Method for preparing alumina-based magnesium aluminate spinel by recycling laboratory waste
By mixing laboratory mud with biphenylaminophenolic epoxy resin and niobium pentoxide after sedimentation and drying, and then pressing it into brick blanks for sintering, the environmental pollution and resource waste problems of laboratory waste are solved, and high-efficiency bauxite-based magnesium aluminum spinel is prepared.
Patent Information
- Application Number
- CN202511384893.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-26
- Publication Date
- 2026-01-16
AI Technical Summary
The mud waste generated during the sample preparation process in the laboratory is not effectively utilized, resulting in environmental pollution and resource waste.
By settling and drying the mud, adding benzylaminophenolic epoxy resin and niobium pentoxide, pressing it into brick blanks and sintering it in a kiln, bauxite-based magnesium aluminum spinel is formed.
This method enables the effective recycling of waste materials, reduces environmental pollution, improves resource utilization efficiency, and produces magnesium aluminum spinel with excellent fire resistance and chemical stability.
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Figure SMS_1
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of laboratory waste treatment, and particularly relates to a method for preparing alumina-based magnesium-aluminum spinel by recycling laboratory waste. BACKGROUND
[0002] In the daily sample preparation process of a laboratory, refractory bricks need to be wet cut, and the mud generated during cutting flows into a settling tank for sedimentation. The mud is periodically collected and cleaned, but it is treated as general solid waste, which not only generates disposal costs, but also causes waste of resources. Therefore, seeking a reasonable recycling method for laboratory waste has become an important direction of current research and application.
[0003] The present application patent collects the mud generated during cutting of the bricks, removes water from the material by airing, crushes the agglomerated material by a rolling mill, and then bags the crushed material. In the crushing process, biphenyl amino formaldehyde epoxy resin and di-niobium pentoxide are added. Finally, the material is pressed into a green brick by a press and then is fired in a kiln, to form a magnesium-aluminum spinel raw material, which can be used for production of magnesium-aluminum spinel bricks. SUMMARY
[0004] To overcome the above technical problems, the purpose of the present application is to provide a method for preparing alumina-based magnesium-aluminum spinel by recycling laboratory waste, which solves the problems of environmental pollution and resource waste caused by the existing laboratory waste.
[0005] The purpose of the present application can be achieved by the following technical solutions. In a first aspect, the present application provides a method for preparing alumina-based magnesium-aluminum spinel by recycling laboratory waste, which is prepared by the following steps: Step A1: A flow guide groove with a filter screen is arranged below a wet cutting station in a laboratory, and refractory bricks are cut, and the generated mud is introduced into a settling tank. The mud is naturally settled in the settling tank for 24-48 hours, and then the supernatant is discharged, and the thick mud at the bottom of the tank is collected; Step A2: The thick mud is transported to a concrete airing groove with a slope, and is naturally aired at 15-35℃. The mud is stirred every 3 hours until the water content of the mud is less than 10%, to obtain dry mud; Step A3: 4,4'-biphenyldimethyl dimethyl ether and methyl isobutyl ketone are added to a three-necked flask equipped with a stirrer and a thermometer, and the same amount is added each time. 4-Aminophenol is added in three portions, hydrochloric acid is added, and the mixture is stirred at 50-100 r / min and 110℃ for 9 hours. The 4-aminophenol is distilled off under reduced pressure at 190℃, and then is added to anhydrous ether, washed with deionized water for 3 times, and then the anhydrous ether is distilled off under reduced pressure. The intermediate product 1 is obtained by drying; Step A4: Add intermediate product 1 and epoxypropane to a three-necked flask equipped with a stirrer and thermometer, transfer to an oil bath and stir at 65℃ and 50-100 r / min for 20-30 min, add tetramethylammonium bromide and stir for 30-40 min, add sodium hydroxide and react for 3 h, filter, wash the filtrate three times with water at 60-70℃, add anhydrous sodium sulfate and dry for 12-14 h, filter again and evaporate by rotary evaporation, place in a drying oven and vacuum dry at 70-80℃ for 5-6 h to obtain biphenylaminophenolic epoxy resin; Step A5: Put dry mud, high-alumina bauxite, niobium pentoxide and biphenylaminophenolic epoxy resin into a mixer, adjust the gap to 1-3mm, start the equipment and roll for 25-35 minutes, add magnesium lignosulfonate aqueous solution and mix for 10 minutes to obtain premix. Step A6: Place the premixed material in a small hydraulic press and press it into brick blanks at 150MPa. Transfer it to a drying oven and dry it at 100-200℃ for 20-40 hours. Then, keep it at 1600-1700℃ for 6-8 hours in a tunnel kiln. After sintering, wait for the blanks to cool to 24-26℃ with the kiln and transfer them to a jaw crusher to crush them to a particle size ≤3mm. Then, sieve them through a 3mm standard sieve and collect the undersized particles to obtain bauxite-based magnesium aluminum spinel.
