CN116835616A - Method for preparing high-dispersion hexagonal flaky magnesium hydroxide by high-activity light-burned magnesium oxide through one-step hydrothermal method - Google Patents
Method for preparing high-dispersion hexagonal flaky magnesium hydroxide by high-activity light-burned magnesium oxide through one-step hydrothermal method Download PDFInfo
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- CN116835616A CN116835616A CN202311101234.0A CN202311101234A CN116835616A CN 116835616 A CN116835616 A CN 116835616A CN 202311101234 A CN202311101234 A CN 202311101234A CN 116835616 A CN116835616 A CN 116835616A
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- VTHJTEIRLNZDEV-UHFFFAOYSA-L magnesium dihydroxide Chemical compound [OH-].[OH-].[Mg+2] VTHJTEIRLNZDEV-UHFFFAOYSA-L 0.000 title claims abstract description 84
- 239000000347 magnesium hydroxide Substances 0.000 title claims abstract description 80
- 229910001862 magnesium hydroxide Inorganic materials 0.000 title claims abstract description 80
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 title claims abstract description 41
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 title claims abstract description 40
- 238000000034 method Methods 0.000 title claims abstract description 38
- 239000000395 magnesium oxide Substances 0.000 title claims abstract description 37
- 239000006185 dispersion Substances 0.000 title claims abstract description 22
- 238000001027 hydrothermal synthesis Methods 0.000 title claims abstract description 17
- 230000000694 effects Effects 0.000 title claims abstract description 16
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims abstract description 30
- 238000010438 heat treatment Methods 0.000 claims abstract description 11
- 239000012752 auxiliary agent Substances 0.000 claims abstract description 10
- 229920000036 polyvinylpyrrolidone Polymers 0.000 claims abstract description 10
- 235000013855 polyvinylpyrrolidone Nutrition 0.000 claims abstract description 10
- 230000008025 crystallization Effects 0.000 claims abstract description 8
- 239000000706 filtrate Substances 0.000 claims abstract description 7
- 238000002425 crystallisation Methods 0.000 claims abstract description 6
- 239000001267 polyvinylpyrrolidone Substances 0.000 claims abstract description 6
- 238000004064 recycling Methods 0.000 claims abstract description 6
- 230000001105 regulatory effect Effects 0.000 claims abstract description 6
- 239000002202 Polyethylene glycol Substances 0.000 claims abstract description 5
- 229920001223 polyethylene glycol Polymers 0.000 claims abstract description 5
- 239000002245 particle Substances 0.000 claims description 22
- 239000013078 crystal Substances 0.000 claims description 21
- 239000000047 product Substances 0.000 claims description 14
- 239000000725 suspension Substances 0.000 claims description 14
- 238000000967 suction filtration Methods 0.000 claims description 12
- 230000009471 action Effects 0.000 claims description 8
- 239000007787 solid Substances 0.000 claims description 8
- 238000001035 drying Methods 0.000 claims description 5
- 238000002386 leaching Methods 0.000 claims description 5
- 238000007789 sealing Methods 0.000 claims description 5
- 238000003756 stirring Methods 0.000 claims description 5
- 238000005303 weighing Methods 0.000 claims description 5
- 238000005216 hydrothermal crystallization Methods 0.000 claims description 2
- 239000000654 additive Substances 0.000 claims 1
- 230000000996 additive effect Effects 0.000 claims 1
- 230000036571 hydration Effects 0.000 abstract description 15
- 238000006703 hydration reaction Methods 0.000 abstract description 15
- 230000008569 process Effects 0.000 abstract description 15
- 238000002360 preparation method Methods 0.000 abstract description 5
- 238000006243 chemical reaction Methods 0.000 abstract description 3
- 239000000203 mixture Substances 0.000 abstract 1
- 238000001878 scanning electron micrograph Methods 0.000 description 15
- 210000004027 cell Anatomy 0.000 description 7
- 238000010335 hydrothermal treatment Methods 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- 238000001556 precipitation Methods 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 238000005054 agglomeration Methods 0.000 description 5
- 230000002776 aggregation Effects 0.000 description 5
- 238000004090 dissolution Methods 0.000 description 5
- 239000011777 magnesium Substances 0.000 description 5
