Gas-liquid-solid three-phase reactor for ammonia distillation crystallization

Abstract

The utility model discloses a gas, liquid and solid three-phase reactor for ammonia distillation crystallization, the gas, liquid and solid three-phase reactor is of a tower structure, at least one horizontally arranged transverse baffle is arranged in the reactor at intervals from bottom to top so as to divide the reactor into a plurality of reaction chambers, the transverse baffle is provided with a shaft hole, and the shaft hole is communicated with the transverse baffle. Each reaction chamber is provided with a vertical longitudinal baffle close to the inner wall, and the stirring shaft of each reaction chamber is provided with at least one layer of stirring paddle. A gas rising hole can be formed in the transverse baffle and is matched with the shaft hole, so that mass and heat transfer of gas and liquid in the reactor is more sufficient. The reactor provided by the utility model can effectively control the decomplexing crystallization process, fulfills the aims of fully recovering ammonia and controlling crystal morphology, particle size distribution, tap density and the like, and can ensure that the reaction can be continuously and stably operated for a long time.

Description

Technical Field

[0001] The invention relates to chemical related fields, and in particular to a gas, liquid and solid three-phase reactor for ammonia evaporation and crystallization. Background Art

[0002] Ammonia leaching is a leaching process in hydrometallurgy, which uses ammonia or a mixture of ammonia and salt as a leaching agent. It is mainly used for the hydrometallurgy of non-ferrous metals such as copper, nickel, cobalt, rare earths, and the preparation of metal materials. During the ammonia leaching process, metal compounds react with ammonia to form ammonia compounds or ammonia complexes.

[0003] Ammonia complexes can be decomplexed and crystallized to obtain metal salt precipitation, which can be filtered and post-processed. The ammonia vapor of ammonia evaporation is condensed and recycled. The process can actually be divided into two processes: ammonia evaporation and metal salt crystallization. Ammonia evaporation crystallization involves the ammonia stripping process of vapor and liquid heat and mass transfer, and the decomplexation crystallization vapor, liquid, and solid three-phase reaction crystallization process. Therefore, a suitable reactor is required to realize the ammonia evaporation crystallization process.

[0004] Patent document RU2055921C1 discloses the use of (NH 4 ) 2 CO 3 A process for preparing ZnO as a leachate, comprising (a) providing a roasted sulfide zinc concentrate comprising zinc oxide and a small amount of sulfur in the form of sulfide and / or sulfate; (b) slurrying the roasted zinc oxide concentrate in an aqueous ammonium carbonate solution to dissolve the zinc contained therein; (c) separating a zinc-containing leachate from the leaching slurry; (d) purifying the zinc-containing leachate to remove at least one metal of copper and cadmium; (e) stripping the purified zinc-containing leachate to remove ammonia and precipitate basic zinc carbonate; and (f) separating the precipitated zinc carbonate and calcining the basic zinc carbonate to produce zinc oxide. In the process of preparing basic carbonate from an ammonia complex solution, the equipment used is a distillation tower.

[0005] Although the use of a distillation tower for the ammonia crystallization process is beneficial to the stripping of ammonia, there is a problem of easy clogging of the tower plate. Decomplexation and crystallization occur simultaneously during ammonia evaporation, and the crystals accumulate on the tower plates, gradually blocking the openings of the tower plates, causing the system to be unable to operate normally. In addition, the mixing process of the distillation tower relies on bubbles to stir the mixed liquid without forced stirring, which is not applicable in some occasions where there are requirements for parameters such as crystal morphology, particle size distribution, and tap density.

[0006] Patent document US5028410A discloses the use of (NH 4 ) 2 CO 3As a process for preparing ZnO from a leaching solution, the invention utilizes optional pre-oxidation and water leaching steps to remove soluble impurities, and utilizes an optional sulfur dioxide aqueous solution leaching step to selectively remove soluble zinc oxide. In the process of preparing basic carbonate from an ammonia complex solution, i.e., the ammonia evaporation crystallization process, the process equipment used is a kettle-type steam ammonia evaporation crystallization sedimentation process to produce basic zinc carbonate.

[0007] Conventional reactors are used for ammonia evaporation and crystallization. Although there is forced stirring and fewer blockages in the system, which is conducive to the control of the crystallization process, the problem is that the deammoniation is not thorough, the ammonia content in the reactor liquid is too high, and there are still a lot of complex ammonia metal salts, which reduce the ammonia recovery rate and metal recovery rate and increase the cost of subsequent treatment; due to the low efficiency of ammonia evaporation, the concentration of recovered ammonia water is not high, which is not conducive to recycling, resulting in large material consumption and high energy consumption in the production process, which is a non-green process.

