Device for synthesizing rare earth mixed precipitant through ammonia carbon reinforcement

Abstract

The utility model belongs to the technical field of rare earth hydrometallurgy and comprehensive utilization of resources, and particularly relates to a device for synthesizing a rare earth mixed precipitant in an ammonia-carbon reinforced manner. The utility model discloses a device for intensively synthesizing a rare earth mixed precipitator by ammonia carbon, which comprises an ammonia carbon intensified synthesis reactor, the ammonia carbon intensified synthesis reactor consists of five groups of plate bundles formed by welding herringbone corrugated plate sheets, and the five groups of plate bundles comprise two groups of gasification plate bundles for gasifying liquid carbon dioxide; the three groups of reaction plate bundles are used for mixing ammonia water and water and reacting with the bulk carbon dioxide, the five groups of plate bundles are wrapped by a metal shell, and an ammonia water, water and liquid carbon dioxide inlet and a circulating cooling water inlet and outlet are reserved outside the shell. Compared with a traditional tower reactor, the tower reactor has the remarkable advantages of being high in equipment integration degree, high in reaction efficiency, low in energy consumption and the like, the energy consumption is saved by 50%, the total investment of equipment is reduced by 50%, the occupied space of the equipment is reduced by 90%, and remarkable innovation is achieved.

Description

Technical Field

[0001] This utility model belongs to the field of rare earth hydrometallurgy and resource comprehensive utilization technology, specifically relating to an apparatus for ammonia-carbon enhanced synthesis of rare earth mixed precipitants. Background Technology

[0002] Rare earth carbonates are the most important intermediate products of rare earth smelting enterprises. Before extraction and separation, rare earth elements are typically transported, sold, and connected to downstream extraction and separation processes in the form of rare earth carbonates. The conversion of single rare earth elements into rare earth oxides, other salt compounds, or rare earth polishing materials, luminescent materials, and rare earth metals also often uses rare earth carbonates as intermediate products. For many years, due to both economic and environmental reasons, ammonium bicarbonate has been used as a precipitant to obtain rare earth carbonates. To improve the utilization rate of carbonate ions in ammonium bicarbonate, many rare earth smelting enterprises have adopted a mixed solution of ammonia and ammonium bicarbonate as a rare earth precipitant in recent years, which is called a rare earth mixed precipitant.

[0003] The industrial preparation method for rare earth mixed precipitants involves dissolving solid ammonium bicarbonate in ammonia water of a certain concentration. The concentration of the rare earth mixed precipitant and the ratio of ammonia water to ammonium bicarbonate vary slightly depending on the rare earth element. Generally, the total ammonium concentration in the mixed precipitant is 3.0–4.0 mol / L, and the amount of ammonium bicarbonate added is 60–90% of the total ammonium concentration. Compared with the traditional reaction of ammonium bicarbonate and rare earth chloride solution to produce rare earth carbonate, the mixed precipitant has significant advantages such as stable rare earth carbonate product composition, low chloride content, low ammonium bicarbonate dosage, low wastewater volume, and high ammonium chloride concentration in the wastewater.

[0004] In recent years, the Northern Rare Earth Smelting Branch has adopted a method of adding lime to ammonium chloride wastewater and passing it through an ammonia stripping tower to obtain ammonia water. This has enabled the recycling of ammonia from rare earth precipitation and extraction wastewater, and the cost of obtaining ammonia water is reduced by approximately 50% compared to direct purchase. However, because ammonia water can only be used for the saponification of extractants in the rare earth element separation process and cannot be directly used as a precipitant for rare earth precipitation, the company faces an imbalance of excess ammonia water and the need to purchase ammonium bicarbonate. Given the cost advantage of regenerated ammonia water, converting it into a mixed precipitant suitable for rare earth precipitation would be profitable and would also resolve the ammonia utilization imbalance within rare earth smelting enterprises, which is of great significance for technological advancement and resource recycling in the rare earth smelting industry.

