Method and system for extracting lithium from ore-forming brine and old brine

Abstract

The present invention provides a method and system for extracting lithium from mineralized brine and old brine. The method includes a lithium extraction process from mineralized brine and a lithium extraction process from old brine; the lithium extraction process from mineralized brine is carried out in a first resin column ion exchange turntable, including adsorption, top material, elution, desorption, top liquid, and top brine in sequence; the lithium extraction process from old brine is carried out in a second resin column ion exchange turntable, including adsorption, elution, desorption, and top liquid in sequence. The method of the present invention avoids the dilution of mineralized brine, has no potassium loss, and significantly improves the comprehensive yield and purity of lithium products at the back end; realizes the simultaneous extraction of lithium from salt lake brine and potassium from carnallite ore drying, realizes the advancement of the lithium extraction link, shortens the lithium extraction cycle, and ensures continuous production throughout the year; has little environmental damage and small investment in production transformation; in summary, the lithium extraction from mineralized brine and lithium extraction from old brine of the present invention have significant practical significance for the utilization of salt lake resources.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium extraction from salt lakes, and in particular to a method and system for jointly extracting lithium from ore-forming brine and old brine. Background Art

[0002] As a typical salt lake, the Qarhan Salt Lake has a total area of ​​5,856 square kilometers. Its lithium resource reserves are 10.56 million tons of lithium carbonate equivalent, accounting for 50% of Qinghai's lithium resources. It is the largest soluble potassium-magnesium salt deposit and potash fertilizer industrial production base in my country, and also the largest industrial production base for lithium carbonate production from salt lakes.

[0003] The brine of Chaerhan Salt Lake belongs to Na + , K + Mg 2+ / / Cl — —H 2 O quaternary water-salt system, Na + , K + Mg 2+ / / Cl - —H 2 O Quaternary water-salt system phase diagram salt precipitation schematic diagram see Figure 1 ,Depend on Figure 1 It can be seen that the phase area to which the original brine belongs is the sodium chloride crystallization area, the phase area to which the mineralizing brine belongs is the carnallite crystallization area, and the phase area to which the old brine belongs is the magnesium chloride crystallization area.

[0004] A typical process flow chart of the salt pan of the Qarhan Salt Lake resource is shown in Figure 2 ,Depend on Figure 2 It can be seen that after the raw brine is mined in the mining area, it is concentrated by multi-stage sodium salt pools (in this process, sodium chloride is precipitated in the sodium salt pool), evaporated and concentrated to the mineralization brine point, and then introduced into multi-stage carnallite pools for sun-drying concentration (in this process, carnallite is precipitated in the carnallite pool), evaporated and concentrated to the old brine point, and then discharged from the carnallite pool as raw material for lithium extraction from old brine.

[0005] The traditional technical route for lithium extraction from salt lakes includes: mining of raw brine, sun-drying of raw brine to remove sodium, sun-drying of mineralized brine to extract potassium, adsorption of old brine to extract lithium, return of tailings to the mining area, and conversion of solid ore into liquid ore. This cycle requires a relatively long salt field evaporation and concentration cycle (production cycle of more than 1 to 2 years), and the lithium recovery rate through the salt field section (sodium salt pool, regulating pool, carnallite pool) is only about 80%, which is the link with the largest loss of entrained lithium.

[0006] Since the adsorption method conforms to the industry trend of "low-grade, low-cost, green lithium extraction technology", the mainstream salt lake lithium process is still the coupling of adsorption + membrane. Compared with the old brine lithium extraction method with "magnesium-lithium separation" as the core, raw brine lithium extraction can avoid about 20% lithium loss in the salt field section after raw brine mining, and shorten the lithium extraction cycle by 1 to 2 years. However, raw brine lithium extraction in the Qarhan Salt Lake has the following problems. First, the Qarhan mining area is geographically remote, hundreds of kilometers away from the industrial park, and it is an uninhabited area. Public utilities such as fresh water, electricity, steam, acid and alkali consumption, road commuting, and rail transportation cannot be guaranteed, which requires huge investment and strong support to solve; second, there are various landforms such as lakes, wetlands, grasslands, and saline-alkali lands coexist in the mining area, which puts great pressure on ecological and environmental protection; third, the existing large-scale brine transportation facilities and salt fields need to be transformed before raw brine lithium extraction can be carried out; fourth, the raw brine lithium content is low, the brine treatment volume is large, and the brine linear velocity in the adsorption tower is high, which can easily lead to rapid damage of the adsorbent, resulting in an increase in production costs after lithium extraction. Therefore, raw brine lithium extraction is difficult to form large-scale production capacity in the Qarhan Salt Lake. Summary of the invention

[0007] The main purpose of the present invention is to provide a method and system for extracting lithium from mineralized brine and old brine, so as to solve the problems of large loss, high cost, large pollution and difficulty in industrialization in the prior art of lithium extraction from salt lakes.

[0008] To achieve the above-mentioned purpose, according to one aspect of the present invention, a method for extracting lithium from ore-forming brine and old brine is provided, including a lithium extraction process from ore-forming brine and a lithium extraction process from old brine; the lithium extraction process from ore-forming brine is carried out in a first resin column ion exchange turntable, a plurality of resin columns are arranged in the first resin column ion exchange turntable, the first resin column ion exchange turntable is divided into a first adsorption zone, a top material zone, a first elution zone, a first desorption zone, a first top liquid zone and a top brine zone, and the first resin column ion exchange turntable is rotated so that the resin columns are rotated to the first adsorption zone as an adsorption column A1, to the top material zone as a top material column A2, to the first elution zone as an elution column A3, to the first desorption zone as a desorption column A4, to the first top liquid zone as a top liquid column A5, to the top brine zone as a top brine column A6, and a periodic cycle is performed; the lithium extraction process from ore-forming brine includes the following steps: step S1, in the first adsorption zone, the ore-forming brine is Water is sent into the adsorption column A1 for the first adsorption to obtain the first adsorption tail liquid, and the first adsorption tail liquid is sent into the carnallite pool to perform beach drying and potassium extraction to obtain potassium products; step S2, in the top material area, the old brine is sent from the bottom of the column to the top material column A2 to push out the liquid in the column to obtain the recovered mineralization brine; step S3, in the first elution area, the first elution water is sent into the elution column A3 to elute the impurity ions in the column into the solution to obtain the first elution liquid ; Step S4, in the first desorption zone, the first desorption water is sent into the desorption column A4 to desorb the lithium chloride in the column into the solution to obtain the first lithium product solution; Step S5, in the first top liquid zone, the old brine is sent from the bottom of the column to the top liquid column A5 to push out the liquid in the column to obtain the first top liquid outlet; Step S6, in the top brine zone, the ore-forming brine and / or the first adsorption tail liquid is sent from the bottom of the column to the top brine column A6 to push out the liquid in the column to obtain the recovered old brine;

[0009] The lithium extraction process of old brine is carried out in the second resin column ion exchange turntable, in which a plurality of resin columns are arranged, and the second resin column ion exchange turntable is divided into a second adsorption zone, a second elution zone, a second desorption zone and a second top liquid zone, and the second resin column ion exchange turntable is rotated so that the resin column is rotated to the second adsorption zone as an adsorption column B1, to the second elution zone as an elution column B2, to the second desorption zone as a desorption column B3, to the second top liquid zone as a top liquid column B4 in sequence, and a periodic cycle is performed; the lithium extraction process of old brine includes the following steps: step Q1, in the second adsorption zone, the second adsorption stock solution is sent to the adsorption Attach column B1 to perform the second adsorption to obtain a second adsorption tail liquid; step Q2, in the second elution zone, send the second elution water into the elution column B2 to elute the impurity ions in the column into the solution to obtain a second elution effluent; step Q3, in the second desorption zone, send the second desorption water into the desorption column B3 to desorb the lithium chloride in the column into the solution to obtain a second lithium product liquid; step Q4, in the second top liquid zone, send the second adsorption tail liquid from the bottom of the column into the top liquid column B4 to push out the liquid in the column to obtain a second top liquid effluent; wherein the second adsorption stock solution includes old brine, the first elution effluent and the optional second elution effluent.

[0010] Furthermore, the method for extracting lithium by combining ore-forming brine and old brine also includes the following steps: returning the recovered ore-forming brine to step S1; and / or returning the recovered old brine and / or the second adsorption tail liquid to one or more of the following steps: step S2, step S5, step Q1; and / or sending the recovered ore-forming brine to a carnallite pool for beach drying to extract potassium to obtain a potassium product.

[0011] Furthermore, step S1 also includes: a first pretreatment: filtering the mineralizing brine to perform a first impurity removal to obtain a cleaned mineralizing brine, and sending it to the adsorption column A1; wherein the solid suspended matter concentration of the cleaned mineralizing brine is less than 50 mg / L; and / or step Q1 also includes: a second pretreatment: filtering the second adsorption stock solution to perform a second impurity removal to obtain a cleaned second adsorption stock solution, and sending it to the adsorption column B1; wherein the solid suspended matter concentration of the cleaned second adsorption stock solution is less than 50 mg / L.

[0012] Further, step S5 also includes: measuring the conductivity of the first top liquid effluent to obtain the first stage recovered water with an effluent conductivity of ≤5mS / cm, and the first stage recovered water with an effluent conductivity of >5mS / cm; preferably, returning the first stage recovered water to step S4 as the first desorption water; and / or step Q4 also includes: measuring the conductivity of the second top liquid effluent to obtain the second stage recovered water with an effluent conductivity of ≤5mS / cm, and the second stage recovered water with an effluent conductivity of >5mS / cm; preferably, returning the second stage recovered water to step Q3 as the second desorption water; preferably, in the second pretreatment, the first stage recovered water and the second stage recovered water are first used to dilute the old brine, and then the second impurity removal is performed.

[0013] Furthermore, the first rinsing water includes one or more of fresh water, brine and the first lithium product liquid; the second rinsing water includes one or more of fresh water and brine; independently, the first desorption water and the second desorption water include one or more of tap water, industrial fresh water, purified water, desalted water, with a temperature of 20 to 40°C and a conductivity of <500μS / cm.

