A method for regenerating industrial waste alumina balls of hydrogen peroxide

Abstract

The application provides a regeneration method of hydrogen peroxide industrial waste alumina balls, which comprises the following steps: mixing the waste alumina balls with a coke oxidation promoter and a phosphate decomposition promoter, and then performing calcination to obtain regenerated alumina balls. The regeneration method provided by the application can realize the regeneration of the waste alumina balls under the calcination condition of 450 DEG C by loading the coke oxidation promoter and the phosphate decomposition promoter into the waste alumina balls before calcination, and the regeneration time can be controlled to be below 90 min, especially below 30 min, so that the calcination temperature and the calcination time of the waste alumina balls are significantly reduced, the energy consumption of the thermal regeneration is effectively reduced, and the regenerated alumina balls maintain the original specific surface and pore structure, and complete regeneration is realized, and the regeneration effect is good.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of resource recycling and recycling, and particularly relates to a regeneration method of hydrogen peroxide industrial waste alumina balls. BACKGROUND

[0002] Hydrogen peroxide has a wide range of applications in the fields of industry, agriculture, national defense, medical and health care. The most common and mature hydrogen peroxide production process is to use anthraquinone substances, first catalytic hydrogenation, and then oxidation to obtain hydrogen peroxide, and the anthraquinone substances are recycled between the two steps of hydrogenation and oxidation. However, in actual production, anthraquinone substances will continuously undergo irreversible molecular structure changes due to hydrogenation and oxidation processes, resulting in increasingly poor hydrogenation and oxidation effects. In this case, active alumina balls are needed to absorb and purify the working liquid containing anthraquinone substances to remove the molecular structure distorted anthraquinone derivatives, so as to restore the hydrogenation / oxidation capacity and activity of the working liquid. The alumina balls used to purify the working liquid lose adsorption activity and become scrap and need to be regularly discharged and treated. The main impurities in the waste alumina balls are diethyl anthraquinone, tricresyl phosphate and a small amount of pseudotri-methyl benzene. Therefore, the waste alumina balls need to be regenerated for the three types of substances.

[0003] CN107572567A and CN107570128A both disclose a waste ball pretreatment method using silane inclusion and nonionic surfactant, and finally obtain good regeneration effect through calcination.

[0004] The literature "Regeneration of hydrogen peroxide industrial waste alumina ball adsorbent" (Environmental Impact Assessment, 2018, 40(6), p71) studies the thermal regeneration process of hydrogen peroxide industrial waste balls, and finds that when the regeneration temperature is higher than 800℃, the specific surface area and pore structure of the sample have a tendency to deteriorate, and at a lower calcination temperature, there is more carbon residue in the ball channel, and the color is gray-black, which cannot meet the use requirements of the hydrogen peroxide industry.

[0005] CN111282557A discloses a regeneration method of waste alumina in hydrogen peroxide production, and the regeneration process of the method includes washing with washing liquid, citric acid / triethylamine system treatment, mixing with pure alumina and calcination in sequence, which can realize the recycling of waste alumina, and the calcination process requires a temperature of 1100-1300℃.

[0006] CN112645372A discloses a method for recycling waste active alumina regenerant for hydrogen peroxide, and the steps of the method include solvent extraction, solvent recovery, drying, activation and calcination process, which realizes the activity regeneration of waste alumina, and the calcination temperature is 400-900℃, and the whole regeneration process is about 10h.

[0007] In the prior art, the regeneration of waste alumina balls is usually carried out by calcination at a high temperature. The alumina balls have a pore structure and a large specific surface area, and the structure thereof is often affected at a high temperature, thereby affecting the activity of the regenerated alumina balls. On the other hand, a high temperature requires a large energy consumption.

[0008] Therefore, in view of the deficiencies of the prior art, there is a need to improve a method for regenerating waste alumina balls at a low temperature. SUMMARY

[0009] The present application aims to provide a method for regenerating waste alumina balls in the hydrogen peroxide industry, so that the waste alumina balls are fully regenerated at a low temperature, and the regeneration efficiency is high.

[0010] To achieve the object of the present application, the following technical solutions are adopted:

[0011] The present application provides a method for regenerating waste alumina balls in the hydrogen peroxide industry, which comprises the following steps:

[0012] The waste alumina balls are mixed with a coke oxidation promoter and a phosphate ester decomposition promoter, and then calcined to obtain regenerated alumina balls.

[0013] The particle size D50 of the waste alumina balls is 1-6 mm.