[0005] The preparation of mixed precipitants based on the reaction of ammonia solution with carbon dioxide faces a major technical bottleneck: the absorption of carbon dioxide by ammonia is limited by mass transfer at the gas-liquid interface, and the reaction process involves multiple intermediate reactions, resulting in low reaction efficiency. The instability and volatility of NH3, CO2, and the product ammonium bicarbonate lead to problems such as NH3 escape and low CO2 absorption efficiency. Carbon dioxide absorption rate and ammonia escape are contradictory; to increase the CO2 capture rate, the concentration of ammonia solution and the absorption reaction temperature are usually increased, but this simultaneously increases the ammonia escape rate. From the perspective of ammonia escape, the absorption temperature should be as low as possible, but this requires additional energy to maintain the low temperature of the ammonia solution. Furthermore, optimizing the reaction equipment for mass transfer mainly involves increasing the gas-liquid contact time, increasing the gas-liquid contact area, and enhancing the degree of gas-liquid mixing. This requires larger reactors or a higher liquid-to-gas ratio, leading to the large-scale development of reaction equipment. Commonly used reaction equipment such as carbonation towers, bubble towers, packed towers, and sieve plate towers can be over ten meters high, or even tens of meters high, with ammonium bicarbonate production typically reaching hundreds of thousands of tons per year. Such equipment not only suffers from high investment per unit processing capacity and low carbon dioxide utilization, but also exhibits unstable ammonium bicarbonate ratios in the synthesized mixed precipitant. Furthermore, complicating matters further, rare earth elements are a collective term for more than ten elements, resulting in a diverse range of rare earth carbonates. Taking the Northern Rare Earth Smelting Branch, the world's largest rare earth smelting company, as an example, its industrial rare earth carbonate products include lanthanum carbonate, cerium carbonate, mixed lanthanum and cerium carbonate, praseodymium and neodymium carbonate, etc. Each rare earth carbonate product requires different concentrations and ratios of ammonia and ammonium bicarbonate in the rare earth mixed precipitant. Clearly, large-scale tower-type equipment is unsuitable for the requirements of preparing rare earth mixed precipitants from ammonia, considering both economic and practical aspects. Utility Model Content

[0006] In view of this, the purpose of this utility model is to address the problems existing in the prior art by providing an apparatus for the ammonia-carbon-enhanced synthesis of rare earth mixed precipitants. Using this apparatus, rare earth mixed precipitants for rare earth carbonates can be synthesized efficiently, with low consumption, in one step, and continuously.

[0007] To achieve the above objectives, the purpose of this utility model is to provide an apparatus for the ammonia-carbon enhanced synthesis of rare earth mixed precipitants, employing the following technical solution:

[0008] An apparatus for ammonia-carbon enhanced synthesis of rare earth mixed precipitants includes: an ammonia-carbon enhanced synthesis reactor 1, wherein the ammonia-carbon enhanced synthesis reactor 1 has a cubic structure and is provided with a rare earth mixed precipitant circulation return inlet 1-8 at the upper end and a rare earth mixed precipitant outlet 1-9 at the lower end. The rare earth mixed precipitant circulation return inlet 1-8 is connected to the rare earth mixed precipitant outlet 1-9 via herringbone plate bundles 1-C, 1-D, and 1-E arranged internally.

[0009] Furthermore, the ammonia-carbon enhanced synthesis reactor 1 is internally equipped with 5 sets of herringbone plate bundles 1-A, 1-B, 1-C, 1-D, and 1-E. Each plate bundle is composed of multiple herringbone plates 1-a and 1-b arranged in opposite perpendicular directions, stacked and welded alternately. A gap of no more than the geometric thickness of the plate is left between each herringbone plate for fluid movement. The cooling liquid passage is arranged in the gaps between the dilution water, ammonia water, and carbon dioxide passages, and flows in opposite directions.

