Method for recovering rare earth and valuable metal in neodymium iron boron waste leaching solution

Abstract

The invention discloses a method for recovering rare earth and valuable metal in neodymium iron boron waste leachate, which comprises the following steps: mixing the neodymium iron boron waste leachate containing rare earth elements and valuable metal elements with an organic extraction agent, and carrying out extraction separation and reverse extraction to obtain single rare earth feed liquid and raffinate, valuable metal elements exist in the raffinate; carrying out adsorption and desorption separation on the single rare earth feed liquid by adopting first resin, and precipitating to obtain a high-purity rare earth compound; and carrying out adsorption and analytical separation on the raffinate by adopting second resin, and precipitating to obtain the high-purity valuable metal compound. Valuable metal elements and rare earth elements are simultaneously and efficiently recovered from neodymium iron boron waste leachate, high-purity rare earth is prepared, the valuable metal elements can be efficiently recovered, the problem that the valuable metal elements affect the purity of a rare earth product is solved, and a high-purity rare earth oxide product is obtained; and high-value utilization of rare earth and valuable metal elements is realized, and remarkable social and economic benefits are generated.

Description

Technical Field

[0001] The invention relates to the field of rare earth resource recovery, and in particular to a method for recovering rare earth and valuable metals in a NdFeB waste leaching solution. Background Art

[0002] After years of development, my country's rare earth industry has established a relatively complete industrial system integrating resource mining, smelting and separation, deep processing, functional materials and downstream applications. With the continuous expansion of rare earth resources in new functional materials and major engineering applications, my country's rare earth consumption has maintained an average annual increase of about 10%. With the increase in demand for rare earths, resource reserves have decreased year by year, and a large amount of rare earth solid waste has also been generated. Taking rare earth permanent magnet materials, the rare earth product with the largest output, the widest application and the fastest development in the global rare earth materials industry, as an example, according to statistics, in 2021, my country's sintered NdFeB magnet production will be about 220,000 tons, accounting for about 90% of the global total production. It is estimated that my country's annual demand for NdFeB blanks will reach 350,000 tons. The industrial solid waste formed in the production and processing of NdFeB, as well as the urban minerals formed at the end of its consumption, have become one of the most concerned rare earth secondary resources. NdFeB permanent magnets contain a variety of rare earth elements such as lanthanum, cerium, praseodymium, neodymium, gadolinium, terbium, dysprosium, and other rare elements, as well as nickel, cobalt, zirconium, molybdenum, niobium and gallium. If the rare earth materials and rare elements that can be mined and utilized in NdFeB waste can be recycled to the maximum extent, it will greatly reduce the large amount of original demand for non-renewable mineral resources and protect the relatively scarce and limited mineral resources.

[0003] At present, for NdFeB waste with poor quality stability and high impurity content, such as waste materials such as machining sludge of sintered NdFeB, an industrialization technology represented by hydrometallurgy has been formed, and the process route is oxidative roasting-acid leaching-impurity removal-P507 extraction and separation of rare earths. Most of the other valuable elements (nickel, cobalt, zirconium, molybdenum, niobium and gallium, etc.) in the extraction process are left in the raffinate, which is not effectively recycled or directly precipitated and enriched for recovery due to low concentration, and the recovery efficiency is low. In addition, trace valuable elements enter the rare earth products with extraction to affect product quality. Current production and research are mainly based on the recovery of rare earth elements, and there is a small amount of research on the recovery of nickel and cobalt, but the recovery of valuable elements such as zirconium, molybdenum, niobium and gallium in the NdFeB waste leachate is less concerned. CN104480316A discloses that the Co element in the leachate is concentrated in the form of Co(OH)3 precipitate and is retained in the hydrolysis precipitate slag and recovered. CN102206755A discloses that hydrochloric acid is used for optimal dissolution, rare earth elements and cobalt are separated in the leaching solution through a P507 extraction system, and the cobalt-enriched solution is extracted, separated, purified and recovered again. "Full extraction method for recovering rare earth and cobalt from NdFeB waste" (China Comprehensive Utilization of Resources, 2004) discloses that concentrated hydrochloric acid is used to fully dissolve NdFeB waste, first N 503Extraction and iron removal, use P507 to extract and separate 99% neodymium oxide and 98% dysprosium oxide products in the iron removal raffinate, and obtain 99% cobalt carbonate by carbonate precipitation of cobalt in the rare earth removal raffinate. In summary, the current wet recovery process of NdFeB waste still has the problem that valuable metals and rare earths are not recycled and utilized at the same time and the purity of rare earths needs to be improved.