[0014] The regeneration method provided by the present application significantly reduces the calcination temperature and calcination time of the waste alumina balls by loading a coke oxidation promoter and a phosphate ester decomposition promoter into the waste alumina balls before the thermal regeneration process, thereby reducing the thermal regeneration energy consumption and protecting the pore structure of the alumina balls.

[0015] The most difficult impurities to be removed by calcination in the waste alumina balls are anthraquinone substances and phosphate ester substances (usually trioctyl phosphate). Anthraquinone substances are easily coked by calcination, and phosphate ester substances are easily converted into phosphides during calcination, thereby promoting the carbonization and coking of organic matter. This is similar to the flame-retardant process of phosphorus-based flame retardants. Therefore, the waste alumina balls in the hydrogen peroxide industry often need to be calcined at a high temperature to completely remove the anthraquinone and phosphate ester substances. After loading the coke oxidation promoter and the phosphate ester decomposition promoter into the waste alumina balls, the coke oxidation promoter can accelerate the oxidation removal of the coke produced by anthraquinone, and the phosphate ester decomposition promoter catalyzes the rupture of the phosphate ester molecules, thereby weakening the inhibition of trioctyl phosphate with high boiling point and high thermal stability on the thermal decomposition of anthraquinone, and greatly improving the decomposition efficiency of the two target impurities from the perspective of molecular dynamics.

[0016] Preferably, the amount of the carbon oxidation promoter is 0.5-10 wt% of the spent alumina balls, for example, it can be 0.5 wt%, 2 wt%, 4 wt%, 5 wt%, 6 wt%, 8 wt% or 10 wt%, but is not limited to the listed values, other values not listed in the value range are also applicable.

[0017] Preferably, the amount of the phosphate decomposition promoter is 0.5-10 wt% of the spent alumina balls, for example, it can be 0.5 wt%, 2 wt%, 4 wt%, 5 wt%, 6 wt%, 8 wt% or 10 wt%, but is not limited to the listed values, other values not listed in the value range are also applicable.

[0018] If the amount of the carbon oxidation promoter and the phosphate decomposition promoter is too low, the efficiency of the oxidation elimination of the carbon deposit and the decomposition of the phosphate in the spent alumina balls is reduced, and the white-burning time of the spent alumina balls is increased; in the preferred amount range of the carbon oxidation promoter and the phosphate decomposition promoter in the present application, the best white-burning effect can be achieved, further increasing the amount of the promoters does not further shorten the white-burning time, but instead causes excessive use of the promoters and cost increase, and at the same time causes the increase of the salt content in the washing liquid after the washing process and the increase of the difficulty of the wastewater treatment, in addition, excessive use of the promoters also causes the increase of the pollutant concentration in the exhaust gas discharged in the burning process.

[0019] Preferably, the phosphate decomposition promoter comprises a soluble nitrate salt.

[0020] The nitrate ion in the nitrate salt reacts with the organic matter in the spent alumina balls, and the nitrate ion is oxidized to generate NO x Catalyze the decomposition of the phosphate ester.

[0021] Preferably, the soluble nitrate salt comprises any one or a combination of at least two of lithium nitrate, sodium nitrate, potassium nitrate, rubidium nitrate, cesium nitrate, ammonium nitrate or aluminum nitrate, typical but non-limiting combinations include a combination of lithium nitrate and sodium nitrate, a combination of potassium nitrate and rubidium nitrate, a combination of cesium nitrate and ammonium nitrate, a combination of ammonium nitrate and aluminum nitrate, a combination of lithium nitrate, sodium nitrate and potassium nitrate, a combination of rubidium nitrate, cesium nitrate, ammonium nitrate and aluminum nitrate, or a combination of lithium nitrate, sodium nitrate, potassium nitrate, rubidium nitrate, cesium nitrate, ammonium nitrate and aluminum nitrate.

[0022] Preferably, the carbon oxidation promoter comprises any one or a combination of at least two of an alkali metal salt, an alkali metal hydroxide or a soluble zinc salt, typical but non-limiting combinations include a combination of the alkali metal salt and the alkali metal hydroxide, a combination of the alkali metal hydroxide and the soluble zinc salt, a combination of the alkali metal salt and the soluble zinc salt, or a combination of the alkali metal salt, the alkali metal hydroxide and the soluble zinc salt.

[0023] The active cations in the carbon deposit oxidation promoter catalyze the oxidation of carbon deposits produced by anthraquinones, thereby promoting the elimination of carbon deposits.

