CN111826531A - Method for extracting lithium from brine using powdered adsorbent - Google Patents

Abstract

The invention provides a method for extracting lithium from brine by using a powdery adsorbent, which comprises the following steps: vacuum filtering the mixture of the adsorbent and the brine in a brine separation zone to form a filter cake; washing salt from a filter cake obtained in the brine separation zone in a salt washing zone to obtain high-salt low-lithium salt washing brine; and desorbing the filter cake obtained by salt washing in the salt washing area in a desorption area to obtain the low-salt high-lithium desorption solution. The invention greatly reduces the investment cost, can obtain desorption solution with the magnesium-lithium ratio of less than 1:1 and the salt-lithium ratio of less than 10:1, greatly reduces the investment and production cost of the subsequent desalting purification process, and can finally stably obtain battery-grade lithium carbonate or lithium hydroxide. 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%.

Description

Method for extracting lithium from brine using powdered adsorbent

technical field

The application belongs to the field of lithium extraction from salt lake brine, relates to a method for extraction of lithium from brine, and in particular relates to a method for extraction of lithium from brine by using a powdery adsorbent.

Background technique

Lithium has important applications in electronics, metallurgy, chemical industry, medicine and other fields. In nature, lithium mainly exists in lithium ore and salt lake brine, seawater and geothermal water. Salt lake brine has the highest lithium content, accounting for 66% of the world's lithium reserves and more than 80% of lithium reserves. Compared with ore, the extraction of lithium from salt lake brine is simple, low cost, and environmentally friendly, and it meets the market demand. At present, lithium extraction from salt lake has become the main research object in the lithium extraction process.

The methods of lithium extraction from salt lakes mainly include solvent extraction, adsorption, evaporative crystallization, membrane separation and precipitation. At present, the industrial application of adsorption method for lithium extraction from brine mainly adopts the technical route of particle adsorbent combined with adsorption tower, which is also the main application method of adsorption method in conventional water treatment industry. However, there are many problems in the use of granular adsorbents combined with adsorption towers for lithium extraction from brine: 1) In the production stage, a large number of adsorption towers filled with adsorbents need to be constructed, and the investment cost is high; 2) The obtained analytical solution has a magnesium-to-lithium ratio greater than 3:1, the salt-to-lithium ratio TDS:Li is greater than 30:1, which is difficult to meet the requirements of battery-grade lithium carbonate or lithium hydroxide on the impurity content; 3) The lithium recovery rate of the adsorption section is generally less than 60%, if a high lithium recovery rate is to be achieved , it is necessary to set up multiple towers in series and function conversion, which greatly improves the difficulty of industrial continuous production.

For example: Chinese patent application [publication number: CN111041201A] discloses a new method for extracting lithium from salt lake brine. The old halogen feed pipe, the desorption liquid feed pipe, the low magnesium water top desorption liquid feed pipe, and the adsorption tail liquid top desorption liquid feed pipe respectively enter the corresponding adsorption columns through the holes and channels in the multi-way valve system. , from the adsorption tail liquid discharge pipe, the qualified desorption liquid discharge pipe, the lithium-containing old halogen discharge pipe, and the adsorption tail liquid top desorption liquid discharge pipe to complete the whole process.

Another example: Chinese patent application [Publication No.: CN109052435A] discloses a group of adsorption towers for extracting lithium from salt lake brine, including a base, the side walls of the base are respectively provided with inspection holes and a clean outlet, and the top of the base is provided with ≥ 2 The adsorption towers are connected up and down and connected in series. The adsorption tower includes an adsorption tower body. The top of the uppermost adsorption tower body is provided with an upper head, and the lower part of the adsorption tower body connected to the base is provided with a lower head. The two are connected in series. There is a separation head between the adsorption tower bodies, a vent is provided above the liquid discharge port set on the upper side wall of the adsorption tower body, and a manhole is also provided on the upper part of the side wall of each adsorption tower body; the upper head of the adsorption tower The top of the tower is provided with a vent; the tower is filled with adsorbent.

The above two technical solutions both adopt the method of filling the adsorption tower with granular adsorbents into brine to extract lithium, the system structure is complex, the cost is high, and the low-salt lithium ratio desorption liquid cannot be obtained.

SUMMARY OF THE INVENTION

The object of the present invention is to address the above problems, and provide a method for extracting lithium from brine using a powdery adsorbent.