[0006] As a further aspect of the present invention: the water content of the thick mud in step A1 is 40%-50%.
[0007] As a further aspect of the present invention: the refractory brick composition in step A1 is: MgO 56.61%, SiO2 31.57%, Fe2O3 7.11%, CaO 0.97%, Al2O3 2.65%, and loss on ignition 1.09%.
[0008] As a further embodiment of the present invention: the ratio of the amounts of 4,4'-biphenyl dimethyl dimethyl ether, methyl isobutyl ketone, 4-aminophenol, hydrochloric acid and anhydrous diethyl ether in step A3 is 0.1-0.2 mol: 1-2 mol: 0.3-0.6 mol: 0.07-0.14 g: 100-200 g.
[0009] As a further aspect of the present invention: the mass fraction of hydrochloric acid in step A3 is 37%.
[0010] As a further aspect of the present invention: the ratio of intermediate product 1, epichlorohydrin, tetramethylammonium bromide and sodium hydroxide in step A4 is 10.5-21g: 0.5-1mol: 0.125-0.25g: 0.06-0.12mol.
[0011] As a further aspect of the present invention: the ratio of the dry mud, high-alumina bauxite, niobium pentoxide, benzaminophenolic epoxy resin and magnesium lignosulfonate aqueous solution in step A5 is 150-300g: 50-100g: 10-20g: 3-6g: 7.5-15g.
[0012] As a further aspect of the present invention: the concentration of the magnesium lignosulfonate aqueous solution in step A5 is 50 wt%. Beneficial effects
[0013] This invention discloses a method for preparing bauxite-based magnesium aluminum spinel by recycling laboratory waste. The waste is dried by sedimentation and then crushed with high-alumina bauxite, biphenylaminophenol epoxy resin and niobium pentoxide to obtain a premix. After calcination, bauxite-based magnesium aluminum spinel is formed. This method optimizes waste collection, reduces environmental pollution, and has good environmental protection effects.
[0014] The recycling of laboratory waste to prepare bauxite-based magnesium-aluminum spinel involves several steps. First, the laboratory waste is settled, dried, and sun-dried to obtain dry clay. This clay is then mixed with high-alumina bauxite, biphenylaminophenolic epoxy resin, and niobium pentoxide, and pressed into brick blanks for sintering. The aluminum element in the waste is effectively extracted and converted into bauxite components, solving the problem of aluminum resource waste in traditional processing methods and improving resource utilization efficiency. High-alumina bauxite not only provides sufficient silicon-oxygen framework structure but also enhances the stability of the magnesium-aluminum spinel. Niobium pentoxide activates the crystal lattice through solid solution defect reactions, providing a more... The presence of numerous ion diffusion channels enhances the ion diffusion rate, thereby promoting sintering. The preparation of biphenylaminophenolic epoxy resin begins with the preparation of intermediate 1 using 4,4'-biphenyl dimethyl dimethyl ether and 4-aminophenol. Hydrochloric acid provides hydrogen ions, protonating the methoxy group in 4,4'-biphenyl dimethyl dimethyl ether to generate a more stable protonated methoxy group, enhancing electrophilicity. The amino group in 4-aminophenol acts as a nucleophile, attacking the methylene carbon of 4,4'-biphenyl dimethyl dimethyl ether, resulting in a nucleophilic substitution reaction. The oxygen atom of the phenolic hydroxyl group in intermediate 1 acts as a weak nucleophile. The reagent preferentially attacks the carbon ions with lower electron cloud density on the epoxy ring of epichlorohydrin, releasing the epoxy ring strain and breaking the CO bond. The addition of tetramethylammonium bromide accelerates the catalysis. Sodium hydroxide reacts with the phenolic hydroxyl group of intermediate 1, generating a large number of phenoxy anions, which are far more nucleophilic than neutral hydroxyl groups. These anions continuously attack the epoxy groups of epichlorohydrin, generating new secondary hydroxyl groups with each ring-opening. Under alkaline