Equipment for extracting lithium from brine by adsorption method
阅读说明:本技术 用于吸附法卤水提锂的设备 (Equipment for extracting lithium from brine by adsorption method ) 是由 李亦然 沈芳明 马君耀 许挺 张凯 于 2020-07-07 设计创作,主要内容包括:本发明提供了一种用于吸附法卤水提锂的设备,属于吸附提锂设备技术领域。它包括带式真空过滤机,所述的带式真空过滤机连接有用于将卤水和吸附剂混合的固液混合机构,带式真空过滤机上并沿着带式真空过滤机的传动方向依次设有相互连接的原料卤水区、洗盐区和解吸区,固液混合机构连接原料卤水区,输送洗盐液的第一液体输送机构和输送解吸液的第二液体输送机构分别连接洗盐区和解吸区。本发明相比现有的吸附塔吸附,本发明投资成本低,大幅降低了后续除盐提纯工艺的投资和生产成本,最终可以稳定得到电池级碳酸锂或氢氧化锂。(The invention provides equipment for extracting lithium from brine by an adsorption method, and belongs to the technical field of adsorption lithium extraction equipment. It includes belt vacuum filter, belt vacuum filter be connected with and be used for the solid-liquid mixing mechanism with brine and adsorbent mixture, belt vacuum filter is last and be equipped with interconnect's raw materials brine district, salt washing district and desorption district along belt vacuum filter's transmission direction in proper order, raw materials brine district is connected to solid-liquid mixing mechanism, salt washing liquid's first liquid conveying mechanism and the second liquid conveying mechanism who carries desorption liquid are connected respectively and are washed salt district and desorption district. Compared with the existing adsorption tower, the invention has low investment cost, greatly reduces the investment and production cost of the subsequent desalting and purifying process, and can stably obtain the battery-grade lithium carbonate or lithium hydroxide finally.)
1. The utility model provides an equipment for adsorption process brine carries lithium, includes belt vacuum filter (100), its characterized in that, belt vacuum filter (100) be connected with and be used for solid-liquid mixing mechanism (1) with brine and adsorbent mixture, belt vacuum filter (100) go up and be equipped with interconnect's raw materials brine district (2) in proper order along the transmission direction of belt vacuum filter (100), wash salt district (3) and desorption district (4), raw materials brine district (2) is connected in solid-liquid mixing mechanism (1), carry first liquid conveying mechanism (5) of washing salt liquid and carry second liquid conveying mechanism (6) of desorption liquid and connect respectively and wash salt district (3) and desorption district (4).
2. The apparatus for extraction of lithium from adsorption brine according to claim 1, wherein the first liquid delivery mechanism (5) comprises at least two mutually independent and sequentially connected brine-scrubbing circulation assemblies (7), and the different brine-scrubbing circulation assemblies (7) are connected one by one from one side close to the desorption zone (4) to the other side.
3. The equipment for extracting lithium from brine by adsorption method according to claim 2, characterized in that the discharge port of the salt washing liquid circulating component (7) closest to the raw material brine area (2) is connected with the tail part of the belt type vacuum filter (100), a salt washing liquid conveyer is arranged above the salt washing liquid circulating component (7) closest to the desorption area (4), and the discharge port of the salt washing liquid circulating component (7) on one side close to the desorption area (4) in every two adjacent salt washing liquid circulating components (7) is positioned above the belt type vacuum filter (100) and corresponds to the feed port of the other salt washing liquid circulating component (7).
4. The equipment for extracting lithium from brine by adsorption method according to claim 3, wherein the salt washing liquid circulation component (7) comprises a salt washing liquid vacuum box (8) connected with the belt type vacuum filter (100) and a salt washing liquid conveying component (9) connected with the salt washing liquid vacuum box (8), and the discharge port of the salt washing liquid conveying component (9) on the salt washing liquid circulation component (7) close to one side of the desorption area (4) in every two adjacent salt washing liquid circulation components (7) is positioned above the belt type vacuum filter (100) and corresponds to the salt washing liquid vacuum box (8) on the other salt washing liquid circulation component (7).
5. The apparatus for extraction of lithium from adsorptive brine according to claim 1, wherein said second liquid transport mechanism (6) comprises at least two desorption liquid circulation modules (10) independent from each other and connected in sequence, wherein different desorption liquid circulation modules (10) are connected one by one from one side far away from the salt-washing zone (3) to the other.