[0008] In summary, it is of great significance to find an ammonia crystallization reactor that can conveniently control the decomplexation crystallization process, achieve non-clogging of the crystallization reactor, and be able to operate stably for a long time, while controlling the morphology, particle size distribution and tap density of the crystals, under the premise that the concentration and recovery rate of ammonia water recovered by stripping meet the standards. Summary of the invention

[0009] The invention discloses a gas, liquid and solid three-phase reactor for ammonia evaporation crystallization. By arranging transverse baffles and longitudinal baffles in the reactor, the reactor is divided into a plurality of reaction chambers, and through multi-layer stirring, the decomplexation crystallization process can be effectively controlled to achieve the purposes of fully recovering ammonia and controlling the crystal morphology, particle size distribution and tap density, so that the reaction can be continuously and stably operated for a long time.

[0010] A gas, liquid, solid three-phase reactor for ammonia evaporation and crystallization, wherein the gas, liquid, solid three-phase reactor is of a tower structure, and at least one horizontally arranged transverse baffle is arranged from bottom to top in the reactor to divide the reactor into a plurality of reaction chambers, an axial hole is arranged on the transverse baffle, and a vertically arranged longitudinal baffle is arranged near the inner wall of each reaction chamber;

[0011] The stirring shaft of the reactor extends from the top of the reactor through the shaft hole on the transverse baffle to the bottom of the reactor, wherein the diameter of the shaft hole is larger than the diameter of the stirring shaft, and at least one layer of stirring paddles is provided on the stirring shaft of each reaction chamber;

[0012] A steam inlet and a liquid outlet are provided at the bottom of the reactor, a liquid inlet is provided at the top of the reactor, and a steam outlet is provided at the top. The reaction liquid passes through each reaction chamber from top to bottom through the axial hole to react, and the gas generated by the reaction passes through each reaction chamber from bottom to top through the axial hole to reach the top of the reactor for discharge.

[0013] The present invention divides the reactor into multiple reaction chambers by arranging transverse baffles in the reactor, and each chamber is similar to a fully mixed flow reactor. With the longitudinal baffles, the materials can be mixed quickly and evenly, ensuring sufficient contact and reaction between the reactants and improving the reaction efficiency. At the same time, the multiple chambers are connected in series, so that the entire reactor presents the characteristics of a plug flow reactor as a whole, so that the residence time distribution of the materials in the reactor is more uniform, reducing short circuits and dead zone phenomena, which is beneficial to controlling the reaction process and improving the selectivity and yield of the product.

[0014] Since the reaction chambers are arranged up and down, the entire reactor is similar to a stripping tower, and the gas-liquid mass transfer process in each chamber is similar to a tower plate. Therefore, the reactor is similar to a stripping tower, which is conducive to ammonia stripping and ammonia recovery, improves the ammonia recovery rate and recovery efficiency, and enables the concentration of recovered ammonia to be recycled. In addition, the reactor of the reaction device of the present invention has a stepped concentration difference inside, has the ability of continuous crystallization, can provide a complete process of crystal nucleation, growth, agglomeration and fragmentation, and can enable the reaction to be continuously and stably operated for a long time.

[0015] Preferably, the number of the transverse baffles is 1-16, the longitudinal distance between two adjacent transverse baffles is 0.3-3 times the diameter of the reactor, and the height-to-diameter ratio of the gas-liquid-solid three-phase reactor is 2-10:1.

[0016] Under the condition that the motor shaft and the motor can operate stably for a long time, appropriately increasing the reaction chamber is beneficial to improving the steam efficiency and ammonia recovery rate. Therefore, under the condition that the motor efficiency and the ammonia evaporation efficiency are balanced, 1 to 16 transverse baffles are arranged in the reactor.

[0017] Preferably, the diameter of the axial hole on the transverse baffle is 5-60% of the reactor diameter. The setting of the diameter of the axial hole is determined by the ammonia evaporation efficiency of the reactor and the residence time distribution of the reactor. The higher the ammonia evaporation efficiency and the more the residence time distribution tends to be a plug flow reactor, the smaller the diameter of the axial hole.

[0018] Preferably, the transverse baffle is a hollow disc structure, the upper bottom diameter of the disc is the reactor diameter, the lower bottom diameter is the shaft hole diameter, and the angle between the waistline of the disc and the upper bottom is 1-60°, preferably 15-45°. Since the reactor is a crystallization reactor, as the crystals precipitate, if the transverse baffle is a horizontal baffle, the crystals accumulate on the baffle to form an accumulation, while the transverse baffle with a hollow disc structure having an inclined angle is adopted, the solid cannot accumulate on the transverse baffle, and even if there is a small amount of accumulation, as the stirring proceeds, the fluid is constantly flushed, and the particles on the transverse baffle can be flushed down, thereby avoiding blockage in the system.

[0019] Preferably, the transverse baffle is also provided with air lifting holes.