conditions, these hydroxyl groups further dissociate into phenoxy anions, continuing to react with epichlorohydrin to achieve chain growth and form biphenylaminophenolic epoxy resin. The epoxy in the biphenylaminophenolic epoxy resin... The groups react with the hydroxyl groups on the surface of high-alumina bauxite or dry mud to form ether bonds. The amino and phenolic hydroxyl groups can also react with the hydroxyl groups on the surface of high-alumina bauxite or dry mud to form hydrogen bonds, which makes the resin molecules adhere tightly to the surface of the inorganic material, forming an "organic-inorganic composite bonding layer". This improves the bonding degree during the pressing process, reduces the porosity during the sintering process, and increases the density of magnesium aluminum spinel. This preparation method realizes the effective extraction and transformation of useful components in waste materials. The magnesium aluminum spinel obtained has excellent fire resistance and chemical stability and is suitable for a variety of high-temperature applications. Detailed Implementation
[0015] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention. Example 1
[0016] This embodiment describes a method for preparing bauxite-based magnesium aluminum spinel by recycling laboratory waste, including the following steps: Step A1: Set up a guide trough with a filter screen below the wet cutting station in the laboratory to guide the mud generated from cutting into the settling tank. After the mud settles naturally in the settling tank for 24 hours, discharge the upper clear liquid and collect the thick mud with a water content of 40% from the bottom of the tank. Step A2: Transfer the thick mud to a sloping concrete drying trough and let it dry naturally at 15℃. Turn the mud over every 3 hours until the moisture content of the mud is 0.5% to obtain dry mud. Step A3: Add 0.1 mol of 4,4'-biphenyl dimethyl dimethyl ether and 1 mol of methyl isobutyl ketone to a three-necked flask equipped with a stirrer and thermometer, ensuring that the amount added each time is the same. Add 0.3 mol of 4-aminophenol in three portions, followed by 0.3 mol of hydrochloric acid. Stir the mixture at 50 r / min and 110 °C for 9 h. Remove 4-aminophenol by vacuum distillation at 190 °C. Add the mixture to 100 g of anhydrous diethyl ether, wash three times with deionized water, remove anhydrous diethyl ether by vacuum distillation, and dry to obtain intermediate product 1. Step A4: Add 10.5g of intermediate product 1 and 0.5mol of epichlorohydrin to a three-necked flask equipped with a stirrer and thermometer. Transfer the mixture to an oil bath and stir at 65℃ and 50r / min for 20min. Add 0.125g of tetramethylammonium bromide and stir for 30min. Add 0.06mol of sodium hydroxide and react for 3h. Filter the mixture and wash the filtrate three times with water at 60℃. Add anhydrous sodium sulfate and dry for 12h. Filter the mixture again and evaporate by rotary evaporation. Place the filtrate in a drying oven and vacuum dry at 70℃ for 5h to obtain benzaminophenol epoxy resin. Step A5: Add 150g of dry clay, 50g of high-alumina bauxite, 10g of niobium pentoxide and 3g of biphenylaminophenol epoxy resin to a mixing mill, adjust the gap to 1mm, start the equipment and roll for 25min, add 7.5g of magnesium lignosulfonate aqueous solution and mix for 10min to obtain premix. Step A6: Place the premixed material in a small hydraulic press and press it into brick blanks at 150MPa. Transfer it to a drying oven and dry it at 100℃ for 20h. Then, keep it at 1600℃ for 6h in a tunnel kiln. After sintering, wait for the blanks to cool to 24℃ with the kiln and transfer them to a jaw crusher to crush them to a particle size ≤3mm. Then, sieve them through a 3mm standard sieve and collect the undersized particles to obtain bauxite-based magnesium aluminum spinel. Example 2
