Device for continuously preparing low-impurity rare earth carbonate by using mixed precipitant
The continuous preparation of low-impact rare earth carbonate equipment by mixing precipitants is solved, and the problem of impurity generation in high-concentration mixed precipitation systems is realized, and the mass production of low-impact rare earth carbonate is reduced, and production costs are increased.
Patent Information
- Application Number
- CN202422455434.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-11
- Publication Date
- 2025-08-08
- Estimated Expiration
- 2034-10-11
AI Technical Summary
The prior art is difficult to effectively regulate the microstructure of rare earth carbonate products in high concentration mixed precipitation systems to avoid the formation of alkaline salts, resulting in a high impurity content of the product, especially when the ratio of ammonia water to ammonium bicarbonate increases, the impurity content increases significantly.
A device for continuously preparing low-impact rare earth carbonate is made of mixed precipitants, including a series of precipitation tanks, stirring units, flow control systems and filtration systems. By accurately adjusting the flow rate and reaction conditions of the precipitant and rare earth material liquid, the generation of impurities is controlled, and the mass production of low-impact rare earth carbonate is realized.
Massive production of low-impact rare earths of carbonate in high-concentration mixed precipitation system has been achieved, which reduces carbon emissions, reduces production costs, avoids the generation of oxalic acid wastewater, and increases production capacity and reduces labor intensity.
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Figure CN223201613U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of hydrometallurgical equipment, in particular to a device for continuously preparing low-impurity rare earth carbonate by using a mixed precipitant. Background Art
[0002] The synthesis of rare earth carbonates and oxides from rare earth solutions inevitably introduces anions into the rare earth solution system, which are difficult to remove and directly affect the quality of back-end functional materials. For example, chlorine can poison catalysts and decompose at high temperatures to produce hydrogen chloride, which corrodes the technical (alloy) substrate. Thermal decomposition of sulfate and nitrate ions releases sulfur oxides and nitrogen oxides, which can corrode or pollute the environment.
[0003] Impurities in rare earth carbonate and rare earth oxide (Cl - 、NO3 - 、SO4 2- ) are mainly retained in rare earth products in the form of surface adsorption, encapsulation or basic salts. Impurities adsorbed on the surface can be removed by washing with large amounts of clean water. Impurities in the form of encapsulation and basic salts must be comprehensively regulated through crystal structure optimization and reaction limit control. In existing industrial production, there are mainly the following ways to prepare low-impurity rare earth products in batches: First, through homogeneous precipitation of low-concentration rare earth solutions, the encapsulation form is controlled by controlling the extremely low ammonium salt concentration of the reaction system. The second is to dissolve high-impurity rare earth carbonate in nitric acid and then precipitate it. The precipitate is burned and the nitrate ions are decomposed to obtain low-impurity rare earth oxide. The third is to obtain low-impurity products by high-temperature conversion and crystal reconstruction of rare earth carbonate.
[0004] High-concentration rare earth solution and high-concentration precipitant are used to directly synthesize rare earth carbonate, mainly by ammonium bicarbonate, sodium bicarbonate, sodium carbonate precipitation. Some companies also use ammonium bicarbonate and ammonia mixed precipitation technology to achieve low-carbon production. However, all technologies produce rare earth oxide products C l - The content is about 400-600ppm. Especially in the precipitation technology of mixed ammonium bicarbonate and ammonia water, when the ratio of ammonia water to ammonium bicarbonate is increased from 4:6, the ammonia water provides OH - As the ion concentration increases, it is very easy to form basic salts such as RE(OH)2Cl and RE(OH)SO4, which will lead to a significant increase in the impurity content of the product. - In a mixed precipitation system with high concentration, the core technical challenges are to effectively control the product microstructure to avoid encapsulation and to control the reaction limit to avoid the formation of basic salts.
[0005] Based on the above technical problems, the utility model provides a device for continuously preparing low-impurity rare earth carbonate using a mixed precipitant. Utility Model Content
[0006] The purpose of the utility model is to provide a device for continuously preparing low-impurity rare earth carbonate by using a mixed precipitant, so as to solve the problems existing in the prior art.
