Persiella megatherium and method for leaching rare earth elements in waste material by using persiella megatherium

Abstract

The invention relates to the technical field of environment-friendly biological rare earth recovery, in particular to a Pristia megaterium MeR-2 and a method for leaching rare earth elements in waste by using the Pristia megaterium MeR-2. Specifically, the invention provides a method for leaching rare earth elements in waste by using microorganisms and metabolites thereof, and solves the problems of large dosage of chemical reagents, high production cost, serious environmental pollution and the like in the chemical leaching process of rare earth waste. The strain provided by the invention is low in culture cost, high in growth speed and simple in leaching condition, has the capability of leaching rare earth ions in various wastes, and has a relatively good application prospect in the aspects of rare earth waste microorganism recovery and reutilization and the like.

Description

Technical Field

[0001] The invention relates to the technical field of environmentally friendly biological rare earth recovery, in particular to Pristia gigantea and a method for leaching rare earth elements in waste materials. Background Art

[0002] Rare earth elements, including fifteen lanthanides and two metallic elements, scandium and yttrium, are known as "industrial gold" for their critical applications in high-tech fields and cutting-edge research. Due to the limited reserves and uneven geographical distribution of these elements, extracting rare earth elements from secondary resources has become increasingly important, especially with the growing demand in areas such as permanent magnet materials and industrial catalysts.

[0003] At present, conventional methods for extracting rare earth elements from urban minerals mainly rely on physical and chemical leaching techniques using strong acids and organic solvents. These traditional methods are not only complex and energy-intensive, but may also cause serious environmental pollution. Therefore, it is urgent to develop a new environmentally friendly and efficient leaching technology to achieve high leaching rates while minimizing environmental impact.

[0004] Bioleaching, a method of extracting rare earths using microorganisms, provides an environmentally friendly alternative. This method mainly releases rare earth elements from solid matrices through organic acids such as citric acid and lactic acid produced by heterotrophic bacteria or fungi. However, existing commercial microorganisms such as yeast and Gluconobacter oxydans are inefficient and slow in extracting rare earths from discarded FCC catalysts and NdFeB magnets, mainly because these microorganisms have poor tolerance to high concentrations of rare earth ions. Therefore, screening and culturing potent microbial flora from rare earth mines and rare earth wastes are crucial to improving the efficiency of rare earth bioleaching. However, there are still few reports on the application of these special microorganisms. Therefore, providing a new strain of Pristia gigantea that can efficiently leach rare earth ions from waste materials can provide new options and approaches for biometallurgy, which is of great practical significance. Summary of the invention

[0005] In view of this, the present invention provides a method for leaching rare earth elements in waste materials using microorganisms and their metabolites, which solves the problems of large amount of chemical reagents, high production cost, serious environmental pollution, etc. in the chemical leaching process of rare earth waste.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides Priestia megaterium MeR-2, characterized in that its deposit number is CGMCC No.30398.

[0008] In a second aspect, the present invention also provides a method for culturing the Priestia megaterium MeR-2, wherein the Priestia megaterium MeR-2 is selected and cultured at 30° C. and 200 rpm for 2-4 days in a Luria-Bertani liquid culture medium supplemented with 60 g / L glucose or a nutrient-poor Luria-Bertani liquid culture medium supplemented with 60 g / L glucose;

[0009] In the nutrient-deficient Luria-Bertani liquid culture medium, the content of the original components of the LB culture medium is 0.05-50%.

[0010] In a third aspect, the present invention also provides one or more of the inactivated bacteria, exosomes or metabolites of Priestia megaterium MeR-2.

[0011] In a fourth aspect, the present invention also provides a method for preparing the metabolites of Priestia megaterium MeR-2, wherein the Priestia megaterium MeR-2 is selected, and cultured at 30° C. and 200 rpm for 2 to 4 days in a Luria-Bertani liquid culture medium supplemented with 60 g / L glucose or a nutrient-poor Luria-Bertani liquid culture medium supplemented with 60 g / L glucose, and the culture solution is collected and centrifuged at 8000 rpm for 5 min to collect the supernatant;

[0012] In the nutrient-deficient Luria-Bertani liquid culture medium, the content of the original components of the LB culture medium is 0.05-50%.

