Treatment method of phosphorus-containing rare earth ore and application of chlorinated polyolefin material

Abstract

The invention discloses a treatment method of phosphorus-containing rare earth ore and application of a chlorinated polyolefin material. The treatment method comprises the following steps: (1) roasting a mixture comprising a chlorinated polyolefin material and phosphorus-containing rare earth ore at 500-900 DEG C to obtain a roasted product; and (2) the roasted product is soaked in water, and a rare earth solution is obtained. The treatment method has a relatively high decomposition rate.

Description

Technical Field

[0001] The invention relates to a method for treating phosphorus-containing rare earth ore and application of chlorinated polyolefin materials. Background Art

[0002] On the one hand, the treatment methods of rare earth concentrate mainly include acid method, alkali method, oxidative roasting method and chlorination decomposition method. The acid method and subtraction method produce more wastewater, and the oxidative roasting method easily oxidizes trivalent cerium to tetravalent cerium and produces more waste gas.

[0003] CN116732363A discloses a method for treating phosphorus-containing rare earth ore, comprising the following steps: roasting raw materials including phosphorus-containing rare earth ore and magnesium chloride at 600-900°C to obtain roasted ore; leaching the roasted ore with ammonium citrate solution to obtain a phosphorus-containing solution and rare earth filter residue; adjusting the pH of the phosphorus-containing solution to 7.5-10 to obtain magnesium ammonium phosphate; leaching the rare earth filter residue with hydrochloric acid to obtain a rare earth chloride solution. This method requires acid leaching, and the waste liquid output is relatively large.

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

[0005] CN117587271A discloses a method for treating mixed rare earth concentrates, which uses chlorine as a chlorinating agent and requires carbon monoxide as a reducing agent, and these substances are highly toxic to the human body.

[0006] On the other hand, PVC (polyvinyl chloride) is an important material in modern industry and daily life. It is widely used in the construction industry, electrical and electronic industry, medical industry, packaging industry, etc. Therefore, a large amount of PVC waste is generated. At present, the main ways to recycle PVC are landfill, incineration and recycling. Landfill or incineration is prone to cause secondary pollution. Recycling requires dechlorination and catalytic pyrolysis, which is expensive. How to effectively utilize waste PVC has become a problem to be solved. Summary of the invention

[0007] In view of this, one object of the present invention is to provide a method for treating phosphorus-containing rare earth ores. The method utilizes chlorinated polyolefin materials to improve the decomposition rate of rare earth concentrates. Furthermore, the method can reduce the oxidation rate of cerium. Furthermore, the treatment method can reuse waste polymer-containing products and reduce the pollution of waste polymer-containing products to the environment. Another object of the present invention is to provide a use of chlorinated polyolefin materials.

[0008] The above purpose is achieved through the following technical solutions.

[0009] In one aspect, the present invention provides a method for treating a phosphorus-containing rare earth ore, comprising the following steps:

[0010] (1) roasting a mixture including a chlorinated polyolefin material and a phosphorus-containing rare earth ore at 500 to 900° C. to obtain a roasted product;

[0011] (2) Soaking the calcined product in water to obtain a rare earth solution.

[0012] According to the treatment method of the present invention, preferably, the chlorinated polyolefin material is a polymer formed by polymerizing monomers including chlorinated olefins or a product containing the polymer.

[0013] According to the treatment method of the present invention, preferably, the chlorinated olefin is as shown in formula (I):

[0014]

[0015] Among them, R 1 , R 3 , R 5 and R 7 are independently selected from C1-C6 alkylene or a single bond, R 2 , R 4 , R 6 and R 8 are independently selected from H or Cl, and R 2 , R 4 , R 6 and R 8 At least one of them is Cl.

[0016] According to the treatment method of the present invention, preferably, R 1 , R 3 , R 5 and R 7 Each of the following groups is independently selected from methylene, ethylene, n-propylene, isopropylene, n-butylene, isobutylene, sec-butylene, tert-butylene, n-pentylene, methylbutylene, dimethylpropylene, ethylpropylene, n-ethylene, methylpentylene, ethylbutylene, dimethylbutylene, and a single bond.