[0007] To achieve the above-mentioned object, the present invention provides the following solution: The present invention provides a device for continuously preparing low-impurity rare earth carbonate using a mixed precipitant, comprising:
[0008] A sedimentation system comprising a plurality of sedimentation tanks connected in series, wherein a stirring unit is installed in each of the sedimentation tanks;
[0009] A precipitant addition system, comprising a precipitant solution tank, a first delivery pipe being installed at the water outlet of the precipitant solution tank, a plurality of first diversion pipes being fixedly connected to the first delivery pipe, and the first diversion pipes being respectively connected to the precipitation tank;
[0010] A rare earth liquid addition system, comprising a rare earth liquid tank, a second delivery pipe installed at the water outlet of the rare earth liquid tank, a plurality of second diversion pipes installed on the second delivery pipe, and the second diversion pipes communicating with the sedimentation tank;
[0011] A flow control system, comprising a plurality of first flow control units and a plurality of second flow control units, wherein the plurality of first flow control units are respectively mounted on the plurality of first shunt pipes, and the plurality of second flow control units are respectively mounted on the plurality of second shunt pipes;
[0012] A filtration system, the filtration system being connected to the sedimentation tank of the last stage;
[0013] Among them, the top and bottom ends of the side walls of the sedimentation tank are respectively provided with an overflow hole and a water inlet hole, and the overflow port of the sedimentation tank located at the upper level is connected to the water inlet hole of the sedimentation tank located at the lower level through a connecting pipe.
[0014] According to the device for continuously preparing low-impurity rare earth carbonate using a mixed precipitant provided by the utility model, the first flow control unit includes a first flow meter and a first regulating valve, and the first flow meter and the first regulating valve are connected in series to the first diversion pipe.
[0015] According to the device for continuously preparing low-impurity rare earth carbonate using a mixed precipitant provided by the utility model, the second flow control unit includes a second flow meter and a second regulating valve, and the second flow meter and the second regulating valve are connected in series to the second diversion pipe.
[0016] According to the device for continuously preparing low-impurity rare earth carbonate using a mixed precipitant provided by the utility model, the filtration system includes a supernatant storage tank and a filter, and the side wall of the sedimentation tank at the terminal stage is fixedly connected with a first drain pipe and a second drain pipe, the first drain pipe is located above the second drain pipe, one end of the first drain pipe is fixedly connected to the supernatant storage tank, and one end of the second drain pipe is fixedly connected to the filter; the first drain pipe and the second drain pipe are respectively installed with a variable frequency pump.
[0017] According to the device for continuously preparing low-impurity rare earth carbonate using a mixed precipitant provided by the utility model, the stirring unit includes a variable frequency motor installed at the top of the precipitation tank, the output shaft of the variable frequency motor is fixedly connected to a stirring shaft, and the stirring shaft extends vertically into the precipitation tank.
[0018] According to the device for continuously preparing low-impurity rare earth carbonate using a mixed precipitant provided by the utility model, the precipitation tank located at the first stage is fixedly connected to a tap water inlet pipe.
[0019] The utility model discloses the following technical effects:
[0020] This utility model enables the direct batch synthesis of low-impurity rare earth products in a high-concentration mixed precipitation system, effectively reducing carbon emissions during the precipitation process. It also enables the use of carbon precipitation instead of oxalic acid precipitation to synthesize low-impurity precursors for medium and heavy rare earths, reducing production costs and avoiding the generation of oxalic acid-containing wastewater. Furthermore, by combining low-impurity precipitation technology with existing continuous precipitation equipment, it further increases production capacity and reduces labor intensity, providing a technical equipment solution for the continuous preparation of high-quality rare earth products. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0022] Figure 1 This is a schematic structural diagram of a device for continuously preparing low-impurity rare earth carbonate using a mixed precipitant according to the present invention.
[0023] Among them, 1. sedimentation tank; 2. precipitant solution tank; 3. first delivery pipe; 4. first diversion pipe; 5. rare earth material liquid tank; 6. second delivery pipe; 7. second diversion pipe; 8. overflow hole; 9. water inlet hole; 10. first flow meter; 11. first regulating valve; 12. second flow meter; 13. second regulating valve; 14. supernatant liquid storage tank; 15. filter; 16. variable frequency pump; 17. variable frequency motor; 18. tap water inlet pipe. DETAILED DESCRIPTION
[0024] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0025] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific implementation methods.