[0013] In a fifth aspect, the present invention also provides a metabolite obtained by the preparation method.

[0014] In a sixth aspect, the present invention further provides the use of any one of the following in leaching rare earth elements in waste materials;

[0015] (I), Priestia megaterium MeR-2;

[0016] (II), one or more of the inactivated bacteria, exosomes or metabolites;

[0017] (III) the metabolites.

[0018] In some specific embodiments of the present invention, the waste material includes one or more of waste FCC catalyst, waste NdFeB sludge or waste NdFeB powder.

[0019] In some specific embodiments of the present invention, the main framework of the spent FCC catalyst is aluminosilicate, containing rare earth elements and / or transition elements, the content of the rare earth elements and / or transition elements is 0.01% to 10%; the rare earth elements include but are not limited to lanthanum and / or cerium; the transition elements include but are not limited to nickel and / or vanadium;

[0020] The main component of the waste NdFeB sludge is NdFeB (Nd2Fe 14 B) magnet, containing 1% to 30% lubricating oil;

[0021] The main component of the waste NdFeB powder is Nd2Fe 14 B), produced in various links of industrial production of NdFeB magnets, including cutting, compression molding or sintering processes.

[0022] In a seventh aspect, the present invention further provides a product, comprising any of the following:

[0023] (I), Priestia megaterium MeR-2;

[0024] (II), one or more of the inactivated bacteria, exosomes or metabolites;

[0025] (III), the metabolites;

[0026] The products include microecological products, probiotic products, synbiotic products and / or postbiotic products.

[0027] In an eighth aspect, the present invention also provides a method for leaching rare earth elements from waste materials, comprising mixing any one of the following with the waste materials and incubating;

[0028] (I), Priestia megaterium MeR-2;

[0029] (II), one or more of the inactivated bacteria, exosomes or metabolites;

[0030] (III), the metabolites;

[0031] (IV) the product.

[0032] In some specific embodiments of the present invention, the waste material comprises one or more of waste FCC catalyst, waste NdFeB sludge or waste NdFeB powder;

[0033] Preferably, the main framework of the spent FCC catalyst is aluminosilicate, containing rare earth elements and / or transition elements, the content of the rare earth elements and / or transition elements is 0.01% to 10%; the rare earth elements include but are not limited to lanthanum and / or cerium; the transition elements include but are not limited to nickel and / or vanadium;

[0034] The main component of the waste NdFeB sludge is NdFeB (Nd2Fe 14 B) magnet, containing 1% to 30% lubricating oil;

[0035] The main component of the waste NdFeB powder is Nd2Fe 14 B), produced in various links of industrial production of NdFeB magnets, including cutting, compression molding or sintering processes;

[0036] Preferably, the liquid-solid ratio of the Priestia megaterium MeR-2 to the spent FCC catalyst is 1:(2-500);

[0037] The liquid-solid ratio of the Priestia megaterium MeR-2 to the waste NdFeB sludge is 1:(4-500);

[0038] The liquid-solid ratio of the Priestia megaterium MeR-2 to the waste NdFeB powder is 1:(4-500);

[0039] Preferably, the liquid-to-solid ratio of the metabolites to the spent FCC catalyst is 1:(2-500);

[0040] The liquid-to-solid ratio of the metabolites to the waste NdFeB sludge is 1:50;

[0041] The liquid-to-solid ratio of the metabolite to the waste NdFeB powder is 1:50;

[0042] Preferably, the incubation condition is 30° C. and 200 rpm for 2 to 8 days.

[0043] The present invention provides a method for leaching rare earth elements in waste materials using microorganisms and their metabolites, which solves the problems of large amount of chemical reagents, high production cost, serious environmental pollution, etc. in the process of chemical leaching of rare earth waste. The strain provided by the present invention has low cultivation cost, fast growth rate, simple leaching conditions, and has the ability to leach rare earth ions in a variety of waste materials. It has good application prospects in the recovery and reuse of rare earth waste microorganisms.