[0010] Furthermore, the ammonia-carbon enhanced synthesis reactor 1 is externally equipped with a liquid carbon dioxide inlet 1-1, a cooling circulating water outlet 1-2, a carbon dioxide secondary pressure regulator 1-3, a carbon dioxide vaporization outlet 1-4, an ammonia water inlet 1-5, a dilution water inlet 1-6, and a cooling circulating water inlet 1-7, wherein:

[0011] The lower end of the herringbone plate bundle 1-A is provided with a liquid carbon dioxide inlet 1-1 and a cooling circulating water outlet 1-2, and the upper end is provided with a carbon dioxide secondary pressure reducing regulator 1-3.

[0012] The lower end of the herringbone plate bundle 1-B is provided with a carbon dioxide secondary pressure regulator 1-3, and the upper end is provided with a carbon dioxide vaporization outlet 1-4.

[0013] The upper end of the herringbone plate bundle 1-C is provided with an ammonia water inlet 1-5, a dilution water inlet 1-6 and a carbon dioxide gasification outlet 1-4, and a rare earth mixed precipitant outlet 1-8 is also provided at the same end.

[0014] The lower end of the herringbone plate bundle 1-E is provided with a cooling circulating water inlet 1-7 and a rare earth mixed precipitant outlet 1-9.

[0015] Furthermore, the herringbone plates 1-a and 1-b are corrugated plates, and the corrugated geometry conforms to the NB / T 47004 international standard for plate heat exchangers.

[0016] It is worth noting that this invention utilizes circulating cooling water to absorb the heat released by the reaction of ammonia and carbon dioxide, and then uses the heat absorbed by the circulating cooling water to compensate for the heat absorbed by the vaporization of liquid carbon dioxide. Thus, it not only enhances the heat exchange efficiency, but also effectively improves the carbon dioxide absorption efficiency.

[0017] Furthermore, the apparatus for synthesizing rare earth mixed precipitants with ammonia-carbon enhancement also includes: a tail gas ammonia absorber 2, a liquid carbon dioxide storage tank 3, a refrigeration unit 4, and a transfer tank 5.

[0018] The tail gas ammonia absorber 2 has a dilution water inlet 2-1 at the top, and a dilution water outlet 2-3 at the bottom connected to a dilution water inlet 1-6 via a pipeline to form a dilution water passage; the discharge valve 3-1 of the liquid carbon dioxide storage tank 3 is connected to a liquid carbon dioxide inlet 1-1 via a pipeline to form a carbon dioxide passage; the outlet 4-1 of the refrigeration unit 4 is connected to a cooling circulating water inlet 1-7, and the inlet 4-2 is connected to a cooling circulating water outlet 1-2; the vent 5-1 of the transfer tank 5 is connected to the tail gas inlet 2-2 of the tail gas ammonia absorber 2, and the inlet 5-2 is connected to a rare earth mixed precipitant outlet 1-9 via a pipeline, and the bottom of the transfer tank 5 is provided with a finished product outlet 5-4.

[0019] During operation, ammonia water enters the ammonia-carbon enhanced synthesis reactor 1 through ammonia water inlet 1-5. Dilution water enters the ammonia-carbon enhanced synthesis reactor 1 through dilution water inlet 2-1 at the top of the tail gas ammonia absorber 2 and dilution water outlet 2-3 at the bottom of the tail gas ammonia absorber 2, entering the ammonia-carbon enhanced synthesis reactor 1 through dilution water inlet 1-6. Liquid carbon dioxide enters the ammonia-carbon enhanced synthesis reactor 1 through the discharge valve 3-1 of the liquid carbon dioxide storage tank 3 and through the pipeline via liquid carbon dioxide inlet 1-1. The rare earth mixed precipitant synthesized in the ammonia-carbon enhanced synthesis reactor 1 enters the rare earth mixed precipitant transfer tank 5 through outlet 1-8 and transfer tank inlet 5-2. The bottom of the transfer tank 5 is equipped with a circulation outlet 5-3 and a finished product outlet 5-4. The vent 5-1 of the transfer tank is connected to the tail gas inlet 2-2 of the tail gas ammonia absorber 2. Cooling circulating water enters the ammonia-carbon enhanced synthesis reactor 1 through cooling circulating water inlet 1-7 through outlet 4-1 of the chiller 4 and returns to the chiller 4 through inlet 4-2 via cooling circulating water outlet 1-2.