[0020] The present invention provides a gas riser hole on the transverse baffle plate, which cooperates with the axial hole to make the mass and heat transfer of gas and liquid in the reactor more sufficient. The slurry containing complex salt, ammonia and crystallized solid passes through each reaction chamber of the reactor from top to bottom through the gas riser hole and the axial hole of the transverse baffle plate. The ammonia concentration in the liquid decreases from top to bottom, the concentration of metal ammonia complex salt decreases from top to bottom, and the concentration of metal crystals increases from top to bottom. The ammonia-containing steam passes through each reaction chamber of the reactor from bottom to top through the gas riser hole and the axial hole of the transverse baffle plate to mix gas and liquid and generate ammonia evaporation crystallization reaction. The ammonia concentration in the steam increases from bottom to top, and finally improves the recovery rate of ammonia and metal.

[0021] Preferably, the diameter of the gas riser holes is 0.5-30% of the diameter of the reactor, and the number thereof is 1-5000.

[0022] The diameter and number of the riser holes are determined by the ammonia evaporation efficiency of the reactor and the residence time distribution of the reactor. The higher the ammonia evaporation efficiency and the more the residence time distribution tends to be a plug flow reactor, the smaller the diameter of the riser holes and the fewer the number of the riser holes.

[0023] Preferably, the longitudinal baffles in each reaction chamber have the same size, and the longitudinal baffles in different reaction chambers are arranged on the same side in the reactor.

[0024] Preferably, the width of the longitudinal baffle is 5-50% of the reactor diameter, and the length of the longitudinal baffle is 50-100% of the reaction chamber height. The present invention can effectively eliminate the "vortex" phenomenon and improve the mixing efficiency by setting the longitudinal baffle of this structure.

[0025] The function of the transverse baffle is to prevent the reactor from forming a single mixing zone, and to divide the reactor into multiple reaction chambers, each chamber being similar to a fully mixed flow reactor. With the longitudinal baffle, multiple chambers realize a multi-stage series fully mixed flow reactor, so that the reactor has both the mixing effect of a fully mixed flow reactor and the residence time distribution of a plug flow reactor, and has a good mixing effect. By setting the transverse baffle and the longitudinal baffle of the above structure, an excellent mixing effect can be achieved.

[0026] Preferably, the top and / or bottom of the longitudinal baffle does not contact the adjacent transverse baffle. A gap is left between the top and / or bottom of the longitudinal baffle and the adjacent transverse baffle to avoid crystal accumulation at the contact position.

[0027] Preferably, the diameter of the stirring paddle blade is 20-80% of the diameter of the reactor, and the blade structure is one or more of a paddle-type, propeller-type, turbine-type, anchor-type, frame-type or screw-type stirring paddle.

[0028] The present invention also provides a gas-liquid-solid three-phase reaction process for ammonia evaporation crystallization, which is implemented by using the gas-liquid-solid three-phase reactor for ammonia evaporation crystallization, and comprises the following steps:

[0029] The reactor is first filled with water, and steam is introduced from the steam inlet at the bottom of the reactor to start heating and stirring. After the liquid temperature at the bottom of the reactor reaches 100°C, a metal complex liquid is added from the liquid inlet at the top of the reactor. The metal complex liquid contacts the steam for heat and mass transfer, and a decomposition reaction occurs. The generated ammonia and carbon dioxide pass through each reaction chamber from bottom to top to reach the top steam outlet of the reactor for discharge. At the same time, the metal salt precipitate generated by the decomposition of the metal complex liquid passes through each reaction chamber from top to bottom to reach the bottom of the reaction tower and is filtered after passing through the liquid outlet.

[0030] The ammonia evaporation crystallization process of the present invention is carried out in the above-mentioned reaction device. The reactor is divided into multiple reaction chambers by a transverse baffle. The slurry containing complex salt, ammonia and crystalline solid passes through each reaction chamber of the reactor from top to bottom through the axial hole of the transverse baffle, or the axial hole and the air riser hole. The ammonia concentration in the liquid decreases from top to bottom, the concentration of metal ammonia complex salt decreases from top to bottom, and the concentration of metal crystals increases from top to bottom. Ammonia-containing vapor passes through each reaction chamber of the reactor from bottom to top through the axial hole of the transverse baffle, or the axial hole and the air riser hole, to mix gas and liquid to generate an ammonia evaporation crystallization reaction, and the ammonia concentration in the vapor increases from bottom to top.

[0031] By reasonably setting the reactor structure and operating parameters and controlling the reaction process, the selectivity, yield and ammonia recovery rate of the product can be greatly improved, and the morphology and size of the resulting crystal product can be controlled. For example, the main factors affecting the efficiency of ammonia evaporation are the aspect ratio of the reactor, the number of transverse baffles, the diameter of the air riser and the axial hole, the number of air risers, and the steam flow rate. Increasing the aspect ratio of the reactor, increasing the number of transverse baffles, reducing the diameter of the axial hole and the air riser of the transverse baffle, and increasing the steam flow rate can all improve the ammonia recovery rate. By increasing the stirring rate, the evaporation steam flow rate, and appropriately raising the pH value of the reaction solution, the sphericity of the crystalline particles can be improved, the tap density of the particles can be increased, and the uniformity of the particle size distribution can be improved. In actual operation, adjustments can be made according to the demand for the target product.

