阅读说明：本技术 一种盐差驱动的提锂系统 (Lithium extraction system driven by salt difference ) 是由 胡雪蛟 江海峰 洪子鑫 操斌 牛静 欧阳少峰 于 2019-11-15 设计创作，主要内容包括：本发明公开了一种盐差驱动的提锂系统,包括浓盐水腔、普通海水腔和阴离子交换膜,所述浓盐水腔内灌有浓盐水,普通海水腔灌有普通海水；所述阴离子交换膜设于浓盐水腔与普通海水腔之间,阴离子可经阴离子交换膜在浓盐水腔与普通海水腔之间流动；在浓盐水腔内设有浸于浓盐水的锂元素吸附电极,在普通海水腔内设有浸于普通海水的电极板,锂元素吸附电极与电极板通过引出外部的导线相连。本发明的有益效果为：本发明利用盐差能作为驱动能来实现阳离子富集以实现加速锂元素的吸收,无需额外消耗其它高品位能量；且盐差能作为唯一驱动能,不消耗高品质能源,成本低廉,可用于工业持续提锂。(The invention discloses a lithium extraction system driven by salt difference, which comprises a strong brine cavity, a common seawater cavity and an anion exchange membrane, wherein strong brine is filled in the strong brine cavity, and common seawater is filled in the common seawater cavity; the anion exchange membrane is arranged between the strong brine cavity and the common seawater cavity, and anions can flow between the strong brine cavity and the common seawater cavity through the anion exchange membrane; the lithium element adsorption electrode immersed in the strong brine is arranged in the strong brine cavity, the electrode plate immersed in the common seawater is arranged in the common seawater cavity, and the lithium element adsorption electrode is connected with the electrode plate through a lead wire led out of the lithium element adsorption electrode. The invention has the beneficial effects that: the invention realizes cation enrichment by using the salt difference energy as driving energy to realize acceleration of the absorption of lithium element without additional consumption of other high-grade energy; and the salt difference energy is used as the only driving energy, high-quality energy is not consumed, the cost is low, and the method can be used for continuously extracting lithium in industry.)

1. A lithium extraction system driven by salt difference is characterized by comprising a strong brine cavity, a common seawater cavity and an anion exchange membrane, wherein strong brine is filled in the strong brine cavity, and common seawater is filled in the common seawater cavity; the anion exchange membrane is arranged between the strong brine cavity and the common seawater cavity, and anions can flow between the strong brine cavity and the common seawater cavity through the anion exchange membrane; the lithium element adsorption electrode immersed in the strong brine is arranged in the strong brine cavity, the electrode plate immersed in the common seawater is arranged in the common seawater cavity, and the lithium element adsorption electrode is connected with the electrode plate through a lead wire led out of the lithium element adsorption electrode.

2. The system of claim 1, wherein the water inlet of the brine chamber is connected to a brine inlet pipe, the water outlet of the brine chamber is connected to a brine outlet pipe, and the water level of the water inlet of the brine chamber is higher than the water level of the water outlet of the brine chamber.

3. The system of claim 1, wherein the inlet of the normal seawater chamber is connected to the outlet of the normal seawater inlet pipe, the outlet of the normal seawater chamber is connected to the inlet of the normal seawater outlet pipe, and the water level of the inlet of the normal seawater chamber is higher than that of the outlet of the normal seawater chamber.

4. The salt-difference driven lithium extraction system of claim 1, wherein the anion exchange membrane is fastened between the concentrated brine chamber and the normal seawater chamber by a clamping plate or a flange.

5. The salt-difference-driven lithium extraction system according to claim 1, wherein the lithium-adsorbing electrode is a porous spinel-structured electrode.

Technical Field

The invention relates to the technical field of lithium extraction, in particular to a lithium extraction system driven by a salt difference.

Background

Along with the rapid development of lithium ion batteries, the demand of lithium carbonate in various countries in the world is rapidly increased, 265 kilotons of lithium carbonate are needed in the world in 2015, and 498 kilotons of lithium carbonate are needed in the whole world in 2025 [ 1 ]. Lithium ions are becoming a scarce resource in competition throughout the world. The existing lithium extraction technology mainly comprises an adsorption method, a reverse osmosis method and an extraction method, wherein the adsorption method consumes an adsorbent and has low adsorption efficiency; the reverse osmosis method needs to consume high-grade electric energy as driving to separate lithium ions; the extraction method is complex in operation and requires large manual investment. The traditional lithium extraction device is very large, the initial investment is high, and the energy consumption is large. Therefore, how to extract lithium element at low cost is a hot issue in the development of lithium extraction nowadays.

