Preparation method and application of flocculant for spodumene beneficiation wastewater treatment

Abstract

This application provides a method for preparing a flocculant for treating spodumene beneficiation wastewater and its application, belonging to the field of wastewater treatment technology. The method involves sequentially mixing triethanolamine fatty acid ester, dodecyltrimethylammonium chloride, polyaluminum chloride, polyacrylamide, starch, and water at mass percentages of 15-25%, 15-25%, 15-20%, 5-15%, 5-10%, and 5-15%, respectively. The mixture is stirred, and acid is added to adjust the pH to neutral, thus obtaining the flocculant for spodumene beneficiation wastewater treatment. This flocculant is then used for wastewater pretreatment in conjunction with a "natural sedimentation—flocculation sedimentation—dilution with clean water" process. The treated wastewater is then reused in the beneficiation process. Through the synergistic effect of the beneficiation reagents and the beneficiation process, the wastewater meets the standards for use in clean water flotation, and the reagent usage is low. This solves a series of problems such as low wastewater reuse efficiency and poor economic indicators in beneficiation.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a method for preparing a flocculant for treating spodumene ore beneficiation wastewater and its application. Background Technology

[0002] The spodumene beneficiation process generates wastewater containing pollutants such as suspended solids and heavy metal ions. Direct discharge of this wastewater without treatment will pollute surface and groundwater; direct reuse will significantly impact beneficiation indicators. Wastewater recycling and treatment can effectively reduce negative environmental impacts and comply with environmental policies. Furthermore, spodumene beneficiation requires substantial water resources. Recycling and reusing wastewater reduces the amount of fresh water used, thus conserving water resources. This not only reduces water consumption but also lowers treatment and discharge costs.

[0003] In the flotation process of spodumene ore, sodium hydroxide and sodium carbonate are typically used as modifiers, calcium chloride as an activator, and naphthenic acid soap and oxidized paraffin soap as collectors. The flotation tailings pulp contains a large number of carbonate ions, hydroxide ions, and calcium ions, as well as fatty acid collectors, which leads to a significant adverse impact on the flotation performance of spodumene ore after wastewater reuse. Therefore, the purification of these substances is crucial in the treatment of spodumene ore flotation wastewater.

[0004] The current main process for treating spodumene beneficiation wastewater is the low-density lime method. This method involves adding calcium oxide as a flocculant, adjusting the pH of the wastewater with sulfuric acid, and then reusing the treated wastewater back into the process. While the low-density lime method is relatively low-cost and has a simple overall operation, it consumes a large amount of lime after treatment and can lead to scaling, causing pipe blockages. The operating environment is also quite harsh. Furthermore, the recycled water used in spodumene flotation still results in spodumene concentrate grades and recovery rates that are far lower than those of clean water. Summary of the Invention

[0005] In view of the technical problems existing in the background art, this application provides a method for preparing a flocculant for treating spodumene beneficiation wastewater and its application, aiming to solve the problems of low index of existing spodumene beneficiation wastewater and low wastewater reuse efficiency.

[0006] In a first aspect, embodiments of this application provide a method for preparing a flocculant for treating spodumene beneficiation wastewater, comprising the following steps:

[0007] S1. Mix and stir triethanolamine fatty acid ester, dodecyltrimethylammonium chloride, polyaluminum chloride, polyacrylamide, starch, and water sequentially to obtain a mixed solution;

[0008] S2. Add acid to the mixed solution to adjust the pH value to neutral, and the flocculant for treating spodumene ore beneficiation wastewater is obtained.