[0024] Preferably, the alkali metal salt includes any one or a combination of at least two of potassium, sodium, lithium, rubidium, or cesium salts. Typical but non-limiting combinations include combinations of potassium and sodium salts, potassium and lithium salts, potassium and rubidium salts, potassium and cesium salts, potassium, sodium, and lithium salts, or combinations of potassium, sodium, lithium, rubidium, and cesium salts.

[0025] Preferably, the potassium salt includes inorganic potassium salts and / or organic potassium salts.

[0026] Preferably, the sodium salt includes inorganic sodium salt and / or organic sodium salt.

[0027] Preferably, the lithium salt comprises lithium nitrate.

[0028] Preferably, the rubidium salt includes rubidium nitrate.

[0029] Preferably, the cesium salt includes cesium nitrate.

[0030] Preferably, the alkali metal hydroxide includes any one or a combination of at least two of lithium hydroxide, sodium hydroxide, potassium hydroxide, or rubidium hydroxide. Typical but non-limiting combinations include combinations of lithium hydroxide and sodium hydroxide, sodium hydroxide and potassium hydroxide, potassium hydroxide and rubidium hydroxide, lithium hydroxide, sodium hydroxide and potassium hydroxide, sodium hydroxide, potassium hydroxide and rubidium hydroxide, or lithium hydroxide, sodium hydroxide, potassium hydroxide and rubidium hydroxide.

[0031] Preferably, the soluble zinc salt includes any one or a combination of at least two of zinc chloride, zinc sulfate, or zinc nitrate. Typical but non-limiting combinations include combinations of zinc chloride and zinc sulfate, zinc sulfate and zinc nitrate, zinc chloride and zinc nitrate, or combinations of zinc chloride, zinc sulfate, and zinc nitrate.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The regeneration method provided by this invention loads a carbon deposition oxidation promoter and a phosphate ester decomposition promoter onto the waste alumina balls before calcination, enabling the regeneration of the waste alumina balls under calcination conditions of 450°C. The regeneration time can be controlled below 90 minutes, especially as low as 30 minutes, significantly reducing the whitening temperature and calcination time of the waste alumina balls, effectively reducing the energy consumption of thermal regeneration. Furthermore, the regenerated alumina balls retain their original specific surface area and pore structure, achieving complete regeneration with good regeneration effect. Attached Figure Description

[0034] Figure 1 This is a process flow diagram of the regeneration method provided in Embodiment 1 of the present invention. Detailed Implementation

[0035] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0036] Example 1

[0037] This embodiment provides a method such as Figure 1 The method for regenerating waste alumina balls from hydrogen peroxide industry, as shown, includes the following steps:

[0038] Weigh 1000g of waste alumina balls with an average diameter of 3mm, dry them thoroughly, and immerse them in a 70% KNO3 solution (8.75% of the mass of the waste alumina balls). After soaking for 10 minutes, filter out and dry them. Then, ignite the waste alumina balls in an air-filled furnace at 450℃ for 30 minutes. After ignition, the waste alumina balls turn completely white, and there is no gray-black carbon deposit inside the particles. Wash the alumina balls in water to remove residual potassium salts, and dry them to obtain regenerated alumina balls, thus completing the regeneration process.

[0039] In this embodiment, the specific surface area of ​​the waste alumina spheres when unused is 210 μm. 2 / g, average pore size 9nm, pore volume 0.472mL / g. After regeneration, the specific surface area of ​​the regenerated alumina spheres is 210m. 2 / g, with an average pore size of 9nm and a pore volume of 0.472mL / g, its specific surface area characteristics are exactly the same as those of unused alumina spheres.

[0040] In this embodiment, KNO3 acts as both a carbon deposition oxidation promoter and a phosphate ester decomposition promoter. KNO3 decomposes in the presence of phosphate esters and diethylanthraquinone, producing NO... x It catalyzes the decomposition of phosphate esters, and the presence of K ions promotes the oxidation and elimination of carbon deposits generated in subsequent reactions, significantly reducing the whitening temperature of waste alumina balls.

[0041] Example 2

[0042] This embodiment provides a method for regenerating waste alumina balls from the hydrogen peroxide industry, the regeneration method comprising the following steps:

[0043] Weigh 2000g of waste alumina balls from the hydrogen peroxide industry, with an average diameter of 3mm, thoroughly dry them, and immerse them in a 70% NaNO3 solution (8.75% of the mass of the waste alumina balls). After soaking for 10 minutes, filter out and dry them. Then, ignite the waste alumina balls in an air-filled furnace at 450℃ for 45 minutes. After ignition, the waste alumina balls turn completely white, and there is no gray-black carbon deposit inside the particles. Wash the alumina balls in water to remove residual sodium salts, and dry them to obtain regenerated alumina balls, thus completing the regeneration process.