[0044] Biological Deposit Description

[0045] Strain: MER-2; the deposit date is April 22, 2024, the deposit number is CGMCC No.30398, the classification name is Priestia megaterium, the name of the depository is: General Microbiology Center of China Microbiological Culture Collection Administration, and the address of the depository is: Institute of Microbiology, Chinese Academy of Sciences, No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing. DETAILED DESCRIPTION

[0046] The present invention discloses a method for utilizing P. gigantea and leaching rare earth elements from waste materials. Those skilled in the art can refer to the content of this article and appropriately improve the process parameters to achieve the method. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art, and they are all considered to be included in the present invention. The method and application of the present invention have been described through preferred embodiments, and relevant personnel can obviously modify or appropriately change and combine the method and application described herein without departing from the content, spirit and scope of the present invention to implement and apply the technology of the present invention.

[0047] The present invention adopts the following technical solution:

[0048] (1) Screening of leaching strains: The strains were screened using silica-dissolving medium solid plates. Priestia megaterium MeR-2 (CGMCC No. 30398), which can produce an obvious silica-dissolving transparent ring on silica-dissolving medium solid plates, was selected for subsequent research.

[0049] (2) Cultivation of microorganisms: Pristia gigantea MeR-2 was cultured in a Luria-Bertani (LB) liquid medium supplemented with 60 g / L glucose or a nutrient-poor Luria-Bertani (LB) liquid medium supplemented with 60 g / L glucose (the original component content of the LB medium was 0.05-50%) at 30° C. and 200 rpm for 2-4 days.

[0050] (3) Co-cultivation to leaching rare earth elements from spent FCC catalysts (the main framework is aluminosilicate, containing rare earth elements such as lanthanum and cerium and transition elements such as nickel and vanadium, with a content of 0.01%-10%): Pristia gigantea MeR-2 is co-incubated with spent FCC catalysts at a solid-liquid ratio of 1:2-1:500 in a Luria-Bertani (LB) liquid medium supplemented with 60 g / L glucose or a nutrient-poor Luria-Bertani (LB) liquid medium supplemented with 60 g / L glucose (the original component content of the LB medium is 0.05-50%), and cultured at 30° C. and 200 rpm for 2-4 days.

[0051] (4) Co-cultivation leaching of waste NdFeB sludge (main component is NdFeB (Nd2Fe 14 B) magnet, containing 1%-30% rare earth elements in lubricating oil): Pristia gigantea MeR-2 is co-incubated with waste NdFeB sludge at a solid-liquid ratio of 1:4-1:500 in a Luria-Bertani (LB) liquid medium supplemented with 60 g / L glucose or a nutrient-poor Luria-Bertani (LB) liquid medium supplemented with 60 g / L glucose (the original component content of the LB medium is 0.05-50%), and cultured at 30°C, 200 rpm for 2-8 days.

[0052] (5) Co-cultivation leaching of waste NdFeB powder (main component is NdFeB (Nd2Fe 14 B), rare earth elements produced in various links of industrial production of NdFeB magnets, such as cutting, compression molding, sintering process, etc.): Pristia gigantea MeR-2 is co-incubated with waste NdFeB sludge at a liquid-solid ratio of 1:4-1:500 in a Luria-Bertani (LB) liquid culture medium supplemented with 60 g / L glucose or a nutrient-poor Luria-Bertani (LB) liquid culture medium supplemented with 60 g / L glucose (the original component content of the LB culture medium is 0.05-50%), and cultured at 30°C and 200 rpm for 2-8 days.

[0053] (6) Preparation of microbial culture metabolites: The microbial culture solution in step (2) was centrifuged at 8000 rpm for 5 min to collect the supernatant.

[0054] (7) Leaching rare earth elements from waste FCC catalyst (the main framework is aluminosilicate, containing rare earth elements such as lanthanum and cerium and transition elements such as nickel and vanadium, with a content of 0.01%-10%) using microbial culture metabolites: After the supernatant of the leaching solution in step (5) is diluted with ultrapure water (minimum supernatant content is 2%), the original solution or the diluted solution is mixed with the waste FCC catalyst at a solid-liquid ratio of 1:2-1:500, and leaching is carried out at 30° C. and 200 rpm to obtain a leaching solution after 2-4 days.