[0009] In the technical solution of this application embodiment, triethanolamine fatty acid ester, dodecyltrimethylammonium chloride, polyaluminum chloride, polyacrylamide, starch, and water are mixed sequentially, stirred, and acid is added to adjust the pH value to neutral to obtain a flocculant for treating spodumene beneficiation wastewater. Among them, triethanolamine fatty acid ester and dodecyltrimethylammonium chloride are the main flocculants. The hydroxyl groups in triethanolamine fatty acid ester and the quaternary ammonium groups in dodecyltrimethylammonium chloride can undergo nucleophilic substitution reactions to generate new quaternary ammonium salt derivatives. As a strong cationic polyelectrolyte, it contains a large number of positively charged cationic quaternary ammonium salt groups, which can interact electrostatically with anionic particles (such as suspended particles and colloidal particles) in water. As electrostatic attraction proceeds, its long-chain molecules will bridge between multiple anionic particles, forming a "bridging" effect. Polyaluminum chloride can give full play to its charge effect and the bridging and agglomeration advantages of the newly generated quaternary ammonium salt derivatives. The two molecules form a strong cooperation, further enhancing the flocculation effect and increasing the sedimentation rate. Starch, as a natural polymeric flocculant, can not only reduce the content of heavy metal ions in wastewater, but also help stabilize the molecular structure of dodecyltrimethylammonium chloride, preventing its degradation or deactivation under complex water quality conditions. Through the synergistic effect between different components of the flocculant, a flocculant for spodumene beneficiation wastewater with high treatment efficiency and good wastewater indicators is obtained.

[0010] In some embodiments, in step S1, the mass percentages of fatty acid triethanolamine ester, dodecyltrimethylammonium chloride, aluminum chloride, polyacrylamide, starch, and water are 15-25%, 15-25%, 15-20%, 5-15%, 5-10%, and 5-15%, respectively; the stirring temperature is 80-100°C; and the stirring time is 30 min.

[0011] In this embodiment, by mixing the components in a specific ratio at a specific temperature, the components can react fully and achieve a synergistic effect.

[0012] In some embodiments, in step S2, the acid is oxalic acid or sulfuric acid.

[0013] In this embodiment, the newly generated quaternary ammonium salt derivative will hydrolyze into quaternary ammonium base under alkaline conditions, so acid needs to be added to neutralize the pH of the solution to neutral or weakly acidic.

[0014] In some embodiments, in step S2, the starch is corn starch, wheat starch, or potato starch.

[0015] In this embodiment, starch, as a natural polymeric flocculant, can not only reduce the content of heavy metal ions in wastewater, but also help stabilize the molecular structure of polydimethyldiallylammonium chloride, preventing it from degrading or becoming inactive under complex water quality conditions.

[0016] Secondly, this application provides an application of a flocculant for treating spodumene beneficiation wastewater, in which the treated wastewater is reused for spodumene beneficiation, and the beneficiation result reaches the clean water standard.

[0017] In the technical solution of this application embodiment, the flocculant obtained, combined with the wastewater treatment process, solves the problems of low reuse efficiency and poor wastewater indicators in mineral processing wastewater.

[0018] In some embodiments, treating wastewater for reuse in spodumene beneficiation includes the following steps:

[0019] S1. Pretreatment of spodumene beneficiation wastewater: After the beneficiation wastewater settles naturally for 2 hours, take the supernatant, add 80-120 g / t of the flocculant to the supernatant, stir for 10 minutes, and then let it settle naturally for 30 minutes. Take the supernatant and dilute it with water by 50% to obtain the pretreated wastewater.