[0044] In this embodiment, the specific surface area of ​​the waste alumina spheres when unused is 189 μm. 2 / g, average pore size 9.6nm, pore volume 0.45mL / g. After regeneration, the specific surface area of ​​the regenerated alumina spheres is 189m. 2 / g, with an average pore size of 9.6nm and a pore volume of 0.45mL / g, and its specific surface characteristics are exactly the same as those of unused alumina spheres.

[0045] In this embodiment, NaNO3 acts as both a carbon deposition oxidation promoter and a phosphate ester decomposition promoter. NaNO3 decomposes in the presence of phosphate esters and diethylanthraquinone, producing NO. x It catalyzes the decomposition of phosphate esters, and the presence of Na ions promotes the oxidation and elimination of carbon deposits generated in subsequent reactions, significantly reducing the whitening temperature of alumina balls.

[0046] The thermal decomposition temperature of NaNO3 is lower than that of KNO3, and the reaction of its phosphate ester destruction begins earlier and is more complete. However, since the catalytic oxidation ability of Na ions for carbon deposits is lower than that of K ions, the whitening time of the waste alumina balls in this example is slightly longer than that in Example 1.

[0047] Example 3

[0048] This embodiment provides a method for regenerating waste alumina balls from the hydrogen peroxide industry, the regeneration method comprising the following steps:

[0049] 1500g of waste alumina balls from hydrogen peroxide industry, with an average diameter of 3mm, were weighed and thoroughly dried. They were then immersed in a hot solution containing 30% NaCO3 and 40% KNO3 by mass, with each NaCO3 and KNO3 accounting for 8.75% of the mass of the waste alumina balls. After soaking for 10 minutes, the balls were filtered out and dried. The waste alumina balls were then placed in an incineration furnace and incinerated in an air atmosphere at 450℃ for 40 minutes. After incineration, the waste alumina balls turned completely white, and there was no gray-black carbon deposit inside the particles. The alumina balls were then washed in water to remove residual sodium and potassium salts. After drying, regenerated alumina balls were obtained, completing the regeneration process.

[0050] In this embodiment, the specific surface area of ​​the waste alumina spheres when unused is 189 μm. 2 / g, average pore size 9.6nm, pore volume 0.45mL / g. After regeneration, the specific surface area of ​​the regenerated alumina spheres is 189m. 2 / g, with an average pore size of 9.6nm and a pore volume of 0.45mL / g, and its specific surface characteristics are exactly the same as those of unused alumina spheres.

[0051] In this embodiment, NaCO3 is a carbon deposition oxidation promoter, and KNO3 is both a phosphate ester decomposition promoter and a carbon deposition oxidation promoter. KNO3 decomposes in the presence of phosphate ester and diethylanthraquinone, producing NO. x It catalyzes the decomposition of phosphate esters, while the presence of K and Na ions promotes the oxidation and elimination of carbon deposits generated in subsequent reactions, significantly reducing the whitening temperature of waste alumina balls.

[0052] Because NaCO3 has a high thermal decomposition temperature, the catalytic oxidation effect of the resulting carbon deposits is relatively low. Therefore, compared with Example 1, the whitening time of the waste alumina balls in this example is slightly longer.

[0053] Example 4

[0054] This embodiment provides a method for regenerating waste alumina balls from the hydrogen peroxide industry, the regeneration method comprising the following steps:

[0055] 2000g of waste alumina balls from hydrogen peroxide industry, with an average diameter of 3mm, were weighed and thoroughly dried. They were then immersed in a hot solution containing 20% ​​sodium acetate and 60% NaNO3 by mass, with each sodium acetate and NaNO3 accounting for 10% of the mass of the waste alumina balls. After soaking for 10 minutes, the balls were filtered out and dried. The waste alumina balls were then placed in an incineration furnace and incinerated in an air atmosphere at 450℃ for 50 minutes. After incineration, the waste alumina balls turned completely white, and there was no gray-black carbon deposit inside the particles. The alumina balls were then washed in water to remove residual sodium salts and dried to obtain regenerated alumina balls, thus completing the regeneration process.