[0004] The method of simultaneously and efficiently recovering valuable metals and rare earth elements from NdFeB waste leachate and preparing high-purity rare earths helps to efficiently recover valuable elements, while solving the problem of valuable elements affecting the purity of rare earth products, obtaining high-purity rare earth oxide products, and realizing high-value utilization of rare earths and valuable elements, which will produce significant social and economic benefits and have broad application prospects. Summary of the invention

[0005] The purpose of the embodiment of the present invention is to provide a method for recovering rare earths and valuable metals from NdFeB waste leachate, which helps to efficiently recover valuable metal elements and rare earth elements from NdFeB waste leachate and prepare high-purity rare earths, while solving the problem of residual valuable elements affecting the purity of rare earth products, obtaining high-purity rare earth oxide products, and realizing high-value utilization of rare earth and valuable metal elements, which will produce significant social and economic benefits and has broad application prospects.

[0006] In order to solve the above technical problems, the embodiment of the present invention provides a method for recovering rare earth and valuable metals in NdFeB waste leachate, comprising the following steps:

[0007] The NdFeB waste leachate containing rare earth elements and valuable metal elements is mixed with an organic extractant, and subjected to extraction, separation and stripping to obtain a single rare earth feed solution and a raffinate, wherein the valuable metal elements exist in the raffinate;

[0008] Adsorbing and analyzing the single rare earth liquid with a first resin to obtain a high-purity rare earth compound after precipitation;

[0009] The raffinate is subjected to adsorption and analytical separation using a second resin, and a high-purity valuable metal compound is obtained after precipitation.

[0010] Furthermore, the organic extractant includes one or more of P204, P507, P229, P227, C272 and HEOPPA.

[0011] Further, the rare earth element includes: one or more of lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium and yttrium, preferably one or more of lanthanum, cerium, neodymium, praseodymium, gadolinium, terbium and dysprosium;

[0012] The valuable metal elements include: one or more of cobalt, zirconium, molybdenum, nickel, niobium and gallium.

[0013] Further, the first resin includes: one of a strongly acidic cation exchange resin / fiber, a chelating resin, and a leaching resin;

[0014] Preferably, the first resin comprises: strongly acidic cation exchange resin / fiber or leaching resin.

[0015] Furthermore, the single rare earth feed solution is subjected to first resin adsorption and analytical separation, comprising:

[0016] Using inorganic acid analyzers of different concentrations to analyze the rare earth elements adsorbed on the leaching resin in batches;

[0017] Preferably, the inorganic acid analytical agent comprises: hydrochloric acid;

[0018] Wherein, the concentration range of the inorganic acid analytical agent is 0.1mol / L to 3.5mol / L, preferably 0.25mol / L-2.5mol / L, and the elution flow rate of the analytical separation is 0.1cm / min to 1.0cm / min;

[0019] The rare earth element compound is obtained by enriching, collecting and precipitating the effluent liquid in batches.

[0020] Further, the analytical agent used for analytical separation of the first resin includes: one or two of ammonium acetate solution, EDTA salt solution, HEDT salt solution, and citrate solution;

[0021] The concentration range of the analytical agent is 0.01mol / L to 0.35mol / L;

[0022] The pH of the analytical agent is 5.0 to 8.0, preferably 6.5 to 7.0;

[0023] The elution flow rate of the analytical separation is 0.2 cm / min to 3 cm / min, and the elution flow rate can be adjusted and changed in stages;

[0024] The rare earth element compound is obtained by segmentally enriching, collecting and precipitating the effluent liquid.

[0025] Further, the second resin comprises: one of a strongly acidic cation exchange resin / fiber, a chelating resin and a leaching resin;

[0026] Preferably, the second resin comprises: a strongly acidic cation exchange resin / fiber or a chelating resin.

[0027] Furthermore, the analytical agent used for analyzing and separating the second resin adsorbing the valuable metal element includes: hydrochloric acid, EDTA salt solution or HEDTA salt solution.