6. The equipment for extracting lithium from adsorption brine according to claim 5, wherein the discharge port of the desorption liquid circulation assembly (10) closest to the salt washing area (3) is connected with the subsequent finishing section, the feed port of the desorption liquid circulation assembly (10) farthest from the salt washing area (3) is connected with a desorption liquid conveyer positioned above the belt vacuum filter (100), and the discharge port of the desorption liquid circulation assembly (10) on the side far from the salt washing area (3) in each two adjacent desorption liquid circulation assemblies (10) is positioned above the belt vacuum filter (100) and corresponds to the feed port of the other desorption liquid circulation assembly (10).
7. The equipment for extracting lithium from adsorption brine according to claim 6, wherein the desorption liquid circulation assemblies (10) comprise a desorption liquid vacuum box (11) connected with the belt vacuum filter (100) and a desorption liquid conveying assembly (11a) connected with the desorption liquid vacuum box (11), and the desorption liquid conveying assembly (11a) on the desorption liquid circulation assembly (10) on the side far away from the salt washing area (3) in each two adjacent desorption liquid circulation assemblies (10) is positioned above the belt vacuum filter (100) and corresponds to the desorption liquid vacuum box (11) on the other desorption liquid circulation assembly (10).
8. The equipment for extracting lithium from brine by an adsorption method according to claim 1, further comprising a salt washing water return area (12) connected with the desorption area (4), wherein the discharge port of the first liquid conveying mechanism (5) is connected with the salt washing water return area (12).
9. The equipment for extracting lithium from brine by an adsorption method according to claim 2, further comprising a salt washing water return area (12) connected with the desorption area (4), wherein a discharge port of the salt washing liquid circulation component (7) closest to the raw material brine area (2) is connected with the salt washing water return area (12), and the salt washing water return area (12) is connected with the solid-liquid mixing mechanism (1) through a conveying belt (13).
10. The equipment for extracting lithium from adsorption brine according to claim 8 or 9, wherein the salt washing water return area (12) comprises a salt washing water return vacuum box (14) connected with the belt type vacuum filter (100), the salt washing water return vacuum box (14) is connected with a salt washing water return solid-liquid separator (16) through a salt washing water return conveying component (15), and the raw brine area (2) is connected with a raw brine solid-liquid separator (18) through a raw brine conveying component (17).
Technical Field
The invention belongs to the technical field of lithium extraction equipment by adsorption, and relates to equipment for extracting lithium from brine by an adsorption method.
Background
The adsorbent and the use form of the adsorbent are the key of the water treatment technology by the adsorption method. Because of the defects of difficult solid-liquid separation, difficult recovery and the like of the powder adsorbent, the water treatment adsorption method after 90 years in the 20 th century generally adopts a process of combining the particle adsorbent with an adsorption tower.
The water treatment adsorbent is mainly divided into an organic adsorbent and an inorganic adsorbent, the organic adsorbent with the diameter of about 1-2mm forms a mature market, and the water treatment adsorbent is filled in an adsorption tower and is widely applied to various fields of water treatment. The granulation process of inorganic adsorbents represented by iron-based adsorbents, aluminum-based adsorbents and manganese-based adsorbents, particularly hydroxyl iron adsorbents, aluminum adsorbents and manganese adsorbents which cannot be formed by calcination, is still lack of a mature and complete solution at present, the granulated inorganic adsorbents are easy to break, and the activity of the granulated adsorbents is far lower than that of powder.
The adsorption method brine lithium extraction technology has wide adaptability to different salt lakes, and can treat brine with low lithium content. The adsorption method brine lithium extraction technology is industrialized on a large scale in Argentina salt lakes and Qinghai salt lakes in China at present. Meanwhile, the adsorption method brine lithium extraction technology has a great deal of research attention, and relates to a plurality of fields of adsorbent synthesis, lithium extraction efficiency of different brines, adsorption reaction mechanisms and the like.
A great deal of research and practice shows that the most efficient adsorbent for extracting lithium from brine is oxide or hydroxide of aluminum series, manganese series, titanium series and the like. The above mentioned metal oxide or hydroxide adsorbent granulation technology is consistently a difficult problem in the water treatment industry. However, the current industrial production line for extracting lithium from brine still follows the technical route of the traditional water treatment adsorption method and adopts a process of combining a granular adsorbent with an adsorption tower.
Because of the properties of lithium adsorbents extracted from brine, studies and patents have proposed extracting lithium from brine using powder adsorbents. In order to realize the recovery of the powder adsorbent, the solid-liquid separation of the adsorbent and water is realized by utilizing a plate-and-frame filter press, a centrifugal machine and a ceramic membrane; there are also studies and patents that carry the magnetic particles on the adsorbent, and then use a magnetic separator to achieve solid-liquid separation.
