Method for processing phosphorus-containing rare earth ore and use of chlorinated polyolefin material

Abstract

This invention provides a method for processing phosphorus-containing rare earth ores and the use of chlorinated polyolefin materials. [Solution] A method for processing phosphorus-containing rare earth ore includes the steps of (1) roasting a mixture containing a chlorinated polyolefin material and phosphorus-containing rare earth ore at 500 to 900°C to obtain a roasting product, and (2) impregnating the roasting product with water to obtain a rare earth solution. The chlorinated polyolefin material is preferably a polymer formed by polymerization of monomers containing chlorinated olefin or a product containing said polymer.

Description

TECHNICAL FIELD

[0001] The present invention relates to a method for processing phosphorus-containing rare earth ores and the use of chlorinated polyolefin materials.

BACKGROUND ART

[0002] Methods for processing rare earth concentrate ores mainly include acid treatment methods, alkali treatment methods, oxidative roasting methods and chlorination decomposition methods. The acid treatment method and the alkali treatment method have the disadvantage of generating a large amount of wastewater, while the oxidative roasting method has the disadvantages that trivalent cerium is easily oxidized to tetravalent cerium and a large amount of exhaust gas is generated.

[0003] CN116732363A discloses a method for processing phosphorus-containing rare earth ores, which comprises the steps of: roasting a raw material comprising phosphorus-containing rare earth ore and magnesium chloride at 600 to 900°C to obtain a roasted ore, impregnating the roasted ore with an ammonium citrate solution to obtain a phosphorus-containing solution and a rare earth filter residue, adjusting the pH of the phosphorus-containing solution to 7.5 to 10 to obtain ammonium magnesium phosphate, and impregnating the rare earth filter residue with hydrochloric acid to obtain a rare earth chloride solution. This method has the problem that it requires acid impregnation and generates a large amount of waste liquid.

[0004] CN1348997A discloses a method for decomposing rare earth concentrate ores. In this method, calcium oxide and sodium chloride are used as roasting aids, and the addition amount of the aids is 5 to 30 wt%. The roasting temperature is 600 to 950°C, and the roasting time is 10 to 90 minutes. This method achieves a high oxidation rate of cerium element.

[0005] CN117587271A discloses a method for processing mixed rare earth concentrate ores. This method requires the use of chlorine gas as a chlorinating agent and carbon monoxide as a reducing agent. These substances are highly toxic to humans.

[0006] On the other hand, PVC (polyvinyl chloride) is an important material in modern industry and daily life, and is widely used in fields such as construction, electrical and electronics, medical, and packaging. As a result, a large amount of PVC waste is generated. Currently, the main methods of recycling PVC are landfill, incineration, and reuse. Landfill or incineration are prone to causing secondary pollution. Reuse requires dechlorination and catalytic pyrolysis, which is costly. How to effectively utilize waste PVC is an urgent issue that needs to be resolved. [Overview of the project]

[0007] In view of this, one object of the present invention is to provide a method for processing phosphorus-containing rare earth ore. This method is a method for improving the decomposition rate of rare earth concentrate using a chlorinated polyolefin material. Furthermore, this method can reduce the oxidation rate of cerium element. Moreover, this processing method enables the reuse of discarded polymer-containing products and reduces the environmental pollution caused by discarded polymer-containing products. Another object of the present invention is to provide the use of chlorinated polyolefin material.

[0008] The above objective will be achieved by the following technical proposal.

[0009] In one embodiment, the present invention is (1) A step of roasting a mixture containing chlorinated polyolefin material and phosphorus-containing rare earth ore at 500-900°C to obtain a roasting product, (2) A step in which the roasting product is impregnated with water to obtain a rare earth solution, The present invention provides a method for processing phosphorus-containing rare earth ores.

[0010] According to the processing method of the present invention, preferably, the chlorinated polyolefin material is a polymer formed by polymerization of monomers containing a chlorinated olefin, or a product containing said polymer.

[0011] According to the processing method of the present invention, preferably, the chlorinated olefin is represented by formula (I).

[0012] TIFF0007943933000001.tif43170 (where R1, R3, R5, and R7 are each independently selected from alkylene groups or single bonds from C1 to C6, R2, R4, R6, and R8 are each independently selected from H or Cl, and at least one of R2, R4, R6, and R8 is Cl.)