[0014] Furthermore, the ore-forming brine includes: Li + 0.05~1g / L, Mg 2+ 50~110g / L, Na + 3~12g / L, K + 1.8~22g / L, Cl - 150~330g / L; and / or old brine includes: Li + 0.05~1.5g / L, Mg 2+ 110~130g / L, Na + <3g / L, K + <1.8g / L,Cl - 320~400g / L; and / or the first eluent includes: Li + 0.05~1.5g / L, Mg 2+ 77~91g / L, Na + <2.1g / L, K + <1.3g / L,Cl - 230~280g / L; and / or the second eluent includes: Li + 0.05~1.5g / L, Mg 2+ 66~100g / L, Na + <1.8g / L, K + <1.2g / L,Cl - 198~310g / L.

[0015] Furthermore, the first lithium product solution includes: Li+ 0.5~1.5g / L, Mg 2+ <2g / L, Na + <0.1g / L, K + <0.02g / L,Cl - 5~12g / L; and / or the second lithium product liquid includes: Li + 0.5~1.5g / L, Mg 2+ <2g / L, Na + <0.1g / L, K + <0.02g / L,Cl - 5~12g / L.

[0016] Further, independently, the single column rotation unit time of the first resin column ion exchange turntable and the second resin column ion exchange turntable is 10 to 20 minutes; and / or the single column rotation unit time feed volume of the adsorption column A1 is 4 to 40 BV; and / or the single column rotation unit time feed volume of the adsorption column B1 is 2.5 to 40 BV; and / or the single column rotation unit time feed volume of the top feed column A2 is 0.8 to 1.2 BV; and / or independently, the elution column A3 and The feed rate per unit time of single column rotation of the elution column B2 is 0.8~1.2BV; and / or independently, the feed rate per unit time of single column rotation of the desorption column A4 and the desorption column B3 is 2.5~5BV; and / or independently, the feed rate per unit time of single column rotation of the top liquid column A5 and the top liquid column B4 is 1.0~1.5BV; and / or the feed rate per unit time of single column rotation of the top brine column A6 is 0.5~1BV, preferably 0.6~0.8BV.

[0017] According to another aspect of the present invention, a system for lithium extraction from mineralized brine and aged brine is provided, comprising a mineralized brine lithium extraction unit and an aged brine lithium extraction unit; the mineralized brine lithium extraction unit comprises: a first resin column ion-exchange turntable, wherein: a plurality of resin columns are arranged in the first resin column ion-exchange turntable, and the first resin column ion-exchange turntable is divided into a first adsorption zone, a top material zone, a first elution zone, a first desorption zone, a first top liquid zone and a top brine zone; and the first resin column ion-exchange turntable is rotated so that the resin columns are rotated to the first adsorption zone as an adsorption column A1, to the top material zone as a top material column A2, to the first elution zone as an elution column A3, to the first desorption zone as a desorption column A4, to the first top liquid zone as a top liquid column A5, to the top brine zone as a top brine column A6, and a periodic cycle is performed;

[0018] The first storage tank includes: a mineralization brine storage tank, whose outlet is connected to the inlet of the adsorption column A1; a first adsorption tail liquid storage tank, whose inlet is connected to the outlet of the adsorption column A1; an old brine storage tank, whose outlet is connected to the inlet of the top material column A2; a recovery mineralization brine storage tank, whose inlet is connected to the outlet of the top material column A2; a first leaching water storage tank, whose outlet is connected to the inlet of the leaching column A3; a first leaching liquid storage tank, whose inlet is connected to the outlet of the leaching column A3; a first desorption water storage tank, whose outlet is connected to the outlet of the desorption column A4. The inlet of the first lithium product liquid storage tank is connected to the outlet of the desorption column A4; the inlet of the first top liquid material storage tank is connected to the outlet of the old brine storage tank, and the outlet is connected to the inlet of the top liquid column A5; the inlet of the first top liquid outlet storage tank is connected to the outlet of the top liquid column A5; the inlet of the top brine material storage tank is connected to the outlet of the mineralization brine storage tank and the outlet of the first adsorption tail liquid storage tank, respectively, and the outlet is connected to the inlet of the top brine column A6; the old brine recovery storage tank, the inlet of which is connected to the outlet of the top brine column A6;

[0019] The old brine lithium extraction unit comprises: a second resin column ion-exchange turntable, wherein: a plurality of resin columns are arranged in the second resin column ion-exchange turntable, and the second resin column ion-exchange turntable is divided into a second adsorption zone, a second elution zone, a second desorption zone, and a second top liquid zone; and the second resin column ion-exchange turntable is rotated so that the resin column is rotated to the second adsorption zone as an adsorption column B1, to the second elution zone as an elution column B2, to the second desorption zone as a desorption column B3, to the second top liquid zone as a top liquid column B4 in sequence, and a periodic cycle is performed;

[0020] The second storage tank includes: a second adsorption stock solution storage tank, whose outlet is connected to the inlet of the adsorption column B1; a second adsorption tail liquid storage tank, whose inlet is connected to the outlet of the adsorption column B1; a second elution water storage tank, whose outlet is connected to the inlet of the elution column B2; a second elution effluent storage tank, whose inlet is connected to the outlet of the elution column B2; a second desorption water storage tank, whose outlet is connected to the inlet of the desorption column B3; a second lithium product liquid storage tank, whose inlet is connected to the outlet of the desorption column B3; a second top liquid material storage tank, whose inlet is connected to the outlet of the second adsorption tail liquid storage tank, and whose outlet is connected to the inlet of the top liquid column B4; a second top liquid effluent storage tank, whose inlet is connected to the outlet of the top liquid column B4; wherein, the inlet of the second adsorption stock solution storage tank is respectively connected to the outlet of the old brine storage tank, the outlet of the first elution effluent storage tank, and the outlet of the second elution effluent storage tank.

[0021] Furthermore, the outlet of the recovery mineralization brine storage tank is connected to the inlet of the mineralization brine storage tank; and / or the outlet of the recovery old brine storage tank and the outlet of the second adsorption tail liquid storage tank are respectively connected to the inlet of the old brine storage tank; and / or the mineralization brine and old brine combined lithium extraction system also includes a carnallite pool, whose inlet is respectively connected to the outlet of the first adsorption tail liquid storage tank and the outlet of the recovery mineralization brine storage tank.

[0022] Compared with the prior art, the advancement of the present invention is at least reflected in the following aspects:

[0023] 1. In the process of extracting lithium from mineralized brine, the mineralized brine in the resin column adsorbent bed is replaced by adding the old brine top-loading process, and then enters the leaching process. Firstly, it avoids the dilution of potassium caused by the contact of the mineralized brine in the next process with the leaching water, realizes the recovery of the mineralized brine, and finally completes the return of the lithium adsorbed mineralized brine and its adsorption tail liquid to the carnallite pool for potassium extraction without potassium loss; secondly, it reduces the concentration of the main impurity ions of sodium and potassium in the adsorbent bed, so that the concentration of impurity ions such as sodium and potassium in the lithium product liquid is reduced, and the comprehensive yield and purity of lithium products such as lithium carbonate at the back end are significantly improved; thirdly, due to the difference in chloride ion concentration between the old brine and the mineralized brine, a small amount of old brine will inevitably enter the recovered mineralized brine during the old brine top-loading process. After the top-loading is completed, the two brines are further mixed in the carnallite salt field. Due to the common ion effect of chloride ions, it is helpful to quickly precipitate carnallite in the salt field, thereby improving the yield of the carnallite salt field.

[0024] 2. In the process of extracting lithium from mineralized brine, by adding the old brine top liquid process, after the adsorption and desorption of mineralized brine is completed, the residual desorption water in the adsorbent bed is pushed out by using the old brine to avoid the residual desorption water from contacting with the subsequent mineralized brine or its adsorption tail liquid, causing the mineralized brine or its adsorption tail liquid to be diluted. The mineralized brine adsorption tail liquid is further sent to the carnallite pool (potash fertilizer carnallite salt field) to continue to dry the ore and extract potassium. Since the mineralized brine adsorption tail liquid is not diluted, other components except lithium concentration are almost unchanged, and the carnallite drying and potassium extraction cycle is not affected, so that the lithium extraction of salt lake brine and the carnallite drying and potassium extraction can be carried out simultaneously, which has high economic value.

[0025] 3. Compared with the traditional old brine lithium extraction process, the method of extracting lithium by combining mineralizing brine and old brine of the present invention can reduce the loss of lithium entrained by mineralizing brine in the carnallite section, realize the advancement of the lithium extraction link, improve the yield of salt lake lithium resources, and shorten the lithium extraction cycle by about 0.5 to 1 year.

[0026] 4. The present invention adopts the method of extracting lithium from mineralized brine in combination with old brine to solve the problem of insufficient supply of old brine due to climate influence, and ensures continuous production throughout the year. At the same time, since mineralized brine is generally in industrial parks, public auxiliary projects are relatively complete, ecological environment damage is small, there is no need to transform salt field facilities and infrastructure, and the investment in production transformation is small. Therefore, the method of extracting lithium from mineralized brine in combination with old brine has significant practical significance for the utilization of salt lake resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0028] Figure 1 It shows that Na + , K + Mg 2+ / / Cl - —H 2 O Schematic diagram of salt precipitation in the phase diagram of quaternary water-salt system;

[0029] Figure 2 The process flow chart of the salt pan of the Qarhan Salt Lake resources is shown;

[0030] Figure 3 A process roadmap for extracting lithium from mineralized brine and old brine in combination according to an embodiment of the present invention is shown;

[0031] Figure 4 The process route diagram for lithium extraction from mineralized brine in a single system of Comparative Example 1 is shown;

[0032] Figure 5 A diagram of a process device for extracting lithium from mineralized brine and old brine in combination according to an embodiment of the present invention is shown;

[0033] The above drawings include the following reference numerals:

[0034] 1. Lithium extraction unit from mineralized brine; 10. First resin column ion exchange turntable; 101. First adsorption zone; 102. Top material zone; 103. First elution zone; 104. First desorption zone; 105. First top liquid zone; 106. Top brine zone; 11. First storage tank; 111. Mineralized brine storage tank; 112. First adsorption tail liquid storage tank; 113. Old brine storage tank; 114. Mineralized brine recovery tank; 115. First elution water storage tank; 116. First elution effluent storage tank; 117. First desorption water storage tank; 118. First lithium product liquid storage tank; 119. First top liquid material storage tank; 120. First top liquid effluent storage tank; 121. Top brine material storage tank; 122. Old brine recovery tank;

[0035] 2. Lithium extraction unit from old brine; 20. Second resin column ion exchange turntable; 201. Second adsorption zone; 202. Second elution zone; 203. Second desorption zone; 204. Second top liquid zone; 21. Second storage tank; 211. Second adsorption stock liquid storage tank; 212. Second adsorption tail liquid storage tank; 213. Second elution water storage tank; 214. Second elution effluent storage tank; 215. Second desorption water storage tank; 216. Second lithium product liquid storage tank; 217. Second top liquid material storage tank; 218. Second top liquid effluent storage tank;

[0036] 3. Carnallite pool. DETAILED DESCRIPTION

[0037] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0038] Terminology explanation:

[0039] BV: Bed Volume, refers to the volume of resin loaded in the resin column. The feed volume per unit time of a single column rotation is 1BV, which means the feed volume per unit time of a single column rotation is 1 bed volume.

