Filtration and adsorption device covered with micro-powder adsorbent and application of filtration and adsorption device

Abstract

The invention discloses a filtration and adsorption device covered with a micro-powder adsorbent, the filtration and adsorption device comprises a first filter and a second filter, the top of the first filter and the top of the second filter are communicated through a pipeline, the first filter and the second filter are both internally provided with a filter plate, and the filter plate of the first filter is covered with a micro-powder lithium adsorbent; the bottom of the first filter is respectively connected with a brine tank and a desorption liquid tank, the bottom of the second filter is respectively connected with a desorption agent tank and a tail liquid tank, and a first circulating pump and a second circulating pump are respectively arranged between the brine tank and the first filter and between the desorption agent tank and the second filter. Meanwhile, the invention further discloses application of the filtration and adsorption device in extraction of lithium from salt lake brine. According to the filtration and adsorption device provided by the invention, by controlling the flow rate, the material liquid recoil micro-powder lithium adsorbent is in a suspended state, so that the filtration difficulty is avoided, the energy consumption is reduced, and meanwhile, the large-flux and high-efficiency application of the lithium adsorbent is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of adsorption and separation, and in particular relates to a filtering and adsorption device covered with a micropowder adsorbent and an application thereof. Background Art

[0002] Lithium extraction from brine is currently the main process for lithium extraction, and most of the lithium extraction from brine adopts the adsorption method. In the application process, the adsorption column filled with conventional adsorbent particles cannot achieve high recovery rate under large flux to adsorb lithium ions in brine. For brine with low lithium content, the application efficiency is low. In addition, in industrial production, lithium adsorbents generally need to be granulated and then loaded into adsorption towers for adsorption and desorption cycle operation. The mechanical strength of the adsorbent is poor during use, and the dissolution rate is large. There will be problems such as excessive column pressure and clogging of the filter plate of the adsorption tower, resulting in low recycling rate of the adsorbent. Therefore, it is necessary to develop an adsorption process with large adsorption capacity, low dissolution rate and strong selectivity for lithium extraction from salt lakes.

[0003] Patent CN 111621640 A discloses an adsorption tower, which is filled with a manganese-based lithium ion adsorbent. The filtered salt lake brine enters the adsorption tower, so that the lithium ions in the salt lake brine are adsorbed on the adsorbent, and then the eluent enters the adsorption tower to desorb to obtain a desorbed liquid, and the desorbed liquid is concentrated to obtain a lithium-containing solution. However, in the invention, a manganese-based granular adsorbent is used in the adsorption tower, and a dilute acid is used as a desorbent. During multiple adsorption and desorption processes, the dissolution rate of the adsorbent is large and the service life is short. If a micro-powder adsorbent is used, it is easy to cause clogging of the filter plate, resulting in difficulty in filtering. Summary of the invention

[0004] In view of the defects of the prior art, the present invention provides a filtering and adsorption device covered with a micropowder adsorbent and its application. By applying the micropowder adsorbent to the filter, the process of adsorption-filtration-desorption-filtration is realized, which can meet the application requirements of lithium adsorbents at high flux and high efficiency.

[0005] A filtering and adsorption device covered with a micro-powder adsorbent comprises a first filter and a second filter, the tops of the first filter and the second filter are connected by a pipeline, and the first filter and the second filter are both provided with filter plates, and the filter plate of the first filter is covered with a micro-powder lithium adsorbent; the bottom of the first filter is respectively connected to a brine tank and a desorption liquid tank, the bottom of the second filter is respectively connected to a desorbent tank and a tail liquid tank, and a first circulation pump and a second circulation pump are respectively provided between the brine tank and the first filter and between the desorbent tank and the second filter.

[0006] Preferably, the micro powder lithium adsorbent is an aluminum salt adsorbent, a titanium-based ion sieve lithium adsorbent or a manganese-based ion sieve lithium adsorbent.

[0007] Preferably, the micro-powder lithium adsorbent is a powder prepared by a sintering method.

[0008] Preferably, the particle size of the micro-powder lithium adsorbent is 1 μm to 500 μm, and the length is 50 μm to 500 mm.

[0009] The application of the filtering and adsorption device covered with micropowder adsorbent in extracting lithium from salt lake brine is as follows: (1) Control the first circulation pump to slowly pump the salt lake brine from the brine tank into the first filter, so that the micro-powder lithium adsorbent in the first filter is suspended by the brine recoil, and then increase the pumping speed. The mixed system in the first filter enters the second filter through the pipeline. After the brine is injected, compressed gas is introduced from the brine tank to discharge all the residual brine in the first filter into the second filter; the second filter is filtered under the action of the filter plate, and the micro-powder lithium adsorbent is retained on the filter plate, and the filtrate enters the tail liquid tank; in this process, the adsorbent exchanges and adsorbs lithium ions, and the filtration is completed; (2) Control the second circulation pump to slowly pump the desorbent from the desorbent tank into the second filter, so that the lithium adsorbent in the second filter is suspended by the backwash of the desorbent, and then increase the pumping speed. The mixed system in the second filter enters the first filter through the pipeline. After the desorbent is injected, the residual desorbent in the second filter is discharged into the first filter using compressed gas; filtration occurs under the action of the filter plate in the first filter, and the micro-powder lithium adsorbent is retained on the filter plate, and the filtrate enters the desorption liquid tank; in this process, the adsorbent exchanges and desorbs lithium ions, and the filtration is completed.

