Efficient carbonization tower for purifying lithium carbonate

Abstract

The utility model relates to the technical field of equipment for purifying lithium carbonate, in particular to an efficient carbonization tower for purifying lithium carbonate. The carbonization tower is specifically an internal circulation carbonization tower, a feeding port and a gas outlet are formed in the top of a tower body, and a lithium carbonate aqueous solution is introduced into the feeding port; a discharge hole and a gas inlet are formed in the bottom of the tower body, and carbon dioxide gas is introduced into the gas inlet. The carbonization barrel is sequentially provided with a heat exchange device, a stirring paddle, a sieve plate and a downcomer from bottom to top, wherein the sieve plate and the downcomer are non-uniformly arranged and play a role in flow penetration; and a catalyst is uniformly distributed on the sieve plate. The sieve plate holes and the catalyst are distributed according to the principle of denseness to sparseness from inside to outside. The high-efficiency carbonization tower disclosed by the utility model can effectively increase the gas-liquid reaction area and the reaction activity.

Description

Technical Field

[0001] The utility model relates to the technical field of carbonization towers, in particular to a high-efficiency carbonization tower for purifying lithium carbonate. Background Art

[0002] High-purity Li2CO3 is a necessity in the magnetic materials industry, atomic energy industry, electronics industry, and optical instrument industry. In the electronics industry, high-purity Li2CO3 can be used as the positive electrode material and electrolyte raw material of lithium-ion batteries.

[0003] Lithium carbonate purification refers to the treatment of lithium carbonate containing impurities to make its purity reach a certain requirement; in the production process of lithium carbonate, the high-efficiency carbonization tower is a commonly used equipment for separation and purification in the lithium carbonate purification process. The raw material lithium carbonate and water are mixed to obtain a lithium carbonate solution; the lithium carbonate solution is fed to the top of the high-efficiency carbonization tower, and the solvent is evenly sprayed onto the tower plate or packing layer through a sprayer or nozzle, and contacts and reacts with the lithium carbonate solution.

[0004] On the tray or material layer, through material exchange and reaction, impurities may be adsorbed or reacted by the solvent and gradually removed from the solution, while pure lithium carbonate is collected from the bottom outlet. Through step-by-step treatment, a high-purity lithium carbonate product is obtained. However, the contact surface between carbon dioxide and lithium carbonate solution in the existing carbonization tower is small, and the reaction efficiency in the carbonization tower is low, so the purity of Li2CO3 cannot be further improved.

[0005] Utility model patent CN210457499U discloses an efficient carbonization tower for lithium carbonate purification. A diffuser pipe connected to the air inlet is provided in the tower body, and multiple vents are provided on the branch pipe of the diffuser pipe, thereby promoting gas flow and promoting efficient reaction of the carbonization tower. However, only promoting gas flow locally cannot achieve the reaction rate of lithium carbonate solution and carbon dioxide gas in the entire tower body. Utility Model Content

[0006] In order to solve the drawbacks of small contact surface between carbon dioxide and lithium carbonate solution in the existing carbonization tower and low reaction efficiency in the carbonization tower, the utility model adds a stirring paddle and further transforms the sieve plate on the basis of the existing carbonization tower. The specific technical scheme is as follows:

[0007] The invention discloses an internal circulation carbonization tower for purifying lithium carbonate. The carbonization tower is divided into an inner cylinder and an outer cylinder. Stirring paddles are arranged at intervals on both sides of the inner cylinder. A plurality of sieve plates are arranged above the stirring paddles. The sieve plates are provided with non-uniformly arranged sieve holes, and the number of sieve holes decreases from dense to sparse from the center to the outside. A catalyst for promoting the reaction of carbon dioxide and lithium carbonate aqueous solution is placed on the sieve plates, and the sieve plates play a role of penetrating the catalyst.

[0008] As a further solution of the utility model, a feed port and an air outlet are arranged at the top of the carbonization tower; a feed port and an air inlet are arranged at the bottom; a lithium carbonate aqueous solution is introduced into the feed port, and carbon dioxide gas is introduced into the air inlet.

[0009] As a further solution of the utility model, a heat exchange device is arranged at the bottom of the carbonization tower and above the air inlet, specifically a shell-and-tube heat exchanger.

[0010] As a further solution of the utility model, the stirring paddle includes a main shaft driven by a motor and fan-shaped blades distributed on the main shaft.

[0011] As a further solution of the utility model, a downcomer is arranged between the upper and lower sieve plates to reduce the back mixing of the gas phase between the plates.

[0012] The advantages of the utility model are:

[0013] The improved internal circulation tower designed by the utility model has stirring paddles evenly spaced on both sides of the inner cylinder, and the stirring paddles are rotated to improve the gas-liquid distribution and mass transfer conditions. In addition, the stirring paddles are used as baffles to impact the liquid and increase the reaction rate.