- 229920000642 polymer Polymers 0.000 description 5
- UNYOJUYSNFGNDV-UHFFFAOYSA-M magnesium monohydroxide Chemical compound [Mg]O UNYOJUYSNFGNDV-UHFFFAOYSA-M 0.000 description 3
- 238000001953 recrystallisation Methods 0.000 description 3
- 239000013049 sediment Substances 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 238000011049 filling Methods 0.000 description 2
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 2
- 150000002500 ions Chemical group 0.000 description 2
- RNFJDJUURJAICM-UHFFFAOYSA-N 2,2,4,4,6,6-hexaphenoxy-1,3,5-triaza-2$l^{5},4$l^{5},6$l^{5}-triphosphacyclohexa-1,3,5-triene Chemical compound N=1P(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP=1(OC=1C=CC=CC=1)OC1=CC=CC=C1 RNFJDJUURJAICM-UHFFFAOYSA-N 0.000 description 1
- JLVVSXFLKOJNIY-UHFFFAOYSA-N Magnesium ion Chemical compound [Mg+2] JLVVSXFLKOJNIY-UHFFFAOYSA-N 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 239000012736 aqueous medium Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000005388 borosilicate glass Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 210000002858 crystal cell Anatomy 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000003795 desorption Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000003063 flame retardant Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 229910001425 magnesium ion Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F5/00—Compounds of magnesium
- C01F5/14—Magnesium hydroxide
- C01F5/16—Magnesium hydroxide by treating magnesia, e.g. calcined dolomite, with water or solutions of salts not containing magnesium
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/01—Particle morphology depicted by an image
- C01P2004/03—Particle morphology depicted by an image obtained by SEM
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/20—Particle morphology extending in two dimensions, e.g. plate-like
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Inorganic Chemistry (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
Abstract
The invention discloses a method for preparing high-dispersion hexagonal flaky magnesium hydroxide by a one-step hydrothermal method of high-activity light-burned magnesium oxide, belonging to the technical field of magnesium hydroxide preparation; the specific method comprises the following steps: adding a certain amount of high-activity light-burned magnesium oxide, a crystallization mineralizer sodium hydroxide and a structure regulating auxiliary agent polyethylene glycol (PEG) or polyvinylpyrrolidone (PVP) into a hydrothermal autoclave, directly heating the mixture to 180-200 ℃ to hydrate and crystallize the active magnesium oxide under a high-temperature hydrothermal condition to obtain the high-dispersion hexagonal flaky magnesium hydroxide. Because the process is carried out at high temperature and high pressure, the hydration and crystallization time is short, and the process is simple and efficient. After the reaction is finished, hexagonal flaky magnesium hydroxide with good crystallinity is obtained, the hexagonal flaky magnesium hydroxide is easy to filter and separate, and the filtered filtrate can be added with magnesium oxide again for recycling.
Description
Technical Field
The invention relates to the technical field of preparation of hexagonal flaky magnesium hydroxide, in particular to a method for preparing high-dispersion hexagonal flaky magnesium hydroxide by using high-activity light-burned magnesium oxide.
Background
Magnesium hydroxide is widely used in various fields of life due to its unique properties while being an environmentally friendly material. The magnesium hydroxide unit cell is similar to CdI 2 The layered structure of HCP-type hexagonal close-packed unit cells of (1) as shown in FIG. 2 of the drawings, each Mg 2+ And six OH groups - Combine to form a regular octahedral structure, mg in each unit cell 2+ At the node position of the origin of the hexagonal lattice, three Mg 2+ Form a triangular plane, OH - Is distributed alternately on the upper and lower sides of the triangular plane, mg 2+ The coordination number of (2) OH is 6 - . Thus, mg (OH) 2 Equivalent to two layers of OH - And a layer of Mg 2+ And the three ions form a unit layer. The interior of each unit layer is connected by ionic bonds, and the layers are formed by van der Waals attraction and hydrogen bonds, so that the magnesium hydroxide crystal is a layered structure compound formed by hexagonal close-packed unit cells.