To achieve the above object, the present invention has adopted the following technical solutions:

The present invention creatively provides a method for extracting lithium from brine using a powdery adsorbent, which is characterized in that it comprises the following steps:

1) the mixture of adsorbent and brine is subjected to vacuum filtration in brine separation zone to form filter cake;

2) the filter cake obtained in the brine separation zone is washed with salt in the salt washing zone to obtain high-salt and low-lithium washing brine;

3) desorb the filter cake obtained by washing the salt in the salt washing zone in the desorption zone to obtain a low-salt and high-lithium desorption solution.

In the above-mentioned method for extracting lithium from brine by using powdered adsorbent, the filter cake obtained in the brine separation zone continuously passes through the salt washing zone and the desorption zone.

In the above-mentioned method for extracting lithium from brine by using a powdery adsorbent, the filter cake obtained in the desorption zone is washed with salt backwater, and the high-salt and low-lithium washing brine obtained in the salt-washing zone in step 2) is used to wash salt backwater. The filter cake in the zone is rinsed.

In the above-mentioned method for extracting lithium from brine with powdered adsorbent, the salt washing zone in step 2) includes several stages of salt washing and leaching sections arranged along the movement direction of the filter cake.

In the above-mentioned method for extracting lithium from brine by using powdered adsorbent, the first-stage salt-washing section located at the downstream end of the filter cake movement direction in the salt-washing sections of all levels is washed with clean water as the mobile phase of the washing salt, and the rest The salt washing and leaching sections at all levels use the washing salt water close to the downstream side of the filter cake movement direction as the washing salt mobile phase for step-by-step gradient leaching. Low lithium wash brine.

In the above-mentioned method for extracting lithium from brine using a powdered adsorbent, the desorption zone in step 3) includes several stages of desorption and leaching sections sequentially arranged from the upstream direction to the downstream direction.

In the above-mentioned method for extracting lithium from brine using powdered adsorbents, the first-level desorption and leaching sections located at the downstream end of the filter cake moving direction in the desorption and leaching sections of all levels are leached with clean water as the desorption mobile phase, and the remaining levels of desorption and leaching are used for leaching. The leaching section uses the desorption liquid near the downstream side of the filter cake movement direction as the desorption mobile phase for step-by-step gradient leaching.

In the above-mentioned method for extracting lithium from brine by using a powdered adsorbent, the filter cake obtained in the salt-washing backwater zone is mixed and adsorbed with brine and then sent to step 1) for recycling.

In the above-mentioned method for extracting lithium from brine by using a powdery adsorbent, the filtrate obtained by vacuum filtration in the brine separation zone in step 1) is subjected to solid-liquid separation to recover the adsorbent.

In the above-mentioned method for extracting lithium from brine by using a powdered adsorbent, the filtrate obtained from the salt-washing backwater zone is subjected to solid-liquid separation to recover the adsorbent.

Compared with the prior art, the present invention has the following advantages:

1) The present invention greatly reduces the investment cost, and the present invention can obtain a desorption solution with a magnesium-lithium ratio of less than 1:1 and a salt-to-lithium ratio (TDS/Li) of less than 10:1, which greatly reduces the investment and cost of the subsequent desalination and purification process. Production cost, and finally, battery-grade lithium carbonate or lithium hydroxide can be stably obtained. The new equipment proposed by the invention can recover the lithium ions lost in the salt washing process, so that the lithium ion recovery rate of the brine adsorption and desorption process can reach more than 80%.

2) Wash the salt by leaching in the salt washing area, shorten the contact time between the mobile phase of the washing salt and the filter cake, reduce the possibility that the washing salt water brings out the lithium ions in the filter cake, and reduce the content of lithium ions in the washing salt water .

3) Wash salts by means of reverse gradient elution. The washed brine obtained in the latter stage in the salt washing zone is repeatedly entered into the previous stage as the mobile phase of washing salt, and then contacts with the adsorbent in the filter cake for combined recovery, so that high salt concentration and low lithium concentration can be obtained in the salt washing zone. Wash with salt water.

The desorption is carried out by means of reverse gradient elution, so that a desorption solution with high lithium concentration and low salt concentration is obtained in the desorption zone, and a regenerated adsorbent is obtained.