[0026] Reference Figure 1 The utility model provides a device for continuously preparing low-impurity rare earth carbonate using a mixed precipitant, comprising:
[0027] The sedimentation system comprises a plurality of sedimentation tanks 1 connected in series, and a stirring unit is installed in each sedimentation tank 1;
[0028] The precipitant addition system includes a precipitant solution tank 2, a first delivery pipe 3 is installed at the water outlet of the precipitant solution tank 2, and a plurality of first diversion pipes 4 are fixedly connected to the first delivery pipe 3, and the first diversion pipes 4 are respectively connected to the precipitation tank 1;
[0029] A rare earth liquid addition system includes a rare earth liquid tank 5, a second delivery pipe 6 is installed at the water outlet of the rare earth liquid tank 5, and a plurality of second diversion pipes 7 are installed on the second delivery pipe 6, and the second diversion pipes 7 are connected to the sedimentation tank 1;
[0030] The flow control system includes a plurality of first flow control units and a plurality of second flow control units. The plurality of first flow control units are respectively installed on the plurality of first shunt pipes 4, and the plurality of second flow control units are respectively installed on the plurality of second shunt pipes 7.
[0031] Filtration system, the filtration system is connected to the last stage sedimentation tank 1;
[0032] Among them, the top and bottom ends of the side wall of the sedimentation tank 1 are respectively provided with an overflow hole 8 and a water inlet hole 9, and the overflow port of the sedimentation tank 1 at the upper level is connected to the water inlet hole 9 of the sedimentation tank 1 at the lower level through a connecting pipe.
[0033] This utility model enables the direct batch synthesis of low-impurity rare earth products in a high-concentration mixed precipitation system, effectively reducing carbon emissions during the precipitation process. It also enables the use of carbon precipitation instead of oxalic acid precipitation to synthesize low-impurity precursors for medium and heavy rare earths, reducing production costs and avoiding the generation of oxalic acid-containing wastewater. Furthermore, by combining low-impurity precipitation technology with existing continuous precipitation equipment, it further increases production capacity and reduces labor intensity, providing a technical equipment solution for the continuous preparation of high-quality rare earth products.
[0034] According to a further optimized solution, the first flow control unit includes a first flow meter 10 and a first regulating valve 11 , and the first flow meter 10 and the first regulating valve 11 are connected in series on the first shunt pipe 4 .
[0035] According to a further optimized solution, the second flow control unit includes a second flow meter 12 and a second regulating valve 13 , and the second flow meter 12 and the second regulating valve 13 are connected in series to the second shunt pipe 7 .
[0036] To further optimize the solution, the filtration system includes a supernatant storage tank 14 and a filter 15. The side wall of the final-level sedimentation tank 1 is fixedly connected with a first drain pipe and a second drain pipe. The first drain pipe is located above the second drain pipe. One end of the first drain pipe is fixedly connected to the supernatant storage tank 14, and one end of the second drain pipe is fixedly connected to the filter 15. Variable frequency pumps 16 are respectively installed on the first drain pipe and the second drain pipe.
[0037] According to a further optimized solution, the stirring unit includes a variable frequency motor 17 installed at the top of the sedimentation tank 1 , and a stirring shaft is fixedly connected to the output shaft of the variable frequency motor 17 , and the stirring shaft extends vertically into the sedimentation tank 1 .
[0038] To further optimize the solution, the sedimentation tank 1 at the first stage is fixedly connected to a tap water inlet pipe 18.
[0039] The method for continuously producing crystalline rare earth carbonate specifically comprises the following steps:
[0040] Step 1: The precipitant solution flows through the first electromagnetic flowmeter and the first regulating valve 11 and then enters the first-stage precipitation tank 1. The flow of the precipitant solution is precisely adjusted by the first electromagnetic flowmeter and the first regulating valve 11. The rare earth solution flows through the second electromagnetic flowmeter and the second regulating valve 13 and then enters the first-stage precipitation. The flow of the rare earth solution is precisely adjusted by the second electromagnetic flowmeter and the second regulating valve 13. The precipitation tank 1 is equipped with a tap water pipe, and the amount of tap water added is adjusted according to the mass volume concentration of ammonium salt in the tank.