When magnesium hydroxide is used as a polymer flame retardant material, the dispersibility of the magnesium hydroxide in a base material not only affects the flame retardance of the composite material, but also has an important influence on mechanical properties. The crystallization property and morphology of magnesium hydroxide play an important role in the application property. As the magnesium hydroxide crystal is of a hexagonal lamellar layer structure, as shown in figure 3 of the drawings, the layers 001 and 001 (-) are exposed to OH groups and can be regarded as nonpolar surfaces, and the side surfaces are 6 isosurfaces exposed with magnesium ions and are stress polar surfaces, so that agglomeration is easy to cause. The magnesium hydroxide with large particle size increases the size of the nonpolar layer surface, so that the side surface proportion of the large stress polar surface is relatively reduced, and the agglomeration is reduced, so that the dispersibility is improved. Therefore, the hexagonal flaky magnesium hydroxide with large particle size is of great significance for improving the dispersibility and increasing the filling utilization of the hexagonal flaky magnesium hydroxide.
The preparation method of the hexagonal flaky magnesium hydroxide comprises a direct precipitation method, a magnesium oxide hydration method, a hydrothermal method and the like. The hexagonal flaky magnesium hydroxide with good morphology and large particle size is prepared, and the concentration of reactants, the hydrothermal temperature, the time and other factors are controlled in the preparation process. In addition, the structure directing agent plays a key role in preparing products with more regular morphology and better dispersibility. Under the condition of below 100 ℃, the direct precipitation method and the magnesium oxide hydration method are adopted, when the magnesium hydroxide small unit cell is formed, the magnesium hydroxide small unit cell is easy to quickly aggregate, and the aggregate is difficult to scatter and crystallize to form hexagonal flaky crystals with large particle size.
At present, hexagonal flaky magnesium hydroxide crystals with large particle sizes are mainly prepared by a high-temperature hydrothermal method, and the high temperature is favorable for the growth of the hexagonal flaky magnesium hydroxide crystals. In the high temperature process, the binding force of water adsorbed on the surface of the small crystal is weakened, the small crystal undergoes a dissolving and recrystallizing process, the solution environment is relatively more uniform in the recrystallizing process, the homogeneous precipitation is more prone to be carried out, the crystal growth environment is relatively more free, and the ideal state growth is prone to be carried out; the relative polarity of the surface of the magnesium hydroxide particles is weakened, the microcosmic internal stress is reduced, the structure is more stable, the agglomeration trend is greatly weakened, the particle size is more uniform, the morphology is more regular, and the dispersibility is increased.
The method for preparing hexagonal flaky magnesium hydroxide with large particle size and high dispersion by a hydrothermal method is to directly precipitate magnesium hydroxide obtained by a direct precipitation method or a direct hydration method of magnesium oxide at 100 ℃ at present and then carry out high-temperature hydrothermal treatment. Because the magnesium hydroxide forms an agglomeration structure before the hydrothermal treatment in the process, in the drawings, figures 4, 5 and 6 show that the active magnesium oxide is hydrated at about 80 ℃ to obtain an SEM image of the magnesium hydroxide, so that small grains in the magnesium hydroxide agglomerate are tightly combined, and the agglomeration force greatly prevents the dissolution and recrystallization of the small crystals to form hexagonal flaky crystals with large grain size. Also due to the existence of the agglomerate, if the agglomerate is directly used for filling in a polymer, the agglomerate is difficult to disperse, and the usability is affected. Fig. 7, 8 and 9 of the accompanying drawings are SEM pictures of magnesium hydroxide which has been formed by hydration at 80 ℃ and treated under high temperature hydrothermal conditions at 180 ℃ for 6 hours, and it can be seen that after the hydrothermal treatment, magnesium hydroxide small crystal bonding is improved compared with that before the treatment, but a tightly bonded polymer exists. These polymers remain poorly dispersed in the polymer, severely affecting the performance properties.
Therefore, under the high-temperature hydrothermal condition, the magnesium oxide is directly hydrated in one step to prepare the hexagonal flaky magnesium hydroxide with large particle size and high dispersion, and small magnesium hydroxide crystal cells can be quickly dissolved and recrystallized to form hexagonal flaky crystals with large particle size due to the action of high temperature, so that acting force among different crystal particles is weakened, and the formation of magnesium hydroxide agglomerates formed by crystals with small particle size at lower temperature is avoided, so that the magnesium hydroxide has good dispersion.