4) The washing salt water is circulated to the washing salt water return area, and the lithium ions in the washing salt water are further recovered, so that the recovery rate of lithium ions is improved.

5) Mixed adsorption, brine separation, salt washing, desorption and salt washing backwater are carried out in a continuous manner, eliminating the need for series connection between multiple towers, greatly improving production efficiency and reducing production costs.

Description of drawings

FIG. 1 is a production process flow diagram of an embodiment provided by this application.

FIG. 2 is a production process flow diagram of another embodiment provided by the present application.

FIG. 3 is a production process flow diagram of another embodiment provided by the present application.

Fig. 4 is the production process flow chart of the salt washing zone and the desorption zone provided by the application.

In the figure, belt vacuum filter 1, frame 10, filter cloth 11, collection device 12, scraper 13, recovery barrel 14, brine separation zone 2, salt washing zone 3, salt washing and rinsing section 30, first liquid Conveying mechanism 31, washing salt liquid circulation assembly 310, desorption zone 4, desorption washing section 40, second liquid conveying mechanism 41, desorption liquid circulation assembly 410, washing salt water return zone 5, solid-liquid mixing mechanism 6, solid-liquid separation device 7.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings.

The present invention is further illustrated by the following examples:

Example 1

As shown in FIG. 1 , in this embodiment, a belt vacuum filter 1 is used as the main equipment, and the belt vacuum filter 1 is the prior art, and a commercially available product can be used. Specifically, the belt vacuum filter 1 includes a frame 10 and a filter cloth 11 on the frame 10. The filter cloth 11 is connected end-to-end in a ring shape, and the motor on the frame 10 drives the next cycle through components such as tensioning wheels Turn to cycle. The brine separation zone 2 , the salt washing zone 3 and the desorption zone 4 are sequentially connected along the transmission direction of the filter cloth 11 through the belt vacuum filter 1 . Under the upper filter cloth 11, the filtrate is suction filtered by a vacuum pump, and a water collecting tray and a collecting device 12 connected to the water collecting tray are set at corresponding positions in each area to collect the filtrate.

The filter cloth 11 is preferably selected from the filter cloth 11 with a large ventilation volume. The ventilation volume of the filter cloth 11 is greater than 500L/m2·s to ensure the processing capacity of the separation of the brine and the adsorbent. The retention rate of the filter cloth 11 to the adsorbent is greater than 95%.

The salt washing zone 3 is provided with a first liquid conveying mechanism 31, including a conveying pump and a conveying pipeline connected to the conveying pump, for washing the salt washing mobile phase from above the filter cloth 11 to wash the filter cake, and the salt washing mobile phase adopts water.

The desorption zone 4 is provided with a second liquid conveying mechanism 41, including a conveying pump and a conveying pipeline connected to the conveying pump, for washing the filter cake with the desorption mobile phase from the top of the filter cloth 11, and the desorption mobile phase adopts water.

The salt washing zone 3 and the desorption zone 4 are divided by the salt-to-lithium ratio of the filtrate.

Based on the above-mentioned equipment, a method for extracting lithium from brine by utilizing a powdery adsorbent, the steps are:

1) Brine separation zone 2: The brine mixed with adsorbent enters the belt vacuum filter 1 at a flow rate of about 300 m ³ /h, and forms a filter cake in the brine separation zone 2 through vacuum filtration. Among them, the adsorbent is an aluminum-based magnetic powder adsorbent with a particle size range of 50-100 μm. The average residence time of the adsorbent and brine in the solid-liquid mixing mechanism 6 is 10-20 minutes, so as to achieve full mixing and adsorption. The filtrate is collected by a vacuum pump, and the solid-liquid separation is carried out by a magnetic separator. A small amount of adsorbent filtered is recovered, and the separated liquid phase is transported back to the salt field.

2) Salt washing zone 3: The filter cake obtained by the belt vacuum filter 1 driving the brine separation zone 2 passes through the salt washing zone 3, and in the salt washing zone 3, water is used as the salt washing mobile phase, and the salt washing mobile phase is transported by the first liquid The mechanism 31 rinses the filter cake at a flow rate of 100 m ³ /h. And through the method of suction filtration, the water quickly passes through the filter cake, reducing the contact time between the water and the filter cake, and the high content of salt in the filter cake is taken out, and the loss of lithium ions in the filter cake is greatly reduced, thereby obtaining high salt and low lithium. Wash with salt water. The salt concentration TDS in the high-salt low-lithium washing brine obtained in the salt-washing zone 3 is greater than 30 g/L, and the lithium concentration is less than 0.05 g/L. The high-salt and low-lithium washed brine finally obtained in the salt washing zone 3 is circulated and transported back to the salt field.