[0017] This embodiment describes a method for preparing bauxite-based magnesium aluminum spinel by recycling laboratory waste, including the following steps: Step A1: Set up a guide trough with a filter screen below the wet cutting station in the laboratory to guide the mud generated from cutting into the settling tank. After the mud settles naturally in the settling tank for 36 hours, discharge the upper clear liquid and collect the thick mud with a water content of 45% from the bottom of the tank. Step A2: Transfer the thick mud to a sloping concrete drying trough and let it dry naturally at 20°C. Turn the mud over every 3 hours until the moisture content of the mud is 1.5% to obtain dry mud. Step A3: Add 0.15 mol of 4,4'-biphenyl dimethyl dimethyl ether and 1.5 mol of methyl isobutyl ketone to a three-necked flask equipped with a stirrer and thermometer, ensuring the same amount is added each time. Add 0.45 mol of 4-aminophenol and 0.45 mol of hydrochloric acid in three portions. Stir the reaction at 75 r / min and 110 °C for 9 h. Remove 4-aminophenol by vacuum distillation at 190 °C. Add the product to 150 g of anhydrous diethyl ether, wash three times with deionized water, remove anhydrous diethyl ether by vacuum distillation, and dry to obtain intermediate product 1. Step A4: Add 15.75g of intermediate product 1 and 0.75mol of epichlorohydrin to a three-necked flask equipped with a stirrer and thermometer. Transfer the mixture to an oil bath and stir at 65℃ and 75r / min for 25min. Add 0.188g of tetramethylammonium bromide and stir for 35min. Add 0.09mol of sodium hydroxide and react for 3h. Filter the mixture and wash the filtrate three times with water at 65℃. Add anhydrous sodium sulfate and dry for 13h. Filter the mixture and evaporate it by rotary evaporation. Place the filtrate in a drying oven and vacuum dry at 75℃ for 5.5h to obtain biphenylaminophenol epoxy resin. Step A5: Add 225g of dry clay, 75g of high-alumina bauxite, 15g of niobium pentoxide and 4.5g of biphenylaminophenolic epoxy resin to the mixer, adjust the gap to 2mm, start the equipment and roll for 20min, add 11.25g of magnesium lignosulfonate aqueous solution and mix for 10min to obtain the premix. Step A6: Place the premixed material in a small hydraulic press and press it into brick blanks at 150MPa. Transfer it to a drying oven and dry it at 150℃ for 30h. Then, keep it at 1650℃ for 7h in a tunnel kiln. After sintering, wait for the blanks to cool to 25℃ with the kiln and transfer them to a jaw crusher to crush them to a particle size ≤3mm. Then, sieve them through a 3mm standard sieve and collect the undersized particles to obtain bauxite-based magnesium aluminum spinel. Example 3
[0018] This embodiment describes a method for preparing bauxite-based magnesium aluminum spinel by recycling laboratory waste, including the following steps: Step A1: Set up a guide trough with a filter screen below the wet cutting station in the laboratory to guide the mud generated from cutting into the settling tank. After the mud settles naturally in the settling tank for 48 hours, discharge the upper clear liquid and collect the thick mud with a water content of 50% at the bottom of the tank. Step A2: Transfer the thick mud to a sloping concrete drying trough and let it dry naturally at 35°C. Turn the mud over every 3 hours until the moisture content of the mud is 2.5% to obtain dry mud. Step A3: Add 0.2 mol of 4,4'-biphenyl dimethyl dimethyl ether and 2 mol of methyl isobutyl ketone to a three-necked flask equipped with a stirrer and thermometer, ensuring that the amount added each time is the same. Add 0.6 mol of 4-aminophenol and 0.6 mol of hydrochloric acid in three portions. Stir the reaction at 100 r / min and 110 °C for 9 h. Remove 4-aminophenol by vacuum distillation at 190 °C. Add the product to 200 g of anhydrous diethyl ether, wash three times with deionized water, remove anhydrous diethyl ether by vacuum distillation, and dry to obtain intermediate product 1. Step A4: Add 21g of