[0032] Preferably, the stirring speed is 50-500 rpm.

[0033] Preferably, the metal ammonia complex solution can be an ammonia complex solution of a metal such as copper, nickel, cobalt, silver, zinc, or a rare earth. The metal cation in the metal ammonia complex solution can be Cu(NH 3 ) 4 2+ 、Ni(NH 3 ) 6 2+ 、Co(NH3 ) 6 3+ 、Ag(NH 3 ) 2 + 、Zn(NH 3 ) 4 2+ or La(NH 3 ) 2 3+ The anion may be one or more of chloride, sulfate, carbonate, and hydroxide.

[0034] Preferably, the content of the metal complex in the metal ammine complex solution is 1-30wt%, the content of free ammonia in the metal ammine complex solution is 1-10wt%, the total content of free ammonia and complexed ammonia is 5-30wt%, and the content of carbonate / bicarbonate is 1-15wt%.

[0035] Preferably, the mass ratio of the steam introduced per unit time to the metal ammonia complex liquid is 1:2-10. Controlling the mass ratio of the steam introduced per unit time to the metal ammonia complex liquid within the above range can allow the reaction to proceed fully, obtain a higher ammonia recovery rate, and ensure the quality of the bottom product, while reducing unnecessary energy consumption.

[0036] The metal ammonia complex liquid is added from the liquid inlet at the top of the reactor, and conducts heat and mass transfer with the steam inside the reactor. The metal ion complex liquid is decomposed by heat to release ammonia, and the formed metal cations combine with anions to form metal salt precipitation. The metal complex liquid and steam undergo gas-liquid exchange, and the ammonia in the liquid is vaporized and gradually evaporated, and the metal salt precipitates to form a crystal nucleus, which forms a single crystal or polycrystal after secondary growth.

[0037] Taking copper as an example, the metal carbonate, basic carbonate, basic sulfate, basic chloride, basic nitrate and hydroxide precipitates formed are CuCO 3 、CuCO 3 ﹒ Cu(OH) 2 、CuSO 4 ﹒ Cu(OH) 2 、Cu(OH) 3 CL, Cu(NO3) 2 ·3Cu(OH) 2 、Cu(OH) 2 Ammonia and ammonium bicarbonate are used as complexing liquids to react with electrolytic copper to form copper-ammonia complex ions. The reaction that occurs after the complexing liquid is heated is:

[0038] 2Cu(NH 3 ) 4 CO 3 +H2 O——>CuCO 3 ·Cu(OH) 2 ↓+8NH 3 ↑+CO 2 ↑

[0039] The crystallization process is divided into several parts, including nucleation, growth, agglomeration and fragmentation. The complexing liquid is added from the top of the reactor, and it is decomposed by heat when it contacts the steam inside the reactor. The complexing ammonia part is vaporized, and the metal salt precipitates, forming a crystal nucleus.

[0040] As the complexing liquid and crystal nuclei move from top to bottom in the reactor, the ammonia in the complexing liquid is continuously vaporized and more and more precipitates are formed. The remaining metal salt precipitates will attach and grow on the crystal surface of the crystal nucleus. Crystal growth can eventually form a variety of morphologies (usually anisotropic). The reasons for different growth morphologies include internal and external. The internal reasons are determined by the crystal structure, while there are many external reasons, including the concentration and flow rate of the complexing liquid and operating conditions such as reaction temperature, steam flow rate, stirring rate, stirring intensity, etc.

[0041] In addition to growth, because crystallization is a two-phase state of solid and liquid, in addition to fluids and crystals, the crystallizer also has components such as the crystallizer wall, longitudinal baffles, transverse baffles, and stirring paddles. Therefore, the movement of crystal particles in the crystallizer also includes the movement of stirring paddles, which will inevitably collide with the above-mentioned components. At the same time, collisions may also occur between crystal particles, which may lead to crystal breakage.

[0042] Two or more small crystals may collide and stick together to grow and form agglomeration. The growth process of the crystal can be controlled by adjusting the ratio and concentration of the complexing liquid, or adjusting the crystallization temperature and the form of the stirring paddle, such as spherical particle products, particle size distribution, tap density, etc.

[0043] Preferably, the steam introduced from the bottom of the reactor satisfies: 0.05 MPa<steam pressure<1 MPa, steam temperature>101°C.

[0044] Preferably, during the reaction process, the pressure in the reactor is controlled at 0.3-1.5 bar (absolute pressure), and the temperature is controlled at 60-150°C.