[0013] According to the processing method of the present invention, R1, R3, R5, and R7 are each independently selected from a methylene group, an ethylene group, an n-propylene group, an isopropylene group, an n-butylene group, an isobutylene group, an s-butylene group, a t-butylene group, an n-pentylene group, a methylbutylene group, a dimethylpropylene group, an ethylpropylene group, an n-ethylene group, a methylpentylene group, an ethylbutylene group, a dimethylbutylene group, and a single bond.

[0014] According to the processing method of the present invention, preferably, in the phosphorus-containing rare earth ore, the content of rare earth elements is equal to or greater than 50 wt%, where the content of rare earth elements is calculated using REO.

[0015] The mass ratio of phosphorus-containing rare earth ore to chlorinated polyolefin material is 1:(4~9). The mass of the phosphorus-containing rare earth ore is calculated by converting the rare earth elements contained therein to the corresponding rare earth oxides, and the mass of the chlorinated polyolefin material is calculated based on the polymer contained therein.

[0016] According to the processing method of the present invention, preferably in step (1), the mixture further comprises one or more of the following: water glass, carboxymethylcellulose, bentonite, starch, lignin, alkaline earth metal oxide, and alkaline earth metal hydroxide, with the content of these being 0.1 to 3 wt%.

[0017] According to the processing method of the present invention, preferably in step (2), water and the roasting product are mixed in a volume ratio of (1 to 10):1, and the mixture is impregnated in water at 50 to 90°C for 0.5 to 3 hours.

[0018] In another embodiment, the present invention provides the use of chlorinated polyolefin materials in the decomposition of phosphorus-containing rare earth ores.

[0019] In use according to the present invention, preferably, the chlorinated polyolefin material is a polymer formed by polymerization of monomers containing a chlorinated olefin, or a product containing said polymer.

[0020] According to the use of the present invention, preferably, the phosphorus-containing rare earth ore comprises at least one of monazite or xenotimeite.

[0021] This invention provides a method for chlorinating and decomposing rare earth minerals by roasting phosphorus-containing rare earth ore and a chlorinated polyolefin material under appropriate conditions. The chlorides produced by the chlorinated polyolefin material at high temperatures fix resources such as phosphorus in the phosphorus-containing rare earth ore in a solid form, enabling separation from the rare earth elements. In the method according to this invention, cerium is present in the phosphorus-containing rare earth ore in a trivalent state, reducing the oxidation rate of cerium chlorine. A rare earth solution can be obtained simply by impregnating the roasting product with water, reducing the amount of acid used. The chlorinated polyolefin material according to this invention can be supplied from discarded products containing the polymer, reducing the difficulty of recovering discarded polymer products, decreasing environmental pollution, and lowering the cost of mineral decomposition. [Modes for carrying out the invention]

[0022] The present invention will be further described below based on specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0023] The phosphorus-containing rare earth ore in the present invention refers to a rare earth ore containing elemental phosphorus, which may be monazite ore or xenotime ore, or may be a mixed rare earth ore. The content of monazite ore and / or xenotime ore in the mixed rare earth ore is ≥5wt%, preferably, the content of monazite ore and / or xenotime ore is ≥10wt%. In some embodiments, the content of monazite ore and / or xenotime ore in the mixed rare earth ore is 10 to 40 wt%. The mixed rare earth ore may further comprise bastnaesite in addition to monazite ore and / or xenotime ore. In some embodiments, the phosphorus-containing rare earth ore is a mixed ore of monazite ore and bastnaesite. Usually, the phosphorus-containing rare earth ore is preferably a monazite concentrate ore. The concentrate ore is obtained by processing the raw ore. These processing methods are well known to those skilled in the art and will not be described in detail herein.

[0024] The chlorinated polyolefin material according to the present invention refers to a material in which part or all of the hydrogen atoms of a polyolefin are substituted with chlorine atoms. The chlorinated polyolefin may be obtained by subjecting a polyolefin to a chlorination reaction, or may be obtained by polymerizing a chlorinated olefin monomer and another comonomer, or may be obtained by polymerizing a chlorinated olefin monomer. The chlorinated polyolefin material may be a polymer, or may be a product comprising the above polymer and other additives / auxiliaries.