[0017] According to the treatment method of the present invention, preferably, the content of rare earth elements in the phosphorus-containing rare earth ore is greater than or equal to 50wt%, wherein the content of rare earth elements is calculated as REO;

[0018] The mass ratio of the phosphorus-containing rare earth ore to the 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 into the mass of the rare earth oxide corresponding to the rare earth elements, and the mass of the chlorinated polyolefin material is calculated by the polymer contained therein.

[0019] According to the treatment method of the present invention, preferably, in step (1), the mixture further contains one or more of the following substances: water glass, carboxymethyl cellulose, bentonite, starch, lignin, alkaline earth metal oxides, alkaline earth metal hydroxides; the content of the above substances is 0.1 to 3 wt%.

[0020] According to the treatment method of the present invention, preferably, in step (2), water and the roasting product are mixed in a volume ratio of (1-10):1, and immersed in water at 50-90°C for 0.5-3h.

[0021] In another aspect, the present invention provides a use of a chlorinated polyolefin material in decomposing phosphorus-containing rare earth ores.

[0022] According to the use of the present invention, preferably, the chlorinated polyolefin material is a polymer formed by polymerizing monomers including chlorinated olefins or a product containing the polymer.

[0023] According to the use of the present invention, preferably, the phosphorus-containing rare earth ore contains at least one of monazite or xenotime.

[0024] The present invention roasts the phosphorus-containing rare earth ore and the chlorinated polyolefin material under appropriate conditions to chlorinate and decompose the rare earth ore. The chloride salt produced by the chlorinated polyolefin material under high temperature conditions fixes the phosphorus and other resources in the phosphorus-containing rare earth ore in a solid form, thereby achieving separation from the rare earth. The method of the present invention enables the cerium element in the phosphorus-containing rare earth ore to exist in a trivalent form, thereby reducing the oxidation rate of the cerium element. The present invention obtains a rare earth solution by soaking the roasted product in water, thereby reducing the consumption of acid. The chlorinated polyolefin material of the present invention can be provided by waste products containing the polymer, thereby reducing the difficulty of recycling waste polymer products and the pollution to the environment, and also reducing the cost of mineral decomposition. DETAILED DESCRIPTION

[0025] The present invention is further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto.

[0026] The phosphorus-containing rare earth ore of the present invention refers to a rare earth ore containing phosphorus, which may be monazite or xenotime, or a mixed rare earth ore. The content of monazite and / or xenotime in the mixed rare earth ore is ≥5wt%; preferably, the content of monazite and / or xenotime is ≥10wt%. In some embodiments, the content of monazite and / or xenotime in the mixed rare earth ore is 10-40wt%. In addition to monazite and / or xenotime, the mixed rare earth ore may also contain fluorocarbon cerium. In some embodiments, the phosphorus-containing rare earth ore is a mixture of monazite and fluorocarbon cerium. Generally, the phosphorus-containing rare earth ore is preferably monazite concentrate. Concentrate refers to the product obtained by processing the original ore. These treatment methods are well known in the art and will not be repeated here.

[0027] The chlorinated polyolefin material of the present invention refers to a material in which part or all of the hydrogen elements of a polyolefin are replaced by chlorine elements. The chlorinated polyolefin can be obtained by chlorination of a polyolefin, or by polymerization of a chlorinated olefin monomer and other comonomers, or by polymerization of a chlorinated olefin monomer. The chlorinated polyolefin material can be a polymer, or a product containing the above polymer and other auxiliary materials / auxiliaries.

[0028] The green body of the present invention refers to a preform formed by pressing the mixture. Before the rare earth ore is roasted, it is usually necessary to press the mixture into a green body. The pressing method is well known in the art and will not be described here.

[0029] <Processing Methods for Phosphorus-Containing Rare Earth Ores>

[0030] The method for treating phosphorus-containing rare earth ore of the present invention comprises the following steps: (1) a roasting step; and (2) a water leaching step, which will be described in detail below.

[0031] Roasting steps

[0032] The invention roasts a mixture of chlorinated polyolefin material and phosphorus-containing rare earth ore at 500-900 DEG C to obtain a roasted product.