[0045] Preferably, the ammonia content in the exhaust gas from the top of the tower is above 10 wt %; the free ammonia content in the bottom liquid is lower than 1000 mg / L, or even as low as 100 mg / L; and the complex metal content is lower than 200 mg / L.

[0046] The vapor phase of the reactor passes through each reaction chamber from bottom to top and then gathers at the top of the reactor and is discharged from the ammonia vapor outlet. The ammonia content in the vapor is above 10wt%, and then goes to the condenser to condense into ammonia water or a mixture of ammonia and ammonium bicarbonate for reuse. The liquid phase in the reactor passes through each reaction chamber from top to bottom from the ascending air holes of the transverse baffle to the bottom of the reactor. The free ammonia content is less than 1000mg / L and the complex metal content is less than 200mg / L. The process in which the ammonia concentration in the liquid phase in the reactor gradually decreases and the ammonia concentration in the vapor phase gradually increases is similar to the ammonia stripping process, and the reactor plays the role of an ammonia stripping tower.

[0047] Compared with the prior art, the present invention has at least the following beneficial effects:

[0048] (1) The present invention adopts a hollow disc-shaped transverse baffle to avoid the deposition of crystals on the transverse baffle, which affects the stable operation of the reaction; the longitudinal baffle is adopted to eliminate the "vortex" phenomenon and improve the efficiency of stirring and mixing. The transverse baffle and the longitudinal baffle are combined to provide an excellent mixing effect for the reaction chamber, reduce the dead zone, and facilitate the uniformity of the crystals. At the same time, the multi-reaction chamber design enables the reactor to adapt to chemical reactions of different types and conditions. The present invention can flexibly change the performance of the reactor by adjusting the number, size, position and structure of the chambers, etc., to meet the needs of different processes.

[0049] (2) The ammonia evaporation crystallization process of the present invention is carried out in a tower multi-stage stirred reactor, which is divided into multiple reaction chambers by transverse baffles. The slurry containing complex salt, ammonia, and crystallized solid passes through each reaction chamber of the reactor from top to bottom. The ammonia concentration in the liquid decreases from top to bottom, the concentration of metal ammonia complex salt decreases from top to bottom, and the concentration of metal crystals increases from top to bottom. Ammonia-containing vapor passes through each reaction chamber of the reactor from bottom to top to mix gas and liquid to generate ammonia evaporation crystallization reaction. The ammonia concentration in the vapor increases from bottom to top. By reasonably setting the reactor structure and operating parameters, the recovery rate of ammonia can be greatly improved (over 98%).

[0050] (3) The process and reactor characteristics of the present invention have the functions of recovering ammonia by evaporating ammonia and decomplexing and crystallizing at the same time. The reactor has the characteristics of a multi-stage reactor and a stripping tower, and one reaction chamber is equivalent to a plate of a distillation tower. The present invention can effectively control the decomplexing and crystallizing process by controlling the flow rate, stirring intensity and speed, steam volume, etc. of the metal ammonia complex liquid, thereby controlling parameters such as crystal morphology, particle size distribution and tap density. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a schematic structural diagram of the gas, liquid and solid three-phase reaction device for ammonia evaporation and crystallization of the present invention.

[0052] Figure 2It is a three-dimensional perspective view of the gas, liquid and solid three-phase reactor of the present invention.

[0053] Figure 3 It is a top view of the transverse baffle of the present invention.

[0054] Figure 4 It is a cross-sectional view of the transverse baffle of the present invention.

[0055] Figure 5 This is the SEM image of the nickel-cobalt-manganese ternary precursor prepared in Example 2.

[0056] In the figure: 1- horizontal baffle; 2- longitudinal baffle; 3- stirring shaft; 4- stirring paddle; 5- condenser; 6- shaft hole; 7- air riser hole. DETAILED DESCRIPTION

[0057] The present invention will be further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto.

[0058] The gas, liquid and solid three-phase reactor for ammonia evaporation crystallization according to the embodiment of the present invention is as follows: Figure 1 As shown, the gas, liquid and solid three-phase reactor is of a tower structure, and at least one horizontally arranged transverse baffle 1 is arranged from bottom to top in the reactor to divide the reactor into a plurality of reaction chambers, and an axial hole 6 is provided on the transverse baffle, and a vertically arranged longitudinal baffle 2 is provided on the inner wall of each reaction chamber, and the side of the longitudinal baffle 2 is welded or fixed to the reactor cylinder or the reinforcing plate, and the top or bottom end of the longitudinal baffle 2 is flush with the transverse baffle 1 with a gap to avoid crystal accumulation at the contact position;

[0059] A motor is provided at the top of the reactor, and the motor is connected to a stirring shaft 3, and the stirring shaft 3 extends from the top of the reactor through the shaft hole 6 on the transverse baffle 1 to the bottom of the reactor, wherein the diameter of the shaft hole 2 is larger than the diameter of the stirring shaft 3, and at least one layer of stirring paddles 4 is provided on the stirring shaft of each reaction chamber;

[0060] A steam inlet and a liquid outlet are provided at the bottom of the reactor, a liquid inlet is provided at the top of the reactor, and a steam outlet is provided at the top. The reaction liquid passes through each reaction chamber from top to bottom through the axial hole 6 to react, and the gas generated by the reaction passes through each reaction chamber from bottom to top through the axial hole 6 to reach the top of the reactor for discharge. The obtained gas is added with water and condensed in the condenser 5 for recycling.