The technical route of particle adsorbent combined with adsorption tower for lithium extraction from brine has some problems: 1) in the production stage, a large number of adsorption towers filled with the adsorbent are required to be constructed, so that the investment cost is high; 2) magnesium to lithium ratio of greater than 3:1, salt to lithium ratio TDS: a desorption solution with Li larger than 30: 1; 3) the lithium recovery rate of the adsorption section is generally less than 60%, and if high lithium recovery rate is to be realized, multi-tower series connection and function conversion are required, so that the difficulty of industrial continuous production is greatly improved.
The brine lithium extraction process of combining a powder adsorbent with a plate-and-frame filter press, a centrifuge, a precise filter or a ceramic membrane is still in a laboratory or a pilot-scale stage at present, relevant documents and patents only pay attention to solid-liquid separation of the powder adsorbent and brine, and the understanding and the attention to the washing process of the adsorbent in the brine lithium extraction process are lacked, so that desorption liquid with low salt-lithium ratio cannot be obtained by the processes.
The total salinity of the brine can reach hundreds of grams per liter, and the lithium content is only dozens to hundreds of milligrams per liter. Through a large number of research experiments, the applicant finds that how to reduce the ratio of the lithium salt in the desorption solution to the maximum extent in the process of extracting the lithium in the brine by using the adsorption method is the key point of extracting the lithium from the brine by using the adsorption method.
Disclosure of Invention
The invention aims to solve the problems and provides equipment for extracting lithium from brine by an adsorption method.
In order to achieve the purpose, the invention adopts the following technical scheme:
the utility model provides an equipment for lithium is carried to adsorption process brine, includes belt vacuum filter, belt vacuum filter be connected with and be used for the solid-liquid mixing mechanism who mixes brine and adsorbent, belt vacuum filter is last and be equipped with interconnect's raw materials brine district, salt washing district and desorption district along belt vacuum filter's transmission direction in proper order, raw materials brine district is connected to solid-liquid mixing mechanism, salt washing liquid's first liquid conveying mechanism and the second liquid conveying mechanism who carries desorption liquid are connected respectively and are washed salt district and desorption district.
In foretell equipment for adsorption process brine carries lithium, first liquid conveying mechanism include at least two mutually independent and wash salt solution circulation subassembly that connects gradually, different wash salt solution circulation subassemblies are connected one by a side to the opposite side that is close to desorption district.
In the above-mentioned equipment for adsorption process brine lithium extraction, the discharge gate of the salt washing liquid circulation component closest to the raw material brine area is connected with the tail of the belt vacuum filter, the salt washing liquid conveyor is arranged above the salt washing liquid circulation component closest to the desorption area, and the discharge gate of the salt washing liquid circulation component on one side close to the desorption area in every two adjacent salt washing liquid circulation components is positioned above the belt vacuum filter and corresponds to the feed inlet of the other salt washing liquid circulation component.
In foretell equipment for adsorption process brine carries lithium, the salt solution circulation subassembly wash salt solution vacuum box including connecting belt vacuum filter to and connect the salt solution conveying assembly who washes the salt solution vacuum box, every two adjacent salt solution circulation subassemblies wash salt solution conveying assembly's that is close to on the salt solution circulation subassembly of desorption district one side discharge gate is located belt vacuum filter top and corresponds with the salt solution vacuum box that washes on another salt solution circulation subassembly.
In the above-mentioned equipment for adsorption process brine lithium extraction, second liquid conveying mechanism include at least two desorption liquid circulation subassemblies that are independent each other and connect gradually, different desorption liquid circulation subassemblies are connected one by one to the opposite side by keeping away from one side in salt washing district.
In the above-mentioned equipment for adsorption method brine lithium extraction, the discharge port of the desorption liquid circulation component closest to the salt washing zone is connected with the subsequent finishing process, the feed port of the desorption liquid circulation component farthest from the salt washing zone is connected with the desorption liquid conveyor located above the belt vacuum filter, and the discharge port of the desorption liquid circulation component on one side of each two adjacent desorption liquid circulation components far from the salt washing zone is located above the belt vacuum filter and corresponds to the feed port of the other desorption liquid circulation component.