[0040] As described in the background technology of the present invention, the prior art has the problems of large loss, high cost, large pollution and difficulty in industrialization in lithium extraction from salt lakes. In order to solve the above problems, in a typical embodiment of the present invention, a method for extracting lithium from mineralized brine and old brine is provided, including a lithium extraction process of mineralized brine and a lithium extraction process of old brine; the lithium extraction process of mineralized brine is carried out in the first resin column ion exchange turntable, and a plurality of resin columns are arranged in the first resin column ion exchange turntable, and the first resin column ion exchange turntable is divided into a first adsorption zone, a top material zone, a first elution zone, a first desorption zone, a first top liquid zone and a top brine zone, and the first resin column ion exchange turntable is rotated so that the resin column is rotated to the first adsorption zone as an adsorption column A1, to the top material zone as a top material column A2, to the first elution zone as an elution column A3, to the first desorption zone as a desorption column A4, to the first top liquid zone as a top liquid column A5, to the top brine zone as a top brine column A6, and a periodic cycle is performed; the lithium extraction process of mineralized brine includes the following steps:

[0041] Step S1, in the first adsorption zone, the ore-forming brine is sent to the adsorption column A1 to perform the first adsorption to obtain the first adsorption tail liquid, and the first adsorption tail liquid is sent to the carnallite pool to perform beach drying and potassium extraction to obtain the potassium product; Step S2, in the top material zone, the old brine is sent from the bottom of the column to the top material column A2 to push out the liquid in the column to obtain the recovered ore-forming brine; Step S3, in the first elution zone, the first elution water is sent to the elution column A3 to elute the impurity ions in the column into the solution, A first elution solution is obtained; step S4, in the first desorption zone, the first desorption water is sent into the desorption column A4 to desorb the lithium chloride in the column into the solution to obtain a first lithium product solution; step S5, in the first top liquid zone, the old brine is sent from the bottom of the column into the top liquid column A5 to push out the liquid in the column to obtain a first top liquid solution; step S6, in the top brine zone, the ore-forming brine and / or the first adsorption tail liquid is sent from the bottom of the column into the top brine column A6 to push out the liquid in the column to obtain recovered old brine;

[0042] The lithium extraction process of old brine is carried out in the second resin column ion exchange turntable, in which a plurality of resin columns are arranged, and the second resin column ion exchange turntable is divided into a second adsorption zone, a second elution zone, a second desorption zone and a second top liquid zone, and the second resin column ion exchange turntable is rotated so that the resin column is rotated to the second adsorption zone as an adsorption column B1, to the second elution zone as an elution column B2, to the second desorption zone as a desorption column B3, to the second top liquid zone as a top liquid column B4 in sequence, and a periodic cycle is performed; the lithium extraction process of old brine comprises the following steps:

[0043] Step Q1, in the second adsorption zone, the second adsorption stock solution is sent into the adsorption column B1 to perform the second adsorption to obtain the second adsorption tail liquid; Step Q2, in the second elution zone, the second elution water is sent into the elution column B2 to elute the impurity ions in the column into the solution to obtain the second elution effluent; Step Q3, in the second desorption zone, the second desorption water is sent into the desorption column B3 to desorb the lithium chloride in the column into the solution to obtain the second lithium product liquid; Step Q4, in the second top liquid zone, the second adsorption tail liquid is sent from the bottom of the column into the top liquid column B4 to push out the liquid in the column to obtain the second top liquid effluent; wherein, the second adsorption stock solution includes old brine, the first elution effluent, and the second elution effluent.

[0044] Among them, the adsorption column A1, the top material column A2, the elution column A3, the desorption column A4, the top liquid column A5, the top brine column A6, and the adsorption column B1, the elution column B2, the desorption column B3, and the top liquid column B4 can all be one or more resin columns, and the connection method of the multiple resin columns is series or parallel, which can be adjusted according to actual production needs. In addition, the ratio of the first adsorption tail liquid sent to the carnallite pool and the ratio of the first adsorption tail liquid sent to the top brine column A6 can also be adjusted according to actual production needs. These are understandable to those skilled in the art and will not be repeated here.

[0045] For example, the device used in the process of extracting lithium from mineralized brine can be composed of 20 to 30 resin columns, a first resin column ion exchange turntable, a storage tank, a water pump, a control system and supporting pipelines. Each resin column is filled with an aluminum adsorbent as a selective adsorption material for lithium ions. The unit time of a single column rotation is 10 to 20 minutes. When the turntable rotates, different functional areas are switched, and continuous production is carried out in this cycle. The same is true for the process of extracting lithium from old brine.

[0046] The adsorbent in the resin column includes a conventional aluminum-based lithium adsorbent, and the chemical formula of the aluminum-based lithium adsorbent is mLiCl·2Al(OH) 3 ·nH 2 O, 0<m<1, 0<n<2, adsorption capacity is>2g / L. Impurity ions include one or more of sodium ions, potassium ions and magnesium ions.

[0047] The advantages of extracting lithium from mineralized brine combined with old brine absorption are as follows: First, compared with the chlorinated brine system, the raw brine is sun-dried to remove sodium at the front end, lithium is extracted in the middle, and potassium is extracted by sun-dried carnallite at the end. This can also realize the advancement of the lithium extraction link, avoiding many problems caused by raw brine lithium extraction, and is more practical for the utilization of salt lake resources. Second, the discharge of old brine from carnallite salt fields fluctuates with the seasons. In winter, due to the low temperature and low evaporation in the salt lake area, the brine is slow to reach the old brine point. In order to ensure the optimal operating water level of the salt mining ship, the carnallite pool discharges very little old brine from the carnallite salt field in winter. Therefore, the production capacity of lithium extraction from old brine in winter is greatly limited. The mineralized brine combined with old brine absorption and lithium extraction can solve this actual production problem and achieve continuous production throughout the year.

[0048] During the research process, the inventor unexpectedly found that compared with the extraction of lithium from old brine with "magnesium-lithium separation" as the core and the extraction of lithium from raw brine with "lithium-sodium separation" as the core, the main impurity ions of potassium, sodium and magnesium in the mineralizing brine are between the raw brine and the old brine. The lithium extraction processes are similar, but the details are different. How to avoid the loss of potassium and the dilution of fresh water, and to achieve the simultaneous extraction of lithium from salt lakes and the extraction of potassium from carnallite without affecting each other, is the core issue in the process of lithium extraction from mineralizing brine.

[0049] Specifically, in the lithium extraction process of mineralization brine, the present application first feeds the mineralization brine into the adsorption column A1 for the first adsorption. The adsorbent in the resin column bed can absorb the Li + The ore-forming brine is adsorbed into the bed, and the adsorbed ore-forming brine is discharged to obtain the first adsorption tail liquid, which is sent to the carnallite pool for beach drying and potassium extraction, and potassium products are obtained simultaneously. The ore-forming brine is pumped into the continuous moving bed for adsorption, and the adsorption column A1 can be an even number of columns. The adsorption column A1 is evenly divided into multiple series zones. The ore-forming brine flows into the multiple series zones through the first series zone, and flows out after adsorption to return to the carnallite pool as a raw material for potassium extraction, and the lithium adsorption yield is more than 85%.

[0050] Subsequently, the old brine is sent to the top material column A2 to push out the liquid in the column to obtain the recovered ore-forming brine. The present invention replaces the ore-forming brine in the resin column adsorbent bed first by adding the old brine top material process, and then enters the leaching process. First, it avoids the dilution of potassium caused by the contact of the ore-forming brine in the next process with the leaching water, realizes the recovery of the ore-forming brine, and finally completes the return of the lithium-adsorbed ore-forming brine and its adsorption tail liquid to the carnallite pool for potassium extraction without potassium loss; second, it reduces the concentration of the main impurity ions of sodium and potassium in the adsorbent bed, so that the concentration of impurity ions such as sodium and potassium in the lithium product liquid is reduced, and the comprehensive yield and purity of lithium products such as lithium carbonate at the rear end are significantly improved; third, due to the difference in chloride ion concentration between the old brine and the ore-forming brine, a small amount of old brine will inevitably enter the ore-forming brine. After the top material is completed, the two brines are further mixed in the carnallite salt field. Due to the common ion effect of chloride ions, it is helpful for the rapid precipitation of carnallite in the salt field, thereby improving the yield of the carnallite salt field.

[0051] Then the first elution water is sent to the elution column A3 to elute the main sodium, potassium and magnesium impurity ions in the column from the bed into the solution, and the first elution solution with high magnesium, low potassium and high lithium is obtained as the adsorption stock solution feed of the old brine lithium extraction process; then the first desorption water is sent to the desorption column A4 to desorb the lithium chloride in the desorption zone from the adsorbent bed into the solution, and the first lithium product solution with high purity and yield is obtained; then the old brine is sent to the top liquid column A5 to push out the liquid in the column to avoid the residual desorption water from contacting with the subsequent mineralization brine or its adsorption tail liquid, causing the mineralization brine or its adsorption tail liquid to be diluted, and the first top liquid is obtained; the mineralization brine adsorption tail liquid is further sent to the carnallite pool (potash fertilizer carnallite salt field) to continue to dry the ore and extract potassium. Since the mineralization brine adsorption tail liquid is not diluted, other components except lithium concentration are almost unchanged, and the carnallite drying and potassium extraction cycle is not affected, so that the salt lake brine lithium extraction and carnallite drying and potassium extraction can be carried out simultaneously. Finally, the ore-forming brine and / or the first adsorption tail liquid are sent to the top brine column A6 to push out the liquid in the column, and the recovered old brine is discharged into the old brine channel.

