New process for operation of ion exchange resin

Abstract

The invention belongs to the technical field of metal resource recovery, and provides a novel ion exchange resin operation process which comprises the steps that ion exchange resin is sequentially subjected to cleaning, adsorption, washing and desorption, an initial washing agent used for washing is water, an initial desorption agent used for desorption is acid, enrichment liquid obtained after desorption is divided into two parts, and the two parts are separated from each other; the first part is diluted by adding water to serve as a washing agent for the next round, and the second part is prepared into a desorption agent for the next round by adding acid. According to the method, one part of the enrichment liquid obtained after resin desorption is periodically diluted by adding water to serve as a washing agent of the resin, and the other part of the enrichment liquid is periodically diluted by adding acid to serve as a desorption agent of the resin, so that the purification degree and the enrichment degree of the resin on metal are effectively improved, and the process is simple and convenient to operate and suitable for large-scale industrial application.

Description

Technical Field

[0001] This invention belongs to the field of metal resource recycling, and relates to a method of using an ion exchange resin for purifying and enriching metals, and particularly to a new process for operating the ion exchange resin. Background Technology

[0002] Ion exchange resins play a vital role in the metallurgical industry by separating and extracting metals, such as rare earth metals, precious metals, heavy metals, and other valuable metals, from aqueous solutions through ion exchange. In the 1960s, the emergence of macroporous network resins solved the problems of easy contamination and low water efficiency associated with traditional gel resins when treating high-turbidity, organic-containing metallurgical wastewater. This led to the widespread application of resins in the advanced treatment of various metallurgical wastewaters. From the late 21st century to the present, with improvements in resin exchange capacity, regeneration efficiency, and selectivity for metal ions, ion exchange tree technology has been integrated with leaching, solvent extraction, membrane technology, and evaporation crystallization to achieve full-process recovery of metal resources, such as zinc electrolyte purification and nickel-cobalt recovery from laterite nickel ore. With advancements in modern green recycling and intelligent technologies, resins will drive the upgrading of industrial and environmental needs in the field of resource recycling.

[0003] As is well known, compared to solvent extraction, ion exchange resin methods do not have the problem of organic solvent pollution and are more environmentally friendly. However, ion exchange resins exist in solid form, and their solid-phase characteristics limit the dynamic mass transfer efficiency between the resin and liquid phases, between resins, and within the liquid phase during the ion exchange process. This prevents the achievement of a countercurrent contact mode between the water and oil phases, similar to that in liquid-liquid extraction. This significantly affects the enrichment and purity of metals in the metal salt solutions obtained by ion exchange resin purification.

[0004] Currently, to improve product purity, industrial water is typically used to wash the resin after adsorption to remove impurity ions. However, this not only fails to completely remove the impurity ions but also leaches some of the target metal during the washing process, thus reducing the purity and concentration of the target metal in the resin desorption solution. Therefore, ion exchange processes often require subsequent solvent extraction, crystallization, and concentration steps to obtain a metal salt solution with the purity and concentration required for material synthesis, thereby increasing the cost of metal recovery and limiting the company's production efficiency. Summary of the Invention

[0005] In view of the problems existing in the prior art, the purpose of this invention is to provide a new process for operating ion exchange resins, including sequentially washing, adsorbing, rinsing, and desorbing the ion exchange resin. The initial washing agent used is water, and the initial desorbing agent used is acid. The enriched solution obtained after desorption is divided into two parts: the first part is diluted with water and used as the washing agent for the next round, and the second part is prepared with acid to serve as the desorbing agent for the next round. By periodically diluting one part of the enriched solution obtained from resin desorption with water as the resin washing agent and periodically adding acid to the other part as the resin desorbing agent, the purification and enrichment of metals by the resin are effectively improved. This process is simple and convenient to operate, and suitable for large-scale industrial applications.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a novel process for operating ion exchange resins, comprising:

[0008] (1) Provide resin, wash and then adsorb to obtain adsorption tail liquid and adsorption resin;

[0009] (2) The adsorption resin is washed to obtain washing tail liquid and washing resin; the initial detergent used in the washing is water;

[0010] (3) Desorb the washing resin to obtain an enriched solution and a desorbed resin; the initial desorbent used for the desorption is acid;

[0011] (4) The enrichment solution is divided into two parts. The first part is diluted with water and used as the detergent for the next round. The second part is prepared with acid as the desorbent for the next round.