[0020] Furthermore, the bottom of the transfer tank 5 is also provided with a circulation outlet 5-3, which is connected to the rare earth mixed precipitant circulation return inlet 1-8.

[0021] When using the apparatus for ammonia-carbon enhanced synthesis of rare earth mixed precipitants, ammonia water, dilution water, and carbon dioxide are simultaneously introduced into the ammonia-carbon enhanced synthesis reactor 1 to synthesize rare earth mixed precipitants, and cooling circulating water is used to control the temperature of the reaction.

[0022] Among them, the herringbone-shaped plate bundles 1-A and 1-B are liquid carbon dioxide vaporization plate bundles, and the herringbone-shaped plate bundles 1-C, 1-D and 1-E are gaseous carbon dioxide and ammonia reaction plate bundles.

[0023] The temperature of the cooling circulating water within the herringbone plate bundle 1-A is -30 to -10℃, the temperature within the herringbone plate bundle 1-B is 0 to 10℃, the temperature within the herringbone plate bundles 1-C, 1-D, and 1-E is 15 to 50℃, the temperature of the rare earth mixed precipitant outlet 1-9 is 15 to -25℃, the temperature of the cooling circulating water inlet 1-7 is 5 to 10℃, and the temperature of the cooling circulating water outlet 1-2 is 10 to 25℃.

[0024] Furthermore, the pressure of the liquid carbon dioxide storage tank 3 is 1.6-2.2 MPa, and is adjusted to 0.9-1.6 MPa after entering the herringbone plate bundle 1-A. The liquid carbon dioxide is converted from liquid to gas in the herringbone plate bundle 1-A. After entering the herringbone plate bundle 1-B, the pressure is further adjusted to 0.1-0.9 MPa. In the herringbone plate bundle 1-B, all the carbon dioxide is converted into gas. The gaseous carbon dioxide enters the herringbone plate bundle 1-C from the carbon dioxide vaporization outlet 1-4 at a pressure of 0.1-0.2 MPa.

[0025] Furthermore, the carbon dioxide flows through the ammonia-carbon enhanced synthesis reactor 1 in the direction of 1-A→1-B→1-C→1-D→1-E, the ammonia water and dilution water flow through the ammonia-carbon enhanced synthesis reactor 1 in the direction of 1-C→1-D→1-E, and the cooling circulating water flow through the ammonia-carbon enhanced synthesis reactor 1 in the direction of 1-E→1-D→1-C→1-B→1-A.

[0026] Furthermore, the ammonia water is ammonia water absorbed by the reaction of ammonium chloride and calcium alkali solution, with a concentration of 3.5–11 mol / L; the rare earth mixed precipitant is NH4+. 4+ CO3 2- HCO3 - A mixed solution containing NH4+ 4+ The concentration is 2.0–4.5 mol / L, CO3 2- With HCO3 - The sum of the concentrations is less than NH 4+ Concentration, pH of rare earth mixed precipitant > 8.