[0020] S2. The pretreated wastewater is reused in the closed-circuit flotation test of spodumene. After wet grinding the crushed ore, the pretreated wastewater is added to bring the slurry concentration to 30-40%. 450-550 g / t of NaOH and 45-55 g / t of CaCl2 are added to the slurry. After stirring for 2 minutes, 250-350 g / t of sodium oleate and 280-320 g / t of oxidized paraffin soap are added. After stirring for 2 minutes, the bubbles are skimmed off to obtain spodumene rough concentrate and roughing tailings. 180-220 g / t of Na2CO3 is added to the rough concentrate for a first-stage cleaning process. 180 g / t of Na2CO3 is added to the first-stage cleaning concentrate. ~220 g / t of Na2CO3 is added to the concentrate of the second stage of the cleaning process. Then, 80-120 g / t of Na2CO3 is added to the concentrate of the second stage of the cleaning process to obtain the final spodumene concentrate. 80-120 g / t of sodium oleate and 80-120 g / t of oxidized paraffin soap are added to the tailings of the roughing process to obtain the first stage of the scavenging process. 45-55 g / t of sodium oleate and 45-55 g / t of oxidized paraffin soap are added to the tailings of the first stage of the scavenging process to obtain the final tailings. The tailings of the first stage of the cleaning process and the concentrate of the first stage of the scavenging process are returned to the roughing process, the tailings of the second stage of the cleaning process are returned to the first stage of the cleaning process, the tailings of the third stage of the cleaning process are returned to the second stage of the cleaning process, and the concentrate of the second stage of the scavenging process is returned to the first stage of the scavenging process.

[0021] In this embodiment, the spodumene wastewater treatment method achieves good wastewater quality and requires less reagent.

[0022] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in this application will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0024] Figure 1 This is a flowchart illustrating the spodumene beneficiation wastewater treatment process according to an embodiment of this application.

[0025] Figure 2 This is a flowchart illustrating the preparation of spodumene beneficiation wastewater in Example 1 of this application;

[0026] Figure 3 This is a flowchart of the spodumene beneficiation wastewater reuse process in Example 1 of this application. Detailed Implementation

[0027] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0029] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0030] To address the issues of low pollutant levels and inefficient wastewater reuse in existing spodumene beneficiation wastewater treatment methods, this application provides a method for preparing a flocculant for spodumene beneficiation wastewater treatment and its application. Specifically, this application discovers that the hydroxyl groups in triethanolamine fatty acid esters and the quaternary ammonium groups in dodecyltrimethylammonium chloride can undergo nucleophilic substitution reactions to generate new quaternary ammonium salt derivatives. As strong cationic polyelectrolytes, these derivatives contain a large number of positively charged cationic quaternary ammonium salt groups, enabling electrostatic interactions with anionic particles (such as suspended particles and colloidal particles) in water. With the progress of electrostatic attraction, the long-chain molecules bridge multiple anionic particles, forming a "bridging" effect. Polyaluminum chloride can fully utilize its charge effect and the bridging and agglomeration advantages of the newly generated quaternary ammonium salt derivatives, forming a strong synergistic effect between the two molecules, further enhancing the flocculation effect and increasing the settling velocity. Starch, as a natural polymeric flocculant, not only reduces the content of heavy metal ions in wastewater but also helps stabilize the molecular structure of dodecyltrimethylammonium chloride, preventing its degradation or deactivation under complex water quality conditions. Therefore, this application uses triethanolamine fatty acid ester, dodecyltrimethylammonium chloride, aluminum chloride, polyacrylamide, starch, and water as raw materials to prepare a flocculant for treating spodumene beneficiation wastewater. This flocculant achieves high treatment efficiency for spodumene beneficiation wastewater and good indicators for the treated wastewater through the synergistic effect between different components.

[0031] On one hand, embodiments of this application provide a method for preparing a flocculant for treating spodumene beneficiation wastewater, comprising the following steps:

[0032] S1. Mix and stir triethanolamine fatty acid ester, dodecyltrimethylammonium chloride, polyaluminum chloride, polyacrylamide, starch, and water sequentially to obtain a mixed solution;

[0033] S2. Add acid to the mixed solution to adjust the pH value to neutral, and the flocculant for treating spodumene ore beneficiation wastewater is obtained.