[0012] The novel process for operating the ion exchange resin described in this invention involves periodically diluting a portion of the resin enrichment solution with water as a detergent. Compared to using pure water, this detergent contains a certain concentration of adsorbed target ions, thus effectively eluting impurity ions during washing, which helps improve purity, while also inhibiting and reducing the loss of adsorbed target ions. Simultaneously, another portion of the resin enrichment solution is periodically diluted with acid as a desorbent. After cyclic desorption, the enrichment degree of adsorbed target ions in the enrichment solution can be effectively improved. This process is simple and convenient to operate, and suitable for large-scale industrial applications.

[0013] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The technical objectives and beneficial effects of the present invention can be better achieved and realized through the following technical solutions.

[0014] As a preferred technical solution of the present invention, in step (1), the resin is washed until the effluent is clear before the adsorption is performed.

[0015] The present invention does not limit the type of resin used. Exemplarily, the resin preferably includes any one of D854, D851, HP606, LSC-495, HP4080 or LSC-930.

[0016] As a preferred technical solution of the present invention, in step (1), the adsorbed target ions include metal ions.

[0017] The present invention does not limit the metal ions adsorbed by the resin, and can be adapted to the actual situation and needs. For example, the metal ions can be any one of copper, nickel, cobalt or manganese.

[0018] For example, the resin can be used to adsorb nickel in a nickel-cobalt solution after iron and aluminum removal from laterite nickel ore.

[0019] Preferably, adsorption is stopped when the concentration of the target ion in the adsorption tail liquid is >1.5 mg / L.

[0020] Preferably, in the adsorption process, the flow rate of the stock solution to be adsorbed through the column is 0.5~30 BV / h, for example, it can be 0.5 BV / h, 1 BV / h, 2 BV / h, 3 BV / h, 4 BV / h, 5 BV / h, 8 BV / h, 10 BV / h, 13 BV / h, 15 BV / h, 18 BV / h, 20 BV / h, 22 BV / h, 25 BV / h, 28 BV / h or 30 BV / h, but it is not limited to the values ​​listed above. Other unlisted values ​​within the above range are also applicable.

[0021] Preferably, in the adsorption process, the number of resin cascade stages is 1 to 30, for example, it can be 1, 2, 3, 5, 8, 10, 12, 14, 16, 18, 20, 23, 25, 28 or 30 stages, but it is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0022] As a preferred technical solution of the present invention, in step (2), during the washing process, the flow rate of the detergent through the column is 0.5~20 BV / h, for example, it can be 0.5 BV / h, 1 BV / h, 2 BV / h, 3 BV / h, 4 BV / h, 5 BV / h, 7 BV / h, 9 BV / h, 10 BV / h, 12 BV / h, 14 BV / h, 16 BV / h, 18 BV / h, or 20 BV / h, etc. The washing is stopped when the concentration of the adsorbed target ion in the washing tail liquid is <1.5 mg / L. However, it is not limited to the values ​​listed above; other unlisted values ​​within the above range are also applicable.

[0023] As a preferred technical solution of the present invention, in step (3), the acid concentration of the initial desorbent is 5% to 30%, for example, it can be 5%, 8%, 10%, 12%, 14%, 16%, 18%, 20%, 23%, 25%, 28% or 30%, etc., but it is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0024] Preferably, in the desorption process, the flow rate of the desorbent through the column is 0.5~20 BV / h, for example, it can be 0.5 BV / h, 1 BV / h, 2 BV / h, 3 BV / h, 4 BV / h, 5 BV / h, 8 BV / h, 10 BV / h, 12 BV / h, 14 BV / h, 16 BV / h, 18 BV / h or 20 BV / h, etc. When the pH of the enrichment solution is >1.5, desorption is stopped, but it is not limited to the values ​​listed above; other unlisted values ​​within the above range are also applicable.

[0025] As a preferred technical solution of the present invention, in step (4), the first part of the enrichment solution accounts for 0.1% to 20% of the total amount of the enrichment solution. For example, it can be 0.1%, 0.3%, 0.5%, 0.8%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, or 20%, etc., but it is not limited to the values ​​listed. Other unlisted values ​​within the above range are also applicable.