[0027] Furthermore, the synthesized rare earth mixed precipitant enters the transfer tank 5. Part of the rare earth mixed precipitant in the transfer tank 5 is circulated back to the rare earth mixed precipitant in the reactor 1 via the circulation outlet 5-3 by a pump, and then mixed with ammonia water, dilution water, and carbon dioxide. The other part is pumped out from the finished product outlet 5-4 in the same amount as ammonia water. Moreover, the outlet flow rate of the circulation outlet 5-3 is 3 to 10 times that of the finished product outlet 5-4.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The ammonia-carbon enhanced synthesis reactor disclosed in this utility model integrates five functional requirements into one set of equipment: mixing and diluting ammonia with water, high-efficiency reaction of ammonia with carbon dioxide, exothermic reaction of ammonia with carbon dioxide, and endothermic vaporization of liquid carbon dioxide. The herringbone corrugated plate structure enhances liquid-liquid mixing, gas-liquid reaction, and heat exchange. It has significant advantages such as high equipment integration, high reaction efficiency, and low energy consumption. Compared with traditional tower reactors, the process of synthesizing rare earth mixed precipitants from ammonia with carbon dioxide saves 50% in energy consumption, reduces total equipment investment by 50%, and reduces equipment footprint by 90%, which is a significant innovation. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the overall structure of the apparatus for ammonia-carbon enhanced synthesis of rare earth mixed precipitants according to this utility model. The apparatus includes: an ammonia-carbon enhanced synthesis reactor 1; a rare earth mixed precipitant circulation return inlet 1-8; a rare earth mixed precipitant outlet 1-9; a tail gas ammonia absorber 2; a dilution water inlet 2-1; a tail gas ammonia absorber 2-2; a dilution water outlet 2-3; a liquid carbon dioxide storage tank 3; a liquid carbon dioxide discharge valve 3-1; cooling circulating water supplied by a chiller 4; a circulating coolant outlet 4-1; a circulating coolant inlet 4-2; a rare earth mixed precipitant transfer tank 5; a rare earth mixed precipitant transfer tank vent 5-1; a rare earth mixed precipitant transfer tank inlet 5-2; a circulation outlet 5-3; and a finished product outlet 5-4.

[0032] Figure 2 This is a schematic diagram of the structure of the ammonia-carbon enhanced synthesis reactor 1 of this utility model, wherein the herringbone plate bundles are 1-A, 1-B, 1-C, 1-D, and 1-E; the liquid carbon dioxide inlet is 1-1; the cooling circulating water outlet is 1-2; the carbon dioxide secondary pressure regulator is 1-3; the carbon dioxide gasification outlet is 1-4; the ammonia water inlet is 1-5; the dilution water inlet is 1-6; and the cooling circulating water inlet is 1-7.

[0033] Figure 3 This is a schematic diagram of the herringbone plate bundle and the plate structure that makes up the plate bundle inside the ammonia-carbon enhanced synthesis reactor of this utility model. In this diagram, (1) and (2) are herringbone plates 1-a and 1-b, respectively. (3) is a side view of herringbone plates 1-a and 1-b stacked alternately. (4) is a front view of herringbone plates 1-a and 1-b stacked alternately.

[0034] Figure 4This is a schematic diagram of the fluid flow direction inside the herringbone plate bundle of this utility model, wherein (1) is the fluid flow direction inside the herringbone plate bundles 1-C, 1-D, and 1-E, (2) is the fluid flow direction inside the herringbone plate bundles 1-A and 1-B, and (3) is a front view of the fluid flow direction. Detailed Implementation

[0035] The technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0036] The term "embodiment" used herein, as an example, is not necessarily to be construed as superior to or better than other embodiments. Performance testing in the embodiments of this application, unless otherwise specified, employs conventional testing methods in the art. It should be understood that the terminology used in this application is merely for describing particular implementations and is not intended to limit the scope of this disclosure.

[0037] Unless otherwise stated, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; other experimental methods and technical means not specifically mentioned herein refer to experimental methods and technical means commonly used by one of ordinary skill in the art.

[0038] To better illustrate the content of this application, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that this application can be implemented even without certain specific details. In the embodiments, some methods, means, instruments, and devices well-known to those skilled in the art are not described in detail in order to highlight the main points of this application.

[0039] In the description of this utility model, it should be understood that the terms "inner", "outer", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing this utility model, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0040] Without conflict, the technical features disclosed in the embodiments of this application can be combined arbitrarily, and the resulting technical solution belongs to the content disclosed in the embodiments of this application.