[0025] The green body of the present invention refers to a preform obtained by pressing a mixture. Before roasting the rare earth ore, it is usually necessary to press the mixture to prepare a green body. The pressing method is well known to those skilled in the art and will not be described in detail herein.

[0026] <Method for processing phosphorus-containing rare earth ore> The method for processing phosphorus-containing rare earth ore according to the present invention comprises a roasting step (1) and a step (2) of impregnating in water. This will be described in detail below.

[0027] Roasting process The present invention involves roasting a mixture containing a chlorinated polyolefin material and phosphorus-containing rare earth ore at 500 to 900°C to obtain a roasted product.

[0028] In some embodiments, the chlorinated polyolefin material is a polymer formed by polymerizing monomers containing chlorinated olefins, or a product comprising the said polymer. The chlorinated olefin is represented by Formula (I).

[0029] TIFF0007943933000002.tif37170(wherein R1, R3, R5 and R7 are each independently selected from a C1~C6 alkylene group or a single bond, R2, R4, R6 and R8 are each independently selected from H and Cl, and at least one of R2, R4, R6 and R8 is Cl.)

[0030] In the present invention, R1, R3, R5 and R7 are each independently selected from a C1~C6 alkylene group or a single bond. Preferably, R1, R3, R5 and R7 are each independently selected from a C1~C3 alkylene group or a single bond. In some embodiments, R1, R3, R5 and R7 are each independently selected from a methylene group, ethylene group, n-propylene group, isopropylene group, n-butylene group, isobutylene group, s-butylene group, t-butylene group, n-pentylene group, methylbutylene group, dimethylpropylene group, ethylpropylene group, n-hexylene group, methylpentylene group, ethylbutylene group, dimethylbutylene group, and a single bond.

[0031] According to one embodiment of the present invention, R1, R3, R5 and R7 are all single bonds. When R1 is a single bond, R2 and C are directly bonded via a single bond. The same applies when R3, R5 and R7 are single bonds.

[0032] In the present invention, R2, R4, R6, and R8 are each independently selected from H and Cl, and at least one of R2, R4, R6, and R8 is Cl. In some embodiments, two of R2, R4, R6, and R8 are Cl. In some other embodiments, one of R2, R4, R6, and R8 is Cl.

[0033] The polymer according to the present invention is formed by the polymerization of monomers represented by formula (I). Specifically, the polymerization is an addition polymerization reaction. The polymer according to the present invention may be one or more selected from polyvinyl chloride, polyvinylidene chloride, and polytetrachloroethylene. According to one embodiment of the present invention, the polymer is polyvinyl chloride.

[0034] The product containing the polymer according to the present invention may be a discarded product. In the product containing the polymer, the content of the polymer is equal to or greater than 30 wt%, preferably equal to or greater than 40 wt%, more preferably equal to or greater than 50 wt%, and most preferably equal to or greater than 70 wt%.

[0035] In some embodiments, the polymer product may further contain polymers that do not contain chlorine elements, such as ester compounds. Examples of ester compounds include dimethyl phthalate, diethyl phthalate, dipropyl phthalate, dibutyl phthalate, dipentyl phthalate, dihexyl phthalate, diheptyl phthalate, dioctyl phthalate, dimethyl o-phenylenediacetate, diethyl o-phenylenediacetate, dipropyl o-phenylenediacetate, dibutyl o-phenylenediacetate, dipentyl o-phenylenediacetate, dihexyl o-phenylenediacetate, and o-phenylenediacetate. This includes, but is not limited to, diheptyl, dioctyl o-phenylenediacetate, dimethyl o-phenylenedipropionate, diethyl o-phenylenedipropionate, dipropyl o-phenylenedipropionate, dibutyl o-phenylenedipropionate, dipentyl o-phenylenedipropionate, dihexyl o-phenylenedipropionate, diheptyl o-phenylenedipropionate, and dioctyl o-phenylenedipropionate. The content of these polymers may be equal to or less than 40 wt%, preferably equal to or less than 20 wt%, and more preferably equal to or less than 10 wt%. For example, 3 to 7 wt%.