[0041] Step 2: The feed liquid (precipitant solution, rare earth solution) reacts in the precipitation tank 1, and the slurry produced by the reaction is stirred evenly by the variable frequency motor 17. The slurry flows from the overflow hole 8 to the next level precipitation tank 1, and so on. Each level of precipitation tank 1 enters the feed liquid (precipitant solution, rare earth solution) at the same time;
[0042] Step 3: After the reaction is complete, the supernatant enters the supernatant storage tank and the concentrated slurry enters the filter 15;
[0043] Keep the temperature of sedimentation tank 1 between 20-99℃. Keep each level of sedimentation tank 1RE 3+ With CO3 2- The molar ratio of the two is the effective combined molar ratio, which is 1:1.3-1.8. The relative flow rate of the M1-grade rare earth solution and the mixed precipitant solution is 1:2.0-2.2, the relative flow rate of the M2 to Mn-1-grade rare earth solutions and the mixed precipitant solution is 1:1.8-2, and the relative flow rate of the Mn rare earth solution and the mixed precipitant solution is 1:22-2.3. The pH value of the M1-Mn-1-grade reaction system is maintained at 5.6-6.2, and the pH value of the Mn-grade reaction system is maintained at 6.5-7.0.
[0044] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present invention.
[0045] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements to the technical solutions of the present invention made by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.
Claims
1. A device for continuously preparing low-impurity rare earth carbonate using a mixed precipitant, characterized in that: include: A precipitation system, comprising a plurality of precipitation tanks (1) connected in series, wherein a stirring unit is installed in each of the precipitation tanks (1); A precipitant addition system, comprising a precipitant solution tank (2), a first delivery pipe (3) being installed at the water outlet of the precipitant solution tank (2), a plurality of first diversion pipes (4) being fixedly connected to the first delivery pipe (3), and the first diversion pipes (4) being respectively connected to the precipitation tank (1); A rare earth liquid addition system, comprising a rare earth liquid tank (5), a second delivery pipe (6) installed at the water outlet of the rare earth liquid tank (5), a plurality of second diversion pipes (7) installed on the second delivery pipe (6), and the second diversion pipes (7) communicating with the sedimentation tank (1); A flow control system, comprising a plurality of first flow control units and a plurality of second flow control units, wherein the plurality of first flow control units are respectively mounted on the plurality of first shunt pipes (4), and the plurality of second flow control units are respectively mounted on the plurality of second shunt pipes (7); A filtration system, the filtration system being in communication with the last stage of the sedimentation tank (1); The top and bottom ends of the side walls of the sedimentation tank (1) are respectively provided with an overflow hole (8) and a water inlet hole (9), and the overflow port of the sedimentation tank (1) at the upper level and the water inlet hole (9) of the sedimentation tank (1) at the lower level are connected via a connecting pipe.
2. The device for continuously preparing low-impurity rare earth carbonate using a mixed precipitant according to claim 1, characterized in that: The first flow control unit comprises a first flow meter (10) and a first regulating valve (11), and the first flow meter (10) and the first regulating valve (11) are connected in series to the first shunt pipe (4).
3. The device for continuously preparing low-impurity rare earth carbonate using a mixed precipitant according to claim 1, characterized in that: The second flow control unit comprises a second flow meter (12) and a second regulating valve (13), and the second flow meter (12) and the second regulating valve (13) are connected in series to the second shunt pipe (7).
4. The device for continuously preparing low-impurity rare earth carbonate using a mixed precipitant according to claim 1, characterized in that: The filtration system comprises a supernatant liquid storage tank (14) and a filter (15); a first drain pipe and a second drain pipe are fixedly connected to the side wall of the sedimentation tank (1) at the terminal stage; the first drain pipe is located above the second drain pipe; one end of the first drain pipe is fixedly connected to the supernatant liquid storage tank (14), and one end of the second drain pipe is fixedly connected to the filter (15); a variable frequency pump (16) is respectively installed on the first drain pipe and the second drain pipe.
5. The device for continuously preparing low-impurity rare earth carbonate using a mixed precipitant according to claim 1, characterized in that: The stirring unit comprises a variable frequency motor (17) mounted on the top of the sedimentation tank (1), and a stirring shaft is fixedly connected to the output shaft of the variable frequency motor (17), and the stirring shaft extends vertically into the sedimentation tank (1).
6. The device for continuously preparing low-impurity rare earth carbonate using a mixed precipitant according to claim 1, characterized in that: The sedimentation tank (1) at the first stage is fixedly connected to a tap water inlet pipe (18).