CaO, CaCl2 or Ca(OH)2.

5. The method for preparing magnesium oxychloride lightweight partition board from activated regenerated micropowder according to claim 1, characterized in that: The calcination process in step S3 is: first calcining at a temperature of 700-800° C. for 1-3 hours, then heating to 900-1000° C. for 1-2 hours.

6. The method for preparing a lightweight partition board of magnesium oxychloride from activated regenerated micropowder according to claim 1, characterized in that: The mass ratio of the light-burned magnesium oxide, magnesium chloride, activated regenerated micropowder C, water, and boric acid in step S4 is 120-150:30-60:80-120:100-200:5-10.

7. The method for preparing magnesium oxychloride lightweight partition board from activated regenerated micropowder according to claim 1, characterized in that: The foaming agent in step S5 is a protein foaming agent or a physical foaming agent; The foam stabilizer is fatty acid methanol amide; The mass ratio of the foaming agent to the foam stabilizer is 200-1000:

1.

8. The method for preparing magnesium oxychloride lightweight partition board from activated regenerated micropowder according to claim 1, characterized in that: The volume ratio of the slurry D to the foam in step S5 is 1-4:1-6.

9. The method for preparing magnesium oxychloride lightweight partition board from activated regenerated micropowder according to claim 1, characterized in that: In step S6, the engineering fiber is short-cut polyvinyl alcohol fiber with a fiber length of 5-10 mm; the mass ratio of the slurry E to the short-cut polyvinyl alcohol fiber is 300-3000:

1.

10. The method for preparing magnesium oxychloride lightweight partition board from activated regenerated micropowder according to claim 1, characterized in that: The mass ratio of the slurry F to the expanded perlite in step S7 is 3.5 to 5:1.

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