[0034] In the technical solution of this application embodiment, triethanolamine fatty acid ester, dodecyltrimethylammonium chloride, polyaluminum chloride, polyacrylamide, starch, and water are mixed sequentially, stirred, and acid is added to adjust the pH value to neutral to obtain a flocculant for treating spodumene beneficiation wastewater. Among them, triethanolamine fatty acid ester and dodecyltrimethylammonium chloride are the main flocculants. The hydroxyl groups in triethanolamine fatty acid ester and the quaternary ammonium groups in dodecyltrimethylammonium chloride can undergo nucleophilic substitution reactions to generate new quaternary ammonium salt derivatives. As a strong cationic polyelectrolyte, it contains a large number of positively charged cationic quaternary ammonium salt groups, which can interact electrostatically with anionic particles (such as suspended particles and colloidal particles) in water. As electrostatic attraction proceeds, its long-chain molecules will bridge between multiple anionic particles, forming a "bridging" effect. Polyaluminum chloride can give full play to its charge effect and the bridging and agglomeration advantages of the newly generated quaternary ammonium salt derivatives. The two molecules form a strong cooperation, further enhancing the flocculation effect and increasing the sedimentation rate. Starch, as a natural polymeric flocculant, can not only reduce the content of heavy metal ions in wastewater, but also help stabilize the molecular structure of dodecyltrimethylammonium chloride, preventing its degradation or deactivation under complex water quality conditions. Through the synergistic effect between different components of the flocculant, a flocculant for spodumene beneficiation wastewater with high treatment efficiency and good wastewater indicators is obtained.

[0035] Furthermore, in some embodiments, in step S1, the mass percentages of fatty acid triethanolamine ester, dodecyltrimethylammonium chloride, aluminum chloride, polyacrylamide, starch, and water are 15-25%, 15-25%, 15-20%, 5-15%, 5-10%, and 5-15%, respectively; the stirring temperature is 80-100°C; and the stirring time is 30 minutes.

[0036] In the technical solution of this application embodiment, by mixing the components in a specific proportion at a specific temperature, the components can react fully and achieve a synergistic effect.

[0037] Furthermore, in some embodiments, in step S2, the acid is oxalic acid or sulfuric acid.

[0038] In the technical solution of this application embodiment, the newly generated quaternary ammonium salt derivative will hydrolyze into quaternary ammonium base under alkaline conditions, so acid needs to be added to neutralize the pH of the solution to neutral or weakly acidic.

[0039] Furthermore, in some embodiments, in step S2, the starch is corn starch, wheat starch, or potato starch.

[0040] In the technical solution of this application embodiment, starch, as a natural polymeric flocculant, can not only reduce the content of heavy metal ions in wastewater, but also help stabilize the molecular structure of polydimethyldiallyl ammonium chloride, preventing it from degrading or deactivating under complex water quality conditions.

[0041] Secondly, this application provides an application of a flocculant for treating spodumene beneficiation wastewater, in which the treated wastewater is reused for spodumene beneficiation, and the beneficiation result reaches the clean water standard.

[0042] In the technical solution of this application embodiment, the flocculant obtained, combined with the wastewater treatment process, solves the problems of low reuse efficiency and poor wastewater indicators in mineral processing wastewater.

[0043] Furthermore, in some embodiments, treating wastewater for reuse in spodumene beneficiation includes the following steps:

[0044] S1. Pretreatment of spodumene beneficiation wastewater: After the beneficiation wastewater settles naturally for 2 hours, the supernatant is taken, 100 g / t of the flocculant is added to the supernatant, stirred for 10 minutes, and then settled naturally for 30 minutes. The supernatant is then taken and diluted with water by 50% to obtain pretreated wastewater; wherein, the beneficiation wastewater is the upper suspension obtained after roughing.

