A method and device for separating heavy metal ions with ion exchange resin

Abstract

The present invention discloses a method and device for separating heavy metal ions by using ion exchange resin, and belongs to the technical field of separation equipment. The present invention provides a device for separating heavy metal ions by using ion exchange resin, which is used for separating heavy metal ions represented by magnesium ions from salt lake brine. The device comprises a filtering and separating component; the filtering and separating component is a first fixed bed reactor, a second fixed bed reactor, a plurality of third fixed bed reactors, and a fourth fixed bed reactor connected in sequence from top to bottom; a lithium adsorbent is provided in the first fixed bed reactor, an ion exchange resin is provided in the second fixed bed reactor, an ion exchange resin and a chelating resin are provided in the third fixed bed reactor, and a chelating resin is provided in the fourth fixed bed reactor. The present invention can complete the efficient separation of magnesium ions in salt lake brine under a conventional reaction environment by continuously changing the ion exchange material components, without pressurizing and heating during the treatment process.

Description

Technical Field

[0001] The invention belongs to the technical field of separation equipment and relates to a method and a device for separating heavy metal ions with ion exchange resin. Background Art

[0002] Lithium, as the first metal element in the periodic table, is the lightest metal. It has excellent properties such as active chemical properties, large specific heat capacity, and low expansion coefficient. It is widely used in batteries, glass ceramics, grease, nuclear energy and other fields. It is an indispensable key raw material for the development of the new energy vehicle industry. Extracting lithium from salt lake brine is the main way to produce lithium salts. In industry, evaporation, crystallization, and precipitation processes are generally used, and the final product is lithium carbonate. The adsorption method is a lithium extraction technology that has great advantages from an environmental and economic perspective. In particular, the advantages of extracting lithium from low-grade high-magnesium lithium brine and seawater are more obvious. The key to this method is to develop adsorbents with excellent performance. From the initial organic adsorbents to inorganic ion exchangers, the adsorption method has achieved the extraction of lithium from dilute solutions.

[0003] Patent CN109019642A discloses a method for extracting lithium carbonate from salt lake brine, which comprises: passing a gas inlet at the lower end of a heating device and heating a gas containing CO at a temperature not less than 500°C. 2 The gas is input into the heating device to improve the production efficiency of lithium carbonate salt. Patent CN115287468A discloses a process for extracting lithium ions from salt lake brine, which uses a multi-stage electric adsorption device to simultaneously perform series adsorption, the multi-stage electric adsorption device is simultaneously cleaned, and the multi-stage electric adsorption device is simultaneously desorbed. The entire process is cyclically carried out, and multi-stage electric adsorption and multi-stage desorption are used to improve the adsorption efficiency. Patent CN102417194A discloses a chelating resin deep magnesium removal method for extracting lithium from salt lake brine, which uses a chelating resin to further remove magnesium after a magnesium removal, and uses a jacketed organic glass resin column to pretreat the resin to keep the temperature of the resin column constant and stable. It can be seen from the above patents that in order to improve the efficiency of separating magnesium ions and / or lithium ions from salt lake brine, complex equipment such as heating equipment, insulation equipment or electric adsorption devices are used, and the stability requirements of the entire separation device are high, which is not conducive to scale up industrial production. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a method and device for separating heavy metal ions using ion exchange resins.

[0005] On the one hand, the present invention relates to a device for separating heavy metal ions by using an ion exchange resin, comprising a filtering and separating component, wherein the filtering and separating component is a first fixed bed reactor, a second fixed bed reactor, a plurality of third fixed bed reactors, and a fourth fixed bed reactor connected in sequence from top to bottom;

[0006] The first fixed bed reactor is provided with a lithium adsorbent, the second fixed bed reactor is provided with an ion exchange resin, the third fixed bed reactor is provided with an ion exchange resin and a chelating resin, and the fourth fixed bed reactor is provided with a chelating resin;

[0007] Along the liquid flow direction, the mass proportion of the ion exchange resin in the plurality of third fixed bed reactors gradually decreases;

[0008] The mass ratio of the ion exchange resin to the chelating resin in the third fixed bed reactor is 3:1 to 1:3.