The currently accepted magnesium oxide hydration mechanism has two principles of shell shrinkage theory and dissolution precipitation theory. The shell shrinkage theory considers that magnesium hydroxide sediment is formed on the surface of magnesium oxide crystal and in the gaps of grain boundaries, the difference between the magnesium hydroxide sediment and the pure magnesium oxide structure is obvious, the solubility of the magnesium hydroxide sediment in water is far higher than that of the pure magnesium oxide, stress is generated between grains due to enrichment of magnesium hydroxide in the gaps of the grain boundaries, and the stress can be used for expanding magnesium hydroxide grains, so that the inner magnesium oxide layer is continuously hydrated until hydration is completed.
The theory of dissolution precipitation believes that there are four steps: (1) MgO is H in water + The (proton) provides electrons forming a positively charged surface, mgO (S) +H 2 O(L)→MgOH + (surface)+OH − (aq)
(2) Positively charged surface attracts OH − ，MgOH + (surface)+OH − (aq)→MgOH + ·OH − (surface)
(3) Mg in aqueous Medium 2+ And OH (OH) − Desorption from the surface, mgOH + ·OH − (surface)→Mg 2+ (aq)+2OH − (aq)
(4) The ions reach supersaturation in the solution and begin to precipitate on the MgO surface to form a magnesium hydroxide layer, which diffuses away in water, and the inner MgO layer continues to hydrate until completion.
For the two hydration theories, the hydration process is greatly accelerated under the high-temperature hydrothermal condition, and the high-temperature hydrothermal condition is favorable for forming a magnesium hydroxide small crystal layer to be redissolved and crystallized, so that the hexagonal flaky magnesium hydroxide with large particle size in an ideal state is formed. In order to further accelerate the dissolution and recrystallization processes, a crystallization mineralizer and a structure adjusting auxiliary agent can be added into the system to obtain hexagonal flaky magnesium hydroxide with large particle size.
Based on the above, the invention provides a method for preparing large-particle-size high-dispersion hexagonal flaky magnesium hydroxide by a one-step hydrothermal method of high-activity light-burned magnesium oxide.
Disclosure of Invention
Aiming at the defects existing in the prior art, the invention provides borosilicate glass with high ultraviolet transmittance and a preparation method thereof, which realize the following aims: provides a method for preparing hexagonal flaky magnesium hydroxide with large particle size and high dispersion by a one-step hydrothermal method of high-activity light-burned magnesium oxide.
In order to achieve the aim of the invention, the invention adopts the following technical scheme:
a method for preparing high-dispersion hexagonal flaky magnesium hydroxide by taking high-activity light-burned magnesium oxide as a raw material is characterized in that the high-activity magnesium oxide is directly hydrated under the high-temperature hydrothermal condition, and crystals grow into hexagonal flaky magnesium hydroxide with large particle size and high dispersion under the action of a crystal mineralizer and a structure regulating auxiliary agent;
the following is a further improvement of the above technical scheme:
1. weighing a certain amount of magnesium oxide, a structure adjusting auxiliary agent and a sodium hydroxide solution, stirring and dispersing uniformly to form a suspension, then adding the suspension into a hydrothermal autoclave, wherein the volume of the suspension is 65-75% of the volume of the autoclave, and sealing the hydrothermal autoclave;
the mass ratio of the magnesium oxide to the structure adjusting auxiliary agent to the sodium hydroxide solution is 100:1-3:1200-1500;
the structure regulating auxiliary agent is polyethylene glycol PEG1200 or polyvinylpyrrolidone PVP K12;
the concentration of the sodium hydroxide solution is 4-5 mol/L.
2. Heating the hydrothermal autoclave to 180-200 ℃, and performing hydrothermal action for 3-4 hours under the pressure of 1.1-1.6 MPa;
3. stopping heating after the hydrothermal reaction and crystallization are finished, carrying out suction filtration on the suspension in the hydrothermal autoclave after the temperature of the hydrothermal autoclave is reduced to 60-70 ℃, collecting filtrate obtained by suction filtration, recycling, leaching the solid for 3-5 times, and drying at 100-105 ℃ to obtain the high-dispersion hexagonal flaky magnesium hydroxide product.