[0033] In certain embodiments, the chlorinated polyolefin material is a polymer formed by polymerization of monomers including chlorinated olefins or a product containing the polymer. The chlorinated olefin is shown in formula (I).

[0034]

[0035] In formula (I), R 1 , R 3 , R 5 and R 7 are independently selected from C1-C6 alkylene or a single bond, R 2 , R 4 , R 6 and R 8 are independently selected from H, Cl, and R 2 , R 4 , R 6 and R 8 At least one of them is Cl.

[0036] In the present invention, R 1 , R 3 , R 5 and R 7 are independently selected from C1-C6 alkylene or a single bond. 1 , R 3 , R 5and R 7 are independently selected from C1 to C3 alkylene or a single bond. 1 , R 3 , R 5 and R 7 Each of the following groups is independently selected from methylene, ethylene, n-propylene, isopropylene, n-butylene, isobutylene, sec-butylene, tert-butylene, n-pentylene, methylbutylene, dimethylpropylene, ethylpropylene, n-ethylene, methylpentylene, ethylbutylene, dimethylbutylene, and a single bond.

[0037] According to one embodiment of the present invention, R 1 , R 3 , R 5 and R 7 All are single bonds. 1 When it is a single bond, R 2 It is directly connected to C by a single bond. 3 , R 5 and R 7 The same applies to single bonds.

[0038] In the present invention, R 2 , R 4 , R 6 and R 8 are independently selected from H, Cl, and R 2 , R 4 , R 6 and R 8 In certain embodiments, at least one of R 2 , R 4 , R 6 and R 8 In some other embodiments, R 2 , R 4 , R 6 and R 8 One of them is Cl.

[0039] The polymer of the present invention is formed by polymerization of the monomer represented by formula (I). The polymerization is specifically a polyaddition reaction. The polymer of the present invention can be selected from one or more of polyvinyl chloride, polyvinylidene chloride, and polytetrachloroethylene. According to one embodiment of the present invention, the polymer is polyvinyl chloride.

[0040] The product containing the polymer of the present invention can be a waste product. In the product containing the polymer, the content of the polymer is greater than or equal to 30wt%; preferably, greater than or equal to 40wt%; more preferably, greater than or equal to 50wt%; most preferably, greater than or equal to 70wt%.

[0041] In some embodiments, the polymer product may also contain a polymer that does not contain chlorine, such as an ester compound. Ester compounds include, but are not limited to, dimethyl phthalate, diethyl phthalate, dipropyl phthalate, dibutyl phthalate, dipentyl phthalate, dihexyl phthalate, diheptyl phthalate, dioctyl phthalate, dimethyl phthalate, diethyl phthalate, dipropyl phthalate, dibutyl phthalate, dipentyl phthalate, dihexyl phthalate, diheptyl phthalate, dioctyl phthalate, dimethyl phthalate, diethyl phthalate, dipropyl phthalate, dibutyl phthalate, dipentyl phthalate, dihexyl phthalate, diheptyl phthalate, dioctyl phthalate, dimethyl phthalate, diethyl phthalate, dipropyl phthalate, dibutyl phthalate, dipentyl phthalate, dihexyl phthalate, diheptyl phthalate, and dioctyl phthalate. The content of these polymers may be less than or equal to 40 wt %, preferably less than or equal to 20 wt %, more preferably less than or equal to 10 wt %, for example, 3 to 7 wt %.

[0042] In some embodiments, the polymer product may also contain alkaline earth metal stearate, such as calcium stearate, magnesium stearate, barium stearate, etc. The content of the alkaline earth metal stearate may be less than or equal to 40 wt %; preferably, less than or equal to 20 wt %; more preferably, less than or equal to 10 wt %, such as 3 to 7 wt %.

[0043] In some embodiments, the polymer product may also contain alkaline earth metal carbonates, such as calcium carbonate, magnesium carbonate, barium carbonate, etc. The content of the alkaline earth metal carbonate may be less than or equal to 40 wt %; preferably, less than or equal to 20 wt %; more preferably, less than or equal to 10 wt %, such as 3 to 7 wt %.