[0009] Furthermore, in the device for separating heavy metal ions with ion exchange resin provided by the present invention, the lithium adsorbent is aluminum hydroxide-based lithium adsorbent AI-8, the ion exchange resin is cation exchange resin LSD-010, and the chelating resin is LSC-100 aminocarboxylic acid type chelating resin.

[0010] Furthermore, in the device for separating heavy metal ions with an ion exchange resin provided by the present invention, along the liquid flow direction, the plurality of third fixed bed reactors are composed of a No. 1 third fixed bed reactor, a No. 2 third fixed bed reactor and a No. 3 third fixed bed reactor;

[0011] The mass ratio of ion exchange resin to chelating resin in the No. 1 third fixed bed reactor is 3:1, the mass ratio of ion exchange resin to chelating resin in the No. 2 third fixed bed reactor is 1:1, and the mass ratio of ion exchange resin to chelating resin in the No. 3 third fixed bed reactor is 1:3.

[0012] Furthermore, in the device for separating heavy metal ions with ion exchange resin provided by the present invention, it also includes a first water storage tank;

[0013] The first water storage tank is connected to a first flow controller, and the first flow controller is connected to a liquid inlet of the first fixed bed reactor;

[0014] A second flow controller is provided between the second fixed bed reactor and the plurality of third fixed bed reactors;

[0015] A third flow controller is provided between the final liquid outlets of the plurality of third fixed bed reactors and the fourth fixed bed reactor;

[0016] The liquid outlet of the fourth fixed bed reactor is connected to a peristaltic pump, and the liquid outlet of the peristaltic pump is connected to a third water storage tank.

[0017] Furthermore, in the device for separating heavy metal ions with ion exchange resin provided by the present invention, a second water storage tank is also included;

[0018] Along the liquid flow direction, the final liquid outlets of the plurality of third fixed bed reactors are connected to the second water storage tank, and the liquid outlet of the second water storage tank is connected to the initial liquid inlets of the plurality of third fixed bed reactors.

[0019] On the other hand, the present invention relates to a method for separating heavy metal ions with ion exchange resin, which uses the device for separating heavy metal ions with ion exchange resin to separate magnesium ions and / or lithium ions from salt lake brine.

[0020] Furthermore, in the method for separating heavy metal ions with ion exchange resin provided by the present invention, the flow rate of the liquid passing through the filtering and separating component is controlled to be 5-15 BV / h.

[0021] Furthermore, in the method for separating heavy metal ions with an ion exchange resin provided by the present invention, after being activated, the ion exchange resin is rinsed once with a fatty acid methyl ester ethoxylate sulfonate solution.

[0022] Furthermore, in the method for separating heavy metal ions with an ion exchange resin provided by the present invention, the concentration of the fatty acid methyl ester ethoxylate sulfonate solution is 10 wt %.

[0023] Compared with the prior art, the technical solution provided by the present invention has at least the following beneficial effects or advantages:

[0024] The present invention uses continuously changing ion exchange material components, and does not require pressurization and heating during the treatment process, and can complete the efficient separation of magnesium ions in salt lake brine under conventional reaction conditions. The present invention can further reduce the magnesium content without changing the lithium concentration, thereby improving the yield and purity of subsequent sodium carbonate precipitation of lithium carbonate. The method and device for separating heavy metal ions with ion exchange resins provided by the present invention do not require additional insulation or heating devices, and can tolerate faster flow rates, which can further improve the efficiency of separating magnesium ions and / or lithium ions from salt lake brine. The present invention has found in experiments that after being rinsed with a fatty acid methyl ester ethoxylate sulfonate solution, the efficiency of separating magnesium ions and / or lithium ions from salt lake brine is further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 It is a structural diagram of the device for separating heavy metal ions using ion exchange resin according to the present invention.

[0027] The reference numerals are explained as follows: 110 is the first water storage tank, 120 is the second water storage tank, 130 is the third water storage tank; 210 is the first flow controller, 220 is the second flow controller, 230 is the third flow controller; 310 is the first fixed bed reactor, 320 is the second fixed bed reactor, 330 is the fourth fixed bed reactor; 410 is the third fixed bed reactor No. 1, 420 is the third fixed bed reactor No. 2, 430 is the third fixed bed reactor No. 3; 500 is a peristaltic pump. DETAILED DESCRIPTION

[0028] The technical scheme of the present invention is described below in conjunction with the embodiments, but the present invention is not limited to the following embodiments. The experimental methods and detection methods described in each embodiment are conventional methods unless otherwise specified; the reagents and materials described are all commercially available unless otherwise specified.