[0056] In this embodiment, the specific surface area of ​​the waste alumina spheres when unused is 210 μm. 2 / g, average pore size 8.8nm, pore volume 0.46mL / g. After regeneration, the specific surface area of ​​the regenerated alumina spheres is 210m. 2 / g, with an average pore size of 8.8nm and a pore volume of 0.46mL / g, and its specific surface area characteristics are exactly the same as those of unused alumina spheres.

[0057] In this embodiment, sodium acetate is a carbon deposition oxidation promoter, and NaNO3 is both a phosphate ester decomposition promoter and a carbon deposition oxidation promoter. NaNO3 decomposes in the presence of phosphate ester and diethylanthraquinone, producing NO.x It catalyzes the decomposition of phosphate esters, and the presence of Na ions promotes the oxidation and elimination of carbon deposits generated in subsequent reactions, significantly reducing the whitening temperature of waste alumina balls.

[0058] Sodium acetate decomposes into sodium carbonate, which has a very high decomposition temperature. Sodium carbonate does not strongly promote the decomposition of carbon deposits. Therefore, compared with Example 2, the whitening time of the waste alumina balls in this example is slightly longer.

[0059] Example 5

[0060] This embodiment provides a method for regenerating waste alumina balls from the hydrogen peroxide industry, the regeneration method comprising the following steps:

[0061] 4000g of waste alumina balls from hydrogen peroxide industry, with an average diameter of 3mm, were weighed and thoroughly dried. They were then immersed in a hot solution containing 20% ​​potassium oxalate and 60% KNO3 by mass, with each amount of potassium oxalate and KNO3 accounting for 10% of the mass of the waste alumina balls. After soaking for 10 minutes, the balls were filtered out and dried. The waste alumina balls were then placed in an incineration furnace and incinerated in an air atmosphere at 450℃ for 38 minutes. After incineration, the waste alumina balls turned completely white, and there was no gray-black carbon deposit inside the particles. The alumina balls were then washed in water to remove residual potassium salts and dried to obtain regenerated alumina balls, thus completing the regeneration process.

[0062] In this embodiment, the specific surface area of ​​the unused waste alumina spheres is 200 μm. 2 / g, average pore size 10.2nm, pore volume 0.51mL / g. After regeneration, the specific surface area of ​​the regenerated alumina spheres is 200m. 2 / g, with an average pore size of 10.2nm and a pore volume of 0.51mL / g, and its specific surface characteristics are exactly the same as those of unused alumina spheres.

[0063] In this embodiment, potassium oxalate is used as a carbon deposition oxidation promoter, and KNO3 is simultaneously a phosphate ester decomposition promoter and a carbon deposition oxidation promoter. KNO3 decomposes in the presence of phosphate ester and diethylanthraquinone, producing NO. x It catalyzes the decomposition of phosphate esters, and the presence of K ions promotes the oxidation and elimination of carbon deposits generated in subsequent reactions, significantly reducing the whitening temperature of waste alumina balls.

[0064] Since potassium oxalate decomposes into potassium carbonate at a very high decomposition temperature, its promoting effect on carbon deposition is not strong. Therefore, compared with Example 1, the whitening time of the waste alumina balls in this example is slightly longer.

[0065] Example 6

[0066] This embodiment provides a method for regenerating waste alumina balls from the hydrogen peroxide industry, the regeneration method comprising the following steps:

[0067] 3000g of waste alumina balls from hydrogen peroxide industry, with an average diameter of 1.5mm, were weighed and thoroughly dried. They were then immersed in a hot solution containing 40% KNO3 and 30% NH4NO3 by mass, with each KNO3 and NH4NO3 accounting for 8.75% of the mass of the waste alumina balls. After soaking for 10 minutes, the balls were filtered out and dried. The waste alumina balls were then placed in an incineration furnace and incinerated in an air atmosphere at 450℃ for 27 minutes. After incineration, the waste alumina balls turned completely white, and there was no gray-black carbon deposit inside the particles. The alumina balls were then washed in water to remove residual potassium and ammonium salts. After drying, regenerated alumina balls were obtained, completing the regeneration process.

[0068] In this embodiment, the specific surface area of ​​the waste alumina spheres when unused is 215 μm. 2 / g, average pore size 9.2nm, pore volume 0.49mL / g. After regeneration, the specific surface area of ​​the regenerated alumina spheres is 215m. 2 / g, with an average pore size of 9.2nm and a pore volume of 0.49mL / g, and its specific surface characteristics are exactly the same as those of unused alumina spheres.