[0014] In addition, by setting up non-uniformly arranged sieve plates inside the inner circulation tower to play a flow-through role, the number of sieve holes on the sieve plates follows the principle of becoming sparse from the center to the outside, and a catalyst that promotes the reaction between carbon dioxide and lithium carbonate aqueous solution is also placed on the sieve plates accordingly; thereby, the forward progress of the reaction is promoted under the adaptation of the stirring paddle structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the internal structure of an internal circulation carbonization tower for lithium carbonate purification;

[0016] Figure 2 This is a partial enlarged view of the sieve plate-sieve hole-catalyst stack.

[0017] Reference numerals:

[0018] 1-feed port; 2-gas outlet; 3-discharge port; 4-gas inlet; 5-heat exchange device; 6-catalyst; 7-sieve plate; 8-downcomer; 9-agitation paddle. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the utility model.

[0020] See also Figure 1 , an efficient carbonization tower for purifying lithium carbonate, a feed inlet 1 and an air outlet 2 are arranged at the top of the tower body, and an outlet 3 and an air inlet 4 are arranged at the bottom. The lithium carbonate aqueous solution enters from the feed inlet 4 at the top of the carbonization tower, and carbon dioxide is introduced from the air inlet 4 of the carbonization tower.

[0021] A heat exchange device is arranged on the upper side of the carbonization tower air inlet 4, and the heat exchange device is specifically a shell-and-tube heat exchanger horizontally placed inside the tower body.

[0022] The carbonization tower adopts an internal circulation carbonization tower. Carbon dioxide gas enters the inner cylinder of the reactor through the air inlet 4, and stirring paddles 9 are spaced on both sides of the inner cylinder to improve the gas-liquid distribution and mass transfer conditions and promote the uniform distribution of lithium carbonate aqueous solution and gas. In addition, the stirring paddle 9 can also serve as a vertical baffle, and the bubbles are hit by the baffle to form many small bubbles, which are evenly dispersed in the entire reactor, thereby increasing the reaction rate and shortening the reaction time of lithium carbonate and carbon dioxide.

[0023] See also Figure 2 , multiple sieve plates 7 are arranged inside the inner circulation tower and above the stirring paddle 9, and the sieve plates 7 play a role of flow penetration. The sieve plates 7 are provided with non-uniformly arranged sieve holes, the opening rate of which is low in the center and high in the surrounding area. The part with a higher opening rate of the sieve plate 7 and the mass transfer stirring paddle 9 are located on the same side, so that the reaction activity on both sides is improved while adapting to the carbonization tower structure. In addition, a catalyst 6 is placed on the sieve plate 7 to promote the reaction of carbon dioxide and lithium carbonate aqueous solution; its distribution also follows the principle of more on both sides and less in the center.

[0024] The sieve plate 7 and the downcomer 8 guide the flow into a "bow" shape, and the gas and liquid flow in a cross-shaped manner, and the gas and liquid flow in separate paths without interfering with each other.

[0025] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An efficient carbonization tower for purifying lithium carbonate, characterized in that: The carbonization tower is divided into an inner cylinder and an outer cylinder; stirring paddles (9) are arranged at intervals on both sides of the inner cylinder; a plurality of sieve plates (7) are arranged above the stirring paddles (9); the sieve plates (7) are provided with non-uniformly arranged sieve holes, the number of which decreases from dense to sparse from the center to the outside; a catalyst (6) for promoting the reaction of carbon dioxide and lithium carbonate aqueous solution is placed on the sieve plates (7); the sieve plates (7) play a role in penetrating the catalyst (6).

2. The efficient carbonization tower for purifying lithium carbonate according to claim 1, characterized in that: The top of the carbonization tower is provided with a feed inlet (1) and a gas outlet (2); the bottom is provided with a feed outlet (3) and a gas inlet (4); the feed inlet (1) is introduced into a lithium carbonate aqueous solution, and the gas inlet (4) is introduced into carbon dioxide gas.

3. The efficient carbonization tower for purifying lithium carbonate according to claim 1, characterized in that: A heat exchange device is arranged at the bottom of the carbonization tower and above the air inlet (4), specifically a shell-and-tube heat exchanger.

4. The efficient carbonization tower for purifying lithium carbonate according to claim 1, characterized in that: The stirring paddle (9) comprises a main shaft driven by a motor and fan-shaped blades distributed on the main shaft.

5. The efficient carbonization tower for purifying lithium carbonate according to claim 1, characterized in that: A downcomer (8) is provided between the upper and lower sieve plates (7) to reduce backmixing of the gas phase between the plates.

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