[0036] In some embodiments, the polymer product may further contain alkaline earth metal stearates, such as calcium stearate, magnesium stearate, and barium stearate. The content of alkaline earth metal stearate may be equal to or less than 40 wt%, preferably equal to or less than 20 wt%, and more preferably equal to or less than 10 wt%. For example, it may be 3 to 7 wt%.

[0037] In some embodiments, the polymer product may further contain alkaline earth metal carbonates, such as calcium carbonate, magnesium carbonate, and barium carbonate. The content of alkaline earth metal carbonates may be 40 wt% or less, preferably 20 wt% or less, and more preferably 10 wt% or less. For example, it may be 3 to 7 wt%.

[0038] Products containing the polymer include, but are not limited to, tubes, window frames, electrical wires, insulating layers for cables, infusion bags, catheters, surgical instruments, packaging bags, and packaging paper.

[0039] The particle size of the chlorinated polyolefin material may be 200 mesh or less, preferably 300 mesh or less, and more preferably 400 mesh or less.

[0040] In the present invention, the phosphorus-containing rare earth ore comprises at least one of monazite ore and xenotimeite. Preferably, the phosphorus-containing rare earth ore comprises monazite ore. More preferably, the phosphorus-containing rare earth ore comprises monazite ore. In some embodiments, the phosphorus-containing rare earth ore is a mixed rare earth ore. In the mixed rare earth ore, the content of monazite ore and / or xenotimeite is ≥ 5 wt%, preferably ≥ 10 wt%. In some embodiments, the content of monazite ore and / or xenotimeite in the mixed rare earth ore is 10 to 40 wt%. In the mixed rare earth ore, in addition to monazite ore and / or xenotimeite, bastnäsite may also be included. In some embodiments, the phosphorus-containing rare earth ore is a mixed ore of monazite ore and bastnäsite.

[0041] Phosphorus-containing rare earth ore is phosphorus-containing rare earth concentrate. The content of rare earth elements in phosphorus-containing rare earth ore is equal to or greater than 50 wt%, preferably equal to or greater than 60 wt%. The mass of rare earth elements is calculated using REO.

[0042] The particle size of the phosphorus-containing rare earth ore may be 200 mesh or less, preferably 300 mesh or less, and more preferably 400 mesh or less.

[0043] The mass ratio of phosphorus-containing rare earth ore to chlorinated polyolefin material may be 1:(4-9), preferably 1:(5-8), and more preferably 1:(5-6). The mass of the phosphorus-containing rare earth ore is calculated by converting the rare earth elements contained therein to the corresponding rare earth oxides. The mass of the chlorinated polyolefin material is calculated based on the polymer contained therein.

[0044] The mixture according to the present invention may further contain one or more of the following: water glass, carboxymethylcellulose, bentonite, starch, lignin, alkaline earth metal oxide, and alkaline earth metal hydroxide. The alkaline earth metal oxide may be one or more selected from magnesium oxide, calcium oxide, and barium oxide. The alkaline earth metal hydroxide may be one or more selected from magnesium hydroxide, calcium hydroxide, and barium hydroxide. According to one embodiment of the present invention, the mixture further contains calcium hydroxide (slaked lime). In the mixture, the content of these may be 0.1 to 3 wt%, preferably 0.5 to 2.5 wt%, and more preferably 1.5 to 2 wt%. Preferably, the mixture of the present invention consists of a polymer, a phosphorus-containing rare earth ore, and the aforementioned substances.

[0045] In some embodiments, the raw material is prepared into a base and then roasted. The diameter of the base may be 10 to 30 mm, preferably 12 to 25 mm, and more preferably 15 to 20 mm. If the base is spherical, the diameter is the diameter of the sphere. If the base is non-spherical, the diameter is the diameter of the smallest contained sphere. Examples of non-spherical shapes include rectangular prisms, cubes, rods, and irregular shapes.

[0046] The roasting temperature is 500 to 900°C, preferably 600 to 850°C, and more preferably 700 to 800°C.

[0047] The roasting time may be 0.5 to 4 hours, preferably 1 to 3 hours, and more preferably 2 to 2.5 hours.