[0044] Products containing the polymer include but are not limited to pipes, window frames, wires, cable insulation layers, infusion bags, catheters, surgical instruments, packaging bags, wrapping paper, etc.

[0045] The particle size of the chlorinated polyolefin material may be below 200 meshes, preferably below 300 meshes, and more preferably below 400 meshes.

[0046] In the present invention, in the present invention, the phosphorus-containing rare earth ore contains at least one of monazite and xenotime. Preferably, the phosphorus-containing rare earth ore contains monazite. More preferably, the phosphorus-containing rare earth ore is monazite. In some embodiments, the phosphorus-containing rare earth ore may be a mixed rare earth ore. In the mixed rare earth ore, the content of monazite and / or xenotime is ≥5wt%; preferably, the content of monazite and / or xenotime is ≥10wt%. In some embodiments, in the mixed rare earth ore, the content of monazite and / or xenotime is 10 to 40wt%. In addition to monazite and / or xenotime, the mixed rare earth ore may also contain fluorocarbon cerium. In some embodiments, the phosphorus-containing rare earth ore is a mixture of monazite and fluorocarbon cerium.

[0047] The phosphorus-containing rare earth ore is a phosphorus-containing rare earth concentrate. The content of rare earth elements in the phosphorus-containing rare earth ore is greater than or equal to 50wt%; preferably, the content of rare earth elements in the phosphorus-containing rare earth ore is greater than or equal to 60wt%. The mass of the rare earth elements is calculated as REO.

[0048] The particle size of the phosphorus-containing rare earth ore may be less than 200 meshes, preferably less than 300 meshes, and more preferably less than 400 meshes.

[0049] The mass ratio of the phosphorus-containing rare earth ore to the chlorinated polyolefin material can be 1:(4-9); preferably 1:(5-8); more preferably 1:(5-6). The mass of the phosphorus-containing rare earth ore is calculated by the mass of the rare earth oxide corresponding to the rare earth element converted into the rare earth element. The mass of the chlorinated polyolefin material is calculated by the mass of the polymer contained in it.

[0050] The mixture of the present invention may also contain one or more of water glass, carboxymethyl cellulose, bentonite, starch, lignin, alkaline earth metal oxides, and alkaline earth metal hydroxides. Alkaline earth metal oxides may be selected from one or more of magnesium oxide, calcium oxide, and barium oxide. Alkaline earth metal hydroxides may be selected from one or more of magnesium hydroxide, calcium hydroxide, and barium hydroxide. According to one embodiment of the present invention, the mixture also contains calcium hydroxide (slaked lime). In the mixture, the content of the above substances may be 0.1 to 3 wt%; preferably 0.5 to 2.5 wt%; 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 above substances.

[0051] In some embodiments, the raw material may be made into a green body and then calcined. The diameter of the green body may be 10 to 30 mm, preferably 12 to 25 mm, and more preferably 15 to 20 mm. When the green body is spherical, the above diameter is the diameter of the sphere. When the green body is a non-spherical body, the diameter is the diameter of the smallest surrounding sphere. Non-spherical bodies include, for example, rectangular parallelepiped, cube, rod, and irregular shapes.

[0052] The calcination temperature is 500 to 900°C, preferably 600 to 850°C, and more preferably 700 to 800°C.

[0053] The calcination time may be 0.5 to 4 hours, preferably 1 to 3 hours, and more preferably 2 to 2.5 hours.

[0054] The heating rate from the initial temperature to the calcination temperature may be 0.5 to 30° C. / min, preferably 0.5 to 20° C. / min, and more preferably 1 to 10° C. / min.

[0055] Calcination can be carried out in a rotary kiln.

[0056] The green body may be dried before calcining at a temperature of 40 to 120°C, preferably 45 to 100°C, and more preferably 50 to 70°C.

[0057] The drying time may be 0.5 to 4 hours, preferably 1 to 3 hours, and more preferably 1 to 2 hours.

[0058] In some embodiments, the method further comprises the step of preparing a green body: mixing the chlorinated polyolefin material with the phosphorus-containing rare earth ore, and then grinding to obtain a ground product, mixing the ground product with other raw materials to obtain a premix, and manufacturing the premix into a green body.