intermediate product 1 and 1mol of epichlorohydrin to a three-necked flask equipped with a stirrer and thermometer, transfer to an oil bath and stir at 65℃ and 100r / min for 30min. Add 0.25g of tetramethylammonium bromide and stir for 40min. Add 0.12mol of sodium hydroxide and react for 3h. Filter and wash the filtrate three times with water at 70℃. Add anhydrous sodium sulfate and dry for 14h. Filter again and evaporate by rotary evaporation. Place in a drying oven and vacuum dry at 80℃ for 6h to obtain biphenylaminophenol epoxy resin. Step A5: Add 300g of dry clay, 100g of high-alumina bauxite, 20g of niobium pentoxide and 6g of biphenylaminophenol epoxy resin to a mixing mill, adjust the gap to 3mm, start the equipment and roll for 35min, add 15g of magnesium lignosulfonate aqueous solution and mix for 10min to obtain premix. Step A6: Place the premixed material in a small hydraulic press and press it into brick blanks at 150MPa. Transfer it to a drying oven and dry it at 200℃ for 40h. Then, keep it at 1700℃ for 8h in a tunnel kiln. After sintering, wait for the blanks to cool to 26℃ with the kiln and transfer them to a jaw crusher to crush them to a particle size ≤3mm. Then, sieve them through a 3mm standard sieve and collect the undersized particles to obtain bauxite-based magnesium aluminum spinel.
[0019] Comparative Example 1: This embodiment describes a method for preparing bauxite-based magnesium aluminum spinel by recycling laboratory waste, including the following steps: Step A1: Set up a guide trough with a filter screen below the wet cutting station in the laboratory to guide the mud generated from cutting into the settling tank. After the mud settles naturally in the settling tank for 48 hours, discharge the upper clear liquid and collect the thick mud with a water content of 50% at the bottom of the tank. Step A2: Transfer the thick mud to a sloping concrete drying trough and let it dry naturally at 35°C. Turn the mud over every 3 hours until the moisture content of the mud is 2.5% to obtain dry mud. Step A3: Add 0.2 mol of 4,4'-biphenyl dimethyl dimethyl ether and 2 mol of methyl isobutyl ketone to a three-necked flask equipped with a stirrer and thermometer, ensuring that the amount added each time is the same. Add 0.6 mol of 4-aminophenol and 0.6 mol of hydrochloric acid in three portions. Stir the reaction at 100 r / min and 110 °C for 9 h. Remove 4-aminophenol by vacuum distillation at 190 °C. Add the product to 200 g of anhydrous diethyl ether, wash three times with deionized water, remove anhydrous diethyl ether by vacuum distillation, and dry to obtain intermediate product 1. Step A4: Add 21g of intermediate product 1 and 1mol of epichlorohydrin to a three-necked flask equipped with a stirrer and thermometer, transfer to an oil bath and stir at 65℃ and 100r / min for 30min. Add 0.25g of tetramethylammonium bromide and stir for 40min. Add 0.12mol of sodium hydroxide and react for 3h. Filter and wash the filtrate three times with water at 70℃. Add anhydrous sodium sulfate and dry for 14h. Filter again and evaporate by rotary evaporation. Place in a drying oven and vacuum dry at 80℃ for 6h to obtain biphenylaminophenol epoxy resin. Step A5: Add 300g of dry clay, 100g of high-alumina bauxite and 6g of biphenylaminophenol epoxy resin to the mixer, adjust the gap to 3mm, start the equipment and roll for 35min, add 15g of magnesium lignosulfonate aqueous solution and mix for 10min to obtain premix. Step A6: Place the premixed material in a small hydraulic press and press it into brick blanks at 150MPa. Transfer it to a drying oven and dry it at 200℃ for 40h. Then, keep it at 1700℃ for 8h in a tunnel kiln. After sintering, wait for the blanks to cool to 26℃ with the kiln and transfer them to a jaw crusher to crush them to a particle size ≤3mm. Then, sieve them through a 3mm standard sieve and collect the undersized particles to obtain bauxite-based magnesium aluminum spinel.