[0026] Preferably, the first portion of the enrichment solution is diluted with water to a concentration of adsorbed target ions < 0.5 g / L. For example, it can be 0.01 g / L, 0.03 g / L, 0.05 g / L, 0.08 g / L, 0.1 g / L, 0.13 g / L, 0.15 g / L, 0.18 g / L, 0.2 g / L, 0.23 g / L, 0.25 g / L, 0.28 g / L, 0.3 g / L, 0.33 g / L, 0.35 g / L, 0.38 g / L, 0.4 g / L, 0.42 g / L, 0.45 g / L, 0.48 g / L, or 0.49 g / L, etc., but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0027] As a preferred technical solution of the present invention, in step (4), the second part of the enrichment solution accounts for 80% to 99.9% of the total amount of the enrichment solution. For example, it can be 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 99.9%, etc., but it is not limited to the values ​​listed. Other unlisted values ​​within the above range are also applicable.

[0028] Preferably, the second part of the enrichment solution contains an acid with a concentration of 5% to 30%, for example, 5%, 8%, 10%, 12%, 14%, 16%, 18%, 20%, 23%, 25%, 28%, or 30%, but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0029] In this invention, the amount of initial desorbent and the acid content and pH of the second part of the enrichment solution after acid addition are related to the properties of the resin, the operating process, the number of cycles of the enrichment solution, and the required concentration of the original solution to be adsorbed. They should be adjusted adaptively according to the actual situation.

[0030] As a preferred technical solution of the present invention, the new process further includes step (5), which includes: backwashing the desorption resin obtained in step (3) using water until the effluent is clear, and then stopping the backwashing to obtain backwashed resin.

[0031] As a preferred technical solution of the present invention, step (5) further includes regenerating the backwashing resin to obtain regenerated resin.

[0032] It should be noted that the regeneration of the resin described in this invention is generally carried out when the resin can no longer perform normal adsorption, and is not necessarily required after each desorption. For example, the continuous use time of the resin can be one week, one month, or one year. When it is found that the cyclic adsorption performance of the resin cannot meet the usage requirements, regeneration can be performed. For example, hydrochloric acid can be used to wash or soak the impurity metal ions enriched on the resin, and then rinsed until the pH meets the requirements. The concentration of the regenerating agent hydrochloric acid and the regeneration time can be determined according to the ease of resin regeneration. The ease of resin regeneration is related to the properties of the resin itself, the binding force between the resin and the impurity metal ions, the type of impurities, and their enrichment concentration on the resin.

[0033] Furthermore, depending on the properties of the resin and the actual situation and needs, the resin can be transformed using alkaline substances before adsorption or after resin regeneration and rinsing. These alkaline substances include liquid alkali, ammonium sulfate, ammonia, etc.

[0034] Preferably, the regenerating agent used in the regeneration includes hydrochloric acid with a concentration of 5% to 35%, such as 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 18%, 23%, 25%, 28%, 30%, 32%, or 35%, but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0035] Preferably, when using a regenerant for regeneration, the regeneration method includes column running and / or soaking.

[0036] Preferably, in the regeneration, the column flow rate of the regenerant is 0.5~10 BV / h, for example, it can be 0.5 BV / h, 1 BV / h, 2 BV / h, 3 BV / h, 4 BV / h, 5 BV / h, 6 BV / h, 7 BV / h, 8 BV / h, 9 BV / h or 10 BV / h, etc., but it is not limited to the values ​​listed above. Other unlisted values ​​within the above range are also applicable.

[0037] As a preferred technical solution of the present invention, step (5) further includes rinsing the regenerated resin with water until the pH of the effluent is greater than 3, and then reusing it for adsorption in step (1).

[0038] It is understandable that steps (4) and (5) are steps to process and use the enrichment solution and desorption resin obtained in step (3) respectively. Therefore, the two steps are not sequential and can be performed simultaneously.

[0039] Compared with existing technical solutions, the present invention has at least the following beneficial effects:

[0040] The novel process for operating ion exchange resin provided by this invention involves periodically diluting a portion of the resin enrichment solution with water as a detergent. Compared to using pure water, this detergent contains a certain concentration of adsorbed target ions, thus effectively eluting impurity ions during washing, which is beneficial for improving purity, while also inhibiting and reducing the loss of adsorbed target ions. Simultaneously, another portion of the resin enrichment solution is periodically added with acid as a desorbent. After cyclic desorption, the enrichment degree of adsorbed target ions in the enrichment solution can be effectively improved. This process is simple and convenient to operate, and is suitable for large-scale industrial applications. Attached Figure Description

[0041] Figure 1 This is a schematic flowchart of the new process for operating the ion exchange resin in Example 1. Detailed Implementation

[0042] The technical solution of the present invention will be further illustrated below through specific embodiments.