[0059] Steps of flooding

[0060] The present invention soaks the roasted product in water to obtain a rare earth solution. The present invention directly soaks the roasted product in water to obtain a rare earth solution. In the treatment method of the present invention, the roasted product does not need to be acid-leached. The treatment method of the present invention does not include the step of acid-leaching. The treatment method of the present invention does not need to use acid, thereby reducing costs.

[0061] In the present invention, the roasted product is immersed in water at 50-90°C; preferably, the roasted product is immersed in water at 50-85°C; more preferably, the roasted product is immersed in water at 60-80°C.

[0062] The water immersion time may be 0.5 to 3 hours, preferably 0.8 to 1.8 hours, and more preferably 1 to 1.5 hours.

[0063] 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 calcined product.

[0064] The decomposition rate of the phosphorus-containing rare earth ore is greater than or equal to 80wt%; preferably, greater than or equal to 85wt%.

[0065] The oxidation rate of the cerium element is ≤1wt%; preferably, the oxidation rate of the cerium element is ≤0.8wt%; more preferably, the oxidation rate of the cerium element is ≤0.7wt%.

[0066] <Uses of polymers>

[0067] The present invention provides a use of a chlorinated polyolefin material in decomposing phosphorus-containing rare earth ores. Preferably, the chlorinated polyolefin material is a polymer formed by polymerizing monomers including chlorinated olefins or a product containing the polymer. The chlorinated olefin can be as shown in formula (I);

[0068]

[0069] Among them, R 1 , R 3 , R 5 and R 7 are independently selected from C1-C6 alkylene or a single bond, R 2 , R 4 , R 6 and R 8 are independently selected from H, Cl, and R 2 , R 4 , R 6 and R 8 At least one of them is Cl.

[0070] In the present invention, R 1 , R 3 , R 5 and R 7 are independently selected from C1-C6 alkylene or a single bond. 1 , R 3 , R 5 and R 7 are independently selected from C1 to C3 alkylene or a single bond. 1 , R 3 , R 5 and R 7 Each of the following groups is independently selected from methylene, ethylene, n-propylene, isopropylene, n-butylene, isobutylene, sec-butylene, tert-butylene, n-pentylene, methylbutylene, dimethylpropylene, ethylpropylene, n-ethylene, methylpentylene, ethylbutylene, dimethylbutylene, and a single bond.

[0071] According to one embodiment of the present invention, R 1 , R 3 , R 5 and R 7 All are single bonds. 1 When it is a single bond, R 2 It is directly connected to C by a single bond. 3 , R 5 and R 7 The same applies to single bonds.

[0072] In the present invention, R 2 , R 4 , R 6 and R 8 are independently selected from H, Cl, and R 2 , R 4 , R 6 and R 8 In certain embodiments, at least one of R 2 , R 4 , R 6 and R 8 In some other embodiments, R 2 , R 4 , R 6 and R 8 One of them is Cl.

[0073] The polymer of the present invention is formed by polymerization of the monomer represented by formula (I). The polymerization is specifically a polyaddition reaction. The polymer of the present invention can be selected from one or more of polyvinyl chloride, polyvinylidene chloride, and polytetrachloroethylene. According to one embodiment of the present invention, the polymer is polyvinyl chloride.

[0074] The product containing the polymer of the present invention can be a waste product. In the product containing the polymer, the content of the polymer is greater than or equal to 30wt%; preferably, greater than or equal to 40wt%; more preferably, greater than or equal to 50wt%; most preferably, greater than or equal to 70wt%.

[0075] Products containing the polymer include but are not limited to pipes, window frames, wires, cable insulation layers, infusion bags, catheters, surgical instruments, packaging bags, wrapping paper, etc.