[0048] The heating rate from the initial temperature to the roasting temperature may be 0.5 to 30°C / min, preferably 0.5 to 20°C / min, and more preferably 1 to 10°C / min.

[0049] Roasting can be performed in a rotary kiln.

[0050] The base material may be dried before roasting. The drying temperature may be 40 to 120°C, preferably 45 to 100°C, and more preferably 50 to 70°C.

[0051] The drying time may be 0.5 to 4 hours, preferably 1 to 3 hours, and more preferably 1 to 2 hours.

[0052] In some embodiments, the process further includes a base material manufacturing step. That is, a chlorinated polyolefin material and a phosphorus-containing rare earth ore are mixed and polished to obtain an abrasive. The abrasive is mixed with other raw materials to obtain a premix. A base material is manufactured from the premix.

[0053] Process of immersion in water This invention provides a rare earth solution by impregnating a roasting product with water. This invention allows obtaining a rare earth solution simply by impregnating the roasting product directly with water. In the processing method according to this invention, the roasting product does not need to be impregnated with acid. The processing method according to this invention does not include a step of impregnation with acid. The processing method according to this invention does not use acid, thus reducing costs.

[0054] The present invention involves impregnating the roasting product with water at 50 to 90°C, preferably at 50 to 85°C, and more preferably at 60 to 80°C.

[0055] The immersion time in water may be 0.5 to 3 hours, preferably 0.8 to 1.8 hours, and more preferably 1 to 1.5 hours.

[0056] The liquid-to-solid ratio may be (1-10):1, preferably (2-8):1, and more preferably (3-6):1. The liquid-to-solid ratio refers to the volume ratio of water to the roasting product.

[0057] The decomposition rate of the phosphorus-containing rare earth ore is equal to or greater than 80 wt%, preferably equal to or greater than 85 wt%.

[0058] The oxidation rate of cerium is ≤1 wt%, preferably ≤0.8 wt%, and more preferably ≤0.7 wt%.

[0059] <Use of polymers> The present invention provides the use of chlorinated polyolefin materials in the decomposition of phosphorus-containing rare earth ores. Preferably, the chlorinated polyolefin material is a polymer formed by polymerization of monomers containing a chlorinated olefin, or a product containing such polymer. The chlorinated olefin may be, for example, represented by formula (I).

[0060] TIFF0007943933000003.tif38170 (where R1, R3, R5, and R7 are each independently selected from alkylene groups or single bonds of C1 to C6, and R2, R4, R6, and R8 are each independently selected from H and Cl, and at least one of R2, R4, R6, and R8 is Cl.)

[0061] In the present invention, R1, R3, R5, and R7 are each independently selected from C1-C6 alkylene groups or single bonds. Preferably, R1, R3, R5, and R7 are each independently selected from C1-C3 alkylene groups or single bonds. In some embodiments, R1, R3, R5, and R7 are each independently selected from methylene groups, ethylene groups, n-propylene groups, isopropylene groups, n-butylene groups, isobutylene groups, s-butylene groups, t-butylene groups, n-pentylene groups, methylbutylene groups, dimethylpropylene groups, ethylpropylene groups, n-ethylene groups, methylpentylene groups, ethylbutylene groups, dimethylbutylene groups, and single bonds.

[0062] According to one embodiment of the present invention, R1, R3, R5, and R7 are all single bonds. When R1 is a single bond, R2 and C are directly bonded by a single bond. The same applies when R3, R5, and R7 are single bonds.

[0063] In the present invention, R2, R4, R6, and R8 are each independently selected from H and Cl, and at least one of R2, R4, R6, and R8 is Cl. In some embodiments, two of R2, R4, R6, and R8 are Cl. In some other embodiments, one of R2, R4, R6, and R8 is Cl.

[0064] The polymer according to the present invention is formed by polymerizing monomers shown in formula (I). The polymerization is specifically an addition polymerization reaction. The polymer of the present invention may be one or more selected from polyvinyl chloride, polyvinylidene chloride, and polytetrachloroethylene. According to one embodiment of the present invention, the polymer is polyvinyl chloride.

[0065] The product containing the polymer according to the present invention may be a discarded product. The content of the polymer in the product containing the polymer is equal to or greater than 30 wt%, preferably equal to or greater than 40 wt%, more preferably equal to or greater than 50 wt%, and most preferably equal to or greater than 70 wt%.