Compared with the prior art, the invention has the following beneficial effects:
under the high-temperature hydrothermal condition, the high activity of high-temperature high-pressure water is beneficial to hydration of magnesium oxide and dissolution and recrystallization of a magnesium hydroxide layer. Because the method is carried out at high temperature, the process is efficient, the reaction time is short, and the process is simple. Because the reaction is carried out in a closed system, the problem of volatile component escape is avoided, after the reaction is finished, the obtained hexagonal flaky magnesium hydroxide with large particle size is easy to filter, the filtrate containing the crystallization mineralizer and the structure regulating auxiliary agent can be recycled, and the process is environment-friendly.
Drawings
Fig. 1 is a schematic diagram of a process for preparing hexagonal flaky magnesium hydroxide with large particle size and high dispersion by a one-step hydrothermal method of high-activity light burned magnesium oxide.
Fig. 2 is a schematic diagram of hexagonal unit cell structure of magnesium hydroxide.
Fig. 3 is a six-sided schematic view of a hexagonal sheet crystal of magnesium hydroxide.
Fig. 4 is an SEM image of activated magnesium oxide hydrated at about 80 ℃ to obtain magnesium hydroxide at 2 ten thousand magnification.
Fig. 5 is an SEM image of activated magnesium oxide hydrated at about 80 ℃ to obtain magnesium hydroxide at 1 ten thousand magnification.
Fig. 6 is an SEM image of activated magnesium oxide hydrated at about 80 ℃ to give magnesium hydroxide at 2 thousand times magnification.
Fig. 7 is an SEM image of magnesium hydroxide obtained by hydration of activated magnesium oxide at about 80 ℃ and further enlarged by 5 ten thousand times by hydrothermal treatment at 180 ℃ for 6 hours.
Fig. 8 is an SEM image of magnesium hydroxide obtained by hydration of activated magnesium oxide at about 80 ℃ and further enlarged by 2 ten thousand times by hydrothermal treatment at 180 ℃ for 6 hours.
Fig. 9 is an SEM image of magnesium hydroxide obtained by hydration of activated magnesium oxide at about 80 ℃ and further enlarged by 1 ten thousand times by hydrothermal treatment at 180 ℃ for 6 hours.
Fig. 10 is an SEM image of the magnesium hydroxide product obtained in example 1 at 5 ten thousand times magnification.
Fig. 11 is an SEM image of the magnesium hydroxide product obtained in example 1 at 2 ten thousand times magnification.
Fig. 12 is an SEM image of the magnesium hydroxide product obtained in example 1 at 1 ten thousand times magnification.
Fig. 13 is an SEM image of the magnesium hydroxide product obtained in example 2 at 5 ten thousand times magnification.
Fig. 14 is an SEM image of the magnesium hydroxide product obtained in example 2 at 2 ten thousand times magnification.
Fig. 15 is an SEM image of the magnesium hydroxide product obtained in example 2 at 1 ten thousand times magnification.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Example 1:
1. weighing 10 g of magnesium oxide and 0.1 g of polyethylene glycol PEG1200, adding 120 g of 5mol/L sodium hydroxide solution, stirring and dispersing uniformly, then adding into a hydrothermal autoclave, wherein the volume of the suspension is 65% of the volume of the autoclave, and sealing the hydrothermal autoclave;
2. heating the hydrothermal autoclave to 180 ℃, and generating high pressure of 1.1 MPa by the materials, wherein the hydrothermal action time is 4 hours at 180 ℃;
3. stopping heating after the hydrothermal reaction at 180 ℃ for 4 hours, opening the autoclave after the hydrothermal autoclave is cooled to 70 ℃, carrying out suction filtration on the suspension, collecting and storing filtrate obtained by suction filtration, recycling, leaching and filtering the solid for 3 times, and drying the solid at 105 ℃ for 2 hours to obtain a high-dispersion hexagonal flaky magnesium hydroxide product;
fig. 10, 11 and 12 are SEM images of the magnesium hydroxide product obtained in example 1, from which it can be seen that magnesium hydroxide forms hexagonal flaky magnesium hydroxide grains of larger particle size.