[0055] (8) Leaching of waste NdFeB sludge (main component is NdFeB (Nd2Fe 14 B) magnet, containing 1%-30% rare earth elements in lubricating oil): after the supernatant of the leaching solution in step (5) is diluted with ultrapure water (minimum supernatant content 2%), the original solution or the diluted solution is mixed with the waste NdFeB sludge in a solid-liquid ratio of 1:50, and leaching is carried out at 30°C and 200rpm to obtain a leaching solution after 2 days.

[0056] (9) Leaching of waste NdFeB powder (main component is NdFeB (Nd2Fe 14 B), rare earth elements produced in various links of industrial production of NdFeB magnets, such as cutting, compression molding, sintering process, etc.): after the supernatant of the leaching solution in step (5) is diluted with ultrapure water (minimum supernatant content is 2%), the original solution or the diluted solution is mixed with the waste NdFeB sintering or compression molding powder in a solid-liquid ratio of 1:50, and leaching is carried out at 30°C and 200rpm to obtain the leaching solution after 2 days.

[0057] (10) The leaching ability of MeR-2 was identified by detecting the content and type of rare earth elements in steps (3)(4)(5)(7)(8)(9) through ICP-OES and ICP-MS.

[0058] The strain provided by the present invention has low culture cost, fast growth rate, simple leaching conditions, and the ability to leach rare earth ions in various wastes. It has good application prospects in the recovery and reuse of rare earth waste microorganisms.

[0059] In the Pristia gigantea and the method for leaching rare earth elements from waste materials provided by the invention, the raw materials and reagents used can be purchased from the market.

[0060] The present invention will be further described below in conjunction with embodiments:

[0061] Example 1 Screening of rare earth leaching strains and determination of their ability to dissolve insoluble silicates

[0062] A single colony of purified Priestia megaterium MeR-2 was picked from an LB solid medium containing 1.5-3% agar and placed in 4 mL LB liquid medium. The culture was carried out overnight at 30°C and 200 rpm in a constant temperature shaking incubator. 2 μL of the bacterial liquid was added dropwise to a silica-dissolving medium solid culture plate. After ten days of culture, the results were observed and recorded. The appearance of a transparent ring was recorded as positive, indicating that the strain had the ability to dissolve insoluble silicates. The strain was biologically preserved and the preservation number was CGMCC No. 30398.

[0063] Example 2: Leaching of rare earth elements from spent FCC catalysts by co-cultivation of MeR-2 microorganisms

[0064] From the LB solid medium containing 1.5-3% agar, a single colony of purified MeR-2 (deposited as CGMCC No. 30398) was picked and placed in 4 mL LB liquid medium, and cultured overnight at 30°C, 200 rpm in a constant temperature shaking incubator until the OD value reached 0.8-1.2 as a seed solution. A 1% volume ratio of the seed solution (final OD value 0.008-0.012) was inoculated into a LB liquid medium containing 60 g / L of glucose, which contained a spent FCC catalyst (the main framework was aluminosilicate, containing rare earth elements such as lanthanum and cerium, and transition elements such as nickel and vanadium, with a content of 0.01%-10%) at a solid-liquid ratio of 1:2-1:500. Cultured at 30°C, 200 rpm in a constant temperature shaking incubator for 2-4 days. Centrifuged at 8000 rpm for 5 min to collect the supernatant.

[0065] After the solution becomes clear and transparent, dilute and fix the volume to a target element content of 1ppb-10ppm, and conduct quantitative analysis of the rare earth elements in it by ICP-OES and ICP-MS (refer to the national standard GB / T18115-2021 Chemical analysis method for rare earth impurities in rare earth metals and their oxides for determination).