3) Desorption zone 4: The desalted filter cake obtained by the belt vacuum filter 1 drives the salt washing zone 3 to pass through the desorption zone 4. The method of suction filtration allows the water to pass through the filter cake quickly, taking out the lithium ions in the filter cake after desalination, and obtaining a low-salt and high-lithium desorption solution to enter the next section. In the low-salt and high-lithium desorption solution obtained in desorption zone 4, the salt-lithium ratio TDS/Li<10:1, the magnesium-lithium ratio Mg/Li<1:1, and the lithium concentration>0.3g/L.

Embodiment 2

The device structure adopted in this embodiment is basically the same as that in the first embodiment, and the differences are:

As shown in FIG. 2 , the belt vacuum filter 1 is provided with a salt-washing backwater zone 5 downstream of the desorption zone 4, and the high-salt and low-lithium salt-washing brine in the salt-washing zone 3 is transported to the salt-washing water through the salt-washing backwater assembly. Above the filter cloth 11 in the backwater zone 5, the filter cake is rinsed. Below the upper filter cloth 11 of the washing salt water return area 5 is also provided a water collecting tray and a collecting device 12 for filtrate. The filtrate collected by the collecting device 12 is transported back to the salt field.

The retention rate of the filter cloth 11 to the adsorbent in the salt washing zone 3, the desorption zone 4 and the washing salt water reuse zone is greater than 98%.

In order to fully recover the adsorbent, in the brine separation zone 2, salt washing zone 3, desorption zone 4 or salt washing backwater zone 5 where the filtrate needs to be transported back to the salt field or the next section, the collecting device 12 in this area can pass the solid The liquid separation device 7 recovers a small amount of adsorbent filtered, and then recycles it back to the salt field. The solid-liquid separation device 7 can be selected from any one of a magnetic separator, a precision filter, a ceramic membrane, a centrifuge or a plate and frame filter press.

Based on the above-mentioned equipment, a method for extracting lithium from brine by utilizing a powdery adsorbent, the steps are:

1) Mixed adsorption: The adsorbent and brine are continuously mixed and adsorbed through the stirring tank respectively, so that the adsorbent adsorbs lithium ions in the brine.

2) Brine separation zone 2: The brine mixed with adsorbent enters the belt vacuum filter 1, and in the brine separation zone 2, a filter cake is formed by vacuum filtration. And the filtrate is collected by a vacuum pump, and the solid-liquid separation is carried out by a magnetic separator, a small amount of adsorbent filtered is recovered, and the separated liquid phase is transported back to the salt field.

3) Salt washing zone 3: The filter cake obtained by the belt vacuum filter 1 driving the brine separation zone 2 passes through the salt washing zone 3, and in the salt washing zone 3, water is used as the salt washing mobile phase, and the salt washing is carried out by means of rinsing, And through the method of suction filtration, the water quickly passes through the filter cake, reducing the contact time between the water and the filter cake, and the high content of salt in the filter cake is taken out, and at the same time, the loss of lithium ions in the filter cake is greatly reduced, so as to obtain high salt and low lithium. Wash with salt water. The salt concentration TDS in the high-salt low-lithium washing brine obtained in the salt-washing zone 3 is greater than 30 g/L, and the lithium concentration is less than 0.05 g/L.

4) Desorption zone 4: The desalted filter cake obtained by the belt vacuum filter 1 drives the salt washing zone 3 to pass through the desorption zone 4. The method of suction filtration allows the water to pass through the filter cake quickly, taking out the lithium ions in the filter cake after desalination, and obtaining a low-salt and high-lithium desorption solution to enter the next section. In the low-salt and high-lithium desorption solution obtained in desorption zone 4, the salt-lithium ratio TDS/Li<10:1, the magnesium-lithium ratio Mg/Li<1:1, and the lithium concentration>0.3g/L.