Example 2:
1. weighing 10 g of magnesium oxide and 0.3 g of polyvinylpyrrolidone PVP K12, adding 150 g of 4mol/L sodium hydroxide solution, stirring and dispersing uniformly, then adding into a hydrothermal autoclave, wherein the volume of the suspension is 75% of the volume of the autoclave, and sealing the hydrothermal autoclave;
2. heating the hydrothermal autoclave to 200 ℃, and generating high pressure of 1.6MPa by the materials, wherein the hydrothermal action time is 3 hours at 200 ℃;
3. after the hydrothermal reaction at 200 ℃ for 3 hours, stopping heating, opening the hydrothermal autoclave after the temperature of the hydrothermal autoclave is reduced to 60 ℃, carrying out suction filtration on the suspension, collecting filtrate obtained by suction filtration, storing, recycling, leaching and suction filtration on solids for 4 times, and drying the solid at about 100 ℃ to obtain a high-dispersion hexagonal flaky magnesium hydroxide product;
fig. 13, 14 and 15 are SEM images of the magnesium hydroxide product obtained in example 2, from which it can be seen that magnesium hydroxide forms hexagonal flaky magnesium hydroxide grains of larger particle size.
Example 3:
1. weighing 10 g of magnesium oxide and 0.2 g of polyvinylpyrrolidone PVP K12, adding 130 g of 4.5mol/L sodium hydroxide solution, stirring and dispersing uniformly, then adding into a hydrothermal autoclave, wherein the volume of the suspension is 70% of the volume of the autoclave, and sealing the hydrothermal autoclave;
2. heating the hydrothermal autoclave to 195 ℃, and generating high pressure of 1.5 MPa by the materials, wherein the hydrothermal action time is 3.6 hours at 195 ℃;
3. after the hydrothermal reaction at 195 ℃ for 3.6 hours, stopping heating, opening the hydrothermal autoclave after the hydrothermal autoclave is cooled to 66 ℃, carrying out suction filtration on the suspension, collecting filtrate obtained by suction filtration, storing, recycling, leaching and suction filtration on solids for 5 times, and drying the solid at about 102 ℃ to obtain the high-dispersion hexagonal flaky magnesium hydroxide product.
By combining the descriptions of examples 1, 2 and 3, it is known that the high activity of water is utilized under the high-temperature hydrothermal condition, the hydration of magnesium oxide is facilitated, and the magnesium hydroxide formed by the hydration can be rapidly dissolved and recrystallized to form hexagonal flaky magnesium hydroxide crystals with large particle size. The process is simple and efficient, and is environment-friendly.
It should be noted that the term "comprises," "comprising," or any other variation thereof is intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (3)
1. A method for preparing high-dispersion hexagonal flaky magnesium hydroxide by a one-step hydrothermal method of high-activity light-burned magnesium oxide is characterized by comprising the following steps of:
under the high-temperature hydrothermal condition, high-activity magnesium oxide is directly hydrated, and under the action of a crystallization mineralizer and a structure regulating auxiliary agent, crystals grow into hexagonal flaky magnesium hydroxide with large particle size and high dispersion, and the method specifically comprises the following steps:
s1, weighing a certain amount of magnesium oxide, a structure adjusting additive and a sodium hydroxide solution, stirring and dispersing uniformly to form a suspension, then adding the suspension into a hydrothermal autoclave, wherein the volume of the suspension is 65-75% of the volume of the autoclave, and sealing the hydrothermal autoclave;
s2, heating the hydrothermal autoclave to 180-200 ℃, and performing hydrothermal action for 3-4 hours under the pressure of 1.1-1.6 MPa;
and S3, stopping heating after the hydrothermal reaction and crystallization are finished, carrying out suction filtration on the suspension in the hydrothermal autoclave after the hydrothermal autoclave is cooled to 60-70 ℃, collecting filtrate obtained by suction filtration, recycling, leaching the solid for 3-5 times, and drying at 100-105 ℃ to obtain the high-dispersion hexagonal flaky magnesium hydroxide product.