[0010] Preferably, in step (1), the flow rate of the salt lake brine slowly pumped in is 0.4-0.6 cm / s, the time of slow pumping is 180-240 min, and the flow rate of increasing the pumping speed is 5-10 cm / s.

[0011] Preferably, in step (2), the flow rate of the desorbent when slowly pumped in is 1-1.2 cm / s, the time for slow pumping is 40-60 min, and the flow rate of increasing the pumping speed is 5-10 cm / s.

[0012] Advantages of the present invention: (1) The filtering and adsorption device covered with a lithium powder adsorbent provided by the present invention controls the flow rate so that the lithium powder adsorbent is in a suspended state when the feed liquid recoils, and the ion exchange efficiency is high. When in the suspended state, the lithium powder adsorbent does not reach the filter plate of the second filter, which will not cause filtration difficulties and reduce energy consumption; (2) The lithium powder adsorbent used in the present invention is micron-grade, has a small particle size, a large specific surface area, and a fast adsorption speed. It can reach adsorption saturation in a short time, and the concentration of the analyzed qualified solution is high. Compared with the traditional single-tower adsorption process, the amount of adsorbent used is significantly reduced, and the investment and operating costs are reduced; (3) After adsorption and desorption are completed, compressed air is used to remove the remaining liquid, avoiding mutual contamination between the liquid and the feed; (4) The filtration and adsorption device of the present invention has a simple structure, flexible installation and assembly, integrates adsorption, filtration and desorption, has a strong lithium ion adsorption capacity, and can achieve deep treatment of brine through the cyclic coordination of the four processes of adsorption-filtration-desorption-filtration, while realizing the application of lithium adsorbent with high flux and high efficiency; (5) The use of micro-powder lithium adsorbent can avoid the adsorbent granulation process and has good strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A schematic structural diagram of the filtering and adsorption device of the present invention. DETAILED DESCRIPTION

[0014] Example 1 A filtering and adsorption device covered with a micro-powder adsorbent comprises a first filter and a second filter, the tops of the first filter and the second filter are connected by a pipeline, and the first filter and the second filter are both provided with filter plates, and the filter plate of the first filter is covered with a micro-powder lithium adsorbent; the bottom of the first filter is respectively connected to a brine tank and a desorption liquid tank, the bottom of the second filter is respectively connected to a desorbent tank and a tail liquid tank, and a first circulation pump and a second circulation pump are respectively provided between the brine tank and the first filter and between the desorbent tank and the second filter.

[0015] The micro powder lithium adsorbent is an aluminum salt adsorbent, a titanium series ion sieve lithium adsorbent or a manganese series ion sieve lithium adsorbent.

[0016] The micro powder lithium adsorbent is a powder prepared by a sintering method; it does not need to be granulated again and has good strength.

[0017] The particle size of the micro-powder lithium adsorbent is 1 μm to 500 μm, and the length is 50 μm to 500 mm.

[0018] Example 2 The device described in Example 1 is used to extract lithium from salt lake brine, wherein the filter plate of the first filter is covered with an aluminum-based micro-powder lithium adsorbent, as follows: (1) Control the first circulation pump to slowly pump the salt lake brine from the brine tank into the first filter at a flow rate of 0.6 cm / s for 180 min, so that the micro-powder lithium adsorbent in the first filter is suspended by the brine recoil, and then increase the pumping speed to 5 cm / s. The mixed system in the first filter enters the second filter through the pipeline. After the brine is injected, compressed gas is introduced from the brine tank to discharge all the residual brine in the first filter into the second filter; filtering occurs under the action of the filter plate in the second filter, and the micro-powder lithium adsorbent is retained on the filter plate, and the filtrate enters the tail liquid tank; in this process, the adsorbent exchanges and adsorbs lithium ions, and the filtration is completed; (2) Control the second circulation pump to slowly pump the desorbent ultrapure water from the desorbent tank into the second filter at a flow rate of 1.2 cm / s and a time of 40 min, so that the lithium adsorbent in the second filter is suspended by the backwash of the desorbent, and then increase the pumping speed. The mixed system in the second filter enters the first filter through the pipeline. After the desorbent is injected, the residual desorbent in the second filter is discharged into the first filter using compressed gas; filtration occurs under the action of the filter plate in the first filter, and the micro-powder lithium adsorbent is retained on the filter plate, and the filtrate enters the desorption liquid tank; in this process, the adsorbent exchanges and desorbs lithium ions, and filtration is completed.