[0045] S2. The pretreated wastewater is reused in the closed-circuit flotation test of spodumene. After wet grinding the crushed ore, the pretreated wastewater is added to bring the slurry concentration to 30-40%. 450-550 g / t NaOH and 45-55 g / t CaCl2 are added to the slurry. After stirring for 2 minutes, 250-350 g / t sodium oleate and 280-320 g / t oxidized paraffin soap are added. After stirring for 2 minutes, the bubbles are skimmed off to obtain spodumene rough concentrate and roughing tailings. 200 g / t Na2CO3 is added to the rough concentrate for a finishing process (refining 1). 2... 00 g / t Na2CO3 is added to the concentrate of the second stage of the cleaning process. 100 g / t Na2CO3 is added to the concentrate of the second stage of the cleaning process to obtain the final spodumene concentrate. 80-120 g / t sodium oleate and 80-120 g / t paraffin soap oxide are added to the tailings of the roughing process to obtain the first stage of the scavenging process. 45-55 g / t sodium oleate and 45-55 g / t paraffin soap oxide are added to the tailings of the first stage of the scavenging process to obtain the final tailings. The tailings of the first stage of the cleaning process and the concentrate of the first stage of the scavenging process are returned to the roughing process. The tailings of the second stage of the cleaning process are returned to the first stage of the cleaning process. The tailings of the third stage of the cleaning process are returned to the second stage of the cleaning process. The concentrate of the second stage of the scavenging process is returned to the first stage of the scavenging process.

[0046] In the technical solution of this application embodiment, the spodumene wastewater treatment method achieves good spodumene wastewater indicators and requires less reagent dosage.

[0047] The following are some specific embodiments. It should be noted that the embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0048] Example 1

[0049] This embodiment provides a method for preparing a flocculant for treating spodumene beneficiation wastewater and its application, specifically including the following steps:

[0050] 1. Preparation of flocculant: Weigh 20g of triethanolamine fatty acid ester, 20g of dodecyltrimethylammonium chloride, 15g of polyaluminum chloride, 5g of polyacrylamide, 5g of corn starch and 10g of water respectively, add them to a measuring cup in sequence, stir at 90℃ for 30min, and then add 15mol / L oxalic acid to adjust the pH value to neutral.

[0051] 2. Preparation process of spodumene beneficiation wastewater: such as Figure 2 As shown, the raw ore is crushed to -2mm, and then the crushed ore is wet-milled. During the milling process, 1000g / t Na2CO3 is added, and the milling fineness is -0.074mm, accounting for 72%. Water is added until the slurry concentration is 30%. Then, 500g / t NaOH and 50g / t CaCl2 are added, and after stirring for 2 minutes, 300g / t sodium oleate and 300g / t oxidized paraffin soap (i.e., 731) are added. After stirring for 2 minutes, the bubbles are skimmed off to obtain spodumene rough concentrate and tailings. After standing for 10 minutes, the upper suspension is taken as mineral processing wastewater.

[0052] 3. Pretreatment process for spodumene beneficiation wastewater: such as... Figure 1 As shown, after the mineral processing wastewater is allowed to settle naturally for 2 hours, the supernatant is taken, 15 mg / L flocculant is added to the supernatant, stirred for 10 minutes, and allowed to settle naturally for another 30 minutes. The supernatant is then taken and diluted with water by 50% to obtain the pretreated wastewater.

[0053] 4. The pretreated wastewater is reused in the closed-circuit flotation test of spodumene. The test procedure is as follows: Figure 3As shown, the raw ore is crushed to -2mm, and then the crushed ore is wet-milled. During milling, 1000g / t Na2CO3 is added, and the milling fineness is -0.074mm (72%). Water is added until the slurry concentration is 30%. Then, 500g / t NaOH and 50g / t CaCl2 are added, and after stirring for 2 minutes, 200g / t sodium oleate and 200g / t oxidized paraffin soap (i.e., 731) are added, and after stirring for 2 minutes, the bubbles are skimmed off to obtain spodumene rough concentrate and roughing tailings. 200g / t Na2CO3 is added to the rough concentrate for the first refining process, and 200g / t Na2CO3 is added to the first refining concentrate for the second refining process. 100g / t Na2CO3 is added to the second refining concentrate. Na2CO3 is used in the 3rd fine process to obtain the final spodumene concentrate. 100g / t sodium oleate and 100g / t paraffin soap (i.e., 731) are added to the roughing tailings for the 1st scavenging process. 50g / t sodium oleate and 50g / t paraffin soap (i.e., 731) are added to the 1st scavenging tailings for the 2nd scavenging process to obtain the final tailings. The tailings from the 1st fine process and the 1st scavenging concentrate are returned to the roughing process, the tailings from the 2nd fine process are returned to the 1st fine process, the tailings from the 3rd fine process are returned to the 2nd fine process, and the concentrate from the 2nd scavenging process is returned to the 1st scavenging process.