[0066] Products containing the polymer include, but are not limited to, tubes, window frames, electrical wires, insulating layers for cables, infusion bags, catheters, surgical instruments, packaging bags, and packaging paper.

[0067] In the present invention, the phosphorus-containing rare earth ore comprises at least one of monazite ore and xenotimeite. Preferably, the phosphorus-containing rare earth ore comprises monazite ore. More preferably, the phosphorus-containing rare earth ore comprises monazite ore. In some embodiments, the phosphorus-containing rare earth ore may be a mixed rare earth ore. The content of monazite ore and / or xenotimeite in the mixed rare earth ore is ≥ 5 wt%, preferably ≥ 10 wt%. In some embodiments, the content of monazite ore and / or xenotimeite in the mixed rare earth ore is 10 to 40 wt%. In addition to monazite ore and / or xenotimeite, the mixed rare earth ore may further contain bastnäsite. In some embodiments, the phosphorus-containing rare earth ore is a mixed ore of monazite ore and bastnäsite.

[0068] Phosphorus-containing rare earth ore is phosphorus-containing rare earth concentrate. The content of rare earth elements in phosphorus-containing rare earth ore is equal to or greater than 50 wt%, preferably equal to or greater than 60 wt%. The mass of rare earth elements is calculated using REO.

[0069] The mass ratio of phosphorus-containing rare earth ore to chlorinated polyolefin material is 1:(4-9), preferably 1:(5-8), and more preferably 1:(5-6). The mass of the phosphorus-containing rare earth ore is calculated by converting the rare earth elements contained therein to the corresponding rare earth oxides. The mass of the chlorinated polyolefin material is calculated by the polymer contained therein.

[0070] Specifically, the process includes (1) roasting a mixture containing chlorinated polyolefin material and phosphorus-containing rare earth ore at 500-900°C to obtain a roasting product, and (2) impregnating the roasting product with water to obtain a rare earth solution. The details of the roasting process and the water impregnation process are as described above and will not be repeated here.

[0071] The measurement methods for this embodiment and comparative example are described below.

[0072] (1) Decomposition rate of phosphorus-containing rare earth ore: The decomposition rate of phosphorus-containing rare earth ore is calculated using the following formula.

[0073] TIFF0007943933000004.tif22170 (Here, μ represents the decomposition rate of phosphorus-containing rare earth ore, in wt%, C represents the REO-equivalent concentration of rare earth chloride in the rare earth solution, in g / L, V represents the volume of the rare earth solution, in L, ω represents the REO-equivalent content of rare earth compounds in phosphorus-containing rare earth ore, in wt%, and m represents the weight of phosphorus-containing rare earth ore, in g.)

[0074] To measure the concentration of rare earth chlorides in rare earth solutions, the REO-equivalent concentration of rare earth chlorides is measured by inductively coupled plasma mass spectrometry.

[0075] To measure the content of rare earth compounds in phosphorus-containing rare earth ores, the REO-equivalent content of rare earth compounds in phosphorus-containing rare earth ores is measured by inductively coupled plasma atomic emission spectrometry.

[0076] (2) Oxidation rate of cerium The rare earth solution is heated in an electric heating furnace until it is slightly boiling, then allowed to cool to room temperature for 30 minutes, and finally filtered by suction. The Ce(IV) content of the filtrate is analyzed and measured to calculate the cerium oxidation rate.

[0077] The formula for calculating the oxidation state η of cerium is as follows:

[0078] TIFF0007943933000005.tif18170(where, η is the oxidation rate of cerium, and the unit is %, C Ce4 is the REO-equivalent concentration of cerium(IV) compounds in the filtrate, in units of g / L, V is the volume of the filtrate, in units of L, ω is the REO-equivalent content of rare earth compounds in the monazite concentrate, in units of wt%, m is the mass of the monazite concentrate, in units of g, and δ Ce This represents the ratio of cerium element to the total rare earth elements in monazite concentrate, expressed as a rare earth oxide, and the unit is wt%.

[0079] The raw materials for the examples and comparative examples are described below.