[0052] In the process of extracting lithium from old brine, the first elution solution produced by the process of extracting lithium from old brine and mineralized brine is first sent to the adsorption column B1 for the second adsorption. The adsorbent in the resin column bed can absorb the Li + After being adsorbed into the bed, the adsorbed old brine is discharged to obtain the second adsorption tail liquid which is discharged into the old brine channel; then the second elution water is sent to the elution column B2 to elute the impurity ions in the column into the solution, and the second elution liquid is returned to the adsorption column B1 as the adsorption stock solution for further adsorption; then the second desorption water is sent to the desorption column B3 to desorb the lithium chloride in the column into the solution to obtain the second lithium product liquid; finally, the second adsorption tail liquid is sent to the top liquid column B4 to push out the liquid in the column to obtain the second top liquid outlet.

[0053] The present invention has at least the following advantages:

[0054] Advantage 1: In the process of extracting lithium from ore-forming brine, as for potassium loss, the ore-forming brine in the adsorbent bed is replaced by adding the old brine top material process, and then enters the elution process to avoid the dilution of potassium caused by the contact of the ore-forming brine in the next process with the elution water, so as to realize the recovery of the ore-forming brine, and finally complete the return of the lithium-adsorbed ore-forming brine and its adsorption tail liquid to the carnallite pool for potassium extraction without potassium loss.

[0055] Advantage 2: In terms of fresh water dilution rate, after the adsorption and desorption of the mineralized brine is completed, the desorption water remaining in the adsorbent bed is pushed out by using the old brine to avoid the residual desorption water from contacting with the subsequent mineralized brine or its adsorption tail liquid, causing the mineralized brine or its adsorption tail liquid to be diluted. The adsorption tail liquid of the mineralized brine is used to remove potassium fertilizer and continue to dry the ore to extract potassium in the carnallite salt field. Since the adsorption tail liquid is not diluted, other components except the lithium concentration remain almost unchanged, and the carnallite drying and potassium extraction cycle is not affected, thereby realizing the simultaneous extraction of lithium from salt lake brine and potassium from carnallite.

[0056] Advantage 3: Compared with the traditional old brine lithium extraction process, the present invention can reduce the loss of lithium entrained in the carnallite section of the mineralizing brine, realize the advancement of the lithium extraction link, improve the yield of salt lake lithium resources, and shorten the lithium extraction cycle by about 0.5 to 1 year.

[0057] Advantage 4: Compared with lithium extraction from old brine, affected by climate, the temperature in the salt lake area is low in winter, the evaporation is small, and the mineralized brine is slow to reach the old brine point. In order to ensure the best operating water level for mining operations, the amount of brine discharged from the carnallite salt field in winter is very small. Therefore, lithium extraction from old brine is greatly restricted. The present invention adopts the method of extracting lithium from mineralized brine in combination with old brine to solve the production problem of insufficient supply of lithium from old brine, which is easily affected by climate, and ensures continuous production throughout the year. Compared with lithium extraction from raw brine, first, mineralized brine is generally in industrial parks, and public auxiliary projects are relatively complete. Second, because it is an industrial park, there is no problem of ecological environmental damage. Third, there is no need to transform salt field facilities and infrastructure, and the investment in production transformation is small. Therefore, lithium extraction from mineralized brine in combination with old brine has significant practical significance for the utilization of salt lake resources.

[0058] Advantage 5: Lithium extraction from mineralized brine, because sodium and potassium ions in qualified solution have a great influence on the subsequent lithium extraction process, specifically: first, sodium and potassium cannot be removed in the subsequent membrane section (divalent calcium and magnesium can be removed in the later section), affecting the entire lithium carbonate production; second, the high salt content of TDS (total dissolved solids) leads to high operating pressure of the back-end reverse osmosis membrane and short membrane life; third, the sodium and potassium in the qualified solution are too high, which easily leads to low lithium concentration in the electrodialysis concentrate (lithium migration rate is less than sodium); fourth, the lithium concentration multiple of MVR (steam mechanical recompression) high lithium solution is low (sodium and potassium concentration is too high to easily lead to sodium chloride precipitation during evaporation); fifth, the sodium chloride concentration is too high during lithium precipitation, causing lithium carbonate to wrap sodium chloride ions during the crystallization nucleation process, affecting its product purity, and the large amount of washing water leads to a large amount of lithium precipitation mother liquor, which ultimately affects the overall yield of lithium carbonate. Therefore, by adding the old brine top material process, the mineralized brine in the adsorption bed can be replaced with old brine, reducing the concentration of the main impurity ions of sodium and potassium in the adsorbent bed.

[0059] Advantage 6: In the process of old brine topping mineralizing brine (top material), due to the difference in chloride ion concentration between old brine and mineralizing brine, a small amount of old brine will inevitably enter the mineralizing brine. After the topping is completed, the two brines are sent to the carnallite salt field for complete mixing. Due to the common ion effect of chloride ions, it helps the rapid precipitation of carnallite in the salt field and improves the yield of the carnallite salt field.

[0060] In order to further reduce the cost of lithium extraction from salt lakes and realize material circulation and full utilization, in a preferred embodiment, the method for jointly extracting lithium from ore-forming brine and old brine also includes the following steps: returning the recovered ore-forming brine to step S1; and / or returning the recovered old brine and / or the second adsorption tail liquid to one or more of the following steps: step S2, step S5, step Q1; and / or sending the recovered ore-forming brine to a carnallite pool for beach drying to extract potassium to obtain potassium products, thereby realizing more full utilization of potassium resources.

[0061] In a preferred embodiment, step S1 also includes: a first pretreatment: filtering the mineralizing brine to perform a first impurity removal to obtain a cleaned mineralizing brine, and sending it to an adsorption column A1; wherein the solid suspended matter concentration of the mineralizing brine is 50 to 2100 mg / L, and the solid suspended matter concentration of the cleaned mineralizing brine is <50 mg / L; and / or step Q1 also includes: a second pretreatment: filtering the second adsorption stock solution to perform a second impurity removal to obtain a cleaned second adsorption stock solution, and sending it to an adsorption column B1; wherein the solid suspended matter concentration of the second adsorption stock solution is 50 to 2100 mg / L, and the solid suspended matter concentration of the cleaned second adsorption stock solution is <50 mg / L.

[0062] The above-mentioned pretreatment can filter and separate large particles of mud and other large particles of impurities in mineralizing brine and old brine, further reducing the clogging of resin column adsorbent pores by large particles and causing a decrease in adsorption capacity. The filtration equipment can adopt conventional filtration equipment according to actual production, such as plate and frame filter press, organic membrane, inorganic membrane filter, etc.

[0063] In a preferred embodiment, step S5 also includes: measuring the conductivity of the first top liquid effluent to obtain the first stage recovered water (salt water) with an effluent conductivity of ≤5mS / cm, and the first stage recovered water (concentrated brine) with an effluent conductivity of >5mS / cm; preferably, the first stage recovered water is returned to step S4 as the first desorption water; and / or step Q4 also includes: measuring the conductivity of the second top liquid effluent to obtain the second stage recovered water (salt water) with an effluent conductivity of ≤5mS / cm, and the second stage recovered water (concentrated brine) with an effluent conductivity of >5mS / cm; preferably, the second stage recovered water is returned to step Q3 as the second desorption water; preferably, in the second pretreatment, the first stage recovered water and the second stage recovered water are first used to dilute the old brine, and then the second impurity removal is performed.

[0064] The first stage recycled water has a low salt content and can be returned to the previous process as hot water for desorption, making fuller use of fresh water resources. The second stage recycled water is used for pretreatment of the old brine lithium extraction process, which can further reduce the viscosity of the old brine, avoid salt formation during the pretreatment process, and more fully recover the lithium in it.

[0065] The water used in the process of combined lithium extraction of mineralizing brine and old brine can be conventional fresh water in the art. To further reduce costs, in a preferred embodiment, the first rinsing water includes one or more of fresh water, fresh brine and the first lithium product liquid; the second rinsing water includes one or more of fresh water and fresh brine; independently, the first desorption water and the second desorption water include one or more of tap water, industrial fresh water, purified water, and desalted water, with a temperature of 20 to 40°C and a conductivity of <500μS / cm, which can be selected according to production needs.

[0066] Specifically, in a preferred embodiment, the ore-forming brine comprises: Li + 0.05~1g / L, Mg 2+ 50~110g / L, Na + 3~12g / L, K + 1.8~22g / L, Cl - 150~330g / L; and / or old brine includes: Li + 0.05~1.5g / L, Mg 2+ 110~130g / L, Na + <3g / L, K + <1.8g / L,Cl - 320~400g / L; and / or the first eluent includes: Li + 0.05~1.5g / L, Mg 2+ 77~91g / L, Na + <2.1g / L, K + <1.3g / L,Cl - 230~280g / L; and / or the second eluent includes: Li + 0.05~1.5g / L, Mg 2+ 66~100g / L, Na + <1.8g / L, K + <1.2g / L,Cl - 198~310g / L.

[0067] In addition, the recovered mineralization brine includes: Li + 0.05~1g / L, Mg 2+ 50~120g / L, Na + <12g / L, K+ 1.5~22g / L, Cl - 150~350g / L.

[0068] As described above, the method of the present invention can significantly improve the lithium yield and lithium purity of the final product. In a preferred embodiment, the first lithium product solution comprises: Li + 0.5~1.5g / L, Mg 2+ <2g / L, Na + <0.1g / L, K + <0.02g / L,Cl - 5~12g / L; and / or the second lithium product liquid includes: Li + 0.5~1.5g / L, Mg 2+ <2g / L, Na + <0.1g / L, K + <0.02g / L,Cl - 5~12g / L. The lithium content in the lithium product liquid is high, while the content of impurity ions such as sodium, potassium, and magnesium is low.