[0028] Further, the second resin adsorption and analytical separation of the raffinate includes:

[0029] Using inorganic acid analyzers of different concentrations to analyze the valuable metal elements adsorbed on the second resin in batches;

[0030] Preferably, the inorganic acid analytical agent includes: hydrochloric acid or sulfuric acid;

[0031] Wherein, the hydrogen ion concentration in the inorganic acid analytical agent is 0.1 mol / L to 6 mol / L, and the elution flow rate of the analytical separation is 0.1 BV / h to 5 BV / h.

[0032] Further, the concentration range of the EDTA salt solution or the HEDTA salt solution is 0.01 mol / L to 0.35 mol / L;

[0033] The pH of the EDTA salt solution or the HEDTA salt solution is 5 to 8.5, preferably 5.5 to 7.0;

[0034] The elution flow rate of the EDTA salt solution or the HEDTA salt solution is 0.1 BV / h to 5 BV / h;

[0035] The valuable metal element compound is obtained by segmentally enriching, collecting and precipitating the effluent liquid.

[0036] The above technical solution of the embodiment of the present invention has the following beneficial technical effects:

[0037] By efficiently recovering valuable metal elements and rare earth elements from the NdFeB waste leachate and preparing high-purity rare earths, it is helpful to efficiently recover valuable metal elements, while solving the problem of valuable metal elements affecting the purity of rare earth products, obtaining high-purity rare earth compound products, and realizing high-value utilization of rare earth and valuable metal elements, which will produce significant social and economic benefits and have broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The present invention provides a flowchart of a method for recovering rare earth and valuable metals from NdFeB waste leachate. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0040] Please refer to Figure 1 The embodiment of the present invention provides a method for recovering rare earth and valuable metals in a NdFeB waste leachate, comprising the following steps:

[0041] S1: Mixing the NdFeB waste leachate containing rare earth elements and valuable metal elements with an organic extractant, and performing extraction separation and stripping to obtain a single rare earth feed solution and a raffinate, wherein the valuable metal elements exist in the raffinate.

[0042] S2: The single rare earth liquid is subjected to adsorption and analytical separation using the first resin, and a high-purity rare earth compound is obtained after precipitation.

[0043] S3: The raffinate is subjected to adsorption and analytical separation using a second resin, and a high-purity valuable metal compound is obtained after precipitation.

[0044] In a real-time method of an embodiment of the present invention, the organic extractant includes one or more of: P204, P507, P229, P227, C272 and HEOPPA.

[0045] Furthermore, the rare earth elements include: one or more of lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium and yttrium, preferably one or more of lanthanum, cerium, neodymium, praseodymium, gadolinium, terbium and dysprosium; the valuable metal elements include: one or more of nickel, cobalt, zirconium, molybdenum, niobium and gallium.

[0046] In a specific embodiment of the present invention, the first resin includes: one of: strongly acidic cation exchange resin / fiber, chelating resin, and leaching resin; preferably, the first resin includes: strongly acidic cation exchange resin / fiber or leaching resin.

[0047] When strong acidic cation exchange resin / fiber is used for adsorption, the adsorption capacity is 50%-100% of the saturated adsorption capacity of the resin in the adsorption column, while when leaching resin is used for adsorption, the adsorption capacity is 0.5%-60% of the saturated adsorption capacity.

[0048] Optionally, a single rare earth liquid is subjected to a first resin adsorption and analytical separation, comprising: using inorganic acid analytical agents of different concentrations to analyze the rare earth elements adsorbed on the leaching resin in batches; preferably, the inorganic acid analytical agent comprises: hydrochloric acid; wherein the concentration range of the hydrochloric acid analytical agent is 0.1mol / L to 3.5mol / L, preferably 0.25mol / L-2.5mol / L, and the elution flow rate of the analytical separation is 0.1cm / min to 1.0cm / min.

[0049] High-purity rare earth compounds are obtained by enriching, collecting and precipitating the effluent liquid in batches.