[0019] Example 3 The device described in Example 1 is used to extract lithium from salt lake brine, wherein the filter plate of the first filter is covered with a titanium-based micro-powder lithium adsorbent, as follows: (1) Control the first circulation pump to slowly pump the salt lake brine from the brine tank into the first filter at a flow rate of 0.5 cm / s for 200 min, so that the micro-powder lithium adsorbent in the first filter is suspended by the brine recoil, and then increase the pumping speed to 5 cm / s. The mixed system in the first filter enters the second filter through the pipeline. After the brine is injected, compressed gas is introduced from the brine tank to discharge all the residual brine in the first filter into the second filter; filtering occurs under the action of the filter plate in the second filter, and the micro-powder lithium adsorbent is retained on the filter plate, and the filtrate enters the tail liquid tank; in this process, the adsorbent exchanges and adsorbs lithium ions, and the filtration is completed; (2) Control the second circulation pump to slowly pump the desorbent from the desorbent tank into the second filter at a flow rate of 1.0 cm / s for 60 min, so that the lithium adsorbent in the second filter is suspended by the backwash of the desorbent, and then increase the pumping speed to 5 cm / s. The mixed system in the second filter enters the first filter through the pipeline. After the desorbent is injected, the residual desorbent in the second filter is discharged into the first filter using compressed gas; filtration occurs under the action of the filter plate in the first filter, and the micro-powder lithium adsorbent is retained on the filter plate, and the filtrate enters the desorption liquid tank; in this process, the adsorbent exchanges and desorbs lithium ions, and filtration is completed.

Claims

1. A filtering and adsorption device covered with a micropowder adsorbent, characterized in that: It includes a first filter and a second filter, the tops of the first filter and the second filter are connected by a pipeline, and filter plates are provided in the first filter and the second filter, and the filter plate of the first filter is covered with a micro-powder lithium adsorbent; the bottom of the first filter is respectively connected to a brine tank and a desorption liquid tank, the bottom of the second filter is respectively connected to a desorbent tank and a tail liquid tank, and a first circulation pump and a second circulation pump are respectively provided between the brine tank and the first filter and between the desorbent tank and the second filter.

2. The filtering and adsorption device covered with a micro powder adsorbent according to claim 1, characterized in that: The micro powder lithium adsorbent is an aluminum salt adsorbent, a titanium series ion sieve lithium adsorbent or a manganese series ion sieve lithium adsorbent.

3. The filtering and adsorption device covered with a micro powder adsorbent according to claim 2, characterized in that: The micro powder lithium adsorbent is a powder prepared by a sintering method.

4. The filtering and adsorption device covered with a micro powder adsorbent according to claim 3, characterized in that: The particle size of the micro-powder lithium adsorbent is 1-μm~500μm, and the length is 50μm~500mm.

5. The use of the filtration adsorption device covered with micropowder adsorbent according to claim 1 in extracting lithium from salt lake brine, characterized in that: The application is as follows: (1) Control the first circulation pump to slowly pump the salt lake brine from the brine tank into the first filter, so that the micro-powder lithium adsorbent in the first filter is suspended by the brine backwash, and then increase the pumping speed, and the mixed system in the first filter enters the second filter through the pipeline. After the brine is injected, compressed gas is introduced from the brine tank to discharge all the residual brine in the first filter into the second filter; the second filter is filtered under the action of the filter plate, and the micro-powder lithium adsorbent is retained on the filter plate, and the filtrate enters the tail liquid tank; (2) Control the second circulation pump to slowly pump the desorbent from the desorbent tank into the second filter, so that the lithium adsorbent in the second filter is suspended by the backwash of the desorbent, and then increase the pumping speed. The mixed system in the second filter enters the first filter through the pipeline. After the desorbent is injected, the residual desorbent in the second filter is discharged into the first filter using compressed gas; the first filter is filtered under the action of the filter plate, and the micro powder lithium adsorbent is retained on the filter plate, and the filtrate enters the desorption liquid tank.

6. The use of the filtration adsorption device covered with micropowder adsorbent according to claim 5 in extracting lithium from salt lake brine, characterized in that: In step (1), the flow rate of the salt lake brine slowly pumped in is 0.4-0.6 cm / s, the time of slow pumping is 180-240 min, and the flow rate of increasing the pumping speed is 5-10 cm / s.

7. Use of the filtration adsorption device covered with micropowder adsorbent according to claim 5 in extracting lithium from salt lake brine, characterized in that: In step (2), the flow rate of the desorbent when slowly pumped in is 1.0-1.2 cm / s, the time for slow pumping is 40-60 min, and the flow rate of increasing the pumping speed is 5-10 cm / s.

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