5) Washing salt backwater zone 5: The belt vacuum filter 1 drives the filter cake obtained in the desorption zone 4 to enter the salt washing backwater zone 5, and the high-salt and low-lithium washing salt water obtained in step 3) is sent to the salt-washing water by circulating pump Backwater area 5, the filter cake in the wash salt backwater area 5 is rinsed, and the filtrate is collected by a vacuum pump, and the solid-liquid separation is performed by a magnetic separator, and a small amount of adsorbent filtered is recovered, and the separated liquid phase transported back to the salt field. Step 3) After the medium-high-salt low-lithium washing brine passes through the adsorbent filter cake again, its lithium concentration is less than 0.02 g/L, which further improves the recovery rate of lithium ions in the adsorption section.

Embodiment 3

The device structure adopted in this embodiment is basically the same as that in the second embodiment, and the differences are:

As shown in FIG. 3 , the brine separation zone 2 is connected to a solid-liquid mixing mechanism 6 for mixing and adsorbing the adsorbent and brine. The solid-liquid mixing mechanism 6 can be selected from commercially available stirring barrels or reaction kettles, and is carried out by stirring. Solid-liquid mixing to achieve the purpose of adsorption. The scraper 13 and the recovery bucket 14 are arranged at the end of the belt vacuum filter 1, the filter cake is scraped into the recovery bucket 14 through the scraper 13, and then transported to the solid-liquid mixing mechanism 6 by crawler conveying, screw conveying or other conveying methods , mixed with brine again.

Based on the above-mentioned equipment, a method for extracting lithium from brine by utilizing a powdery adsorbent, the steps are:

1) Mixed adsorption: The adsorbent and brine are continuously mixed and adsorbed through the solid-liquid mixing mechanism 6 respectively, so that the adsorbent adsorbs lithium ions in the brine. The mass ratio of the feed amount of the adsorbent to the feed amount of the brine is less than 50%, preferably 10-30%.

2) Brine separation zone 2: The brine mixed with adsorbent enters the belt vacuum filter 1, and in the brine separation zone 2, a filter cake is formed by vacuum filtration. And the filtrate is collected by a vacuum pump, and the solid-liquid separation is carried out by a magnetic separator, a small amount of adsorbent filtered is recovered, and the separated liquid phase is transported back to the salt field.

3) Salt washing zone 3: The filter cake obtained by the belt vacuum filter 1 driving the brine separation zone 2 passes through the salt washing zone 3, and in the salt washing zone 3, water is used as the salt washing mobile phase, and the salt washing is carried out by means of rinsing, And through the method of suction filtration, the water quickly passes through the filter cake, reducing the contact time between the water and the filter cake, and the high content of salt in the filter cake is taken out, and at the same time, the loss of lithium ions in the filter cake is greatly reduced, so as to obtain high salt and low lithium. Wash with salt water. The salt concentration TDS in the high-salt low-lithium washing brine obtained in the salt-washing zone 3 is greater than 30 g/L, and the lithium concentration is less than 0.05 g/L.

4) Desorption zone 4: The desalted filter cake obtained by the belt vacuum filter 1 drives the salt washing zone 3 to pass through the desorption zone 4. The method of suction filtration allows the water to pass through the filter cake quickly, taking out the lithium ions in the filter cake after desalination, and obtaining a low-salt and high-lithium desorption solution to enter the next section. In the low-salt and high-lithium desorption solution obtained in desorption zone 4, the salt-lithium ratio TDS/Li<10:1, the magnesium-lithium ratio Mg/Li<1:1, and the lithium concentration>0.3g/L.

5) Washing salt backwater zone 5: The belt vacuum filter 1 drives the filter cake obtained in the desorption zone 4 to enter the salt washing backwater zone 5, and the high-salt and low-lithium washing salt water obtained in step 3) is sent to the salt-washing water by circulating pump Backwater area 5, the filter cake in the wash salt backwater area 5 is rinsed, and the filtrate is collected by a vacuum pump, and the solid-liquid separation is performed by a magnetic separator, and a small amount of adsorbent filtered is recovered, and the separated liquid phase transported back to the salt field.

6) Recycling: The filter cake obtained by the belt vacuum filter 1 after washing the salt and returning to the water zone 5 is a regenerated adsorbent, which is transported and circulated by the crawler to the reactor for reuse.