[0076] In the present invention, the phosphorus-containing rare earth ore contains at least one of monazite and xenotime. Preferably, the phosphorus-containing rare earth ore contains monazite. More preferably, the phosphorus-containing rare earth ore is monazite. In some embodiments, the phosphorus-containing rare earth ore may be a mixed rare earth ore. In the mixed rare earth ore, the content of monazite and / or xenotime is ≥5wt%; preferably, the content of monazite and / or xenotime is ≥10wt%. In some embodiments, in the mixed rare earth ore, the content of monazite and / or xenotime is 10 to 40wt%. In addition to and / or xenotime, the mixed rare earth ore may also contain fluorocarbon cerium. In some embodiments, the phosphorus-containing rare earth ore is a mixture of monazite and fluorocarbon cerium.

[0077] The phosphorus-containing rare earth ore is a phosphorus-containing rare earth concentrate. The content of rare earth elements in the phosphorus-containing rare earth ore is greater than or equal to 50wt%; preferably, the content of rare earth elements in the phosphorus-containing rare earth ore is greater than or equal to 60wt%. The mass of the rare earth elements is calculated as REO.

[0078] The mass ratio of the phosphorus-containing rare earth ore to the chlorinated polyolefin material is 1:(4-9); preferably 1:(5-8); more preferably 1:(5-6). The mass of the phosphorus-containing rare earth ore is calculated by converting the rare earth element contained therein into the mass of the rare earth oxide corresponding to the rare earth element. The mass of the chlorinated polyolefin material is calculated by the mass of the polymer contained therein.

[0079] Specifically, the method comprises the following steps: (1) roasting a mixture of a chlorinated polyolefin material and a phosphorus-containing rare earth ore at 500-900° C. to obtain a roasted product; (2) soaking the roasted product in water to obtain a rare earth solution. The roasting and soaking steps are as described above and will not be repeated here.

[0080] The test methods of this embodiment and the comparative example are described below:

[0081] (1) Decomposition rate of phosphorus-containing rare earth minerals:

[0082] The decomposition rate of phosphorus-containing rare earth ore is calculated using the following formula:

[0083]

[0084] Among them, μ represents the decomposition rate of the phosphorus-containing rare earth ore, in wt%; C represents the concentration of rare earth chloride in the rare earth solution as REO, in g / L; V represents the volume of the rare earth solution, in L; ω represents the content of rare earth compounds in the phosphorus-containing rare earth ore as REO, in wt%; m represents the weight of the phosphorus-containing rare earth ore, in g.

[0085] The concentration of rare earth chloride in the rare earth solution is measured by the following method: the concentration of rare earth chloride calculated as REO is determined by inductively coupled plasma mass spectrometry.

[0086] The content of rare earth compounds in the phosphorus-containing rare earth ore is tested by the following method: the content of rare earth compounds in the phosphorus-containing rare earth ore in terms of REO is determined by inductively coupled plasma emission spectrometry.

[0087] (2) Oxidation rate of cerium:

[0088] The rare earth solution was heated to a slight boil in an electric furnace and kept for 30 minutes, and then filtered after the rare earth solution was cooled to room temperature. The content of Ce(IV) in the filtrate was analyzed and determined, and the cerium oxidation rate was calculated.

[0089] The calculation formula of cerium oxidation rate η is as follows:

[0090]

[0091] Wherein, η is the cerium oxidation rate, unit is %; C Ce4is the concentration of cerium (IV) compounds in the filtrate in terms of REO, in g / L; V is the volume of the filtrate, in L; ω is the content of rare earth compounds in the monazite concentrate in terms of REO, in wt%; m is the mass of the monazite concentrate, in g; δ Ce It is the ratio of cerium element calculated as rare earth oxide to all rare earth elements in monazite concentrate, in wt%.

[0092] The raw materials of the embodiments and comparative examples are introduced below:

[0093] Waste polyvinyl chloride pipes: The polyvinyl chloride content is 80wt%, and it also contains 5wt% dioctyl phthalate (DOP), 5wt% calcium stearate, and 6wt% calcium carbonate.

[0094] Example 1

[0095] 200 g of waste polyvinyl chloride pipes were crushed, and then the obtained product was evenly mixed with 50 g of monazite concentrate (REO content was 60.3 wt%), and ground to less than 400 meshes to obtain a ground product. The ground product was mixed with 5 g of slaked lime to obtain a premix.