[0050] Optionally, the analytical agent used for analytical separation of the first resin includes: one or two of ammonium acetate solution, EDTA salt solution, HEDT salt solution, and citrate solution; the concentration range of the analytical agent is 0.01mol / L to 0.35mol / L; the pH of the analytical agent is 5.0 to 8.0, preferably 6.5 to 7.0; the elution flow rate of analytical separation is 0.2cm / min to 3cm / min. The elution flow rate can be adjusted and changed in stages; high-purity rare earth compounds are obtained by segmented enrichment, collection, and precipitation of the effluent liquid.

[0051] The effluent from the cross-mixing zone of each element is returned for extraction again or a second resin is used for adsorption to extract the valuable metals and separate and purify them.

[0052] The properties of rare earth elements are slightly different and the separation is difficult. Although the NdFeB waste leachate can obtain a single rare earth liquid (98.0% to 99.99%) of a certain purity by solvent extraction, further improving the purity and removing impurities requires the support of a high extraction level, and the acid and alkali consumption is large, the process is long, and the purity is difficult to meet the standard. The present invention adopts one of a strong acid cation exchange resin / fiber, a chelating resin, and an extraction resin, and according to the different adsorption matrices, a specific analytical agent is selected to analyze the rare earth elements loaded on the resin section by section, and the synergistic selectivity of the analytical agent and the resin is used to control the concentration of the analytical agent, pH, flow rate, etc. to control the content of rare earth elements and impurity elements in the effluent at different stages, reduce the mixed intersection area of ​​the main rare earth elements and impurity elements, and realize the efficient purification of rare earth elements; the eluent of the main rare earth element enrichment peak stage (removing the intersection area with the impurity elements) is collected and precipitated to obtain high-purity rare earth compounds. The eluent in the crossover zone has a lower concentration and purity, so it is returned for extraction and separation to obtain a single rare earth element, or a second resin is used to adsorb and extract valuable metals and separate and purify them, thereby improving the overall recovery rate of rare earth and valuable elements.

[0053] In a specific embodiment of the present invention, the second resin comprises: one of a strongly acidic cation exchange resin / fiber, a chelating resin and a leaching resin; preferably, the second resin comprises: a strongly acidic cation exchange resin / fiber or a chelating resin.

[0054] Specifically, the analytical agent used for analyzing and separating the second resin adsorbing the valuable metal elements includes: inorganic acid, EDTA salt solution or HEDTA salt solution.

[0055] Optionally, when the analytical agent is an inorganic acid, the process of performing second resin adsorption and analytical separation on the raffinate may specifically include: using different concentrations of inorganic acid analytical agents to analyze the valuable metal elements adsorbed on the second resin in batches; wherein the concentration of the inorganic acid analytical agent is 0.1 mol / L to 6 mol / L, and the elution flow rate of analytical separation is 0.1 BV / h to 5 BV / h. Preferably, the inorganic acid analytical agent includes: hydrochloric acid or sulfuric acid.

[0056] Optionally, when the analytical agent is an EDTA salt solution or a HEDTA salt solution, the concentration range of the EDTA salt solution or the HEDTA salt solution is 0.01 mol / L to 0.35 mol / L; the pH of the EDTA salt solution or the HEDTA salt solution is 5.0 to 8.5, preferably 5.5 to 7.0; the elution flow rate of the EDTA salt solution or the HEDTA salt solution is 0.1 BV / h to 5 BV / h. The valuable metal element compound is obtained by collecting and precipitating the effluent liquid in sections.

[0057] The effluent from the cross-mixing zone of each element is returned again to be adsorbed by the second resin to extract the valuable metals and separate and purify them.

[0058] The concentration of valuable elements in the raffinate is low. If precipitation or extraction enrichment is used, there is a problem of low recovery efficiency. This technology uses one of the strong acid cation exchange resin / fiber, chelating resin, and leaching resin to adsorb low-concentration valuable elements in the raffinate. It has high adsorption efficiency, large processing capacity, and the resin can be reused after regeneration, and the cost is low. Then, according to the different adsorption matrices, a specific analytical agent is selected to analyze the valuable elements loaded on the resin step by step. The synergistic selectivity of the analytical agent and the resin is used to control the content of different valuable elements in the effluent at different stages by controlling the analytical agent concentration, pH, flow rate, etc., reduce the mixed intersection area between different valuable elements, and achieve efficient separation and purification of valuable elements; the eluents of different valuable element enrichment peak stages (excluding the intersection area with other elements) are collected and precipitated to obtain high-purity valuable element compounds. The eluent in the intersection area has a low concentration and purity of valuable elements, so it is returned to the second resin for adsorption and extraction of valuable metals and separation and purification, thereby improving the overall recovery rate of valuable elements.