[0029] Example 1: This example provides the operating mode of the device for separating heavy metal ions using ion exchange resins according to the present invention.

[0030] like Figure 1 As shown, the first water storage tank 110 stores salt lake brine to be treated, and its liquid outlet is connected to the first flow controller 210. After the first flow controller 210 adjusts the control flow rate to 5-15 BV / h, the salt lake brine is output to the first fixed bed reactor 310. The first fixed bed reactor 310 is filled with aluminum hydroxide-based lithium adsorbent AI-8 (provided by Beijing Chemical Metallurgy Research Institute of Nuclear Industry), and the liquid outlet of the first fixed bed reactor 310 is connected to the second fixed bed reactor 320, and the second fixed bed reactor 320 is filled with cation exchange resin LSD-010. After being treated with lithium adsorbent and ion exchange resin, the salt lake brine is output to the second flow controller 220. After the second flow controller 220 adjusts the control flow rate to 5~15BV / h, it is output to a fixed bed reactor composed of multiple third fixed bed reactors. Along the liquid flow direction, it is connected in series by the third fixed bed reactor No. 1 410, the third fixed bed reactor No. 2 420, and the third fixed bed reactor No. 3 430. The mass ratio of the ion exchange resin to the chelating resin in the third fixed bed reactor No. 1 410, the third fixed bed reactor No. 2 420, and the third fixed bed reactor No. 3 430 is 3:1~1:3; along the liquid flow direction, the mass proportion of the ion exchange resin in the multiple third fixed bed reactors gradually decreases; the ion exchange resin used in the third fixed bed reactor is the cation exchange resin LSD-010, and the chelating resin is the aminocarboxylic acid type chelating resin LSC-100, both of which are provided by Xi'an Lanxiao Technology Co., Ltd.

[0031] Illustratively, the mass ratio of ion exchange resin to chelating resin in the No. 1 third fixed bed reactor 410 is 3:1, the mass ratio of ion exchange resin to chelating resin in the No. 2 third fixed bed reactor 420 is 1:1, and the mass ratio of ion exchange resin to chelating resin in the No. 3 third fixed bed reactor 430 is 1:3.

[0032] Optionally, the device is also provided with a second water storage tank 120 for collecting the liquid that does not meet the magnesium ion removal standard (generally set to reduce the magnesium content to below 1 mg / L) produced by the third fixed bed reactor No. 3 430, and then outputting it to the liquid inlet of the third fixed bed reactor No. 1 410 for re-exchange and adsorption.

[0033] Along the liquid flow direction, a third flow controller 230 is provided between the final liquid outlets of the plurality of third fixed bed reactors and the fourth fixed bed reactor 330. The fourth fixed bed reactor 330 is filled with LSC-100 aminocarboxylic acid type chelating resin. The third flow controller 230 adjusts the control flow rate to 5-15 BV / h and outputs to the fourth fixed bed reactor 330. The liquid outlet of the fourth fixed bed reactor 330 is connected to a peristaltic pump 500, and the liquid outlet of the peristaltic pump is connected to the third water storage tank 130. The peristaltic pump 500 provides power for the operation of the equipment, and together with the first flow controller 210, the second flow controller 220, and the third flow controller 230, adjusts the overall flow rate of the filtering and separation components in the equipment.

[0034] Example 2: This example provides an experiment of using an ion exchange resin device to separate heavy metal ions to separate magnesium ions and / or lithium ions from salt lake brine.

[0035] The composition of salt lake brine is 6.2g / L lithium ion, 2.71g / L sodium ion, 124.64g / L magnesium ion, 370.12g / L chloride ion, and 6.58g / L sulfate ion.

[0036] Experimental Group 1: The salt lake brine was treated by the device provided in Example 1, wherein the cation exchange resin LSD-010 was activated or regenerated, rinsed once with a 10 wt % fatty acid methyl ester ethoxylate sulfonate solution, and then placed in the second fixed bed reactor 320.