[0066] Table 1

[0067] Solid-liquid ratio Leaching rate (%) 1:2 32.57917555 1:5 41.99451777 1:10 53.43641953 1:50 58.01421873 1:100 70.7524405 1:500 98.57917555

[0068] Example 3: Leaching of rare earth elements from spent FCC catalyst by co-cultivation of MeR-2 microorganisms

[0069] The purified MeR-2 single colony (deposit number CGMCC No. 30398) was picked from the LB solid medium containing 1.5-3% agar and placed in 4 mL LB liquid medium, and cultured overnight at 30°C, 200 rpm in a constant temperature shaking incubator until the OD value reached 0.8-1.2 as a seed solution. A 1% volume ratio of the seed solution (final OD value 0.008-0.012) was inoculated into a nutrient-poor Luria-Bertani (LB) liquid medium (the original component content of the LB medium was 0.05-50%) with 60 g / L glucose added, and the medium contained a waste FCC catalyst (the main framework was aluminosilicate, containing rare earth elements such as lanthanum and cerium, and transition elements such as nickel and vanadium, with a content of 0.01%-10%) with a liquid-solid ratio of 1:2-1:500. Cultured in a constant temperature shaking incubator at 30°C, 200 rpm for 2-4 days. Centrifuged at 8000 rpm for 5 min to collect the supernatant.

[0070] Example 4: MeR-2 co-cultivation to leaching rare earth elements from waste NdFeB oil sludge

[0071] The purified MeR-2 single colony (deposit number CGMCC No. 30398) was picked from the LB solid medium containing 1.5-3% agar and added to 4mL LB liquid medium. It was cultured overnight at 30°C and 200rpm in a constant temperature shaking incubator until the OD value was 0.8-1.2 as seed liquid. The seed liquid with a volume ratio of 1% (final OD value 0.008-0.012) was inoculated into LB liquid medium containing 60g / L glucose, which contained waste NdFeB oil sludge (the main component of which is NdFeB (Nd2Fe 14 B) magnet, containing 1%-30% lubricating oil). Cultivate in a constant temperature shaking incubator at 30°C and 200 rpm for 2-8 days. Centrifuge at 8000 rpm for 5 min to collect the supernatant.

[0072] Example 5: MeR-2 co-cultivation to leaching rare earth elements from waste NdFeB oil sludge

[0073] The purified MeR-2 single colony (deposit number CGMCC No.30398) was picked from the LB solid medium containing 1.5-3% agar and added to 4mL LB liquid medium, and cultured overnight at 30°C, 200rpm in a constant temperature shaking incubator until the OD value was 0.8-1.2 as a seed liquid. A 1% volume ratio of the seed liquid (final OD value 0.008-0.012) was inoculated into a nutrient-poor Luria-Bertani (LB) liquid medium (the original component content of the LB medium was 0.05-50%) with 60g / L glucose added, and the medium contained waste NdFeB oil sludge (the main component was NdFeB (Nd2Fe 14 B) magnet, containing 1%-30% lubricating oil). Cultivate in a constant temperature shaking incubator at 30°C and 200 rpm for 2-8 days. Centrifuge at 8000 rpm for 5 min to collect the supernatant.

[0074] Example 6 MeR-2 co-cultivation leaching of rare earth elements from waste NdFeB powder

[0075] The purified MeR-2 single colony (deposit number CGMCC No. 30398) was picked from the LB solid medium containing 1.5-3% agar and placed in 4 mL LB liquid medium. The culture was continued overnight at 30°C and 200 rpm in a constant temperature shaking incubator until the OD value reached 0.8-1.2 as seed liquid. The seed liquid (final OD value 0.008-0.012) with a volume ratio of 1% was inoculated into LB liquid medium containing 60 g / L glucose, which contained waste NdFeB powder (the main component of which is NdFeB (Nd2Fe 14B), produced in various links of industrial production of NdFeB magnets, such as cutting, pressing, sintering, etc.) Cultivate in a constant temperature shaking shaker at 30°C and 200rpm for 2-8 days. Centrifuge at 8000rpm for 5min to collect the supernatant.