[0096] The premix was made into a spherical body with a diameter of 15 mm. The spherical body was dried at 50°C for 1 hour to form a mixture for calcination. The mixture was placed in a rotary kiln, heated to 800°C at a rate of 2°C / min, and calcined at 800°C for 2 hours to obtain a calcined product.

[0097] Water and the calcined product were mixed in a volume ratio of 4:1, and immersed in water at 50°C for 1.5 hours to obtain a rare earth solution. The concentration of rare earth chloride and the oxidation rate of cerium in the rare earth solution were determined by the above test method. The calculation results are shown in Table 1.

[0098] Example 2

[0099] 200 g of waste polyvinyl chloride pipes were crushed, and then the obtained product was mixed evenly with 30 g of monazite concentrate (REO content was 67.1 wt%), and ground to less than 400 meshes to obtain a ground product. The ground product was mixed with 4 g of slaked lime to obtain a premix.

[0100] The premix was made into a spherical body with a diameter of 15 mm. The spherical body was dried at 50°C for 1 hour to form a mixture for calcination. The mixture was placed in a rotary kiln, heated to 700°C at a rate of 2°C / min, and calcined at 700°C for 2 hours to obtain a calcined product.

[0101] Water and the calcined product were mixed in a volume ratio of 4:1, and immersed in water at 50°C for 1.5 hours to obtain a rare earth solution. The concentration of rare earth chloride and the oxidation rate of cerium in the rare earth solution were determined by the above test method. The calculation results are shown in Table 1.

[0102] Example 3

[0103] 200 g of waste polyvinyl chloride pipes were crushed, and then the obtained product was mixed with 40 g of monazite concentrate (REO content of 53.1 wt%), and ground to less than 400 mesh to obtain a ground product. The ground product was mixed with 5 g of slaked lime to obtain a premix.

[0104] The premix was made into a spherical body with a diameter of 20 mm. The spherical body was dried at 50°C for 1 hour to form a mixture for calcination. The mixture was placed in a rotary kiln, heated to 800°C at a rate of 2°C / min, and calcined at 800°C for 2.5 hours to obtain a calcined product.

[0105] Water and the calcined product were mixed in a volume ratio of 4:1, and immersed in water at 70°C for 2.5 hours to obtain a rare earth solution. The concentration of rare earth chloride and the oxidation rate of cerium in the rare earth solution were determined by the above test method. The calculation results are shown in Table 1.

[0106] Example 4

[0107] 200 g of waste polyvinyl chloride pipes were crushed, and then the obtained product was evenly mixed with 30 g of monazite concentrate (REO content was 67.1 wt%), and ground to less than 400 meshes to obtain a ground product. The ground product was mixed with 3.5 g of slaked lime to obtain a premix.

[0108] The premix was made into a spherical body with a diameter of 20 mm. The spherical body was dried at 50°C for 1 hour to form a mixture for calcination. The mixture was placed in a rotary kiln, heated to 800°C at a rate of 2°C / min, and calcined at 800°C for 2 hours to obtain a calcined product.

[0109] Water and the calcined product were mixed in a volume ratio of 4:1, and immersed in water at 60°C for 2.0 hours to obtain a rare earth solution. The concentration of rare earth chloride and the oxidation rate of cerium in the rare earth solution were determined by the above test method. The calculation results are shown in Table 1.

[0110] Example 5

[0111] 200 g of waste polyvinyl chloride pipes were crushed, and then the obtained product was mixed with 40 g of monazite concentrate (REO content of 53.1 wt%), and ground to less than 400 mesh to obtain a ground product. The ground product was mixed with 5 g of slaked lime to obtain a premix.

[0112] The premix was made into a spherical body with a diameter of 15 mm. The spherical body was dried at 70°C for 2 h to form a mixture for calcination. The mixture was placed in a rotary kiln, heated to 700°C at a rate of 2°C / min, and calcined at 700°C for 2.5 h to obtain a calcined product.

[0113] Water and the calcined product were mixed in a volume ratio of 4:1, and immersed in water at 90°C for 1.0h to obtain a rare earth solution. The concentration of rare earth chloride and the oxidation rate of cerium in the rare earth solution were determined by the above test method. The calculation results are shown in Table 1.