2. The method for preparing the high-dispersion hexagonal flaky magnesium hydroxide by a one-step hydrothermal method of high-activity light-burned magnesium oxide, which is characterized in that:
the mass ratio of the magnesium oxide to the structure adjusting auxiliary agent to the sodium hydroxide solution is 100:1-3:1200-1500.
3. The method for preparing the high-dispersion hexagonal flaky magnesium hydroxide by a one-step hydrothermal method of high-activity light-burned magnesium oxide, which is characterized in that:
the structure regulating auxiliary agent is polyethylene glycol PEG1200 or polyvinylpyrrolidone PVP K12;
the concentration of the sodium hydroxide solution is 4-5 mol/L.
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102101684A (en) * | 2009-12-16 | 2011-06-22 | 中国科学院过程工程研究所 | Method for preparing submicron lamellar magnesium hydroxide by intensifying alkali |
| CN102659146A (en) * | 2012-04-28 | 2012-09-12 | 中国科学院福建物质结构研究所 | Method for preparing flame retardant magnesium hydroxide |
| CN103922368A (en) * | 2014-04-23 | 2014-07-16 | 中北大学 | Preparation method of nano-sheet-based flower-shaped level substructure magnesium hydroxide powder body |
| CN106673027A (en) * | 2016-12-30 | 2017-05-17 | 安徽壹石通材料科技股份有限公司 | Preparation and synthesis method of hexagonal flaky magnesium hydroxide fire retardant |
| CN112408439A (en) * | 2020-11-20 | 2021-02-26 | 洛阳中超新材料股份有限公司 | Method for preparing superfine magnesium hydroxide for flame retardant by using magnesium hydroxide coarse powder as raw material |
| CN113548682A (en) * | 2021-07-22 | 2021-10-26 | 安徽大学绿色产业创新研究院 | Method for preparing hexagonal flaky flame-retardant magnesium hydroxide from natural hydromagnesite |
| CN115231593A (en) * | 2022-03-31 | 2022-10-25 | 定西凯美特新材料科技有限公司 | Method for preparing hexagonal magnesium hydroxide flame retardant by one-step hydrothermal method |
| CN115259185A (en) * | 2022-01-17 | 2022-11-01 | 定西凯美特新材料科技有限公司 | Method for preparing magnesium hydroxide flame retardant with regular structure by hydrothermal method |
-
2023
- 2023-08-30 CN CN202311101234.0A patent/CN116835616A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102101684A (en) * | 2009-12-16 | 2011-06-22 | 中国科学院过程工程研究所 | Method for preparing submicron lamellar magnesium hydroxide by intensifying alkali |
| CN102659146A (en) * | 2012-04-28 | 2012-09-12 | 中国科学院福建物质结构研究所 | Method for preparing flame retardant magnesium hydroxide |
| CN103922368A (en) * | 2014-04-23 | 2014-07-16 | 中北大学 | Preparation method of nano-sheet-based flower-shaped level substructure magnesium hydroxide powder body |
| CN106673027A (en) * | 2016-12-30 | 2017-05-17 | 安徽壹石通材料科技股份有限公司 | Preparation and synthesis method of hexagonal flaky magnesium hydroxide fire retardant |
| CN112408439A (en) * | 2020-11-20 | 2021-02-26 | 洛阳中超新材料股份有限公司 | Method for preparing superfine magnesium hydroxide for flame retardant by using magnesium hydroxide coarse powder as raw material |
| CN113548682A (en) * | 2021-07-22 | 2021-10-26 | 安徽大学绿色产业创新研究院 | Method for preparing hexagonal flaky flame-retardant magnesium hydroxide from natural hydromagnesite |
| CN115259185A (en) * | 2022-01-17 | 2022-11-01 | 定西凯美特新材料科技有限公司 | Method for preparing magnesium hydroxide flame retardant with regular structure by hydrothermal method |
| CN115231593A (en) * | 2022-03-31 | 2022-10-25 | 定西凯美特新材料科技有限公司 | Method for preparing hexagonal magnesium hydroxide flame retardant by one-step hydrothermal method |
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Application publication date: 20231003 |