[0043] Those skilled in the art will understand that the embodiments described are merely illustrative of the invention and should not be construed as limiting the invention.

[0044] Example 1

[0045] This embodiment provides a novel process for operating ion exchange resins, the flowchart of which is shown below. Figure 1 As shown, the new process includes the following steps:

[0046] Step (1): Resin washing and adsorption: Provide new ion exchange resin, then pack the resin into a resin column with 8 stages in series, wash the resin with water until the effluent is clear, the resin is D854; adsorb the crude manganese solution as shown in Table 1 after MHP precipitation of laterite nickel ore through the column at a flow rate of 4 BV / h, and stop adsorption when Mn in the adsorption tail liquid is >1.5 mg / L, to obtain the adsorption resin;

[0047] Table 1 Crude Manganese Solution

[0048]

[0049] Step (2) Resin washing: The detergent flow rate through the column is 3 BV / h. When the Mn in the washing tail liquid is <1.5 mg / L, adsorption is stopped, and the washed resin is obtained. For the first washing of the resin, industrial water is used as the initial detergent.

[0050] Step (3) Resin desorption: For the first desorption, prepare 10% sulfuric acid as the desorbent and pass it through the column at a flow rate of 3.0 BV / h. When the pH of the enrichment solution is greater than 1.5, stop the desorption and obtain the desorbed resin.

[0051] Step (4) Reuse of enriched solution: After resin desorption, 8% of the obtained enriched solution is used as the first part and diluted with water until the Mn concentration is <0.5g / L. Then it is used as the detergent for the next round of resin and returned to step (2) for application. At the same time, the other 92% of the enriched solution is used as the second part. After adding 10% sulfuric acid, it is used as the desorbent for the next round of resin and returned to step (3) for application.

[0052] Step (5) Resin backwashing and regeneration: When the desorption resin fails to operate and loses its metal ion exchange capacity, backwash the resin with clean water until the backwash effluent is clear. Then, regenerate the resin with a regenerant, a 10% HCl solution at a column flow rate of 3 BV / h. Then, rinse the resin with industrial water until the effluent pH is >3, and return to step (1) for adsorption.

[0053] Example 2

[0054] This embodiment provides a new process for operating ion exchange resin. In step (4) of the new process, the proportion of the first part of the enrichment solution is adjusted from 8% to 1%, and the proportion of the first part of the enrichment solution is adjusted from 92% to 99%. Apart from the above, the other conditions are exactly the same as those in Example 1.

[0055] Example 3

[0056] This embodiment provides a new process for operating ion exchange resin. In step (4) of the new process, the proportion of the first part of the enrichment solution is adjusted from 8% to 13%, and the proportion of the first part of the enrichment solution is adjusted from 92% to 87%. Apart from the above, the other conditions are exactly the same as in Example 1.

[0057] Example 4

[0058] This embodiment provides a new process for the operation of ion exchange resin. In step (4) of the new process, 10% sulfuric acid is added to adjust the amount of sulfuric acid to 15%, and then it is used as the desorbent for the next round of resin in step (3). Except for the above, the other conditions are exactly the same as those in Example 3.

[0059] Comparative Example 1

[0060] This comparative example provides a process for operating an ion exchange resin, in which adsorption, washing and desorption are still performed, but step (4) is not performed. The detergent used in each round of washing is industrial water, and the desorbent used in each round of desorption is 10% acid. Except for the above, the other conditions are exactly the same as in Example 1.

[0061] All the enriched solutions obtained in each example and comparative example were collected, and the composition results of the desorption solutions obtained by elemental content testing are shown in Table 2.

[0062] Table 2

[0063]

[0064] As shown in Table 2, compared to Comparative Example 1, Examples 1-4 effectively improved the purity and enrichment of the resin for metals by periodically diluting a portion of the enriched solution obtained after resin desorption with water as a washing agent and periodically adding acid as a desorbent. In Examples 1-3, the first and second portions had different proportions; appropriately increasing the proportion of the first portion effectively improved the purity of the manganese desorption solution. Comparing Examples 3 and 4, it can be seen that reusing the second portion to increase the added acid concentration during desorption resulted in better enrichment of the desorption solution. Comparing Examples 1-4, it can be seen that through comprehensive optimization, the manganese enriched solution obtained in Example 4 has high purity, with impurity concentrations all below the monitoring standards for NCM ternary material preparation. It can be used for direct synthesis of ternary materials or diluted for use in the electrowinning of manganese to obtain high-purity 4N manganese plates.