The seawater is rich in 2500 million tons of lithium resources, but the concentration is only 0.17mg/L, so that the extraction of lithium in the seawater is very difficult. The concentrated brine after seawater desalination is waste material in seawater desalination products, and can cause great damage to the ecological environment when being directly discharged into seawater, but the concentration of lithium ions in the concentrated brine is much higher than that of common seawater, and the concentrated brine is the best raw material for extracting the lithium ions. The salt difference energy is always a hot point of research of various researchers, and the salt difference energy between the strong brine and the common seawater can be used as the driving energy for lithium extraction, so that waste can be changed into valuable, and the environment can be protected.

At present, there is a related technology for extracting lithium from concentrated brine, for example, a method for extracting lithium from old brine in a salt pan is proposed in patent application No. 2018111336368, and the method uses five steps of (1) adsorption to remove magnesium; (2) eluting lithium by variable speed spraying in a segmented manner; (3) deeply removing magnesium by ion exchange resin adsorption; (4) reverse osmosis; (5) lithium carbonate is prepared to prepare lithium carbonate. In patent application No. 2016111226871, a method for extracting lithium from salt lake brine is proposed, in which raw brine saturated or nearly saturated with magnesium ions is passed through a microfiltration device to remove suspended particles, and then is transferred into an electrodialysis device, and a product liquid is obtained by multiple electrodialysis.

However, the above conventional method is complicated in steps, and a whole set of steps takes a lot of time; each individual step requires the preparation of an individual device, which is a huge investment in cost; the whole process needs to consume high-grade energy such as electric energy.

Disclosure of Invention

The invention aims to provide a low-cost lithium extraction system driven by a salt difference without consuming high-quality energy aiming at the defects of the prior art.

The technical scheme adopted by the invention is as follows: a lithium extraction system driven by salt difference comprises a strong brine cavity, a common seawater cavity and an anion exchange membrane, wherein strong brine is filled in the strong brine cavity, and common seawater is filled in the common seawater cavity; the anion exchange membrane is arranged between the strong brine cavity and the common seawater cavity, and anions can flow between the strong brine cavity and the common seawater cavity through the anion exchange membrane; the lithium element adsorption electrode immersed in the strong brine is arranged in the strong brine cavity, the electrode plate immersed in the common seawater is arranged in the common seawater cavity, and the lithium element adsorption electrode is connected with the electrode plate through a lead wire led out of the lithium element adsorption electrode.

According to the above scheme, the water inlet and the strong brine inlet tube intercommunication in strong brine chamber, the delivery port and the strong brine outlet pipe intercommunication in strong brine chamber, and the water inlet surface of water height in strong brine chamber is higher than the delivery port surface of water height in strong brine chamber.

According to the scheme, the water inlet of the common seawater cavity is connected with the outlet of the common seawater inlet pipe, the water outlet of the common seawater cavity is connected with the inlet of the common seawater outlet pipe, and the water surface height of the water inlet of the common seawater cavity is higher than that of the water outlet of the common seawater cavity.

According to the scheme, the anion exchange membrane is fixed between the concentrated salt water cavity and the common seawater cavity through clamping plates or flanges.

According to the scheme, the lithium element adsorption electrode is a porous spinel structure electrode.

The invention has the beneficial effects that:

1. the invention realizes cation enrichment by using the salt difference energy as driving energy to realize acceleration of the absorption of lithium element without additional consumption of other high-grade energy; and the salt difference energy is used as the only driving energy, high-quality energy is not consumed, the cost is low, and the method can be used for continuously extracting lithium in industry.

2. The whole system has good air tightness, the water level height of the strong brine inlet is higher than that of the strong brine outlet, the water level height of the common seawater inlet is higher than that of the common seawater outlet, strong brine and common seawater are promoted to flow by utilizing the siphon effect, and extra pumping work is not required to be consumed; the flow rate of the strong brine is adjusted by controlling the height difference between the water surface of the water inlet of the strong brine cavity and the water surface of the water outlet of the strong brine cavity; the flow rate of the seawater is adjusted by controlling the height difference between the water surface of the water inlet of the common seawater cavity and the water surface of the water outlet of the common seawater cavity.

3. The raw materials of the invention are waste materials in the seawater desalination product, the waste materials are further utilized, rare lithium element is extracted, and the effect of changing waste into valuable is achieved; simultaneously, the strong brine is also desalted.

4. The invention has simple structure and process, low cost and high efficiency, and can realize low-cost industrial lithium extraction by parallel connection.

Drawings

Fig. 1 is a schematic structural diagram of an embodiment of the present invention.

Wherein: 1. a wire; 2. a strong brine cavity; 3. a lithium element-adsorbing electrode; 4. a strong brine outlet pipe; 5. a strong brine inlet pipe; 6. an anion exchange membrane; 7. an electrode plate; 8. a common seawater cavity; 9. fastening a flange; 10. a common seawater outlet pipe; 11. a common seawater inlet pipe.