[0020] Comparative Example 2: This embodiment describes a method for preparing bauxite-based magnesium aluminum spinel by recycling laboratory waste, including the following steps: Step A1: Set up a guide trough with a filter screen below the wet cutting station in the laboratory to guide the mud generated from cutting into the settling tank. After the mud settles naturally in the settling tank for 48 hours, discharge the upper clear liquid and collect the thick mud with a water content of 50% at the bottom of the tank. Step A2: Transfer the thick mud to a sloping concrete drying trough and let it dry naturally at 35°C. Turn the mud over every 3 hours until the moisture content of the mud is 2.5% to obtain dry mud. Step A3: Add 0.2 mol of 4,4'-biphenyl dimethyl dimethyl ether and 2 mol of methyl isobutyl ketone to a three-necked flask equipped with a stirrer and thermometer, ensuring that the amount added each time is the same. Add 0.6 mol of 4-aminophenol and 0.6 mol of hydrochloric acid in three portions. Stir the reaction at 100 r / min and 110 °C for 9 h. Remove 4-aminophenol by vacuum distillation at 190 °C. Add the mixture to 200 g of anhydrous diethyl ether, wash three times with deionized water, remove anhydrous diethyl ether by vacuum distillation, and dry to obtain biphenylaminophenol formaldehyde resin. Step A4: Add 300g of dry clay, 100g of high-alumina bauxite, 20g of niobium pentoxide and 6g of biphenylaminophenol resin to a mixing mill, adjust the gap to 3mm, start the equipment and roll for 35min, add 15g of magnesium lignosulfonate aqueous solution and mix for 10min to obtain premix. Step A5: Place the premixed material in a small hydraulic press and press it into brick blanks at 150MPa. Transfer it to a drying oven and dry it at 200℃ for 40h. Then, keep it at 1700℃ for 8h in a tunnel kiln. After sintering, wait for the blanks to cool to 26℃ with the kiln and transfer them to a jaw crusher to crush them to a particle size ≤3mm. Then, sieve them through a 3mm standard sieve and collect the undersized particles to obtain bauxite-based magnesium aluminum spinel.
[0021] Performance testing The bauxite-based magnesium aluminum spinel samples from Examples 1-3 and Comparative Examples 1-2 were analyzed using X-ray fluorescence spectrometry (AXIOS-MAX, 50kV, 60mA) to determine the contents of silicon oxide, magnesium oxide, and aluminum oxide.
[0022] The sample was dried in a drying oven for 3 hours. After cooling, the sample mass was weighed using an electronic balance. The sample was then immersed in boiling distilled water for 1 hour. The sample was removed, the water adhering to its surface was wiped off, and the mass was weighed on an electronic balance. The sample was then tied with a thin thread, immersed in distilled water, and measured using a suspended balance. The sample density and porosity were calculated.
[0023]
[0024] Referring to the table above, based on the comparison between Examples 1-3 and Comparative Examples 1-2, it can be seen that the density of the bauxite-based magnesium aluminum spinel obtained by the method provided by the present invention can reach up to 3.29 g / cm³. 3 The silicon dioxide content is as low as 2.015 wt%, the magnesium oxide content is as high as 16.25 wt%, the aluminum oxide content is as high as 78.67 wt%, and the porosity is as low as 10.09%.
[0025] Based on the comparison between Example 3 and Comparative Example 1, it can be seen that the porosity of the bauxite-based magnesium aluminum spinel with added benzylaminophenol epoxy resin and niobium pentoxide is smaller than that of the bauxite-based magnesium aluminum spinel with added benzylaminophenol epoxy resin, indicating that the bauxite-based magnesium aluminum spinel with added benzylaminophenol epoxy resin and niobium pentoxide has excellent compressive strength. Based on the comparison between Example 3 and Comparative Example 2, it can be seen that the porosity of the bauxite-based magnesium aluminum spinel with added benzylaminophenolic epoxy resin and niobium pentoxide is smaller than that of the bauxite-based magnesium aluminum spinel with added benzylaminophenolic epoxy resin and niobium pentoxide, indicating that the bauxite-based magnesium aluminum spinel with added benzylaminophenolic epoxy resin and niobium pentoxide has excellent compressive strength.