Embodiment 4

The device structure adopted in this embodiment is basically the same as that in the second embodiment, and the differences are:

As shown in FIG. 4 , the salt washing zone 3 is divided into 2-5 stages of salt washing and leaching sections 30 along the transmission direction of the filter cloth 11 , and the end near the brine separation zone 2 is the upper stage. The first liquid conveying mechanism 31 includes a salt washing liquid circulation assembly 310 independently provided in each stage of the washing salt washing section 30 . The salt washing liquid circulation component 310 in the lowermost washing salt rinsing section 30 is connected to the washing salt water inlet pipeline. The salt washing liquid circulation assembly 310 in the remaining stages is connected to the collecting device 12 in the washing salt washing section 30 of the next stage, and is transported to the top of the filter cloth 11 of the washing salt washing section 30 by the water pump, and is sprayed by the water pump. The filter cloth 11 is rinsed at the water outlet of the head or the conveying pipeline as the mobile phase of the washing salt of this stage. The mobile phase of the washing salt is transported in the reverse direction with the filter cloth 11 to realize the reverse gradient elution. The high-salt and low-lithium washing brine is obtained in the uppermost salt washing and rinsing section 30 .

The desorption zone 4 is divided into multi-stage desorption and leaching sections 40 along the transmission direction of the filter cloth 11, and the end near the salt washing zone 3 is the upper stage. The second liquid transmission mechanism includes a desorption liquid circulation assembly 410 independently provided in each stage of the desorption and washing section 40 . The desorption liquid circulation component 410 in the lowermost desorption washing section 40 is connected to the desorption water inlet pipeline. The desorption liquid circulation assembly 410 in the remaining stages is connected to the collection device 12 in the desorption and washing section 40 of the next stage, and is transported to the top of the filter cloth 11 of the desorption washing section 40 of this stage by a water pump, and is transported through the spray head or The water outlet of the pipeline rinses the filter cloth 11 as the desorption mobile phase of this stage. The desorption mobile phase is transported in the reverse direction with the filter cloth 11 to realize reverse gradient leaching. The low-salt and high-lithium desorption liquid is obtained in the uppermost desorption and leaching section 40 and transported to the next section.

In step 3), the salt washing zone 3 includes 2-5 grades of salt washing and rinsing sections 30 arranged in sequence from the upstream direction to the downstream direction. Taking the upstream direction as the upper stage and the downstream direction as the lower stage, water is used as the initial salt washing mobile phase to enter the lowermost salt washing and washing section 30 located at the downstream end of the salt washing zone 3 for washing. The brine obtained in the section 30 is transported to the upper stage of the brine leaching section 30 as the mobile phase of the brine, and the brine with high salt and low lithium is obtained in the uppermost section 30 . The salt water in the salt washing and rinsing sections 30 at all levels is collected and circulated by a vacuum pump, respectively.

In step 4), the desorption zone 4 includes 2-5 stages of desorption and leaching sections 40 sequentially arranged from the upstream direction to the downstream direction. Taking the upstream direction as the upper stage and the downstream direction as the lower stage, water is used as the initial desorption mobile phase to enter the lowermost desorption and leaching section 40 located at the downstream end of the desorption zone 4 for leaching. The liquid is transported to the desorption washing section 40 of the upper stage as the desorption mobile phase, and the low-salt and high-lithium washing brine is obtained in the desorption washing section 40 of the uppermost stage. The washing brine of the desorption and washing sections 40 at all levels is collected and circulated by the vacuum pump, respectively.

Wash salts by reverse gradient elution. The washed salt water obtained in the latter stage in the salt washing zone 3 repeatedly enters the upper stage as the salt washing mobile phase, and is combined with the adsorbent in the filter cake for recovery, so that high salt concentration and low lithium can be obtained in the salt washing zone 3. concentration of wash brine. The desorption is carried out by means of reverse gradient elution, so that a desorption solution with high lithium concentration and low salt concentration is obtained in the desorption zone 4, and a regenerated adsorbent is obtained.

In the above embodiments 1 to 4, non-magnetic aluminum powder adsorbents or other powder adsorbents can be selected, and a precision filter is used instead of a magnetic separator for solid-liquid separation to achieve the purpose of recovering the adsorbent.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which the present invention pertains can make various modifications or additions to the described specific embodiments or substitute in similar manners, but will not deviate from the spirit of the present invention or go beyond the definition of the appended claims range.