In the above-mentioned equipment for adsorption method brine lithium extraction, the desorption liquid circulation component includes the desorption liquid vacuum box of connecting the belt vacuum filter to and the desorption liquid conveying component of connecting the desorption liquid vacuum box, and the desorption liquid conveying component on the desorption liquid circulation component that keeps away from salt-washing area one side in every two adjacent desorption liquid circulation components is located the belt vacuum filter top and corresponds with the desorption liquid vacuum box on another desorption liquid circulation component.
In foretell equipment for adsorption process brine carries lithium, still include the salt washing return water district of connecting the desorption district, first liquid conveying mechanism's discharge gate connect the salt washing return water district.
In foretell an equipment for lithium is carried to adsorption process brine, still including the salt washing return water district of connecting the desorption district, the salt washing return water district is connected to the discharge gate that is closest to the salt washing liquid circulation subassembly in raw materials brine district, and the salt washing return water district passes through the conveyer belt and connects solid-liquid mixing mechanism.
In foretell be arranged in adsorption process brine to carry lithium equipment, the salt washing return water district including the salt washing return water vacuum box who connects belt vacuum filter, the salt washing return water vacuum box is connected through salt washing return water conveying component and is washed salt recovery solid-liquid separation ware, raw materials brine district passes through raw materials brine conveying component and connects raw materials brine solid-liquid separation ware.
Compared with the prior art, the invention has the advantages that:
1. compared with the existing adsorption tower, the invention has low investment cost, and can reduce the investment cost by about 80 percent.
2. The desorption solution with the magnesium-lithium ratio of less than 1:1 and the salt-lithium ratio (TDS/Li) of less than 10:1 can be obtained by the method, so that the investment and production cost of the subsequent desalting and purifying process are greatly reduced, and finally, the battery-grade lithium carbonate or lithium hydroxide can be stably obtained.
3. The loss of the adsorbent is small, and the leakage rate of the adsorbent in a single adsorption and desorption cycle is less than 0.01 percent.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.
Drawings
FIG. 1 is a schematic structural view of the present invention;
FIG. 2 is a schematic view of a portion of the present invention;
fig. 3 is a partial structural schematic diagram of the present invention.
In the figure: the system comprises a solid-liquid mixing mechanism 1, a mixing tank 1a, a raw material brine area 2, a salt washing area 3, a desorption area 4, a first
Detailed Description
The invention is further described below with reference to the accompanying drawings.
As shown in fig. 1-3, an apparatus for extracting lithium from adsorption-process brine comprises a
In this embodiment, the raw material brine zone 2, the salt-washing zone 3 and the desorption zone 4 are connected to each other in the
The
The solid-liquid mixing mechanism 1 mixes the adsorbent with brine, lithium-containing salt and other salts in the brine are adsorbed by the adsorbent, the solid-liquid mixing mechanism 1 conveys the mixture to the raw material brine area 2, the adsorbent and the brine in the raw material brine area 2 realize solid-liquid separation, the brine penetrates through the
The solid-liquid mixing mechanism 1 comprises a mixing tank 1a, wherein a stirring paddle is arranged in the mixing tank 1a and used for stirring the adsorbent and brine, the mixing tank 1a can be directly arranged above the raw material brine area 2, so that the adsorbent and the brine mixture can be directly sprinkled on the
The salt washing liquid is fresh water and is pumped above the salt washing area 3 by a delivery pump, i.e. the first
As a preferred solution, as shown in fig. 3, the first
The discharge hole of the salt washing liquid circulation component 7 closest to the raw material brine area 2 is connected with the tail part of the belt
A salt washing liquid conveyor is arranged above the salt washing liquid circulating assembly 7 closest to the desorption area 4, is a spray head connected with a conveying pump or a pipeline and the like, and is used for spraying fresh water on the adsorbent of the
In this embodiment, the manner of connecting the multiple brine-washing circulation modules 7 in series actually forms the effect of gradient elution, and also conforms to the principle of a small amount of multiple times in chemistry, so as to elute the miscellaneous salts in the adsorbent in advance.