[0076] Example 7 MeR-2 co-cultivation leaching of rare earth elements from waste NdFeB powder

[0077] The purified MeR-2 single colony (deposit number CGMCC No. 30398) was picked from the LB solid medium containing 1.5-3% agar and added to 4mL LB liquid medium, and cultured overnight at 30°C, 200rpm in a constant temperature shaking incubator until the OD value was 0.8-1.2 as a seed liquid. A 1% volume ratio of the seed liquid (final OD value 0.008-0.012) was inoculated into a nutrient-poor Luria-Bertani (LB) liquid medium (the original component content of the LB medium was 0.05-50%) with 60g / L glucose added, and the medium contained waste NdFeB powder (the main component was NdFeB (Nd2Fe 14 B), produced in various links of industrial production of NdFeB magnets, such as cutting, pressing, sintering, etc.) Cultivate in a constant temperature shaking shaker at 30°C and 200rpm for 2-8 days. Centrifuge at 8000rpm for 5min to collect the supernatant.

[0078] Example 8 Preparation of MeR-2 microbial extract

[0079] From the LB solid medium containing 1.5-3% agar, a single colony of purified MeR-2 (deposit number CGMCC No. 30398) was picked and placed in 4 mL LB liquid medium, and cultured overnight at 30°C, 200 rpm in a constant temperature shaking incubator to an OD value of 0.8-1.2 as a seed liquid. A 1% volume ratio of the seed liquid (final OD value 0.008-0.012) was inoculated into a Luria-Bertani (LB) liquid medium supplemented with 60 g / L glucose, and cultured at 30°C, 200 rpm in a constant temperature shaking incubator to the logarithmic phase. The supernatant was collected by centrifugation at 8000 rpm for 5 min.

[0080] Example 9 Preparation of MeR-2 microbial extract

[0081] From the LB solid medium containing 1.5-3% agar, a single colony of purified MeR-2 (deposit number CGMCC No. 30398) was picked and placed in 4 mL LB liquid medium, and cultured overnight at 30°C, 200 rpm in a constant temperature shaking incubator until the OD value reached 0.8-1.2 as seed liquid. A 1% volume ratio of the seed liquid (final OD value 0.008-0.012) was inoculated into a nutrient-poor Luria-Bertani (LB) liquid medium (the original component content of the LB medium was 0.05-50%), and cultured at 30°C, 200 rpm in a constant temperature shaking incubator until the logarithmic phase. The supernatant was collected by centrifugation at 8000 rpm for 5 minutes.

[0082] Example 10: Leaching rare earth elements from FCC using supernatant of MeR-2 microbial culture

[0083] The microbial culture supernatant stock solution or diluted solution (diluted with ultrapure water, with a minimum supernatant content of 2%) in Example 8 is added to the spent FCC catalyst (the main framework is aluminosilicate, containing rare earth elements such as lanthanum and cerium and transition elements such as nickel and vanadium, with a content of 0.01%-10%), mixed at a liquid-to-solid ratio of 1:2-1:500, placed in a constant temperature shaking table at 30°C and 200rpm, and a leachate is obtained after 2 days.

[0084] Example 11 Leaching of rare earth elements from waste NdFeB sludge using supernatant of MeR-2 microbial culture

[0085] The microbial culture supernatant in Example 8 or the diluted solution (diluted with ultrapure water, the minimum supernatant content is 2%) is added to the waste NdFeB oil sludge (the main component is NdFeB (Nd2Fe 14 B) magnet, containing 1%-30% lubricating oil), mixed according to the liquid-solid ratio of 1:2-1:500, placed in a constant temperature shaking shaker at 30°C and 200rpm, and an leaching solution was obtained after 2 days.

[0086] Example 12: Leaching of rare earth elements from waste NdFeB powder using supernatant of MeR-2 microbial culture

[0087] The microbial culture supernatant in Example 8 or the diluted solution (diluted with ultrapure water, the minimum supernatant content is 2%) is added to the waste NdFeB powder (the main component is NdFeB (Nd2Fe 14 B), produced in various links of industrial production of NdFeB magnets, such as cutting, compression molding, sintering process, etc.), mixed according to the liquid-solid ratio of 1:2-1:500, placed in a constant temperature shaking table at 30°C and 200rpm, and the leaching solution was obtained after 2 days.