[0069] Taking into account the differences in the adsorption capacity and adsorption rate of the adsorbent for brines with different lithium concentrations, in order to make full use of this difference to adsorb and desorb lithium ions, thereby further improving the yield and purity of the lithium product liquid, in a preferred embodiment, the first resin column desorption turntable and the second resin column desorption turntable have a single column rotation unit time of 10 to 20 minutes, respectively and independently; and / or the single column rotation unit time feed rate of the adsorption column A1 is 4 to 40 BV; and / or the single column rotation unit time feed rate of the adsorption column B1 is 2.5 to 40 BV; and / or the top feed column A2 has a single column rotation unit time feed rate of 1.5 to 20 BV; and / or the top feed column A3 has a single column rotation unit time feed rate of 1.5 to 20 BV; and / or the top feed column A4 has a single column rotation unit time feed rate of 1.5 to 20 BV; and / or the top feed column A5 has a single column rotation unit time feed rate of 1.5 to 20 BV; and / or the top feed column A6 has a single column rotation unit time feed rate of 1.5 to 20 BV; and / or the top feed column A7 has a single column rotation unit time feed rate of 1.5 to 20 BV; and / or the top feed column A8 has a single column rotation unit time feed rate of 1.5 to 20 BV; and / or the top feed column A9 has a single column rotation unit time feed rate of 1.5 to 20 BV; and / or the top feed column A1 has a single column rotation unit time feed rate of 1.5 to 20 BV; and / or the top feed column A2 ... The feed rate per unit time of single column rotation is 0.8~1.2BV; and / or independently, the feed rate per unit time of single column rotation of elution column A3 and elution column B2 is 0.8~1.2BV; and / or independently, the feed rate per unit time of single column rotation of desorption column A4 and desorption column B3 is 2.5~5BV; and / or independently, the feed rate per unit time of single column rotation of top liquid column A5 and top liquid column B4 is 1.0~1.5BV; and / or the feed rate per unit time of single column rotation of top brine column A6 is 0.5~1BV, preferably 0.6~0.8BV.

[0070] like Figure 5As shown, in another typical embodiment of the present invention, a system for extracting lithium from mineralized brine and old brine is provided, including a mineralized brine lithium extraction unit 1 and an old brine lithium extraction unit 2; the mineralized brine lithium extraction unit 1 includes: a first resin column ion exchange turntable 10, wherein: a plurality of resin columns are arranged in the first resin column ion exchange turntable 10, and the first resin column ion exchange turntable 10 is divided into a first adsorption zone 101, a top material zone 102, a first elution zone 103, a first desorption zone 104, and a first desorption zone 105. a top liquid zone 105 and a top brine zone 106; and the first resin column desorption turntable 10 is rotated to make the resin column rotate to the first adsorption zone 101 as an adsorption column A1, rotate to the top material zone 102 as a top material column A2, rotate to the first elution zone 103 as an elution column A3, rotate to the first desorption zone 104 as a desorption column A4, rotate to the first top liquid zone 105 as a top liquid column A5, rotate to the top brine zone 106 as a top brine column A6, and perform periodic circulation;

[0071] The first storage tank 11 includes: a mineralization brine storage tank 111, whose outlet is connected to the inlet of the adsorption column A1; a first adsorption tail liquid storage tank 112, whose inlet is connected to the outlet of the adsorption column A1; an old brine storage tank 113, whose outlet is connected to the inlet of the top material column A2; a recovery mineralization brine storage tank 114, whose inlet is connected to the outlet of the top material column A2; a first leaching water storage tank 115, whose outlet is connected to the inlet of the leaching column A3; a first leaching liquid storage tank 116, whose inlet is connected to the outlet of the leaching column A3; a first desorption water storage tank 117, whose outlet is connected to the outlet of the desorption column A4. The first lithium product liquid storage tank 118, whose inlet is connected to the outlet of the desorption column A4; the first top liquid material storage tank 119, whose inlet is connected to the outlet of the old brine storage tank 113, and whose outlet is connected to the inlet of the top liquid column A5; the first top liquid outlet storage tank 120, whose inlet is connected to the outlet of the top liquid column A5; the top brine material storage tank 121, whose inlet is respectively connected to the outlet of the mineralization brine storage tank 111 and the outlet of the first adsorption tail liquid storage tank 112, and whose outlet is connected to the inlet of the top brine column A6; the recovery old brine storage tank 122, whose inlet is connected to the outlet of the top brine column A6;

[0072] The old brine lithium extraction unit 2 comprises: a second resin column ion exchange turntable 20, wherein: a plurality of resin columns are arranged in the second resin column ion exchange turntable 20, and the second resin column ion exchange turntable 20 is divided into a second adsorption zone 201, a second elution zone 202, a second desorption zone 203 and a second top liquid zone 204; and the second resin column ion exchange turntable 20 is rotated so that the resin columns are rotated to the second adsorption zone 201 as an adsorption column B1, to the second elution zone 202 as an elution column B2, to the second desorption zone 203 as a desorption column B3, to the second top liquid zone 204 as a top liquid column B4 in sequence, and a periodic cycle is performed;

[0073] The second storage tank 21 includes: a second adsorption raw liquid storage tank 211, whose outlet is connected to the inlet of the adsorption column B1; a second adsorption tail liquid storage tank 212, whose inlet is connected to the outlet of the adsorption column B1; a second elution water storage tank 213, whose outlet is connected to the inlet of the elution column B2; a second elution liquid storage tank 214, whose inlet is connected to the outlet of the elution column B2; a second desorption water storage tank 215, whose outlet is connected to the inlet of the desorption column B3; a second lithium product liquid storage tank 21 6, whose inlet is connected to the outlet of the desorption column B3; the second top liquid material storage tank 217, whose inlet is connected to the outlet of the second adsorption tail liquid storage tank 212, and whose outlet is connected to the inlet of the top liquid column B4; the second top liquid output storage tank 218, whose inlet is connected to the outlet of the top liquid column B4; wherein, the inlet of the second adsorption raw liquid storage tank 211 is respectively connected to the outlet of the old brine storage tank 113, the outlet of the first elution liquid storage tank 116, and the outlet of the second elution liquid storage tank 214.

[0074] In a preferred embodiment, the outlet of the recovery mineralization brine storage tank 114 is connected to the inlet of the mineralization brine storage tank 111; and / or the outlet of the recovery old brine storage tank 122 and the outlet of the second adsorption tail liquid storage tank 212 are respectively connected to the inlet of the old brine storage tank 113; and / or the mineralization brine and old brine combined lithium extraction system also includes a carnallite pool 3, whose inlet is respectively connected to the outlet of the first adsorption tail liquid storage tank 112 and the outlet of the recovery mineralization brine storage tank 114, so as to better realize material circulation and full utilization, and further reduce the cost of lithium extraction from salt lakes.

[0075] Those skilled in the art will appreciate that, in order to facilitate the description of the structure and partitioning of the resin column separation turntable, the turntable may be appropriately horizontally expanded. Figure 5 It is only a schematic diagram of a process device for jointly extracting lithium from mineralizing brine and old brine for one embodiment. The actual device used can be composed of a resin column exchange turntable composed of 20 to 30 resin columns, a storage tank, a water pump, a control system and supporting pipelines. When the turntable rotates, different functional areas are switched to each other, so as to carry out continuous production in a cycle. Conventional supporting equipment such as water pumps and control systems are not shown in the figure. Those skilled in the art can set them according to actual production needs. These are understandable to those skilled in the art and will not be repeated here.

[0076] Specifically, in the ore-forming brine lithium extraction unit 1, the ore-forming brine lithium extraction process is carried out in the first resin column ion exchange turntable 10, and the first resin column ion exchange turntable 10 is rotated to rotate the resin column to the first adsorption area 101 as an adsorption column A1, to the top material area 102 as a top material column A2, to the first elution area 103 as an elution column A3, to the first desorption area 104 as a desorption column A4, to the first top liquid area 105 as a top liquid column A5, to the top brine area 106 as a top brine column A6, and a periodic cycle is performed; the ore-forming brine lithium extraction process includes the following steps:

[0077] Step S1, in the first adsorption zone 101, the ore-forming brine in the ore-forming brine storage tank 111 is sent to the adsorption column A1 for the first adsorption, and the first adsorption tail liquid is sent to the first adsorption tail liquid storage tank 112, and a part of it is sent to the carnallite pool for beach drying and potassium extraction to obtain a potassium product; Step S2, in the top material zone 102, the old brine in the old brine storage tank 113 is sent to the top material column A2 to push out the liquid in the column, and the recovered ore-forming brine is sent to the recovered ore-forming brine storage tank 114; Step S3, in the first leaching zone 103, the first leaching water in the first leaching water storage tank 115 is sent to the leaching column A3 to elute the impurity ions in the column into the solution, and the first leaching liquid is sent to the first leaching The eluate storage tank 116; step S4, in the first desorption zone 104, the first desorption water in the first desorption water storage tank 117 is sent to the desorption column A4 to desorb the lithium chloride in the column into the solution, and the first lithium product liquid is sent to the first lithium product liquid storage tank 118; step S5, in the first top liquid zone 105, the old brine in the first top liquid material storage tank 119 is sent to the top liquid column A5 to push out the liquid in the column, and the first top liquid output is sent to the first top liquid output storage tank 120; step S6, in the top brine zone 106, the mineralization brine and / or the first adsorption tail liquid in the top brine material storage tank 121 is sent to the top brine column A6 to push out the liquid in the column, and the recovered old brine is sent to the recovered old brine storage tank 122.

[0078] In the old brine lithium extraction unit 2, the old brine lithium extraction process is carried out in the second resin column ion exchange turntable 20. The second resin column ion exchange turntable 20 rotates to rotate the resin column to the second adsorption zone 201 as the adsorption column B1, to the second elution zone 202 as the elution column B2, to the second desorption zone 203 as the desorption column B3, to the second top liquid zone 204 as the top liquid column B4, and performs a periodic cycle; the old brine lithium extraction process includes the following steps:

[0079] Step Q1, in the second adsorption zone 201, the second adsorption stock solution in the second adsorption stock solution storage tank 211 is sent to the adsorption column B1 to perform the second adsorption, and the obtained second adsorption tail liquid is sent to the second adsorption tail liquid storage tank 212; Step Q2, in the second elution zone 202, the second elution water in the second elution water storage tank 213 is sent to the elution column B2 to elute the impurity ions in the column into the solution, and the obtained second elution liquid is sent to the second elution liquid storage tank 214; Step Q3, in the second desorption zone 203, the second desorption water in the second desorption water storage tank 215 is sent to the desorption column B3 to desorb the lithium chloride in the column into the solution, and the second lithium product liquid is sent to the second lithium product liquid storage tank 216; Step Q4, in the second top liquid zone 204, the second adsorption tail liquid in the second top liquid material storage tank 217 is sent to the top liquid column B4 to push out the liquid in the column, and the second top liquid outlet is sent to the second top liquid outlet storage tank 218.

[0080] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0081] In the following examples, lithium extraction from mineralized brine is referred to as system A or system A, and lithium extraction from old brine is referred to as system B or system B. All examples adopt the A+B system combined lithium extraction, using mineralized brine and old brine as raw materials for systems A and B. Specifically, each example is carried out according to the following steps:

[0082] System A: The unit time of single column rotation of the resin column transfer turntable is 10 minutes.