[0069] In this embodiment, KNO3 is a carbon deposition oxidation promoter and a phosphate ester decomposition promoter, and NH4NO3 is a phosphate ester decomposition promoter. Because NH4NO3 has a low decomposition temperature, it readily produces NO, which can decompose phosphate esters. x Therefore, the decomposition of phosphate esters is significantly accelerated, and K ions promote the oxidation and elimination of carbon deposits generated in subsequent reactions, significantly reducing the whitening temperature of waste alumina balls.

[0070] Compared with Example 1, the calcination time of the waste alumina balls in this example is slightly shorter, but due to the explosiveness of NH4NO3, its dosage cannot be too large and its use requires caution.

[0071] Example 7

[0072] This embodiment provides a method for regenerating waste alumina balls from the hydrogen peroxide industry, the regeneration method comprising the following steps:

[0073] Weigh 500g of waste alumina balls from the hydrogen peroxide industry, with an average diameter of 3mm, thoroughly dry them, and immerse them in a 40% RbNO3 solution (5% of the mass of the waste alumina balls). After soaking for 10 minutes, filter out and dry them. Then, ignite the waste alumina balls in an incineration furnace at 450℃ for 35 minutes in an air atmosphere. After ignition, the waste alumina balls turn completely white, and there is no gray-black carbon deposit inside the particles. Wash the alumina balls in water to remove residual rubidium salts, and dry them to obtain regenerated alumina balls, thus completing the regeneration process.

[0074] In this embodiment, the specific surface area of ​​the waste alumina spheres when unused is 210 μm. 2 / g, average pore size 9nm, pore volume 0.472mL / g. After regeneration, the specific surface area of ​​the regenerated alumina spheres is 210m. 2 / g, with an average pore size of 9nm and a pore volume of 0.472mL / g, its specific surface area characteristics are exactly the same as those of unused alumina spheres.

[0075] RbNO3 acts as both a carbon deposition oxidation promoter and a phosphate ester decomposition promoter. RbNO3 decomposes in the presence of phosphate esters and diethylanthraquinone, producing NO. x It catalyzes the decomposition of phosphate esters, and the presence of Rb ions promotes the oxidation and elimination of carbon deposits generated in subsequent reactions, significantly reducing the whitening temperature of waste alumina balls. However, due to the high price of RbNO3, its use in large quantities is not encouraged.

[0076] Example 8

[0077] This embodiment provides a method for regenerating waste alumina balls from the hydrogen peroxide industry, the regeneration method comprising the following steps:

[0078] 2500g of waste alumina balls from hydrogen peroxide industry, with an average diameter of 2mm, were weighed and thoroughly dried. They were then immersed in a hot solution containing 10% Al(NO3)3 and 30% KNO3 by mass, with each KNO3 and Al(NO3)3 accounting for 5% of the mass of the waste alumina balls. After soaking for 10 minutes, the balls were filtered out and dried. The waste alumina balls were then ignited in an air-filled furnace at 450℃ for 33 minutes. After ignition, the waste alumina balls turned completely white, and there was no gray-black carbon deposit inside the particles. The alumina balls were then washed in water to remove residual potassium and aluminum salts. After drying, regenerated alumina balls were obtained, completing the regeneration process.

[0079] In this embodiment, the specific surface area of ​​the waste alumina spheres when unused is 190 μm. 2 / g, average pore size 9nm, pore volume 0.43mL / g. After regeneration, the specific surface area of ​​the regenerated alumina spheres is 175nm. 2 / g, with an average pore size of 7.8nm and a pore volume of 0.34mL / g, its specific surface area, pore volume and pore size are all lower than those of unused alumina spheres.

[0080] In this embodiment, KNO3 is a carbon deposition oxidation promoter and a phosphate ester decomposition promoter, and Al(NO3)3 is a phosphate ester decomposition promoter. Since the decomposition of Al(NO3)3 and KNO3 produces NO, which can destroy phosphate ester molecules... x Therefore, the decomposition of phosphate esters is significantly accelerated, and K ions promote the oxidation and elimination of carbon deposits generated in subsequent reactions, significantly reducing the calcination temperature of waste alumina balls. However, because the decomposition of Al(NO3)3 leaves a small amount of burlite and gamma alumina in the pores of the alumina balls, the specific surface area, pore size, and pore volume of the resulting recycled alumina balls are slightly reduced compared to unused alumina balls.