[0088] Example 13: Leaching of rare earth elements from FCC using supernatant of MeR-2 microbial culture

[0089] The microbial culture supernatant stock solution or diluted solution (diluted with ultrapure water, with a minimum supernatant content of 2%) in Example 9 is added to the spent FCC catalyst (the main framework is aluminosilicate, containing rare earth elements such as lanthanum and cerium and transition elements such as nickel and vanadium, with a content of 0.01%-10%), mixed at a liquid-solid ratio of 1:2-1:500, placed in a constant temperature shaking shaker at 30°C and 200rpm, and a leachate is obtained after 2 days.

[0090] Example 14: Leaching of rare earth elements from waste NdFeB sludge using supernatant of MeR-2 microbial culture

[0091] The microbial culture supernatant in Example 9 or the diluted solution (diluted with ultrapure water, the minimum supernatant content is 2%) is added to the waste NdFeB oil sludge (the main component is NdFeB (Nd2Fe 14 B) magnet, containing 1%-30% lubricating oil), mixed according to the liquid-solid ratio of 1:2-1:500, placed in a constant temperature shaking shaker at 30°C and 200rpm, and an leaching solution was obtained after 2 days.

[0092] Example 15: Leaching of rare earth elements from waste NdFeB powder using supernatant of MeR-2 microbial culture

[0093] The microbial culture supernatant in Example 9 or the diluted solution (diluted with ultrapure water, the minimum supernatant content is 2%) is added to the waste NdFeB powder (the main component is NdFeB (Nd2Fe 14 B), produced in various links of industrial production of NdFeB magnets, such as cutting, compression molding, sintering process, etc.), mixed according to the liquid-solid ratio of 1:2-1:500, placed in a constant temperature shaking table at 30°C and 200rpm, and the leaching solution was obtained after 2 days.

[0094] Example 16 Detection of the leaching ability of MeR-2 by ICP-MS

[0095] The leachate in Examples 2 to 7, 10 to 15 was filtered with a 0.22 μm needle filter membrane, and the filtrate was collected. A nitric acid-perchloric acid (10:1) mixed acid system was used for digestion on a 210-degree hot plate. After the solution became clear and transparent, it was diluted and fixed to a target element content of 1 ppb-10 ppm, and the rare earth elements therein were quantitatively analyzed by ICP-OES and ICP-MS (refer to the national standard GB / T 18115-2021 Chemical analysis method for rare earth impurities in rare earth metals and their oxides for determination). The experimental results are shown in Tables 2 to 4.

[0096] Table 2 Leaching amount of rare earth elements from spent FCC catalyst by MeR-2 strain

[0097]

[0098] There are significant differences in the leaching rates of La and Ce among Examples 2, 3, 10, and 13, among which Example 13 has the best leaching effect, with a leaching rate of 95.78% for La and a leaching rate of 96.66% for Ce.

[0099] Table 3 Leaching amount of rare earth elements from waste NdFeB sludge by MeR-2 strain

[0100]

[0101]

[0102] The leaching rates of Pr, Nd, Gd, Tb and Dy in Examples 4, 5, 11 and 14 are significantly different between 4 (A), 11 (B) and 5 (C), 14 (C), but not between 5 (C) and 14 (C). Among them, Example 4 has the best leaching effect, with leaching rates of Pr (97.73%), Nd (98.09%), Gd (97.86%), Tb (98.00%) and Dy (97.93%).

[0103] Table 4 Leaching amount of rare earth elements from waste NdFeB powder by MeR-2 strain

[0104]

[0105] The leaching rates of Pr, Nd, Gd, Tb and Dy in Examples 6, 12, 15 and 7 are significantly different between 7 (A), 6 (B) and 12 (C), 15 (C), but not between 12 (C) and 15 (C). Among them, Example 7 has the best leaching effect, with leaching rates of Pr (97.92%), Nd (97.85%), Gd (97.87%), Tb (97.84%) and Dy (98.01%).

[0106] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. Priestia megaterium MeR-2, characterized in that Its deposit number is CGMCC No.30398.

2. The method for culturing Priestia megaterium MeR-2 according to claim 1, characterized in that: The Priestia megaterium MeR-2 was selected and cultured in a Luria-Bertani liquid medium supplemented with 60 g / L glucose or a nutrient-poor Luria-Bertani liquid medium supplemented with 60 g / L glucose at 30° C. and 200 rpm for 2-4 days; In the nutrient-deficient Luria-Bertani liquid culture medium, the content of the original components of the LB culture medium is 0.05-50%.