[0080] Waste polyvinyl chloride tubes: Polyvinyl chloride content 80 wt%, dioctyl phthalate (DOP) 5 wt%, calcium stearate 5 wt%, calcium carbonate 6 wt%.

[0081] Example 1 After crushing 200g of waste polyvinyl chloride tubing, the resulting material was uniformly mixed with 50g of monazite concentrate (REO content 60.3wt%) and polished to a mesh size of 400 or less to obtain polished material. The polished material was mixed with 5g of slaked lime to obtain a premix.

[0082] The premix was prepared into a spherical base with a diameter of 15 mm. The spherical base was dried at 50°C for 1 hour to form the roasting mixture. This was placed in a rotary kiln and heated to 800°C at a heating rate of 2°C / min, and roasted at 800°C for 2 hours to obtain the roasted product.

[0083] Water and the roasting product were mixed in a volume ratio of 4:1 and impregnated in water at 50°C for 1.5 hours to obtain a rare earth solution. The concentration of rare earth chlorides and the oxidation rate of cerium in the rare earth solution were measured using the method described above. The calculation results are shown in Table 1.

[0084] Example 2 After crushing 200g of waste polyvinyl chloride tubing, the resulting material was uniformly mixed with 30g of monazite concentrate (REO content 67.1wt%) and polished to a mesh size of 400 or less to obtain polished material. The polished material was mixed with 4g of slaked lime to obtain a premix.

[0085] The premix was prepared into a spherical base with a diameter of 15 mm. The spherical base was dried at 50°C for 1 hour to form the roasting mixture. This was placed in a rotary kiln and heated to 700°C at a heating rate of 2°C / min, and roasted at 700°C for 2 hours to obtain the roasted product.

[0086] Water and the roasting product were mixed in a volume ratio of 4:1 and impregnated in water at 50°C for 1.5 hours to obtain a rare earth solution. The concentration of rare earth chlorides and the oxidation rate of cerium in the rare earth solution were measured using the method described above. The calculation results are shown in Table 1.

[0087] Example 3 After crushing 200g of waste polyvinyl chloride tubing, the resulting material was uniformly mixed with 40g of monazite concentrate (REO content 53.1wt%) and polished to a mesh size of 400 or less to obtain polished material. The polished material was mixed with 5g of slaked lime to obtain a premix.

[0088] The premix was prepared on a spherical base with a diameter of 20 mm. The spherical base was dried at 50°C for 1 hour to form the roasting mixture. This was placed in a rotary kiln and heated to 800°C at a heating rate of 2°C / min, and roasted at 800°C for 2.5 hours to obtain the roasted product.

[0089] Water and the roasting product were mixed in a volume ratio of 4:1 and impregnated in water at 70°C for 2.5 hours to obtain a rare earth solution. The concentration of rare earth chlorides and the oxidation rate of cerium in the rare earth solution were measured using the method described above. The calculation results are shown in Table 1.

[0090] Example 4 After crushing 200g of waste polyvinyl chloride tubing, the resulting material was uniformly mixed with 30g of monazite concentrate (REO content 67.1wt%) and polished to a mesh size of 400 or less to obtain polished material. The polished material was mixed with 3.5g of slaked lime to obtain a premix.

[0091] The premix was prepared on a spherical base with a diameter of 20 mm. The spherical base was dried at 50°C for 1 hour to form the roasting mixture. This was placed in a rotary kiln and heated to 800°C at a heating rate of 2°C / min, and roasted at 800°C for 2 hours to obtain the roasted product.

[0092] Water and the roasting product were mixed in a volume ratio of 4:1 and impregnated in water at 60°C for 2.0 hours to obtain a rare earth solution. The concentration of rare earth chlorides and the oxidation rate of cerium in the rare earth solution were measured using the method described above. The calculation results are shown in Table 1.

[0093] Example 5 After crushing 200g of waste polyvinyl chloride tubing, the resulting material was uniformly mixed with 40g of monazite concentrate (REO content 53.1wt%) and polished to a mesh size of 400 or less to obtain polished material. The polished material was mixed with 5g of slaked lime to obtain a premix.