[0083] First pretreatment: filtering the mineralization brine to perform the first impurity removal to obtain impurity-removed mineralization brine with a solid suspended matter concentration of <50 mg / L;

[0084] Step S1, in the first adsorption zone, the impurity-free mineralized brine is sent to the adsorption column A1 to perform the first adsorption to obtain the first adsorption tail liquid, and part of the first adsorption tail liquid is sent to the carnallite pool to perform beach drying to extract potassium to obtain a potassium product;

[0085] Step S2, in the top material area, the old brine is sent to the top material column A2 to push out the liquid in the column, and the recovered mineralization brine is partially returned to step S1, and partially sent to the carnallite pool for beach drying and potassium extraction;

[0086] Step S3, in the first elution zone, the brine is sent to the elution column A3 to elute the impurity ions in the column into the solution to obtain the first elution solution, which is sent to the B system as the second adsorption stock solution;

[0087] Step S4, in the first desorption zone, industrial fresh water (referred to as hot water) with a temperature of 30±10°C and a conductivity of <500μS / cm is fed into the desorption column A4 to desorb the lithium chloride in the column into a solution to obtain a first lithium product solution (qualified solution) for subsequent processing of a lithium salt product;

[0088] Step S5, in the first top liquid area, the old brine is sent to the top liquid column A5 to push out the liquid in the column to obtain the first top liquid outlet, and the conductivity is measured to obtain the first stage recovered water (salt water) with an outlet conductivity of less than 5mS / cm, which is returned to step S4 as the first desorption water, and the first second stage recovered water (concentrated brine) with an outlet conductivity of more than 5mS / cm is also obtained, which is used in the second pretreatment process of the B system to dilute the old brine and recover lithium therein;

[0089] Step S6, in the top brine area, the ore-forming brine and the first adsorption tail liquid are sent to the top brine column A6 to push out the liquid in the column to obtain the recovered old brine and discharge it into the old brine channel.

[0090] System B: The unit time of single column rotation of the resin column transfer turntable is 10 minutes.

[0091] Second pretreatment: After the old brine is appropriately diluted with the first and second stage recycled water and the second and second stage recycled water, it is mixed with the first elution solution of system A and filtered to perform the second impurity removal to obtain the impurity-removed second adsorption stock solution;

[0092] Step Q1, in the second adsorption zone, the impurity-removed second adsorption stock solution is sent to the adsorption column B1 to perform the second adsorption, and the second adsorption tail liquid is obtained and discharged into the old brine channel;

[0093] Step Q2, in the second elution zone, the brine is sent to the elution column B2 to elute the impurity ions in the column into the solution to obtain a second elution solution, which is returned to step Q1 as the second adsorption stock solution;

[0094] Step Q3, in the second desorption zone, industrial fresh water with a temperature of 20-40° C. and a conductivity of less than 500 μS / cm is fed into the desorption column B3 to desorb the lithium chloride in the column into the solution to obtain a second lithium product solution (qualified solution);

[0095] Step Q4, in the second top liquid area, the second adsorption tail liquid is sent to the top liquid column B4 to push out the liquid in the column, and the second top liquid effluent is obtained for conductivity measurement, and the second first-stage recovered water (salt water) with an effluent conductivity of ≤5mS / cm is returned to step Q3 as the second desorption water, and the second second-stage recovered water (concentrated brine) with an effluent conductivity of >5mS / cm is also obtained, which is used for the second pretreatment process of system B to dilute the old brine and recover the lithium therein.

[0096] The specific parameters of each embodiment are described as follows, where flow rate refers to the feed and discharge volume per unit time of a single column rotation:

[0097] Example 1

[0098] This embodiment adopts A+B system for combined lithium extraction, using a mineralization brine and old brine as raw materials for A and B systems. The composition of the brine is shown in Table 1.

[0099] Among them, system A: the mineralizing brine is first filtered and treated, and the SS value after filtration is less than 50mg / L; S1, the filtered mineralizing brine is sent to system A for adsorption, the feed volume per unit time of single column rotation is 40BV, the lithium concentration of adsorption tail liquid is less than 5.5mg / L, the lithium yield is 90%, and the adsorption tail liquid enters the carnallite pool; S2, after the adsorption is completed, 0.9BV old brine is used to push the mineralizing brine in the adsorbent bed out of the column, and the pushed mineralizing brine returns to the adsorption tank of system A; S3, after the top feeding is completed, 1BV light brine is used to elute the adsorbent saturated with adsorption, and the eluent enters the adsorption tank of system B; S4, the elution is completed Finally, 3.2BV of hot water is used to desorb the saturated adsorbent, and the qualified desorbed liquid is used to process the lithium salt product in the later stage; S5, after the desorption is completed, the top liquid is carried out, and 1BV of old brine is used to push out the hot water remaining in the adsorbent bed, of which 0.7BV of effluent conductivity is less than 5mS / cm, which is used for S4 desorption hot water, and another 0.3BV of effluent conductivity is higher than 5mS / cm, which is used in the B system pretreatment process to dilute the old brine and recover the lithium therein; S6, after the top liquid is completed, 0.7BV of mineralizing brine is used to replace the old brine remaining in the adsorbent bed, and the topped-out tail brine is discharged into the old brine channel.

[0100] The inlet and outlet liquid indicators and flow rates of each step of the above A system are shown in Table 1.

[0101] Among them, system B:

[0102] Q1, the old brine after appropriate dilution and filtration with concentrated brine, and the elution liquid of S3 in system A are sent to the adsorption device of system B, the feed volume per unit time of single column rotation is 21BV, the lithium concentration of the adsorption tail liquid is less than 10mg / L, the lithium yield is 90%, and the adsorption tail liquid is discharged into the old brine channel; Q2, the operation method is the same as S3 in system A; Q3, the operation method is the same as S4 in system A; Q4, the operation method is the same as S5 in system A, the difference is that the top liquid uses the adsorption tail liquid of step Q1 of system B.

[0103] The inlet and outlet liquid indicators and flow rates of each step of the above B system are shown in Table 2. Among them, the second elution liquid index of step Q2 meets the following requirements: Li + 0.05~1.5g / L, Mg 2+ 66~100g / L, Na + <1.8g / L, K+ <1.2g / L,Cl - 198~310g / L.

[0104] Table 1 Main technical indicators of material input and output of system A in Example 1

[0105]

[0106]

[0107] Flow calculation: Step S1 first adsorption tail liquid = Step S1 ore-forming brine + Step S2 old brine

[0108] (Flow calculation: tailing brine (carnallite pool) = adsorption (ore-forming brine) + top material inlet (old brine))

[0109] Table 2 Main technical indicators of material input and output of system B in Example 1

[0110]

[0111] Example 2

[0112] The difference from Example 1 is that the inlet and outlet liquid indexes and flow rates of each step are different. The inlet and outlet liquid indexes and flow rates of each step of System A are shown in Table 3. The inlet and outlet liquid indexes and flow rates of each step of System B are shown in Table 4.

[0113] The lithium yield of system A is 90%, and the lithium yield of system B is 90%.

[0114] Table 3 Main technical indicators of material input and output of system A in Example 2

[0115]

[0116]

[0117] Flow calculation: tailing brine (carnallite pool) = adsorption (ore-forming brine) + top material inlet (old brine)

[0118] Table 4 Main technical indicators of material input and output of system B in Example 2

[0119]

[0120]

[0121] Example 3

[0122] The difference from Example 1 is that the inlet and outlet liquid indexes and flow rates of each step are different. The inlet and outlet liquid indexes and flow rates of each step of System A are shown in Table 5. The inlet and outlet liquid indexes and flow rates of each step of System B are shown in Table 6.

[0123] The lithium yield of system A is 95%, and the lithium yield of system B is 96%.

[0124] Table 5 Main technical indicators of material input and output of system A in Example 3

[0125]

[0126]

[0127] Flow calculation: tailing brine (carnallite pool) = adsorption (ore-forming brine) + top material inlet (old brine)

[0128] Table 6 Main technical indicators of material input and output of system B in Example 3

[0129]

[0130] Example 4

[0131] The difference from Example 2 is that the inlet and outlet liquid indexes and flow rates of each step are different. The inlet and outlet liquid indexes and flow rates of each step of System A are shown in Table 7. The inlet and outlet liquid indexes and flow rates of each step of System B are shown in Table 8.

[0132] In system A S5, after the hot water is discharged, there is 0.7BV of water with a conductivity less than 5mS / cm, which is used for S4 to desorb hot water. In addition, the 0.8BV of water with a conductivity higher than 5mS / cm is used in the pretreatment process of system B to dilute the old brine and recover the lithium therein.

[0133] Table 7 Main technical indicators of material input and output of system A in Example 4

[0134]

[0135]

[0136] Flow calculation: tailing brine (carnallite pool) = adsorption (ore-forming brine) + top material inlet (old brine)

[0137] Table 8 Main technical indicators of material input and output of system B in Example 4

[0138]

[0139]

[0140] Example 5

[0141] The difference from Example 2 is that the inlet and outlet liquid indexes and flow rates of each step are different. The inlet and outlet liquid indexes and flow rates of each step of System A are shown in Table 9. The inlet and outlet liquid indexes and flow rates of each step of System B are shown in Table 10.

[0142] In system A S5, after the hot water is discharged, there is 0.7BV of water with a conductivity less than 5mS / cm, which is used for S4 to desorb hot water. In addition, the 0.5BV of water with a conductivity higher than 5mS / cm is used in the pretreatment process of system B to dilute the old brine and recover the lithium therein.

[0143] Table 9 Main technical indicators of material input and output of system A in Example 5

[0144]

[0145]

[0146] Flow calculation: tailing brine (carnallite pool) = adsorption (ore-forming brine) + top material inlet (old brine)

[0147] Table 10 Main technical indicators of material input and output of system B in Example 5

[0148]

[0149] Example 6

[0150] The difference from Example 2 is that the inlet and outlet liquid indexes and flow rates of each step are different. The inlet and outlet liquid indexes and flow rates of each step of System A are shown in Table 11. The inlet and outlet liquid indexes and flow rates of each step of System B are shown in Table 12.

[0151] In system A S5, after the hot water is discharged, there is 0.7BV of water with a conductivity less than 5mS / cm, which is used for S4 to desorb hot water. In addition, the 0.6BV of water with a conductivity higher than 5mS / cm is used in the pretreatment process of system B to dilute the old brine and recover the lithium therein.