Detailed Description

For a better understanding of the present invention, reference is made to the following detailed description taken in conjunction with the accompanying drawings.

As shown in fig. 1, the lithium extraction system driven by salt difference comprises a strong brine cavity 2, a common seawater cavity 8 and an anion exchange membrane 6, wherein strong brine is filled in the strong brine cavity 2, and common seawater is filled in the common seawater cavity 8; the anion exchange membrane 6 is arranged between the strong brine cavity 2 and the common seawater cavity 8, and anions can flow between the strong brine cavity 2 and the common seawater cavity 8 through the anion exchange membrane 6; the lithium element adsorption electrode 3 immersed in the strong brine is arranged in the strong brine cavity 2, the electrode plate 7 immersed in the common seawater is arranged in the common seawater cavity 8, and the lithium element adsorption electrode 3 is connected with the electrode plate 7 through the lead 1 led out of the outside. In the invention, an anion exchange membrane 6 is fixed between a strong brine cavity 2 and a common seawater cavity 8 through a clamping plate or a flange buckle 9; the strong brine is derived from a seawater desalination product.

Preferably, the water inlet and the strong brine inlet pipe 5 intercommunication in strong brine chamber 2, the delivery port and the strong brine outlet pipe 4 intercommunication in strong brine chamber 2, and the water inlet surface of water height in strong brine chamber 2 is higher than the delivery port surface of water height in strong brine chamber 2.

Preferably, the water inlet of the common seawater cavity 8 is connected with the outlet of the common seawater inlet pipe 11, the water outlet of the common seawater cavity 8 is connected with the inlet of the common seawater outlet pipe 10, and the water level of the water inlet of the common seawater cavity 8 is higher than that of the water outlet of the common seawater cavity 8.

In the invention, strong brine and common seawater are promoted to flow by utilizing siphon effect; the flow rate of the strong brine is adjusted by controlling the height difference between the water surface of the water inlet of the strong brine cavity 2 and the water surface of the water outlet of the strong brine cavity 2; the flow rate of the seawater is adjusted by controlling the height difference between the water surface of the water inlet of the common seawater cavity 8 and the water surface of the water outlet of the common seawater cavity 8.

In the invention, the lithium element adsorption electrode 3 can be a porous spinel structure electrode, and can also be prepared by adopting lithium titanate, spinel manganese dioxide and the like as raw materials; the electrode plate 7 is made of conductive materials with good conductivity and corrosion resistance, and can be made of conductive materials such as silver sheets, copper sheets or graphite plates; the anion exchange membrane 6 is prepared by adopting a membrane material with better corrosion resistance and selective permeability, and the anion exchange membrane 6 can be replaced by anion exchange resin.

The working principle of the invention is as follows: before the system operates, the strong brine cavity 2, the strong brine inlet pipe 5 and the strong brine outlet pipe 4 are filled with strong brine, and the common seawater cavity 8, the common seawater inlet pipe 11 and the common seawater outlet pipe 10 are filled with seawater. When the strong brine cavity 2 and the common seawater cavity 8 are filled with water, anions (chloride ions, hydroxide ions and the like) are promoted to move from the strong brine cavity 2 to the common seawater cavity 8 through the anion exchange membrane 6 due to concentration difference (the concentration of ions in the strong brine is higher than that of ions in the common seawater); the directional removal of ion produces the electric current, and strong brine chamber 2 and sea water chamber have become galvanic anode and negative pole this moment to constitute the return circuit through outside wire 1, the electric current direction is by sea water chamber flow direction strong brine chamber 2 in the cavity, lead to the cation in the strong brine to adsorb near lithium element adsorption electrode 3 enrichment, the cation enrichment has accelerated the absorption of lithium element, treat to take out from strong brine chamber 2 after lithium element adsorption electrode 3 adsorbs the saturation, it can to carry out the desorption again.

In the present invention, the amount of the adsorbed lithium element can be changed by changing the volume and the specific surface area of the lithium element adsorbing electrode 3 and the material (for example, the electrode is prepared by using spinel manganese dioxide, spinel lithium titanate and the like as the substrate). The device can realize industrialized lithium extraction by connecting a plurality of devices in parallel.

It should be noted that the above-mentioned embodiments are only preferred embodiments of the present invention, and the present invention is not limited thereto, and although the present invention has been described in detail with reference to the embodiments, it will be apparent to those skilled in the art that modifications can be made to the technical solutions described in the above-mentioned embodiments, or equivalent substitutions of some technical features, but any modifications, equivalents, improvements and the like within the spirit and principle of the present invention shall be included in the protection scope of the present invention.