[0094] The premix was prepared into a spherical base with a diameter of 15 mm. The spherical base was dried at 70°C for 2 hours to form the roasting mixture. This was placed in a rotary kiln and heated to 700°C at a heating rate of 2°C / min, and roasted at 700°C for 2.5 hours to obtain the roasted product.

[0095] Water and the roasting product were mixed in a volume ratio of 4:1 and impregnated in water at 90°C for 1.0 hour to obtain a rare earth solution. The concentration of rare earth chlorides and the oxidation rate of cerium in the rare earth solution were measured using the method described above. The calculation results are shown in Table 1.

[0096] Comparative Example 1 200g of polypropylene was crushed, and the resulting material was uniformly mixed with 50g of monazite concentrate (REO content 60.3wt%). The mixture was polished to a mesh size of 400 or less to obtain polished material. The polished material was mixed with 5g of slaked lime to obtain a premix.

[0097] The premix was prepared into a spherical base with a diameter of 15 mm. The spherical base was dried at 50°C for 1 hour to form the roasting mixture. This was placed in a rotary kiln and heated to 800°C at a heating rate of 2°C / min, and roasted at 800°C for 2 hours to obtain the roasted product.

[0098] Water and the roasting product were mixed in a volume ratio of 4:1 and impregnated in water at 50°C for 1.5 hours to obtain a rare earth solution. The concentration of rare earth chlorides and the oxidation rate of cerium in the rare earth solution were measured using the method described above. The calculation results are shown in Table 1.

[0099] TIFF0007943933000006.tif215170

[0100] In Comparative Example 1, polypropylene and monazite concentrate were roasted together. The monazite concentrate hardly decomposed, and the solution obtained by impregnating the roasting product with water contained almost no rare earth elements. From Examples 1 to 5, it can be seen that parameters such as the amount of raw materials used, the diameter of the substrate, and the temperature and time of each process affect the decomposition rate of the monazite concentrate and the oxidation rate of cerium.

[0101] The present invention is not limited to the embodiments described above, and any modifications, improvements, or substitutions conceived by those skilled in the art, without departing from the spirit of the invention, fall within the technical scope of the present invention.

Claims

1. (1) A step of roasting a mixture containing a chlorinated polyolefin material, which is a polymer formed by polymerization of monomers containing chlorinated olefins or a product containing said polymer, at 500 to 900°C to obtain a roasting product, Step (2) involves impregnating the roasting product with water to obtain a rare earth solution, The chlorinated olefin is represented by formula (I), (I) (where R １ , R ３ , R ５ and R ７ are each independently selected from a C1-C6 alkylene group or a single bond, R ２ , R ４ , R ６ and R ８ are each independently selected from H or Cl, and at least one of R ２ , R ４ , R ６ and R ８ is Cl) The content of rare earth elements in the phosphorus-containing rare earth ore is equal to or greater than 50 wt%, where the content of rare earth elements is calculated using REO. A method for processing phosphorus-containing rare earth ore, characterized in that the mass ratio of phosphorus-containing rare earth ore to chlorinated polyolefin material is 1:6.63, 1:9.42, or 1:9.94, the mass of the phosphorus-containing rare earth ore is calculated by converting the rare earth elements contained therein to the corresponding rare earth oxides, and the mass of the chlorinated polyolefin material is calculated by the polymer contained therein.

2. R １ , R ３ , R ５ and R ７ The processing method according to claim 1, characterized in that each of the following is independently selected from a methylene group, an ethylene group, an n-propylene group, an isopropylene group, an n-butylene group, an isobutylene group, an s-butylene group, a t-butylene group, an n-pentylene group, a methylbutylene group, a dimethylpropylene group, an ethylpropylene group, an n-ethylene group, a methylpentylene group, an ethylbutylene group, a dimethylbutylene group, and a single bond.

3. The treatment method according to claim 1, characterized in that in step (1), the mixture further comprises one or more of water glass, carboxymethylcellulose, bentonite, starch, lignin, alkaline earth metal oxides, and alkaline earth metal hydroxides, the content of which is 0.1 to 3 wt%.

4. The processing method according to claim 1, characterized in that in step (2), water and the roasting product are mixed in a volume ratio of (1 to 10):1, and the product is impregnated in water at 50 to 90°C for 0.5 to 3 hours.

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