[0059] After the above treatment process, the purity of rare earth in single rare earth liquid reaches 98.0% to 99.99%; the purity of rare earth in high-purity rare earth compounds reaches 99.99% to 99.9999%; the purity of valuable metal element compounds reaches 99.0% to 99.99%, and the recovery rate is greater than 98.0%.

[0060] Below, several comparative examples and several embodiments are used to further illustrate the specific implementation of the technical solution of the present invention:

[0061] Comparative Example 1

[0062] The NdFeB waste leachate containing rare earth elements and valuable metal elements is mixed with P507 organic extractant, and subjected to multi-stage extraction separation and stripping to obtain one or more of lanthanum chloride, cerium chloride, neodymium chloride, praseodymium chloride, gadolinium chloride, terbium chloride and dysprosium chloride with a purity of 98% to 99.99%. After oxalic acid precipitation and roasting, one or more of lanthanum oxide, cerium oxide, neodymium oxide, praseodymium oxide, gadolinium oxide, terbium oxide and dysprosium oxide are obtained, and the purity of rare earth oxides is 98% to 99.99%. Most of the valuable metal elements such as nickel, cobalt, zirconium, molybdenum, niobium and gallium enter the raffinate, and a precipitant and / or an acid-base regulator are added to the raffinate to precipitate all the valuable metal elements to obtain a mixed precipitation product, and the recovery rate of the valuable metal elements is between 60% and 95%.

[0063] Example 1

[0064] Specifically, Example 1 is a specific implementation method adopted in step S1 of the recovery method of the present invention.

[0065] The NdFeB waste leachate containing rare earth elements and valuable metal elements is mixed with P507 organic extractant, and after multi-stage extraction, separation and stripping, one or more of lanthanum chloride, cerium chloride, neodymium chloride, praseodymium chloride, gadolinium chloride, terbium chloride and dysprosium chloride with a purity of 98% to 99.99% is obtained, and most of the valuable metal elements such as nickel, cobalt, zirconium, molybdenum, niobium and gallium enter the raffinate.

[0066] Example 2-29

[0067] Specifically, Examples 2-29 are several specific implementations of step S2 in the recovery method of the present invention.

[0068] The above-obtained neodymium chloride liquid is adsorbed by a strong acid cation exchange resin. After the strong acid cation exchange resin / fiber in the adsorption column is saturated with adsorption, the rare earth salt solution remaining in the resin / fiber gap is washed out with pure water until the conductivity is less than 10us / cm. The adsorption column and the separation column are connected in series, and the analytical agent-ammonium acetate solution is used to elute and analyze from the top of the adsorption column. The pH of the ammonium acetate solution is 5.0 and the concentration is 0.02mol / L. The analytical agent flows through the adsorption column and the multi-stage separation column in sequence at a flow rate of 1cm / min. Finally, the rare earth elements flow out in sequence, and the effluent liquid is collected in sections. The middle section effluent (main rare earth element enrichment peak area) is combined and enriched and then precipitated to obtain a high-purity neodymium compound with a purity of more than 99.99%. The operation steps of single rare earth liquids such as lanthanum chloride, cerium chloride, praseodymium chloride, gadolinium chloride, terbium chloride and dysprosium chloride are the same.

[0069] Examples 30-32

[0070] Specifically, Examples 30-32 are several specific implementation methods adopted in step S2 in the recovery method of the present invention.

[0071] The lanthanum chloride / cerium chloride / praseodymium chloride / neodymium chloride liquid obtained above is adsorbed by leaching resin. After the leaching resin in the column reaches the expected adsorption amount, the rare earth salt solution remaining in the resin gap is washed out with pure water until the conductivity is less than 10us / cm. 0.1mol / L hydrochloric acid analytical agent is used to elute and analyze from the top of the column, and the analytical agent flow rate is 1cm / min. The effluent of the main rare earth element enrichment peak stage is enriched, combined and precipitated to obtain a high-purity lanthanum / cerium / praseodymium / neodymium compound with a purity of more than 99.999%. After roasting, lanthanum oxide / cerium oxide / praseodymium oxide / neodymium oxide can be obtained.