[0054] In this embodiment, the spodumene concentrate index obtained from the closed-circuit test and the water quality analysis of the pretreated wastewater are shown in Table 1 and Table 2, respectively.

[0055] Table 1. Test results of pretreated wastewater composition in Examples 1-2 and Comparative Examples 1-4.

[0056]

[0057]

[0058] Table 2 shows the final spodumene concentrate indicators obtained from closed-circuit tests in Examples 1-2 and Comparative Examples 1-4.

[0059]

[0060] As can be seen from the test results in Table 1, the COD, SS, and Ca in the pretreated wastewater of Example 1 were significantly lower. 2+ Mg 2+ The concentrations were 32 mg / L, 44 mg / L, 33.75 mg / L, and 4.77 mg / L, respectively. Compared with untreated wastewater, the Ca concentrations in the recycled water were significantly lower. 2+ The content decreased significantly, with COD, SS, and Mg levels also showing improvement. 2+ The content was significantly reduced, and the water quality was significantly improved.

[0061] As can be seen from the test results in Table 2, the closed-circuit test in Example 1 can obtain a Li2O grade of 5.66% in spodumene concentrate and a recovery rate of 83.82%, which is close to the index of the clear water test. This indicates that the pretreated wastewater can be reused for spodumene flotation with almost no impact on the flotation results.

[0062] Examples 2-3 and Comparative Examples 1-2

[0063] Examples 2-3 and Comparative Examples 1-2 respectively provide a method for preparing flocculants for treating spodumene beneficiation wastewater and their application. Compared with Example 1, the difference is that in step 1, the stirring temperature in the preparation of flocculants is 80℃, 100℃, 20℃ and 150℃ respectively. Other steps are roughly the same as in Example 1, and will not be described again here.

[0064] Comparative Example 3

[0065] This comparative example provides a method for preparing a flocculant for treating spodumene beneficiation wastewater and its application. The difference from Example 1 is that in step 1, the pH value was not adjusted by adding acid in the preparation of the flocculant. The other steps are roughly the same as in Example 1 and will not be described again here.

[0066] Comparative Example 4

[0067] This comparative example provides a method for preparing a flocculant for treating spodumene beneficiation wastewater and its application. The difference from Example 1 is that in step 1, triethanolamine fatty acid ester was not added in the preparation of the flocculant. The other steps are roughly the same as in Example 1 and will not be repeated here.

[0068] The spodumene concentrate indicators obtained from the closed-circuit tests in Examples 1-2 and Comparative Examples 1-4, as well as the water quality analysis of the pretreated wastewater, were shown in Tables 3 and 4, respectively.

[0069] Table 3. Test results of pretreated wastewater composition in Examples 2-3 and Comparative Examples 1-4.

[0070] Examples / Comparative Examples COD (mg / L) SS (mg / L) <![CDATA[Ca 2+ (mg / L)]]> <![CDATA[Mg 2+ (mg / L)]]> Clear water 2 0 41.26 1.77 Untreated wastewater 215 242 86.52 7.14 Example 2 35 48 34.62 4.36 Example 3 34 51 36.99 4.29 Comparative Example 1 67 52 45.72 4.93 Comparative Example 2 96 69 44.62 4.74 Comparative Example 3 63 49 41.74 5.08 Comparative Example 4 77 61 47.73 5.11

[0071] Table 4 shows the final spodumene concentrate indicators obtained from closed-circuit tests in Examples 2-3 and Comparative Examples 1-4.