[0152] Table 11 Main technical indicators of material input and output of system A in Example 6

[0153]

[0154]

[0155] Flow calculation: tailing brine (carnallite pool) = adsorption (ore-forming brine) + top material inlet (old brine)

[0156] Table 12 Main technical indicators of material input and output of system B in Example 6

[0157]

[0158]

[0159] Comparative Example 1

[0160] There is only one system in the comparative example, and its operation method is the same as that of system B in Example 1, except that the raw material in step Q1 is the same mineralizing brine as that of system A in Example 1, the feed rate per unit time of single column rotation is 40BV, the lithium concentration of the adsorption tail liquid is less than or equal to 5 mg / L, the lithium yield is 90%, and the adsorption tail liquid is discharged into the carnallite pool; the process parameters of other steps remain basically unchanged.

[0161] The inlet and outlet liquid indicators and flow rates of the above steps are shown in Table 13.

[0162] Table 13 Main technical indicators of input and output of comparative example 1

[0163] project Adsorption stock solution Adsorption tail liquid Lithium product liquid Abbreviation Adsorption (ore-forming brine) Tail brine (carnallite pool) Qualified liquid Traffic(BV) 40 40.3 3 <![CDATA[Li + (mg / L)]]> 50 5 600 <![CDATA[Mg 2+ (mg / L)]]> 50000 49561 900 <![CDATA[Na + (mg / L)]]> 3000 2974 50 <![CDATA[K + (mg / L)]]> 1800 1785 20 <![CDATA[Cl - (mg / L)]]> 154439 152858 5801 TDS(mg / L) 209289 207183 7371

[0164] Comparative Example 2

[0165] There is only one system in the comparative example, and its operation method is the same as that of system B in Example 2, except that the raw material in step Q1 is the same mineralizing brine as that of system A in Example 2, the feed rate per unit time of single column rotation is 12BV, the lithium concentration of the adsorption tail liquid is less than or equal to 30 mg / L, the lithium yield is 90%, and the adsorption tail liquid is discharged into the carnallite pool; the process parameters of other steps remain basically unchanged.

[0166] The inlet and outlet liquid indicators and flow rates of the above steps are shown in Table 14.

[0167] Table 14 Main technical indicators of input and output of comparative example 2

[0168]

[0169]

[0170] Comparative Example 3

[0171] There is only one system in the comparative example, and its operation method is the same as that of system B in Example 3, except that the raw material in step Q1 is the same mineralizing brine as that of system A in Example 3, the feed rate per unit time of single column rotation is 4BV, the lithium concentration of the adsorption tail liquid is less than or equal to 50 mg / L, the lithium yield is 95%, and the adsorption tail liquid is discharged into the carnallite pool; the process parameters of other steps remain basically unchanged.

[0172] The inlet and outlet liquid indicators and flow rates of the above steps are shown in Table 15.

[0173] Table 15 Main technical indicators of input and output of comparative example 3

[0174] project Adsorption stock solution Adsorption tail liquid Lithium product liquid Abbreviation Adsorption (ore-forming brine) Tail brine (carnallite pool) Qualified liquid Traffic(BV) 4 4.3 3.2 <![CDATA[Li + (mg / L)]]> 1000 50 1200 <![CDATA[Mg 2+ (mg / L)]]> 95000 87492 1200 <![CDATA[Na + (mg / L)]]> 12000 11089 100 <![CDATA[K + (mg / L)]]> 22000 20355 150 <![CDATA[Cl - (mg / L)]]> 324660 294728 9927 TDS(mg / L) 454660 413715 12577

[0175] The adsorption tail liquid potassium mass change rate, fresh water dilution rate, total salt concentration change rate, and additional evaporation days indicators of the back-halite pool calculated for system A in the above embodiment and the comparative example are shown in Table 16.

[0176] Table 16 Comparison of main technical indicators of embodiments and comparative examples

[0177]

[0178]

[0179] Note: In the table above, the number preceded by “+” in front of the potassium mass change rate and total salt concentration change rate indicates an increase in mass or concentration, and a number preceded by “-” indicates a decrease. The additional evaporation days refer to the number of evaporation days required for the tailings of the mineralized brine diluted with fresh water to reach the saturation point of carnallite.

[0180] Calculation formula:

[0181] a. Potassium mass change rate (%) = (potassium mass (tail brine (carnallite pool)) ÷ potassium mass (total intake) - 1) × 100%;

[0182] b. Fresh water dilution rate (%) = fresh water introduction amount (tail brine (carnallite pool)) ÷ single column rotation unit time feed amount (adsorption (ore-forming brine)) × 100%;

[0183] c. Total salt concentration change rate (%) = (TDS (tail brine (carnallite pool)) ÷ TDS (adsorption (mineralizing brine)) - 1) × 100%;

[0184] d. When the dilution rate of adsorbed tail liquid fresh water is greater than 0, it means that fresh water has entered the tail brine. It is necessary to consider the time for evaporation of this part of fresh water and the loss of potassium from evaporation salt pan leakage. The calculation basis is the leakage coefficient of 0.85mm / d (data from Qinghai Salt Lake Company), the average evaporation of brine throughout the year is 1.02m (specific evaporation coefficient 0.34, fresh water evaporation in the Chaerhan area 3m), the large-area evaporation coefficient is 0.76, and the salt pan depth is 1m. The specific calculation formula is: evaporation days = (1-TDS (tail brine (carnallite pool)) ÷ TDS (adsorption (ore-forming brine))) × salt pan depth ÷ (brine annual brine evaporation × large-area evaporation coefficient) × 365 days;

[0185] e. Leakage potassium loss rate = evaporation days × (daily brine leakage volume ÷ 1000) × salt field area ÷ adsorption tail liquid volume × 100%.

[0186] Example 1: Process route for extracting lithium from mineralized brine and old brine Figure 3 ; Comparative Example 1: Single System Lithium Extraction Process Route for Ore-forming Brine Figure 4 .

[0187] It can be seen from Table 16 that the embodiment adopts the system A+B combined lithium extraction process route, and the total amount of Na and K ions in the qualified liquid is 15-30 mg / L. The comparative example adopts the mineralization brine single system lithium extraction process route, and the total amount of Na and K ions in the qualified liquid is 70-250 mg / L, which is 4-8 times that of the system A+B combined lithium extraction.

[0188] The embodiment adopts system A+B to jointly extract lithium. In terms of the fresh water dilution rate, since the elution liquid of system A is adsorbed by system B, the hot water in the adsorbent bed after desorption is pushed out with old brine, the concentrated brine pushed out is pretreated in system B, and the light brine pushed out is used for desorption in system A. No fresh water is mixed with tail brine in the whole process.

[0189] The embodiment adopts system A+B to jointly extract lithium. In terms of potassium mass loss, since the potassium extraction tail brine from system A is not diluted by fresh water, there is no need to increase the ore drying cycle, and there is no problem of leakage of potassium extraction tail brine in the salt field due to prolonged evaporation time. Therefore, there is no loss of potassium mass.

[0190] The comparative example adopts a single system and uses only one raw material, mineralized brine, to extract lithium. During the leaching and top-liquid process, there is a problem of mixing fresh water and brine. The tail brine for potassium extraction will be diluted by fresh water, and it is necessary to extend the drying cycle in the salt field to evaporate this part of fresh water. From comparative example 1 to comparative example 3, as the concentration of lithium adsorbed into the mineralized brine increases from 50 mg / L to 1000 mg / L, the proportion of fresh water mixed in the brine increases significantly, and the fresh water dilution rate increases from 0.8% to 7.5%. The mass loss rate of potassium in the tail brine of potassium extraction in the return light halite pool increases from 0.5% to 4.1%, and the total salt concentration decrease rate increases from 1.0% to 9.0%. The corresponding number of evaporation days required to be increased from 4.7 days to 42.4 days will seriously affect the production rhythm of potash fertilizers.

[0191] From the above data analysis, the use of system A+B combined lithium extraction process route can not only ensure better quality of lithium product liquid, facilitate the production process of lithium product liquid to product segment, but also avoid potassium loss and will not extend the potassium extraction cycle. It is significantly better than the single system lithium extraction from mineralizing brine.

[0192] In addition, it can be seen that when each process parameter is within the preferred range of the present invention, the overall effect is better.

[0193] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for extracting lithium by combining ore-forming brine and old brine, characterized in that: It includes the process of extracting lithium from mineralized brine and the process of extracting lithium from old brine; The lithium extraction process of the mineralization brine is carried out in the first resin column ion exchange turntable, and a plurality of resin columns are arranged in the first resin column ion exchange turntable, and the first resin column ion exchange turntable is divided into a first adsorption zone, a top material zone, a first elution zone, a first desorption zone, a first top liquid zone and a top brine zone, and the first resin column ion exchange turntable is rotated so that the resin column is rotated to the first adsorption zone as an adsorption column A1, to the top material zone as a top material column A2, to the first elution zone as an elution column A3, to the first desorption zone as a desorption column A4, to the first top liquid zone as a top liquid column A5, to the top brine zone as a top brine column A6, and a periodic cycle is performed; the lithium extraction process of the mineralization brine comprises the following steps: Step S1, in the first adsorption zone, the ore-forming brine is fed into the adsorption column A1 to perform a first adsorption to obtain a first adsorption tail liquid, and the first adsorption tail liquid is fed into a carnallite pool to perform beach drying to extract potassium to obtain a potassium product; Step S2, in the top-loading area, the old brine is sent from the bottom of the column into the top-loading column A2 to push out the liquid in the column to obtain the recovered mineralization brine; Step S3, in the first elution zone, sending the first elution water into the elution column A3 to elute the impurity ions in the column into the solution to obtain a first elution effluent; Step S4, in the first desorption zone, sending the first desorption water into the desorption column A4 to desorb the lithium chloride in the column into a solution to obtain a first lithium product solution; Step S5, in the first top liquid area, the old brine is sent from the bottom of the column into the top liquid column A5 to push out the liquid in the column to obtain the first top liquid outlet; Step S6, in the top brine area, sending the ore-forming brine and / or the first adsorption tail liquid from the bottom of the column into the top brine column A6 to push out the liquid in the column to obtain recovered old brine; The lithium extraction process of the brine is carried out in the second resin column ion exchange turntable, in which a plurality of resin columns are arranged, and the second resin column ion exchange turntable is divided into a second adsorption zone, a second elution zone, a second desorption zone and a second top liquid zone, and the second resin column ion exchange turntable is rotated so that the resin column is rotated to the second adsorption zone as an adsorption column B1, to the second elution zone as an elution column B2, to the second desorption zone as a desorption column B3, to the second top liquid zone as a top liquid column B4 in sequence, and a periodic cycle is performed; the lithium extraction process of the brine comprises the following steps: Step Q1, in the second adsorption zone, sending the second adsorption stock solution into the adsorption column B1 to perform the second adsorption to obtain the second adsorption tail solution; Step Q2, in the second elution zone, sending the second elution water into the elution column B2 to elute the impurity ions in the column into the solution to obtain a second elution solution; Step Q3, in the second desorption zone, sending the second desorption water into the desorption column B3 to desorb the lithium chloride in the column into the solution to obtain a second lithium product solution; Step Q4, in the second top liquid zone, sending the second adsorption tail liquid from the column bottom into the top liquid column B4 to push out the liquid in the column to obtain a second top liquid outlet; Wherein, the second adsorption stock solution includes the old brine, the first elution solution and the optional second elution solution.