[0072] Examples 33-37

[0073] Specifically, Examples 33-37 are several specific implementation methods adopted in step S2 in the recovery method of the present invention.

[0074] One of the gadolinium chloride, terbium chloride or dysprosium chloride solution obtained above is adsorbed by leaching resin. After the leaching resin in the column reaches the expected adsorption amount, the rare earth salt solution remaining in the resin gap is washed out with pure water until the conductivity is less than 10us / cm. Then, 0.8mol / L hydrochloric acid analytical agent is used to elute and analyze from the top of the column, and the analytical agent flow rate is 1cm / min. The effluent at the main rare earth element enrichment peak stage is enriched, combined and precipitated to obtain a high-purity gadolinium / terbium / dysprosium compound with a purity of more than 99.99%, and after roasting, gadolinium oxide / terbium oxide / dysprosium oxide can be obtained.

[0075] Table 1

[0076]

[0077]

[0078] Examples 38-61

[0079] Specifically, Examples 38-61 are several specific implementations of step S3 in the recovery method of the present invention. The raffinate containing one or more valuable metal elements of nickel, cobalt, zirconium, molybdenum, niobium and gallium obtained above is adsorbed by chelating resin. After the adsorption amount of the chelating resin in the adsorption column reaches the expected adsorption amount, the metal ion solution remaining in the resin gap is washed out with pure water to a conductivity of <10us / cm. Then 0.02mol / L HEDTA solution is used as an analytical agent to start analysis from the top of the column, the pH of the analytical agent is 5.0, the flow rate is 0.8BV / h, the effluent is enriched and merged in sections and then precipitated, and one or more of the compounds of nickel, cobalt, zirconium, molybdenum, niobium and gallium with a purity of >99.0% are obtained respectively, and the total recovery rate of the valuable elements in the effluent is >98.3%, as shown in Table 2.

[0080] Table 2

[0081]

[0082]

[0083] The above Table 1 lists several specific implementations of step S2 in the embodiment of the present invention, and the above Table 2 lists several specific implementations of step S3 in the embodiment of the present invention. The specific implementations in Table 1 and Table 2 can be arbitrarily combined.

[0084] The embodiment of the present invention aims to protect a method for recovering rare earths and valuable metals from NdFeB waste leachate, comprising the following steps: mixing the NdFeB waste leachate with an organic extractant and performing extraction separation and stripping to obtain a single rare earth feed liquid and a raffinate, wherein valuable metal elements are present in the raffinate; using a first resin to perform adsorption and analytical separation on the single rare earth feed liquid, and obtaining a high-purity rare earth compound after precipitation; using a second resin to perform adsorption and analytical separation on the raffinate, and obtaining a high-purity valuable metal compound after precipitation. On the one hand, the present invention efficiently recovers low-concentration valuable metal elements from the raffinate and separates them to obtain products, and on the other hand, further purifies the single rare earth product to remove rare earth impurities and non-rare earth impurities to obtain a high-purity rare earth product. The above technical scheme has the following effects:

[0085] By efficiently recovering valuable metal elements and rare earth elements from the NdFeB waste leachate and preparing high-purity rare earths, it is helpful to efficiently recover valuable metal elements, solve the problem of valuable elements affecting the purity of rare earth products, obtain high-purity rare earth oxide products, and realize high-value utilization of rare earth and valuable metal elements, which will produce significant social and economic benefits and have broad application prospects.

[0086] It should be understood that the above specific embodiments of the present invention are only used to illustrate or explain the principles of the present invention, and do not constitute a limitation of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all changes and modifications that fall within the scope and boundaries of the appended claims, or the equivalent forms of such scope and boundaries.

Claims

1. A method for recovering rare earth and valuable metals from NdFeB waste leachate, characterized in that: The steps include: Mixing the NdFeB waste leachate containing rare earth elements and valuable metal elements with an organic extractant and performing extraction, separation and stripping to obtain a single rare earth feed solution and a raffinate, wherein the valuable metal elements exist in the raffinate; Adsorbing and analyzing the single rare earth liquid with a first resin to obtain a high-purity rare earth compound after precipitation; The raffinate is subjected to adsorption and analytical separation using a second resin, and a high-purity valuable metal compound is obtained after precipitation.