[0061] Specifically, the number of transverse baffles of the present invention is 1-16, the longitudinal distance between two adjacent transverse baffles is 0.3-3 times the diameter of the reactor, the height-to-diameter ratio of the gas-liquid-solid three-phase reactor is 2-10:1, and the diameter of the axial hole on the transverse baffle is 5-60% of the diameter of the reactor.

[0062] The transverse baffle of the present invention is a hollow disc structure, the upper bottom diameter of the disc is the reactor diameter, the lower bottom diameter is the shaft hole diameter, and the angle between the waistline of the disc and the upper bottom is 1-60°, preferably 15-30°.

[0063] The transverse baffle of the present invention may also be provided with gas lifting holes, the diameter of the gas lifting holes is 0.5-30% of the diameter of the reactor, and the number of the gas lifting holes is 1-5000.

[0064] The longitudinal baffles in each reaction chamber of the reactor of the present invention have the same size, and the longitudinal baffles of different reaction chambers are arranged on the same side in the reactor. The width of the longitudinal baffles is 5-50% of the diameter of the reactor, and the length of the longitudinal baffles is 50-100% of the height of the reaction chamber.

[0065] The diameter of the stirring blade of the present invention is 20-80% of the diameter of the reactor, and the blade structure is one or more of paddle-type, propeller-type, turbine-type, anchor-type, frame-type or spiral-type stirring blades.

[0066] A three-dimensional perspective view of a gas, liquid and solid three-phase reactor according to an embodiment of the present invention is shown in FIG. Figure 2 As shown; the top view of the transverse baffle is as shown Figure 3 The cross-sectional view of the transverse baffle is shown in Figure 4 shown.

[0067] The gas-liquid-solid three-phase reaction process for ammonia evaporation crystallization in the embodiment of the present invention is as follows: the reactor is first filled with water, steam is introduced from the steam inlet at the bottom of the reactor to start heating, stirring is started, and after the liquid temperature at the bottom of the reactor reaches 100° C., a metal complex liquid is added from the liquid inlet at the top of the reactor. The metal complex liquid contacts the steam for heat and mass transfer, and a decomposition reaction occurs. The generated ammonia and carbon dioxide pass through each reaction chamber from bottom to top to reach the top steam outlet of the reactor for discharge. At the same time, the metal salt precipitate generated by the decomposition of the metal complex liquid passes through each reaction chamber from top to bottom to reach the bottom of the reaction tower and is filtered after passing through the liquid outlet.

[0068] Example 1

[0069] The reactor has a diameter of 1600mm, a reactor barrel height of 5000mm, an elliptical head at the top of the reactor, and a total height of about 8400mm including a stirring motor. Three hollow disc-structured transverse baffles are arranged in the reactor, the angle between the waistline of the transverse baffle and the upper bottom surface is 15°, the distance between two adjacent transverse baffles is 1200mm, and the height of the transverse baffle is about 115mm, dividing the reactor into four reaction chambers, and an axial hole is opened in the center of the transverse baffle, and the diameter of the axial hole is 800mm. Four longitudinal baffles of the same size are arranged on the side of the reactor, the width of the longitudinal baffle is 160mm, and the length of each longitudinal baffle is 1200mm, which is the same as the bottom of the reactor barrel. Each chamber is provided with a layer of stirring paddles, which are turbine-type and consist of four blades, and the diameter of the stirring paddles is about 50% of the diameter of the reactor. The stirring motor of the reactor is 55kw, connected to the stirring shaft, and the stirring shaft is connected to each layer of stirring paddles through the shaft hole of the transverse baffle. The stirring speed is set to 100rpm, and the speed can be adjusted by a frequency converter.