[0072]

[0073]

[0074] As can be seen from the test results of Examples 2-3 in Tables 3 and 4, when the stirring temperature is 80-100℃ during the preparation of the flocculant, the content of impurity elements in the pretreated wastewater is significantly reduced, the prepared flocculant has a good wastewater treatment effect, and the flotation results in spodumene flotation are close to those of clear water. As can be seen from the test results of Comparative Examples 1-2 in Table 1, when the stirring temperature is too high or too low, the content of impurity elements in the pretreated wastewater is significantly higher than the test results in Example 1, and the grade and recovery rate of the flotation concentrate in spodumene flotation are reduced. This is because when the stirring temperature is below 80℃, the nucleophilic substitution reaction of triethanolamine fatty acid ester and dodecyltrimethylammonium chloride is insufficient, and when the stirring temperature is above 100℃, the newly generated quaternary ammonium salt derivative will undergo thermal decomposition. The bond energy between nitrogen atoms and hydrogen and carbon atoms in the quaternary ammonium salt molecule is weak. When the temperature is too high, the intermolecular forces weaken, resulting in changes in the molecular structure. The test results of Comparative Example 3 show that, in the preparation of the flocculant, the pH value of the flocculant was not adjusted to neutral by adding acid, resulting in higher levels of impurity elements in the pretreated wastewater compared to the test results in Example 1. Furthermore, the grade and recovery rate of the flotation concentrate in the spodumene flotation process were both reduced. This is because the newly generated quaternary ammonium salt derivative from the nucleophilic substitution reaction of triethanolamine fatty acid ester and dodecyltrimethylammonium chloride hydrolyzes into quaternary ammonium base under alkaline conditions. Therefore, acid needs to be added to neutralize the pH of the solution to neutral or weakly acidic. The test results of Comparative Example 4 show that, when triethanolamine fatty acid ester was not added to the flocculant, the content of impurity elements in the pretreated wastewater was higher than the test results in Example 1, and the grade and recovery rate of the flotation concentrate in the spodumene flotation process were both reduced.

[0075] In summary, this application provides a method for preparing a flocculant for treating spodumene beneficiation wastewater and its application. Specifically, this application discovers that the hydroxyl groups in triethanolamine fatty acid esters and the quaternary ammonium groups in dodecyltrimethylammonium chloride can undergo a nucleophilic substitution reaction to generate new quaternary ammonium salt derivatives. As a strong cationic polyelectrolyte, it contains a large number of positively charged cationic quaternary ammonium salt groups, enabling electrostatic interactions with anionic particles (such as suspended particles and colloidal particles) in water. With the progress of electrostatic attraction, its long-chain molecules bridge multiple anionic particles, forming a "bridging" effect. Polyaluminum chloride can fully utilize its charge effect and the bridging and agglomeration advantages of the newly generated quaternary ammonium salt derivatives, forming a strong synergistic effect between the two molecules, further enhancing the flocculation effect and increasing the settling speed. Starch, as a natural polymeric flocculant, not only reduces the content of heavy metal ions in wastewater but also helps stabilize the molecular structure of dodecyltrimethylammonium chloride, preventing its degradation or deactivation under complex water quality conditions. Therefore, this application uses triethanolamine fatty acid ester, dodecyltrimethylammonium chloride, aluminum chloride, polyacrylamide, starch, and water as raw materials to prepare a flocculant for treating spodumene beneficiation wastewater, which solves the problems of low indicators and low wastewater reuse efficiency in existing spodumene beneficiation wastewater.

[0076] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A method for preparing a flocculant for treating spodumene ore beneficiation wastewater, characterized in that, Includes the following steps: S1. Mix and stir triethanolamine fatty acid ester, dodecyltrimethylammonium chloride, polyaluminum chloride, polyacrylamide, starch, and water sequentially to obtain a mixed solution; S2. Add acid to the mixed solution to adjust the pH value to neutral, and the flocculant for treating spodumene ore beneficiation wastewater is obtained.