2. The method for recovering rare earth and valuable metals from NdFeB waste leachate according to claim 1, characterized in that: The organic extractant includes one or more of P204, P507, P229, P227, C272 and HEOPPA.

3. The method for recovering rare earth and valuable metals from NdFeB waste leachate according to claim 1, characterized in that: The rare earth elements include: one or more of lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium and yttrium, preferably one or more of lanthanum, cerium, neodymium, praseodymium, gadolinium, terbium and dysprosium; The valuable metal elements include one or more of nickel, cobalt, zirconium, molybdenum, niobium and gallium.

4. The method for recovering rare earth and valuable metals from NdFeB waste leachate according to any one of claims 1 to 3, characterized in that: The first resin includes: one of a strongly acidic cation exchange resin / fiber, a chelating resin, and a leaching resin; Preferably, the first resin comprises: strongly acidic cation exchange resin / fiber or leaching resin.

5. The method for recovering rare earth and valuable metals from NdFeB waste leachate according to claim 4, characterized in that: The first resin adsorption and analytical separation of the single rare earth feed solution comprises: Using different concentrations of inorganic acid analyzers to analyze the rare earth elements adsorbed on the leaching resin in batches; Preferably, the inorganic acid analytical agent comprises: hydrochloric acid; Wherein, the concentration range of hydrogen ions in the inorganic acid analytical agent is 0.1mol / L to 3.5mol / L, preferably 0.25mol / L-2.5mol / L, and the elution flow rate of the analytical separation is 0.1cm / min to 1.0cm / min; The rare earth element compound is obtained by enriching, collecting and precipitating the effluent liquid in batches.

6. The method for recovering rare earth and valuable metals from NdFeB waste leachate according to claim 4, characterized in that: The analytical agent used for analyzing and separating the first resin includes: one or two of ammonium acetate solution, EDTA salt solution, HEDT salt solution, and citrate solution; The concentration range of the analytical agent is 0.01mol / L to 0.35mol / L; The pH of the analytical agent is 5.0 to 8.0, preferably 6.5 to 7.0; The elution flow rate of the analytical separation is 0.2 cm / min to 3 cm / min, and the elution flow rate can be adjusted and changed in stages; The rare earth element compound is obtained by segmentally enriching, collecting and precipitating the effluent liquid.

7. The method for recovering rare earth and valuable metals from NdFeB waste leachate according to any one of claims 1 to 3, characterized in that: The second resin comprises: one of a strongly acidic cation exchange resin / fiber, a chelating resin and a leaching resin; Preferably, the second resin comprises: a strongly acidic cation exchange resin / fiber or a chelating resin.

8. The method for recovering rare earth and valuable metals from NdFeB waste leachate according to claim 7, characterized in that: The analytical agent used for analyzing and separating the second resin adsorbing the valuable metal element includes: inorganic acid, EDTA salt solution or HEDTA salt solution.

9. The method for recovering rare earth and valuable metals from NdFeB waste leachate according to claim 8, characterized in that: The step of subjecting the raffinate to second resin adsorption and analytical separation comprises: Using inorganic acid analyzers of different concentrations to analyze the valuable metal elements adsorbed on the second resin in batches; Preferably, the inorganic acid analytical agent includes: hydrochloric acid or sulfuric acid; Wherein, the hydrogen ion concentration in the inorganic acid analytical agent is 0.1 mol / L to 6 mol / L, and the elution flow rate of the analytical separation is 0.1 BV / h to 5 BV / h.

10. The method for recovering rare earth and valuable metals from NdFeB waste leachate according to claim 8, characterized in that: The concentration range of the EDTA salt solution or the HEDTA salt solution is 0.01 mol / L to 0.35 mol / L; The pH of the EDTA salt solution or the HEDTA salt solution is 5.0 to 8.5, preferably 5.5 to 7.0; The elution flow rate of the EDTA salt solution or the HEDTA salt solution is 0.1 BV / h to 5 BV / h; The valuable metal element compound is obtained by segmentally enriching, collecting and precipitating the effluent liquid.

Images