[0070] The specific steps of the gas, liquid and solid three-phase reaction process of ammonia evaporation crystallization in this embodiment are as follows:

[0071] Fill the reactor with water, introduce steam, steam pressure is 3-4 bar, steam flow rate is 6.5 t / h, start heating, stir, and control the speed at 100 rpm. When the liquid temperature at the bottom of the reactor reaches 100°C, introduce the metal complex liquid Cu(NH 3 ) 4 CO 3 , Cu(NH 3 ) 4 CO 3 The content is 24wt%, the free ammonia content is 2wt%, the total mass fraction of complex ammonia is 8.5wt%, the carbonate / bicarbonate content is 10.4wt%, the flow rate is 18.2t / h, and the temperature is 75°C. After the complex liquid enters the reactor, it heats up and then decomposes, and the following reactions occur:

[0072] 2Cu(NH 3 ) 4 CO 3 +H 2 O——>CuCO 3 ·Cu(OH) 2 ↓+8NH 3 ↑+CO 2 ↑

[0073] After water vapor is introduced into the bottom of the reactor, it bubbles upward and conducts vapor-liquid heat and mass transfer with the complex liquid in the chamber of the reactor. The concentrations of ammonia and carbon dioxide gradually increase and reach the top of the reactor after passing through the axial hole of the transverse baffle. At this time, the ammonia content in the steam is 41wt%, and the carbon dioxide content is about 17wt%. After adding water and condensing, the ammonia content in the ammonia water is 12wt%, and the ammonium bicarbonate / ammonium carbonate content is 11wt%. Then, carbon dioxide is added to carbonize it into an ammonia leaching solution containing 10wt% of free ammonia and 15wt% of ammonium bicarbonate for recycling. The ammonia content at the bottom of the reactor is less than 500mg / L, and the ammonia recovery rate of the system is greater than 99%.

[0074] As the vapor and liquid transfer heat and mass in each reaction chamber, the copper-ammonia complex ions in the complex liquid are continuously decomposed through the axial holes of the transverse baffle from top to bottom, forming basic copper carbonate precipitation crystals, and the ammonia is vaporized to form ammonia vapor, which reaches the top of the reactor. The concentration of copper ions in the slurry at the bottom of the reactor is about 30 mg / L, ammonia is about 180 mg / L, the solid content is about 13.2wt%, and the mass flow rate is 19.8t / h. It is filtered from the slurry outlet. The basic copper carbonate content obtained after drying is 56.6wt%, and other parameters meet the requirements of HG / T 4825-2015 Class I, and the particle D50 is 12μm.

[0075] Example 2

[0076] The reactor has a diameter of 1600mm, a reactor barrel height of 5000mm, an elliptical head at the top of the reactor, and a total height of about 8400mm including the stirring motor. Three hollow disc-structured transverse baffles are arranged in the reactor, and the angle between the waistline of the transverse baffle and the upper bottom surface is 15°, the distance between two adjacent transverse baffles is 1200mm, and the height of the transverse baffle is about 115mm, dividing the reactor into four reaction chambers. An axial hole with a diameter of 200mm is opened in the center of the transverse baffle, and 30 50mm diameter air riser holes are evenly distributed in the other ranges of the transverse baffle.

[0077] Four longitudinal baffles of the same size are set on the side of the reactor. The width of the longitudinal baffle is 160mm, and the length of each longitudinal baffle is 1200mm, which is the same as the bottom of the reactor cylinder. Each chamber is equipped with a layer of stirring paddles, which are turbine-type and consist of four blades. The stirring motor of the reactor is 55kw, connected to the stirring shaft, and the stirring shaft is connected to each layer of stirring paddles through the shaft hole of the transverse baffle. The diameter of the stirring paddle is 50% of the diameter of the reactor. The stirring speed is set to 100rpm, and the speed can be adjusted by the frequency converter.

[0078] Fill the reactor with water, introduce steam, the steam pressure is 3-4bar, the steam flow rate is 1.0t / h, start heating, the reactor has a strong gas-liquid mixture, start stirring, and control the speed at 100rpm. When the temperature of the water at the bottom of the reactor reaches 100℃, introduce the metal complex liquid from the metal complex liquid inlet at the top of the reactor. The Ni mass content of the nickel-cobalt-ammonia complex mixed solution is 41.2g / L, the cobalt content is 5.5g / L, the ammonia content is 19g / L, the ammonium bicarbonate / ammonium carbonate content is 52g / L, and the flow rate is 2.7t / h. One stream of material is manganese sulfate solution, which contains 10% manganese sulfate, with a flow rate of 158kg / h. After adding it from the manganese solution inlet, it is directly sprayed onto the reactor liquid surface. Another stream of alkali content is 10%, with a flow rate of 78kg / h. After the liquid alkali is added from the alkali inlet of the reactor, it is also directly sprayed onto the reactor liquid surface. The following reaction begins in the reactor:

[0079] 0.8Ni(NH 3 ) 6 CO 3 +0.1Co(NH 3 ) 6 CO 3 +0.1MnSO 4 +0.2NaOH+0.9H 2 O——>Ni 0.8 Co 0.1 Mn 0.1 (OH) 2 ↓+5.4NH 3 ↑+0.9CO 2 ↑+0.1Na 2 SO 4

[0080] After water vapor is introduced into the bottom of the reactor, it bubbles upward and conducts vapor-liquid heat and mass transfer with the complex liquid in the chamber of the reactor. The concentrations of ammonia and carbon dioxide gradually increase, and after passing through the axial hole and the air riser hole of the transverse baffle, it reaches the top of the reactor. At this time, the ammonia content in the steam is 40wt%, and the carbon dioxide content is about 25.5wt%. After adding water and condensing, the ammonia content in the ammonia water is 10wt%, and the ammonium bicarbonate / ammonium carbonate content is 14wt% of the ammonia immersion liquid. A small amount of ammonia water is added, and carbon dioxide is added to carbonize it into ammonia immersion liquid for recycling. The ammonia content at the bottom of the reactor is less than 500mg / L.