3. One or more of the inactivated cells, exosomes or metabolites of Priestia megaterium MeR-2 as claimed in claim 1.

4. The method for preparing the metabolite of Priestia megaterium MeR-2 according to claim 1, characterized in that: The Priestia megaterium MeR-2 was selected, and cultured in a Luria-Bertani liquid medium supplemented with 60 g / L glucose or a nutrient-poor Luria-Bertani liquid medium supplemented with 60 g / L glucose at 30° C. and 200 rpm for 2 to 4 days, and the culture solution was collected and centrifuged at 8000 rpm for 5 min to collect the supernatant; In the nutrient-deficient Luria-Bertani liquid culture medium, the content of the original components of the LB culture medium is 0.05-50%.

5. The metabolite obtained by the preparation method according to claim 4.

6. Use of any of the following in leaching rare earth elements from waste materials; (I) Priestia megaterium MeR-2 as described in claim 1; (II) one or more of the inactivated bacteria, exosomes or metabolites according to claim 3; (III) The metabolite according to claim 5.

7. The use according to claim 6, characterized in that The waste material includes one or more of waste FCC catalyst, waste NdFeB sludge or waste NdFeB powder.

8. The use according to claim 7, characterized in that The main framework of the spent FCC catalyst is aluminosilicate, containing rare earth elements and / or transition elements, the content of the rare earth elements and / or transition elements is 0.01% to 10%; the rare earth elements include but are not limited to lanthanum and / or cerium; the transition elements include but are not limited to nickel and / or vanadium; The main component of the waste NdFeB sludge is NdFeB (Nd2Fe 14 B) magnet, containing 1% to 30% lubricating oil; The main component of the waste NdFeB powder is Nd2Fe 14 B), produced in various links of industrial production of NdFeB magnets, including cutting, compression molding or sintering processes.

9. A product, characterized in that Includes any of the following: (I) Priestia megaterium MeR-2 as described in claim 1; (II) one or more of the inactivated bacteria, exosomes or metabolites according to claim 3; (III) The metabolite according to claim 5; The products include microecological products, probiotic products, synbiotic products and / or postbiotic products.

10. A method for leaching rare earth elements from waste materials, characterized in that: Take any of the following and mix with waste material and incubate; (I) Priestia megaterium MeR-2 as described in claim 1; (II) one or more of the inactivated bacteria, exosomes or metabolites according to claim 3; (III) The metabolite according to claim 5; (IV) The product as claimed in claim 9; Preferably, the waste material comprises one or more of waste FCC catalyst, waste NdFeB sludge or waste NdFeB powder; Preferably, the main framework of the spent FCC catalyst is aluminosilicate, containing rare earth elements and / or transition elements, the content of the rare earth elements and / or transition elements is 0.01% to 10%; the rare earth elements include but are not limited to lanthanum and / or cerium; the transition elements include but are not limited to nickel and / or vanadium; The main component of the waste NdFeB sludge is NdFeB (Nd2Fe 14 B) magnet, containing 1% to 30% lubricating oil; The main component of the waste NdFeB powder is Nd2Fe 14 B), produced in various links of industrial production of NdFeB magnets, including cutting, compression molding or sintering processes; Preferably, the liquid-solid ratio of the Priestia megaterium MeR-2 to the spent FCC catalyst is 1:(2-500); The liquid-solid ratio of the Priestia megaterium MeR-2 to the waste NdFeB sludge is 1:(4-500); The liquid-solid ratio of the Priestia megaterium MeR-2 to the waste NdFeB powder is 1:(4-500); Preferably, the liquid-to-solid ratio of the metabolites to the spent FCC catalyst is 1:(2-500); The liquid-to-solid ratio of the metabolites to the waste NdFeB sludge is 1:50; The liquid-to-solid ratio of the metabolite to the waste NdFeB powder is 1:50; Preferably, the incubation condition is 30° C. and 200 rpm for 2 to 8 days.

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