Although the belt vacuum filter 1, the frame 10, the filter cloth 11, the collecting device 12, the scraper 13, the recovery barrel 14, the brine separation zone 2, the salt washing zone 3, and the salt washing rinsing section 30 are used more in this paper , first liquid conveying mechanism 31, washing salt liquid circulation assembly 310, desorption zone 4, desorption and rinsing section 40, second liquid conveying mechanism 41, desorption liquid circulation assembly 410, washing salt water return zone 5, solid-liquid mixing mechanism 6 , solid-liquid separation device 7 and other terms, but does not exclude the possibility of using other terms. These terms are used only to more conveniently describe and explain the essence of the present invention, and it is contrary to the spirit of the present invention to interpret them as any kind of additional limitation.

Claims (10)

1. a method utilizing powdery adsorbent to carry out brine extraction of lithium, is characterized in that, comprises the following steps: 1) the mixture of adsorbent and brine is subjected to vacuum filtration in brine separation zone (2) to form a filter cake; 2) the filter cake obtained in the brine separation zone (2) is washed salt in the salt washing zone (3) to obtain high-salt low-lithium washing brine; 3) desorb the filter cake obtained by washing salt in the salt washing zone (3) in the desorption zone (4) to obtain a low-salt and high-lithium desorption solution. 2. the method that utilizes powdery adsorbent to carry out brine extraction lithium as claimed in claim 1, it is characterized in that: the filter cake that described brine separation zone (2) obtains is continuous through salt washing zone (3) and desorption zone ( 4). 3. the method that utilizes powdery adsorbent to carry out the method for extracting lithium from brine as claimed in claim 1 or 2, it is characterized in that: the filter cake that described desorption zone (4) obtains is washed salt backwater zone (5), described The high-salt and low-lithium washed brine obtained in the salt-washing zone (3) in step 2) rinses the filter cake in the salt-washing backwater zone (5). 4. the method that utilizes powdery adsorbent to carry out the method for extracting lithium from brine as claimed in claim 2, it is characterized in that: in the described step 2), washing salt zone (3) comprises several grades of washing salt shower set along filter cake movement direction Wash segment (30). 5. the method that utilizes powdery adsorbent to carry out the method for extracting lithium from brine as claimed in claim 4, it is characterized in that: the first-level salt-washing leaching at the downstream end of the filter cake movement direction in the described all-stage salt-washing leaching section (30) The washing section (30) is leached with clean water as the mobile phase of the washing salt, and the remaining washing salt leaching sections (30) use the washing salt near the downstream side of the movement direction of the filter cake as the mobile phase of the washing salt to be washed step by step gradient. and obtain the high-salt and low-lithium washing brine in the first-stage salt washing and leaching section (30) located at the upstream end of the filter cake moving direction. 6. the method that utilizes powdery adsorbent to carry out the method for extracting lithium from brine as claimed in claim 2, it is characterized in that: in described step 3), in desorption zone (4), comprise several stages of desorption arranged successively from upstream direction to downstream direction Rinse section (40). 7. The method for extracting lithium from brine using powdered adsorbent as claimed in claim 6, characterized in that: in the desorption and washing sections (40) at all levels, the first-level desorption and washing sections are located at the downstream end of the filter cake movement direction. (40) Use clear water as the mobile phase for desorption, and the remaining desorption and leaching sections (40) use the desorption liquid near the downstream side of the filter cake movement direction as the desorption mobile phase for step-by-step gradient leaching. The low-salt and high-lithium washing brine is obtained in the first-stage desorption and leaching section (40) at the upstream end of the movement direction. 8. utilize powdery adsorbent as claimed in claim 3 to carry out the method for extracting lithium from brine, it is characterized in that: send into described step 1 after the filter cake obtained through washing salt backwater zone (5) is mixed with brine and adsorbed) used in the cycle. 9. utilize powdery adsorbent to carry out the method for extracting lithium from brine as claimed in claim 1, it is characterized in that: the filtrate obtained by vacuum filtration of brine separation zone (2) in described step 1) is carried out to solid-liquid separation to recover adsorbent . 10 . The method for extracting lithium from brine using a powdery adsorbent as claimed in claim 3 , wherein the filtrate obtained in the salt-washing backwater zone (5) is subjected to solid-liquid separation to recover the adsorbent. 11 .

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