2. The method for extracting lithium by combining ore-forming brine and old brine according to claim 1, characterized in that: The method for extracting lithium by combining ore-forming brine with old brine also includes the following steps: Returning the recovered mineralization brine to step S1; and / or Returning the recovered brine and / or the second adsorption tail liquid to one or more of the following steps: step S2, step S5, step Q1; and / or The recovered mineralization brine is sent to the carnallite pool to carry out the beach sun-drying potassium extraction to obtain the potassium product.

3. The method for extracting lithium by combining ore-forming brine and old brine according to claim 1 or 2, characterized in that: The step S1 further comprises: a first pretreatment: filtering the mineralization brine to perform a first impurity removal to obtain the impurity-removed mineralization brine, and feeding the impurity-removed mineralization brine into the adsorption column A1; wherein the solid suspended matter concentration of the impurity-removed mineralization brine is less than 50 mg / L; and / or The step Q1 also includes: a second pretreatment: filtering the second adsorption stock solution to perform a second impurity removal to obtain a second adsorption stock solution with impurities removed, and sending the solution to the adsorption column B1; wherein the solid suspended matter concentration of the second adsorption stock solution with impurities removed is less than 50 mg / L.

4. The method for extracting lithium by combining ore-forming brine and old brine according to claim 3, characterized in that: The step S5 further comprises: measuring the conductivity of the first top liquid outlet to obtain the first stage recovered water with an outlet conductivity of ≤5mS / cm and the first second stage recovered water with an outlet conductivity of >5mS / cm; returning the first stage recovered water to the step S4 as the first desorption water; and / or The step Q4 further comprises: measuring the conductivity of the second top liquid outlet to obtain the second first stage recovered water with outlet conductivity ≤ 5 mS / cm and the second second stage recovered water with outlet conductivity > 5 mS / cm; returning the second first stage recovered water to the step Q3 as the second desorption water; In the second pretreatment, the old brine is firstly diluted using the first-stage second recycled water and the second-stage second recycled water, and then the second impurity removal is performed.

5. The method for extracting lithium by combining ore-forming brine and old brine according to claim 1 or 2, characterized in that: The first rinsing water includes one or more of fresh water, brine and the first lithium product solution; the second rinsing water includes one or more of fresh water and brine; The first desorption water and the second desorption water both include one or more of tap water, industrial fresh water, purified water, and desalted water, with a temperature of 20-40° C. and a conductivity of less than 500 μS / cm.

6. The method for extracting lithium by combining ore-forming brine and old brine according to claim 1 or 2, characterized in that: The mineralization brine includes: Li + 0.05~1g / L, Mg 2+ 50~110g / L, Na + 3~12g / L, K + 1.8~22g / L, Cl - 150~330g / L; and / or The old brine includes: Li + 0.05~1.5g / L, Mg 2+ 110~130g / L, Na + <3g / L, K + <1.8g / L,Cl - 320~400g / L; and / or The first eluent comprises: Li + 0.05~1.5g / L, Mg 2+ 77~91g / L, Na + <2.1g / L, K + <1.3g / L,Cl - 230~280g / L; and / or The second eluent comprises: Li + 0.05~1.5g / L, Mg 2+ 66~100g / L, Na + <1.8g / L, K + <1.2g / L,Cl - 198~310g / L.

7. The method for extracting lithium by combining ore-forming brine and old brine according to claim 1 or 2, characterized in that: The first lithium product solution includes: Li + 0.5~1.5g / L, Mg 2+ <2g / L, Na + <0.1g / L, K + <0.02g / L,Cl - 5-12 g / L; and / or The second lithium product solution includes: Li + 0.5~1.5g / L, Mg 2+ <2g / L, Na + <0.1g / L, K + <0.02g / L,Cl - 5~12g / L.

8. The method for extracting lithium by combining ore-forming brine and old brine according to claim 1 or 2, characterized in that: The single column rotation unit time of the first resin column ion-exchange turntable and the second resin column ion-exchange turntable is 10 to 20 minutes, wherein: The feed volume per unit time of a single column rotation of the adsorption column A1 is 4-40 BV; and / or the feed volume per unit time of a single column rotation of the adsorption column B1 is 2.5-40 BV; and / or The feeding amount per unit time of a single column rotation of the ejector column A2 is 0.8-1.2 BV; and / or The feed volume per unit time of the single column rotation of the elution column A3 and the elution column B2 is 0.8-1.2 BV; and / or The feed volume per unit time of the desorption column A4 and the desorption column B3 is 2.5-5 BV; and / or The feed volume per unit time of the top liquid column A5 and the top liquid column B4 is 1.0-1.5 BV; and / or The feed rate per unit time of a single column rotation of the top brine column A6 is 0.5~1BV.

9. A system for extracting lithium from mineralized brine and old brine, characterized in that: It includes a mineralization brine lithium extraction unit (1) and an old brine lithium extraction unit (2); The mineralization brine lithium extraction unit (1) comprises: The first resin column ion exchange turntable (10) comprises: A plurality of resin columns are arranged in the first resin column ion-exchange turntable (10), and the first resin column ion-exchange turntable (10) is divided into a first adsorption zone (101), a top material zone (102), a first elution zone (103), a first desorption zone (104), a first top liquid zone (105) and a top brine zone (106); and the first resin column ion-exchange turntable (10) is rotated so that the resin columns are rotated in sequence to the first adsorption zone (101) as an adsorption column A1, to the top material zone (102) as a top material column A2, to the first elution zone (103) as an elution column A3, to the first desorption zone (104) as a desorption column A4, to the first top liquid zone (105) as a top liquid column A5, and to the top brine zone (106) as a top brine column A6, and a periodic cycle is performed; The first storage tank (11) comprises: An ore-forming brine storage tank (111), the outlet of which is connected to the inlet of the adsorption column A1; a first adsorption tail liquid storage tank (112), the inlet of which is connected to the outlet of the adsorption column A1; An old brine storage tank (113), whose outlet is connected to the inlet of the top material column A2; a mineralization brine recovery storage tank (114), whose inlet is connected to the outlet of the top material column A2; A first elution water storage tank (115), the outlet of which is connected to the inlet of the elution column A3; a first elution liquid storage tank (116), the inlet of which is connected to the outlet of the elution column A3; A first desorption water storage tank (117), the outlet of which is connected to the inlet of the desorption column A4; a first lithium product liquid storage tank (118), the inlet of which is connected to the outlet of the desorption column A4; A first top liquid material storage tank (119), whose inlet is connected to the outlet of the old brine storage tank (113), and whose outlet is connected to the inlet of the top liquid column A5; a first top liquid outlet storage tank (120), whose inlet is connected to the outlet of the top liquid column A5; A top brine material storage tank (121), whose inlet is respectively connected to the outlet of the mineralization brine storage tank (111) and the outlet of the first adsorption tail liquid storage tank (112), and whose outlet is connected to the inlet of the top brine column A6; and a recovery brine storage tank (122), whose inlet is connected to the outlet of the top brine column A6; The old brine lithium extraction unit (2) comprises: The second resin column ion exchange turntable (20) comprises: A plurality of resin columns are arranged in the second resin column ion-exchange turntable (20), and the second resin column ion-exchange turntable (20) is divided into a second adsorption zone (201), a second elution zone (202), a second desorption zone (203) and a second top liquid zone (204); and the second resin column ion-exchange turntable (20) is rotated so that the resin columns are rotated in sequence to the second adsorption zone (201) as an adsorption column B1, to the second elution zone (202) as an elution column B2, to the second desorption zone (203) as a desorption column B3, and to the second top liquid zone (204) as a top liquid column B4, and a periodic cycle is performed; The second storage tank (21) comprises: A second adsorption raw liquid storage tank (211), whose outlet is connected to the inlet of the adsorption column B1; a second adsorption tail liquid storage tank (212), whose inlet is connected to the outlet of the adsorption column B1; A second elution water storage tank (213), the outlet of which is connected to the inlet of the elution column B2; a second elution liquid storage tank (214), the inlet of which is connected to the outlet of the elution column B2; A second desorption water storage tank (215), the outlet of which is connected to the inlet of the desorption column B3; a second lithium product liquid storage tank (216), the inlet of which is connected to the outlet of the desorption column B3; a second top liquid material storage tank (217), whose inlet is connected to the outlet of the second adsorption tail liquid storage tank (212), and whose outlet is connected to the inlet of the top liquid column B4; a second top liquid outlet storage tank (218), whose inlet is connected to the outlet of the top liquid column B4; The inlet of the second adsorption raw liquid storage tank (211) is respectively connected to the outlet of the old brine storage tank (113), the outlet of the first elution liquid storage tank (116), and the outlet of the second elution liquid storage tank (214).

10. The system for extracting lithium from mineralized brine and old brine according to claim 9, characterized in that: The outlet of the mineralization brine storage tank (114) is connected to the inlet of the mineralization brine storage tank (111); and / or The outlet of the old brine recovery tank (122) and the outlet of the second adsorption tail liquid storage tank (212) are respectively connected to the inlet of the old brine storage tank (113); and / or The mineralization brine and old brine combined lithium extraction system further comprises a carnallite pool (3), the inlet of which is respectively connected to the outlet of the first adsorption tail liquid storage tank (112) and the outlet of the mineralization brine recovery storage tank (114).

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