The discharge hole of the salt washing liquid circulation assembly 7 close to one side of the desorption area 4 in every two adjacent salt washing liquid circulation assemblies 7 is positioned above the belt
The applicants have found that the lithium salt adsorbed by the adsorbent is less readily desorbed as the salt concentration in the brine is higher, and that the lithium is less readily eluted as the salt-to-lithium ratio (ratio of normal salt to lithium-containing salt) in the adsorbent is higher. The invention provides a gradient elution structure in consideration of satisfying the requirements of desalting by washing and reducing the elution of lithium salt. The principle of the gradient elution structure is: the salt content of the brine discharged from the discharge port of the brine circulation module 7 gradually increases from the direction close to the desorption zone 4 to the direction close to the raw material brine zone 2, that is, the brine closest to the desorption zone 4 is pure water, and the brine closest to the raw material brine zone 2 contains partially desorbed lithium salts and other eluted miscellaneous salts. The advantage is that the salt content of the salt washing solution along the transmission direction of the
In this embodiment, a structure for re-adsorbing and recovering lithium salt from the discharge port of the brine circulating module 7 closest to the raw material brine zone 2 is also provided. Namely, the device also comprises a washed salt
The specific structure of the gradient salt wash is as follows: the salt washing liquid circulating assembly 7 comprises a salt washing liquid vacuum box 8 connected with the belt
The salt washing liquid circulation component 7 comprises a salt washing
The water distribution structure is arranged above the salt washing liquid vacuum box 8, the water distribution structure can be a pipe or a plurality of pipes are arranged at intervals along the axial direction of the belt
The second
It will be appreciated that the desorption
In this embodiment, the desorption
The feed inlet of the desorption
Along the conveying direction of the
The desorption
Similarly, a water distribution structure is also arranged above each desorption
It should be noted that the brine from the brine recycle module 7 closest to the raw brine zone 2 can be directed to the brine pan. However, the treatment can reduce the salt content of brine in the salt pan, and the brine washing also contains certain lithium, which is directly discharged into the salt pan to cause incomplete lithium adsorption, thereby affecting the extraction rate of lithium. Therefore, as a preferable scheme, the present embodiment is provided with a salt washing
The salt washing
The salt washing
In this embodiment, the solid-
The working process of the invention is as follows:
the adsorbent is put into the mixing tank 1a, brine in the salt pan is pumped into the mixing tank, the solid-liquid ratio is 1:10-200, specifically, according to the type selection of the
The mixture of the adsorbent and the brine is put into a raw material brine area 2 from a mixing tank, the brine penetrates through the
After the adsorbent in the salt washing area 3 enters the desorption area 4, the lithium salt in the adsorbent is sucked out after the desorption liquid is washed, and the lithium salt-containing liquid is obtained after the lithium salt-containing liquid is collected by the desorption
The applicant finds through a large number of experiments that the minimum ventilation amount of the filter cloth for different brine separation is not less than 500L/m2 & s, so that the ideal processing capacity of the belt type vacuum filter can be met, and the leakage amount of the adsorbent under different use conditions is different but is generally less than 10%. The content of the adsorbent in the brine, the salt washing liquid and the desorption liquid passing through the filter cloth of the belt type vacuum filter is generally lower than 1 percent.
And performing solid-liquid separation on the brine, the salt washing liquid and the desorption liquid with the solid content of less than 1% by a magnetic separator, a precise filtering device or a ceramic membrane for secondary treatment, and then discharging the brine, the salt washing liquid and the desorption liquid to a salt field or treating the brine, the salt washing liquid and the desorption liquid in a post-system. If the adsorbent contains magnetic substances, the adsorbent can be recovered by a magnetic separator, and if the adsorbent does not contain magnetic substances, the adsorbent can be recovered by a precise filtration device or a ceramic membrane.
The adsorbent filtered by the belt vacuum filter is subjected to secondary capture by a magnetic separator, a precise filtering device and a ceramic membrane, and then backflushed to the corresponding water supply port of the belt vacuum filter, and further returned to the main adsorption and desorption circulation. The trapping rate of the belt filter to the adsorbent is more than 90%, and the trapping rate of the rear-section solid-liquid separation equipment to the adsorbent is more than 99.9%, so that the leakage rate of the adsorbent in a single adsorption and desorption cycle is less than 0.01%.
The belt type vacuum filter provided by the invention can realize the small water volume quick washing of the adsorbent, the desorption regeneration of the adsorbent and the recovery of the lithium lost from salt washing. The desorption solution with the magnesium-lithium ratio of less than 1:1 and the salt-lithium ratio (TDS/Li) of less than 10:1 can be obtained by the method, so that the investment and production cost of the subsequent desalting and purifying process are greatly reduced, and finally, the battery-grade lithium carbonate or lithium hydroxide can be stably obtained. The new equipment provided by the invention can recover lithium ions lost in the salt washing process, so that the lithium ion recovery rate in the brine adsorption and desorption process can reach more than 80%.
The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit of the invention.
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