[0041] This utility model discloses an apparatus for the ammonia-carbon enhanced synthesis of rare earth mixed precipitants, belonging to the field of rare earth hydrometallurgy and resource comprehensive utilization technology. The apparatus for the ammonia-carbon enhanced synthesis of rare earth mixed precipitants disclosed in this utility model includes an ammonia-carbon enhanced synthesis reactor, which is composed of five sets of herringbone corrugated plates welded together. The five sets of plates include two sets of gasification plates for the vaporization of liquid carbon dioxide, and three sets of reaction plates for the mixing of ammonia and water with bulk carbon dioxide. The five sets of plates are encased in a metal shell, with inlets for ammonia, water, and liquid carbon dioxide, as well as inlets and outlets for circulating cooling water. The ammonia-carbon enhanced synthesis reactor integrates five functional requirements into one set of equipment: mixing and diluting ammonia with water, efficient reaction of ammonia with carbon dioxide, exothermic reaction of ammonia with carbon dioxide, and endothermic vaporization of liquid carbon dioxide. The herringbone corrugated plate structure enhances liquid-liquid mixing, gas-liquid reaction, and heat exchange, and has significant advantages such as high equipment integration, high reaction efficiency, and low energy consumption. Compared with traditional tower reactors, the process of synthesizing rare earth mixed precipitants from ammonia and carbon dioxide saves 50% in energy consumption, reduces total equipment investment by 50%, and reduces equipment footprint by 90%, which is a significant innovation.

[0042] To better understand this utility model, the following embodiments will further illustrate this utility model in detail, but they should not be construed as limiting this utility model. Any non-essential improvements and adjustments made by those skilled in the art based on the above-described utility model content are also considered to fall within the protection scope of this utility model.

[0043] Example 1

[0044] refer to Figure 1-4 An apparatus for ammonia-carbon enhanced synthesis of rare earth mixed precipitants includes: an ammonia-carbon enhanced synthesis reactor 1, a tail gas ammonia absorber 2, a liquid carbon dioxide storage tank 3, a refrigerator 4, and a transfer tank 5.

[0045] The ammonia-carbon enhanced synthesis reactor 1 has a cubic structure. Inside the ammonia-carbon enhanced synthesis reactor 1, there are 5 sets of herringbone plate bundles 1-A, 1-B, 1-C, 1-D, and 1-E. The plate bundles are composed of multiple herringbone plates 1-a and 1-b with perpendicular and opposite directions, which are alternately stacked and welded together.

[0046] The ammonia-carbon enhanced synthesis reactor 1 is externally equipped with a liquid carbon dioxide inlet 1-1, a cooling circulating water outlet 1-2, a carbon dioxide secondary pressure regulator 1-3, a carbon dioxide gasification outlet 1-4, an ammonia water inlet 1-5, a dilution water inlet 1-6, a cooling circulating water inlet 1-7, a rare earth mixed precipitant return inlet 1-8, and a rare earth mixed precipitant outlet 1-9.

[0047] Among them, one end of the herringbone plate bundle 1-A is provided with a liquid carbon dioxide inlet 1-1 and a cooling circulating water outlet 1-2, and the other end is provided with a carbon dioxide secondary pressure reducing regulator 1-3;

[0048] One end of the herringbone plate bundle 1-B is provided with a carbon dioxide secondary pressure regulator 1-3, and the other end is provided with a carbon dioxide vaporization outlet 1-4.

[0049] One end of the herringbone plate bundle 1-C is provided with an ammonia water inlet 1-5 and a dilution water inlet 1-6, which are connected to a carbon dioxide vaporization outlet 1-4. At the same end, a rare earth mixed precipitant outlet 1-8 is also provided.

[0050] One end of the herringbone plate bundle 1-E is provided with a cooling circulating water inlet 1-7 and a rare earth mixed precipitant outlet 1-9.

[0051] The tail gas ammonia absorber 2 has a dilution water inlet 2-1 at the top and a dilution water outlet 2-3 at the bottom connected to the dilution water inlet 1-6 via a pipeline.