[0037] Experimental Group 2: The salt lake brine was treated by the device provided in Example 1, wherein the cation exchange resin LSD-010 was placed in the second fixed bed reactor 320 without being rinsed after being activated or regenerated.

[0038] Comparative Group 1: The salt lake brine was treated according to the method provided in Example 9 in CN102417194A.

[0039] Comparative group 2: Referring to experimental group 2, the mass ratio of ion exchange resin to chelating resin was fixed at 1:1.

[0040] The salt lake brine was controlled at a temperature of 20°C or not controlled in temperature and then treated by experimental group 1, experimental group 2, comparison group 1, and comparison group 2. The experimental results are shown in Table 1.

[0041] Table 1 Experimental results

[0042]

[0043] As can be seen from Table 1, the method and device for separating heavy metal ions with ion exchange resin provided by the present invention do not require additional insulation or heating devices, and can tolerate faster flow rates, which can further improve the efficiency of separating magnesium ions and / or lithium ions from salt lake brine.

[0044] The embodiments described above are part of the embodiments of the present invention, but not all of them. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but only represents selected embodiments of the present invention. All other embodiments obtained without creative work and related deductions and substitutions made by ordinary technicians in the field under the conditions of the concept of the present invention belong to the scope of protection of the present invention.

Claims

1. A device for separating heavy metal ions by ion exchange resin, comprising a filtering and separation component, characterized in that: The filtering and separation assembly is a first fixed bed reactor, a second fixed bed reactor, a plurality of third fixed bed reactors, and a fourth fixed bed reactor connected in sequence from top to bottom; The first fixed bed reactor is provided with a lithium adsorbent, the second fixed bed reactor is provided with an ion exchange resin, the third fixed bed reactor is provided with an ion exchange resin and a chelating resin, and the fourth fixed bed reactor is provided with a chelating resin; Along the liquid flow direction, the mass proportion of the ion exchange resin in the plurality of third fixed bed reactors gradually decreases; The mass ratio of the ion exchange resin to the chelating resin in the third fixed bed reactor is 3:1 to 1:3; No additional heat preservation device or heating device is required in the filtering and separation assembly; The device for separating heavy metal ions with ion exchange resin is used to remove magnesium ions from salt lake brine; The lithium adsorbent is aluminum hydroxide-based lithium adsorbent AI-8, the ion exchange resin is cation exchange resin LSD-010, and the chelate resin is LSC-100 aminocarboxylic acid chelate resin; The flow rate of the liquid in the filtration and separation component is controlled to be 5~15BV / h.

2. The device for separating heavy metal ions by ion exchange resin according to claim 1, characterized in that: Along the liquid flow direction, the plurality of third fixed bed reactors are composed of a No. 1 third fixed bed reactor, a No. 2 third fixed bed reactor and a No. 3 third fixed bed reactor; The mass ratio of ion exchange resin to chelating resin in the No. 1 third fixed bed reactor is 3:1, the mass ratio of ion exchange resin to chelating resin in the No. 2 third fixed bed reactor is 1:1, and the mass ratio of ion exchange resin to chelating resin in the No. 3 third fixed bed reactor is 1:

3.

3. The device for separating heavy metal ions by ion exchange resin according to claim 1, characterized in that: Also included is a first water storage tank; The first water storage tank is connected to a first flow controller, and the first flow controller is connected to a liquid inlet of the first fixed bed reactor; A second flow controller is provided between the second fixed bed reactor and the plurality of third fixed bed reactors; The liquid outlet of the fourth fixed bed reactor is connected to a peristaltic pump, and the liquid outlet of the peristaltic pump is connected to a third water storage tank.

4. The device for separating heavy metal ions using ion exchange resin according to claim 3, characterized in that: Also included is a second water storage tank; Along the liquid flow direction, the final liquid outlets of the plurality of third fixed bed reactors are connected to the second water storage tank, and the liquid outlet of the second water storage tank is connected to the initial liquid inlets of the plurality of third fixed bed reactors.

5. A method for separating heavy metal ions using an ion exchange resin, characterized in that: The device for separating heavy metal ions using the ion exchange resin according to any one of claims 1 to 4 is used to separate magnesium ions and / or lithium ions from salt lake brine.

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