2. The method for preparing the flocculant for treating spodumene beneficiation wastewater according to claim 1, characterized in that, In the mixed solution, the mass percentages of fatty acid triethanolamine ester, dodecyltrimethylammonium chloride, polyaluminum chloride, polyacrylamide, starch, and water are 15-25%, 15-25%, 15-20%, 5-15%, 5-10%, and 5-15%, respectively.

3. The method for preparing the flocculant for treating spodumene beneficiation wastewater according to claim 1, characterized in that, In step S1, the stirring temperature is 80~100℃.

4. The method for preparing the flocculant for treating spodumene beneficiation wastewater according to claim 1, characterized in that, In step S1, the stirring time is 30 minutes.

5. The method for preparing the flocculant for treating spodumene beneficiation wastewater according to claim 1, characterized in that, In step S2, the acid is oxalic acid or sulfuric acid.

6. The method for preparing the flocculant for treating spodumene beneficiation wastewater according to claim 1, characterized in that, In step S1, the starch is corn starch, wheat starch, or potato starch.

7. The application of the flocculant for treating spodumene beneficiation wastewater prepared by the method according to any one of claims 1 to 6, characterized in that, The wastewater treated with the flocculant is reused in spodumene beneficiation, and the beneficiation results meet the clean water standard.

8. The application of the flocculant for treating spodumene beneficiation wastewater according to claim 7, characterized in that, The wastewater treated with the flocculant is reused in spodumene beneficiation, which includes the following steps: S1. Pretreatment of spodumene beneficiation wastewater: After the beneficiation wastewater settles naturally for 2 hours, take the supernatant, add 80~120g / t of the flocculant to the supernatant, stir for 10 minutes, and then let it settle naturally for 30 minutes. Take the supernatant and dilute it with water by 50% to obtain the pretreated wastewater. S2. The pretreated wastewater is reused in the flotation closed-circuit test of spodumene: After wet grinding of the crushed ore, the pretreated wastewater is added to the pulp concentration to 30-40%, and after roughing operation, spodumene rough concentrate and roughing tailings are obtained. The spodumene rough concentrate is finely treated to obtain the final spodumene concentrate; the roughing tailings are scavenged to obtain the final tailings.

9. The application of the flocculant for treating spodumene beneficiation wastewater according to claim 8, characterized in that, The roughing operation includes: adding an inhibitor to the slurry, stirring for 2 minutes, adding collector 1, stirring for 2 minutes, skimming off the foam, and obtaining spodumene rough concentrate and tailings; the inhibitor includes 450~550 g / t NaOH and 45~55 g / t CaCl2, and the collector 1 includes 250~350 g / t sodium oleate and 280~320 g / t paraffin soap oxide.

10. The application of the flocculant for treating spodumene beneficiation wastewater according to claim 8, characterized in that, The refining process includes: adding 180-220 g / t of Na2CO3 to the rough concentrate for a refining process 1; adding 180-220 g / t of Na2CO3 to the refining process 1 for a refining process 2; and adding 80-120 g / t of Na2CO3 to the refining process 2 for a refining process 3, to obtain the final spodumene concentrate. The scavenging process includes: adding collector 2 to the rougher tailings for a scavenging process 1; adding collector 3 to the scavenging tailings for a scavenging process 2, to obtain the final tailings. The tailings from refining process 1 and the concentrate from scavenging process 1 are returned to the rougher, the tailings from refining process 2 are returned to refining process 1, the tailings from refining process 3 are returned to refining process 2, and the concentrate from scavenging process 2 is returned to scavenging process 1. The collector 2 comprises 80-120 g / t of sodium oleate and 80-120 g / t of oxidized paraffin soap; the collector 3 comprises 45-55 g / t of sodium oleate and oxidized paraffin soap. Sodium oleate (g / t) and oxidized paraffin soap (45-55 g / t).

Images