[0052] The discharge valve 3-1 of the liquid carbon dioxide storage tank 3 is connected to the liquid carbon dioxide inlet 1-1 via a pipeline;

[0053] The outlet 4-1 of the chiller 4 is connected to the cooling circulating water inlet 1-7, and the inlet 4-2 is connected to the cooling circulating water outlet 1-2;

[0054] The vent 5-1 of the transfer tank 5 is connected to the tail gas inlet 2-2 of the tail gas ammonia absorber 2. The inlet 5-2 is connected to the rare earth mixed precipitant outlet 1-9 through a pipeline. The bottom of the transfer tank 5 is provided with a circulation outlet 5-3 and a finished product outlet 5-4. The circulation outlet 5-3 is connected to the rare earth mixed precipitant circulation return inlet 1-8.

[0055] Furthermore, the herringbone plate bundles 1-A, 1-B, 1-C, 1-D, and 1-E are composed of herringbone plates 1-a and 1-b forming a cubic structure, and there are gaps between each herringbone plate that are no larger than the geometric thickness of the plate for fluid movement.

[0056] Furthermore, the coolant passage is arranged in a space between the dilution water, ammonia, and carbon dioxide passages, and flows in opposite directions.

[0057] Furthermore, the herringbone plates 1-a and 1-b are corrugated plates, and the corrugated geometry conforms to the NB / T 47004 international standard for plate heat exchangers.

[0058] During operation, ammonia water, dilution water, and carbon dioxide are simultaneously introduced into the ammonia-carbon enhanced synthesis reactor 1 to synthesize a rare earth mixed precipitant, and cooling circulating water is used to control the temperature of the reaction.

[0059] The carbon dioxide flows through the ammonia-carbon enhanced synthesis reactor 1 in the following order: 1-A→1-B→1-C→1-D→1-E. The ammonia water and dilution water flow through the reactor in the same order: 1-C→1-D→1-E. The cooling circulating water flows through the reactor in the same order: 1-E→1-D→1-C→1-B→1-A. The synthesized rare earth mixed precipitant enters the transfer tank 5. A portion of the rare earth mixed precipitant in the transfer tank 5 is pumped back from the circulation outlet 5-3 to the inlet 1-8 of the reactor 1, where it is mixed with ammonia water, dilution water, and carbon dioxide. The other portion, in the same amount as the ammonia water, is pumped out from the finished product outlet 5-4. Furthermore, the outlet flow rate of the circulation outlet 5-3 is 3 to 10 times that of the finished product outlet 5-4.

[0060] Among them, the herringbone-shaped plate bundles 1-A and 1-B are liquid carbon dioxide vaporization plate bundles. The pressure of the liquid carbon dioxide storage tank 3 is 1.6-2.2 MPa, which is adjusted to 0.9-1.6 MPa after entering the herringbone-shaped plate bundle 1-A. The liquid carbon dioxide is converted from liquid to gas in the herringbone-shaped plate bundle 1-A. After entering the herringbone-shaped plate bundle 1-B, the pressure is further adjusted to 0.1-0.9 MPa. In the herringbone-shaped plate bundle 1-B, all carbon dioxide is converted into gas. The gaseous carbon dioxide enters the herringbone-shaped plate bundle 1-C from the carbon dioxide vaporization outlet 1-4 at a pressure of 0.1-0.2 MPa.

[0061] The herringbone-shaped plate bundles 1-C, 1-D, and 1-E are reaction plate bundles of gaseous carbon dioxide and ammonia.

[0062] The temperature of the cooling circulating water within the herringbone plate bundle 1-A is -30 to -10℃, the temperature within the herringbone plate bundle 1-B is 0 to 10℃, the temperature within the herringbone plate bundles 1-C, 1-D, and 1-E is 15 to 50℃, the temperature of the rare earth mixed precipitant outlet 1-9 is 15 to -25℃, the temperature of the cooling circulating water inlet 1-7 is 5 to 10℃, and the temperature of the cooling circulating water outlet 1-2 is 10 to 25℃.

[0063] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An apparatus for synthesizing a rare earth mixed precipitator by ammonia carbon intensification, characterized in that, include: The ammonia-carbon enhanced synthesis reactor (1) has a cubic structure and is provided with a rare earth mixed precipitant circulation return inlet (1-8) at the upper end and a rare earth mixed precipitant outlet (1-9) at the lower end. The rare earth mixed precipitant circulation return inlet (1-8) is connected to the rare earth mixed precipitant outlet (1-9) through internally provided herringbone-shaped plate bundles (1-C), (1-D), and (1-E).