[0065] In summary, the novel process for operating the ion exchange resin described in this invention involves periodically diluting a portion of the resin enrichment solution with water as a detergent. Compared to using pure water, this detergent contains a certain concentration of adsorbed target ions, which can exchange with impurity ions adsorbed on the resin during washing, thereby improving the elution rate of impurities and enhancing the resin's purity for the target metal. Simultaneously, another portion is periodically added with acid as a desorbent for the resin. After cyclic desorption, the resin's enrichment for the target metal can be effectively improved. This process is simple and convenient to operate, making it suitable for large-scale industrial applications.

[0066] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0067] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0068] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A novel process for operating ion exchange resins, characterized in that, include: (1) Provide resin, wash and then adsorb to obtain adsorption tail liquid and adsorption resin; (2) The adsorption resin is washed to obtain washing tail liquid and washing resin; The initial detergent used in the washing process is water; (3) Desorb the washing resin to obtain an enriched solution and a desorbed resin; the initial desorbent used for the desorption is acid; (4) The enrichment solution is divided into two parts. The first part is diluted with water and used as the detergent for the next round. The second part is prepared with acid as the desorbent for the next round.

2. The novel process for operating ion exchange resin according to claim 1, characterized in that, In step (1), the resin is washed until the effluent is clear before the adsorption is performed; Preferably, the resin includes any one of D854, D851, HP606, LSC-495, HP4080 or LSC-930.

3. The novel process for operating the ion exchange resin according to claim 1, characterized in that, In step (1), the adsorbed target ions include metal ions; Preferably, adsorption is stopped when the concentration of the target ion in the adsorption tail liquid is >1.5 mg / L; Preferably, in the adsorption process, the flow rate of the stock solution to be adsorbed through the column is 0.5~30 BV / h; Preferably, in the adsorption process, the number of resin cascade orders is 1 to 30.

4. The novel process for operating the ion exchange resin according to claim 1, characterized in that, In step (2), during the washing process, the flow rate of the detergent through the column is 0.5~20 BV / h. When the concentration of the adsorbed target ion in the washing tail liquid is <1.5 mg / L, the washing is stopped.

5. The novel process for operating the ion exchange resin according to claim 1, characterized in that, In step (3), the acid concentration of the desorbent is 5%~30%; Preferably, during desorption, the flow rate of the desorbent through the column is 0.5~20 BV / h, and desorption is stopped when the pH of the enrichment solution is greater than 1.

5.

6. The novel process for operating the ion exchange resin according to claim 1, characterized in that, In step (4), the first portion of the enrichment solution accounts for 0.1% to 20% of the total enrichment solution; Preferably, the first portion of the enrichment solution is diluted with water until the concentration of the adsorbed target ions is <0.5 g / L.

7. The novel process for operating the ion exchange resin according to claim 1, characterized in that, In step (4), the second portion of the enrichment solution accounts for 80% to 99.9% of the total enrichment solution; Preferably, the second part of the enrichment solution contains an acid with a concentration of 5% to 30%.

8. The novel process for operating the ion exchange resin according to claim 1, characterized in that, The new process also includes step (5), which includes: backwashing the desorption resin obtained in step (3) using water until the effluent is clear, and then stopping the backwashing to obtain backwashed resin.

9. The novel process for operating the ion exchange resin according to claim 8, characterized in that, Step (5) further includes regenerating the backwash resin to obtain regenerated resin; Preferably, the regenerator used in the regeneration includes hydrochloric acid with a concentration of 5% to 35%; Preferably, when using a regenerant for regeneration, the regeneration method includes column chromatography and / or soaking; Preferably, in the regeneration, the flow rate of the regenerant through the column is 0.5~10 BV / h.

10. The novel process for operating the ion exchange resin according to claim 9, characterized in that, Step (5) further includes rinsing the regenerated resin with water until the pH of the effluent is greater than 3, and then reusing it for adsorption in step (1).

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