[0081] As the gas and liquid transfer heat and mass in each reaction chamber, the nickel-cobalt-ammonia complex ions in the complex liquid are continuously decomposed through the axial holes and air riser holes of the transverse baffle from top to bottom to form nickel-cobalt hydroxide precipitate crystals. At the bottom of the reactor, the concentrations of nickel, cobalt and manganese ions are less than 100 mg / L, the content of nickel-cobalt-manganese hydroxide is about 6.8%, and the mass flow rate is 3.11 t / h. It is discharged from the slurry outlet, the slurry temperature is reduced to 55°C, and aging begins. The aging time is 12 hours, and then it is filtered, washed and dried to obtain the final product 811 ternary precursor 213 kg / h.

[0082] Figure 5 This is the SEM image of the nickel-cobalt-manganese ternary precursor prepared in this example. Figure 4 It can be seen that the particle size distribution of the ternary precursor prepared in this embodiment is uniform, and it is secondary crystallized from nano-scale flake crystals into spherical shapes, with good sphericity. The nickel, cobalt, and manganese contents were measured to be 52.1%, 7.2%, and 3.1%, respectively; the S content was 110ppm, and the sodium content was 10ppm; the D50 of the obtained nickel-cobalt-manganese ternary precursor was 11.3μm; the tap density was 1.8g / cm 3 .

Claims

1. A gas, liquid and solid three-phase reactor for ammonia evaporation crystallization, characterized in that: The gas, liquid and solid three-phase reactor is of a tower structure, and at least one horizontally arranged transverse baffle is arranged from bottom to top in the reactor to divide the reactor into a plurality of reaction chambers, and an axial hole is provided on the transverse baffle, and a vertically arranged longitudinal baffle is provided near the inner wall of each reaction chamber; The stirring shaft of the reactor extends from the top of the reactor through the shaft hole on the transverse baffle to the bottom of the reactor, wherein the diameter of the shaft hole is larger than the diameter of the stirring shaft, and at least one layer of stirring paddles is provided on the stirring shaft of each reaction chamber; The bottom of the reactor is provided with a steam inlet and a liquid outlet, the upper part of the reactor is provided with a liquid inlet, and the top is provided with a steam outlet. The reaction liquid passes through each reaction chamber from top to bottom through the axial hole to react, and the gas generated by the reaction passes through each reaction chamber from bottom to top through the axial hole to reach the top of the reactor for discharge.

2. The gas, liquid and solid three-phase reactor according to claim 1, characterized in that: The number of the transverse baffles is 1-16, and the longitudinal distance between two adjacent transverse baffles is 0.3-3 times the diameter of the reactor.

3. The gas, liquid and solid three-phase reactor according to claim 1, characterized in that: The diameter of the axial hole on the transverse baffle is 5-60% of the diameter of the reactor.

4. The gas, liquid and solid three-phase reactor according to claim 1, characterized in that: The transverse baffle is a hollow disc structure, the upper bottom surface diameter of the disc is the reactor diameter, the lower bottom surface diameter is the shaft hole diameter, and the angle between the waistline of the disc and the upper bottom surface is 1-60°.

5. The gas, liquid and solid three-phase reactor according to claim 1, characterized in that: The transverse baffle is provided with air lifting holes.

6. The gas, liquid and solid three-phase reactor according to claim 5, characterized in that: The number of the gas-raising holes is 1-5000, and the diameter is 0.5-30% of the diameter of the reactor.

7. The gas, liquid and solid three-phase reactor according to claim 1, characterized in that: The longitudinal baffles in each reaction chamber have the same size, and the longitudinal baffles in different reaction chambers are arranged on the same side in the reactor.

8. The gas, liquid and solid three-phase reactor according to claim 1, characterized in that: The width of the longitudinal baffle is 5-50% of the diameter of the reactor, and the length of the longitudinal baffle is 50-100% of the height of the reaction chamber.

9. The gas, liquid and solid three-phase reactor according to claim 1, characterized in that: The top end and / or the bottom end of the longitudinal baffle does not contact the adjacent transverse baffle.

10. The gas-liquid-solid three-phase reactor according to claim 1, characterized in that: The diameter of the stirring blade is 20-80% of the diameter of the reactor.

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