2. The apparatus for synthesis of rare earth mixed precipitator by ammonia-carbon intensification according to claim 1, characterized in that, The ammonia-carbon enhanced synthesis reactor (1) is equipped with five sets of herringbone plate bundles (1-A), (1-B), (1-C), (1-D), and (1-E). Each plate bundle is composed of multiple herringbone plates (1-a) and (1-b) arranged in opposite directions, stacked and welded alternately. A gap of no more than the geometric thickness of the plate is left between each herringbone plate for fluid movement. The cooling liquid passage is arranged in the gaps between the dilution water, ammonia water, and carbon dioxide passages, and flows in opposite directions.

3. The apparatus for synthesis of rare earth mixed precipitator by ammonia-carbon intensification according to claim 2, characterized in that, The ammonia-carbon enhanced synthesis reactor (1) is externally equipped with a liquid carbon dioxide inlet (1-1), a cooling circulating water outlet (1-2), a carbon dioxide secondary pressure regulator (1-3), a carbon dioxide vaporization outlet (1-4), an ammonia water inlet (1-5), a dilution water inlet (1-6), and a cooling circulating water inlet (1-7), wherein: The lower end of the herringbone plate bundle (1-A) is provided with a liquid carbon dioxide inlet (1-1) and a cooling circulating water outlet (1-2), and the upper end is provided with a carbon dioxide secondary pressure reducing regulator (1-3). The lower end of the herringbone plate bundle (1-B) is provided with a carbon dioxide secondary pressure reducing regulator (1-3), and the upper end is provided with a carbon dioxide vaporization outlet (1-4). The upper end of the herringbone plate bundle (1-C) is provided with an ammonia water inlet (1-5) and a dilution water inlet (1-6), which are connected to a carbon dioxide gasification outlet (1-4). At the same end, a rare earth mixed precipitant outlet (1-8) is also provided. The lower end of the herringbone plate bundle (1-E) is provided with a cooling circulating water inlet (1-7) and a rare earth mixed precipitant outlet (1-9).

4. The apparatus for synthesis of rare earth mixed precipitator by ammonia-carbon intensification according to claim 2, characterized in that, The herringbone plates (1-a) and (1-b) are corrugated plates, and the corrugated geometry conforms to the NB / T47004 international standard for plate heat exchangers.

5. The apparatus for synthesis of rare earth mixed precipitator by ammonia-carbon intensification according to claim 1, characterized in that, Also includes: The system includes a tail gas ammonia absorber (2), a liquid carbon dioxide storage tank (3), a refrigeration unit (4), and a transfer tank (5); among which, The tail gas ammonia absorber (2) has a dilution water inlet (2-1) at the top and a dilution water outlet (2-3) at the bottom connected to the dilution water inlet (1-6) through a pipeline to form a dilution water passage. The discharge valve (3-1) of the liquid carbon dioxide storage tank (3) is connected to the liquid carbon dioxide inlet (1-1) through a pipeline to form a carbon dioxide passage; The outlet (4-1) of the chiller (4) is connected to the cooling circulating water inlet (1-7), and the inlet (4-2) is connected to the cooling circulating water outlet (1-2); The air outlet (5-1) of the transfer tank (5) is connected to the tail gas inlet (2-2) of the tail gas ammonia absorber (2), and the inlet (5-2) is connected to the rare earth mixed precipitant outlet (1-9) through a pipeline. The bottom of the transfer tank (5) is provided with a finished product outlet (5-4).

6. The apparatus for synthesis of rare earth mixed precipitator by ammonia-carbon intensification according to claim 5, characterized in that, The bottom of the transfer tank (5) is also provided with a circulation outlet (5-3), which is connected to the rare earth mixed precipitant circulation return inlet (1-8).

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