[0081] Example 9

[0082] This embodiment provides a method for regenerating waste alumina balls from the hydrogen peroxide industry, the regeneration method comprising the following steps:

[0083] Weigh 3500g of waste alumina balls from the hydrogen peroxide industry, with an average diameter of 3mm, thoroughly dry them, and immerse them in a hot solution of 50% NaNO3 and 20% ZnCl2 by mass fraction. After soaking for 10 minutes, filter out and dry them. Then, ignite the waste alumina balls in an incineration furnace at 450℃ for 53 minutes in an air atmosphere. After ignition, the waste alumina balls turn completely white, and there is no gray-black carbon deposit inside the particles. Wash the alumina balls to remove residual zinc and sodium salts, and dry them to obtain regenerated alumina balls, thus completing the regeneration process.

[0084] In this embodiment, the specific surface area of ​​the waste alumina spheres when unused is 190 μm. 2 / g, average pore size 9nm, pore volume 0.43mL / g. After regeneration, the specific surface area of ​​the regenerated alumina spheres is 185nm. 2 / g, with an average pore size of 9.7nm and a pore volume of 0.449mL / g, its specific surface area, pore volume and pore size are not significantly different from those of unused alumina spheres.

[0085] In this embodiment, NaNO3 is used as a carbon deposition oxidation promoter and a phosphate ester decomposition promoter, while ZnCl2 is used as a carbon deposition oxidation promoter. The decomposition of NaNO3 produces NO, which can destroy phosphate ester molecules. x And Zn 2+ This allows for the catalytic oxidation of carbon deposits produced in subsequent reactions, significantly reducing the whitening temperature of waste alumina balls. However, due to Zn... 2+ The introduction of zinc ions into the washing liquid of alumina balls leads to the presence of zinc ions, which places higher demands on wastewater treatment.

[0086] Example 10

[0087] This embodiment provides a method for regenerating waste alumina balls from the hydrogen peroxide industry, the regeneration method comprising the following steps:

[0088] Weigh 1000g of waste alumina balls from the hydrogen peroxide industry, with an average diameter of 3mm, thoroughly dry them, and immerse them in a 70% KNO3 solution (1% of the mass of the waste alumina balls). After soaking for 10 minutes, filter out and dry them. Then, ignite the waste alumina balls in an incineration furnace at 450℃ for 90 minutes in an air atmosphere. After ignition, the waste alumina balls turn completely white, and there is no gray-black carbon deposit inside the particles. Wash the alumina balls in water to remove residual potassium salts, and dry them to obtain regenerated alumina balls, thus completing the regeneration process.

[0089] In this embodiment, the specific surface area of ​​the waste alumina spheres when unused is 210 μm. 2 / g, average pore size 9nm, pore volume 0.472mL / g. After regeneration, the specific surface area of ​​the regenerated alumina spheres is 210m. 2 / g, with an average pore size of 9nm and a pore volume of 0.472mL / g, its specific surface area characteristics are exactly the same as those of unused alumina spheres.

[0090] In this embodiment, KNO3 acts as both a carbon deposition oxidation promoter and a phosphate ester decomposition promoter, significantly reducing the whitening temperature of waste alumina balls.

[0091] Comparative Example 1

[0092] This comparative example provides a method for regenerating alumina balls from hydrogen peroxide industrial waste, the regeneration method comprising the following steps:

[0093] Weigh 500g of waste alumina balls from the hydrogen peroxide industry, with an average diameter of 1.5mm, and thoroughly dry them. Immerse them in a 4% NaOH solution, where the mass of NaOH is 0.5% of the mass of the waste alumina balls. After soaking for 10 minutes, filter out and dry them. Then, ignite the waste alumina balls in an incineration furnace at 600℃ for 5 hours in an air atmosphere. After ignition, the waste alumina balls turn completely white, and there is no gray-black carbon deposit inside the particles. Wash the alumina balls in water to remove residual sodium hydroxide, and dry them to obtain regenerated alumina balls, thus completing the regeneration process.

[0094] In this embodiment, the specific surface area of ​​the waste alumina spheres when unused is 190 μm. 2 / g, average pore size 9nm, pore volume 0.43mL / g. After regeneration, the specific surface area of ​​the regenerated alumina spheres is 170nm. 2 / g, with an average pore size of 11.3nm and a pore volume of 0.48mL / g, its specific surface area is slightly lower than that of unused alumina spheres, while its pore volume and average pore size are slightly increased. This is because NaOH has a corrosive effect on alumina at high temperatures, which causes the alumina spheres to slightly expand their pores.