[0026] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0027] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in this application, they should all fall within the protection scope of the present invention.
Claims
1. A method for preparing bauxite-based magnesium aluminate spinel from laboratory waste, characterized by, Comprising the following steps: Step A1: A filter groove with a filter screen is arranged below a laboratory wet cutting station, the refractory bricks are cut, and the generated slurry is introduced into a settling tank, the slurry is naturally settled in the settling tank, the supernatant is discharged, and the thick slurry at the bottom of the tank is collected; Step A2: The thick slurry is transported to a sloping concrete drying tank and naturally dried, the slurry is stirred every 3h until the moisture content of the slurry is less than 10%, and dry mud is obtained; Step A3: 4,4'-diphenyl dimethyl dimethyl ether and methyl isobutyl ketone are added to a three-necked flask, the same amount is controlled each time, 4-aminophenol is added in three times, hydrochloric acid is added and stirred to react, and then removed by vacuum distillation, added to anhydrous ether, washed with deionized water, distilled under reduced pressure, and dried to obtain intermediate product 1; Step A4: Intermediate product 1 and epoxy bromopropane are added to a three-necked flask, transferred to an oil bath pot for stirring reaction, tetramethylammonium bromide is added and stirred, sodium hydroxide is added for reaction, filtered, the filtrate is washed with water, anhydrous sodium sulfate is added for drying, filtered, rotary evaporated, and vacuum dried to obtain a biphenyl aminophenolic epoxy resin; Step A5: Dry mud, bauxite, niobium pentoxide, and biphenyl aminophenolic epoxy resin are put into a mixing mill, the gap is adjusted, the equipment is started and rolled, and magnesium lignosulfonate aqueous solution is added and mixed to obtain a premix; Step A6: The premix is placed in a small hydraulic machine to press into a green brick, dried, heat treated in a tunnel kiln, cooled after sintering, transferred to a jaw crusher, crushed to a particle size of ≤3mm, screened through a 3mm standard sieve, and the undersize particles are collected to obtain a bauxite-based magnesium-aluminum spinel.
2. A method of preparing magnesio-alumina spinel from laboratory waste for recycling according to claim 1, characterized in that, The water content of the thick slurry in step A1 is 40%-50%.
3. A method of preparing magnesio-alumina spinel from laboratory waste for recycling according to claim 1, characterized in that, The refractory brick in step A1 comprises: MgO 56.61%, SiO2 31.57%, Fe2O3 7.11%, CaO 0.97%, Al2O3 2.65%, and loss on ignition 1.09%.
4. The method for preparing magnesio-aluminate spinel from laboratory waste according to claim 1, characterized in that, The amount ratio of 4,4'-diphenyl dimethyl dimethyl ether, methyl isobutyl ketone, 4-aminophenol, hydrochloric acid, and anhydrous ether in step A3 is 0.1-0.2mol:1-2mol:0.3-0.6mol:0.07-0.14g:100-200g.
5. The method for preparing magnesio-aluminate spinel from laboratory waste according to claim 1, characterized in that, The mass fraction of hydrochloric acid in step A3 is 37%.
6. The method for preparing magnesio-aluminate spinel from laboratory waste according to claim 1, characterized in that, The amount ratio of intermediate product 1, epoxy bromopropane, tetramethylammonium bromide, and sodium hydroxide in step A4 is 10.5-21g:0.5-1mol:0.125-0.25g:0.06-0.12mol.
7. A method of preparing magnesio-alumina spinel from laboratory waste for recycling according to claim 1, characterized in that, The amount ratio of dry mud, bauxite, niobium pentoxide, biphenyl aminophenolic epoxy resin, and magnesium lignosulfonate aqueous solution in step A5 is 150-300g:50-100g:10-20g:3-6g:7.5-15g.
8. The method of preparing magnesio-aluminate spinel from laboratory waste according to claim 1, characterized in that, The concentration of magnesium lignosulfonate aqueous solution in step A5 is 50wt%.