[0114] Comparative Example 1

[0115] 200 g of polypropylene was crushed, and then the obtained product was mixed with 50 g of monazite concentrate (REO content was 60.3 wt%). The mixture was ground to less than 400 mesh to obtain a ground product. The ground product was mixed with 5 g of slaked lime to obtain a premix.

[0116] The premix was made into a spherical body with a diameter of 15 mm. The spherical body was dried at 50°C for 1 hour to form a mixture for calcination. The mixture was placed in a rotary kiln, heated to 800°C at a rate of 2°C / min, and calcined at 800°C for 2 hours to obtain a calcined product.

[0117] Water and the calcined product were mixed in a volume ratio of 4:1, and immersed in water at 50°C for 1.5 hours to obtain a rare earth solution. The concentration of rare earth chloride and the oxidation rate of cerium in the rare earth solution were determined by the above test method. The calculation results are shown in Table 1.

[0118] Table 1

[0119]

[0120] Comparative Example 1: Polypropylene and monazite concentrate are roasted together, and the monazite concentrate is basically not decomposed, and the solution obtained after the roasted product is soaked in water basically does not contain rare earth elements. It can be seen from Examples 1 to 5 that the amount of raw materials, the diameter of the blank, the temperature and time of each step will have a certain impact on the decomposition rate of the monazite concentrate and the oxidation rate of the cerium element.

[0121] The present invention is not limited to the above-mentioned embodiments. Without departing from the essential content of the present invention, any deformation, improvement and substitution that can be conceived by those skilled in the art shall fall within the scope of the present invention.

Claims

1. A method for treating phosphorus-containing rare earth ores, characterized in that: The steps include: (1) roasting a mixture including a chlorinated polyolefin material and a phosphorus-containing rare earth ore at 500 to 900° C. to obtain a roasted product; (2) Soaking the calcined product in water to obtain a rare earth solution.

2. The processing method according to claim 1, characterized in that: The chlorinated polyolefin material is a polymer formed by polymerizing monomers including chlorinated olefins or a product containing the polymer.

3. The processing method according to claim 2, characterized in that: The chlorinated olefin is shown in formula (I): Wherein, R1, R3, R5 and R7 are independently selected from C1-C6 alkylene or a single bond, R2, R4, R6 and R8 are independently selected from H or Cl, and at least one of R2, R4, R6 and R8 is Cl.

4. The processing method according to claim 3, characterized in that: R1, R3, R5 and R7 are independently selected from methylene, ethylene, n-propylene, isopropylene, n-butylene, isobutylene, sec-butylene, tert-butylene, n-pentylene, methylbutylene, dimethylpropylene, ethylpropylene, n-ethylene, methylpentylene, ethylbutylene, dimethylbutylene and a single bond.

5. The processing method according to claim 2, characterized in that: The content of rare earth elements in the phosphorus-containing rare earth ore is greater than or equal to 50wt%, wherein the content of rare earth elements is calculated as REO; The mass ratio of the phosphorus-containing rare earth ore to the 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 into the mass of the rare earth oxide corresponding to the rare earth elements, and the mass of the chlorinated polyolefin material is calculated by the polymer contained therein.

6. The processing method according to claim 1, characterized in that: In step (1), the mixture further contains one or more of the following substances: water glass, carboxymethyl cellulose, bentonite, starch, lignin, alkaline earth metal oxides, and alkaline earth metal hydroxides; the content of the above substances is 0.1 to 3 wt%.

7. The processing method according to claim 1, characterized in that: In step (2), water and the roasted product are mixed in a volume ratio of (1-10):1, and soaked in water at 50-90° C. for 0.5-3 h.

8. Use of a chlorinated polyolefin material in decomposing phosphorus-containing rare earth ores.

9. The use according to claim 8, characterized in that The chlorinated polyolefin material is a polymer formed by polymerizing monomers including chlorinated olefins or a product containing the polymer.

10. The use according to claim 9, characterized in that The phosphorus-containing rare earth ore contains at least one of monazite or xenotime.

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