[0095] In this embodiment, the Na ions of NaOH provide a carbon deposition oxidation promoter to the system, but do not provide a phosphate ester decomposition promoter, which makes it difficult for the phosphate ester decomposition to proceed efficiently and quickly. Therefore, the calcination temperature of the waste alumina balls is higher and the required calcination time is longer.

[0096] Comparative Example 2

[0097] This comparative example provides a method for regenerating alumina balls from hydrogen peroxide industrial waste, the regeneration method comprising the following steps:

[0098] Weigh 1000g of waste alumina balls from the hydrogen peroxide industry, with an average diameter of 3mm, thoroughly dry them, and immerse them in a 30% NH4NO3 solution (8.75% of the mass of the waste alumina balls). After soaking for 10 minutes, filter out and dry them. Then, ignite the waste alumina balls in an incineration furnace at 500℃ for 60 minutes in an air atmosphere. After ignition, the waste alumina balls turn completely white, and there is no gray-black carbon deposit inside the particles. Wash the alumina balls in water to remove residual potassium salts, and dry them to obtain regenerated alumina balls, thus completing the regeneration process.

[0099] In this embodiment, the specific surface area of ​​the waste alumina spheres when unused is 210 μm. 2 / g, average pore size 9nm, pore volume 0.472mL / g. After regeneration, the specific surface area of ​​the regenerated alumina spheres is 210m. 2 / g, with an average pore size of 9nm and a pore volume of 0.472mL / g, its specific surface area characteristics are exactly the same as those of unused alumina spheres.

[0100] In this embodiment, NH4NO3 is a phosphate ester decomposition promoter. Because NH4NO3 has a low decomposition temperature, it readily produces NO, which can decompose phosphate esters. x However, no carbon deposit oxidation accelerator was provided, making it difficult to remove the carbon deposits that were subsequently generated. As a result, the whitening temperature of the waste alumina balls was higher and the whitening time required was longer.

[0101] In summary, the regeneration method provided by this invention can regenerate waste alumina balls by loading a carbon deposition oxidation promoter and a phosphate ester decomposition promoter onto the waste alumina balls before calcination, under calcination conditions of 450°C. The regeneration time can be controlled below 90 minutes, especially as low as 30 minutes, which significantly reduces the whitening temperature and calcination time of the waste alumina balls, effectively reducing the energy consumption of thermal regeneration. Furthermore, the regenerated alumina balls retain their original specific surface area and pore structure, achieving complete regeneration with good regeneration effect.

[0102] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for regenerating industrial waste alumina balls of hydrogen peroxide, characterized by, The regeneration method comprises the following steps: The waste alumina balls are mixed with a coke oxidation promoter and a phosphate decomposition promoter, the coke oxidation promoter and the phosphate decomposition promoter are loaded into the waste alumina balls, and then the waste alumina balls are dried and calcined to obtain regenerated alumina balls; The coke oxidation promoter comprises an alkali metal salt and / or a soluble zinc salt; The phosphate decomposition promoter comprises at least one of lithium nitrate, sodium nitrate, ammonium nitrate or aluminum nitrate; The particle size D50 of the waste alumina balls is 1-6 mm.

2. The regeneration method according to claim 1, characterized by, The amount of the coke oxidation promoter is 0.5-10 wt% of the waste alumina balls.

3. The regeneration method according to claim 1, characterized by, The amount of the phosphate decomposition promoter is 0.5-10 wt% of the waste alumina balls.

4. The regeneration method according to claim 1, characterized by, The alkali metal salt comprises any one or a combination of at least two of a potassium salt, a sodium salt, a lithium salt, a rubidium salt or a cesium salt.

5. The regeneration method according to claim 4, characterized by, The potassium salt comprises an inorganic potassium salt and / or an organic potassium salt.

6. The regeneration method according to claim 4, characterized by, The sodium salt comprises an inorganic sodium salt and / or an organic sodium salt.

7. The regeneration method according to claim 4, characterized by, The lithium salt comprises lithium nitrate.

8. The regeneration method according to claim 4, characterized by, The rubidium salt comprises rubidium nitrate.

9. The regeneration method according to claim 4, characterized by, The cesium salt comprises cesium nitrate.

10. The regeneration method according to claim 1, characterized by, The soluble zinc salt comprises any one or a combination of at least two of zinc chloride, zinc sulfate or zinc nitrate.

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