Preparation method and application of flocculant for spodumene beneficiation wastewater treatment

Abstract

The invention provides a preparation method and application of a flocculant for spodumene beneficiation wastewater treatment, and belongs to the technical field of wastewater treatment. The preparation method comprises the following steps: sequentially mixing 15-25% by mass of fatty acid triethanolamine ester, 15-25% by mass of dodecyl trimethyl ammonium chloride, 15-20% by mass of polyaluminum chloride, 5-15% by mass of polyacrylamide, 5-10% by mass of starch and 5-15% by mass of water, stirring, and adding acid to adjust the pH value to be neutral, thereby obtaining the spodumene beneficiation wastewater treatment flocculant. The steps of natural settling, flocculating settling and clear water dilution are combined for wastewater pretreatment, the treated wastewater is reused in the beneficiation process, under the synergistic effect of beneficiation reagents and the beneficiation process, the wastewater reaches the indexes of clear water flotation, the reagent usage amount is small, and the problems that beneficiation wastewater recycling efficiency is low, and the beneficiation efficiency is low are solved. Beneficiation economic indexes and the like are solved.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, and in particular to a preparation method and application of a flocculant for treating spodumene ore dressing wastewater. Background Art

[0002] During the spodumene beneficiation process, wastewater containing suspended matter, heavy metal ions and other pollutants will be generated. If these wastewaters are discharged directly without treatment, they will pollute surface water and groundwater. If they are directly reused, they will have a huge impact on the beneficiation indicators. By recycling and treating tail water, the negative impact on the environment can be effectively reduced, which meets the requirements of environmental protection policies. In addition, a large amount of water resources are required during the spodumene beneficiation process. By recycling tail water, the use of new water can be reduced, thereby saving water resources. The recycling of tail water can not only reduce the consumption of water resources, but also reduce the cost of treatment and discharge.

[0003] In the flotation process of spodumene ore, sodium hydroxide and sodium carbonate are usually used as adjusters, calcium chloride is used as activator, naphthenic acid soap and oxidized paraffin soap are used as collectors. There are a large number of carbonate ions, hydroxide ions and calcium ions in the flotation tailings slurry, as well as fatty acid collectors, which lead to obvious adverse effects on the flotation index of spodumene ore after wastewater reuse. Therefore, the purification of the above substances is crucial in the treatment of spodumene ore flotation wastewater.

[0004] For the treatment of spodumene beneficiation wastewater, the current process mainly uses the low-density lime method, which adds calcium oxide as a sedimentation aid and sulfuric acid to adjust the pH of the wastewater, and reuses the treated wastewater in the process. Although the low-density lime method has a relatively low cost and a relatively simple overall operation process, it will consume a lot of lime after the actual treatment is completed, and there will also be scaling, which will lead to pipeline blockage problems. The operating environment is relatively harsh, and the return water used for spodumene flotation still has the problem that the spodumene concentrate grade and recovery rate are far lower than the clean water index. Summary of the invention

[0005] In view of the technical problems existing in the background technology, the present application provides a method for preparing a flocculant for treating spodumene ore dressing wastewater and its application, aiming to solve the problems of low indicators of existing spodumene ore dressing wastewater and low wastewater reuse efficiency.

[0006] In a first aspect, the present application provides a method for preparing a flocculant for treating spodumene ore dressing wastewater, comprising the following steps:

[0007] S1. The fatty acid triethanolamine ester, dodecyltrimethylammonium chloride, polyaluminium chloride, polyacrylamide, starch and water are sequentially mixed and stirred to obtain a mixed solution;

[0008] S2. Acid is added to the mixed solution to adjust the pH value to neutral, thereby obtaining a spodumene beneficiation wastewater treatment flocculant.

[0009] In the technical scheme of the embodiment of the present application, fatty acid triethanolamine ester, dodecyltrimethylammonium chloride, polyaluminum chloride, polyacrylamide, starch, and water are mixed in sequence, stirred, and acid is added to adjust the pH value to neutral to obtain a spodumene ore dressing wastewater treatment flocculant. Among them, fatty acid triethanolamine ester and dodecyl trimethyl ammonium chloride are the main flocculation components. The alcohol hydroxyl group in fatty acid triethanolamine ester and the quaternary ammonium group in dodecyl trimethyl ammonium chloride can undergo 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, which can interact electrostatically with anionic particles in water (such as suspended particles, colloidal particles, etc.). As the electrostatic attraction proceeds, its long-chain molecules will bridge between multiple anionic particles to form a "bridging" effect; polyaluminum chloride can give full play to its charge effect and the bridging and coagulation advantages of the newly generated quaternary ammonium salt derivatives, and a strong cooperation is formed between the molecules of the two, further enhancing the flocculation effect and increasing the sedimentation rate; starch, as a natural polymer flocculant, can not only reduce the content of heavy metal ions in wastewater, but also help stabilize the molecular structure of dodecyl trimethyl ammonium chloride to prevent it from being degraded or inactivated under complex water conditions. Through the synergistic effect between different components of the flocculant, a spodumene beneficiation wastewater flocculant 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 minutes.

[0011] In this embodiment, by mixing the components in a specific ratio at a specific temperature, the components can fully react with each other to 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 be hydrolyzed into a 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 polymer flocculant, can not only reduce the content of heavy metal ions in wastewater, but also help stabilize the molecular structure of polydimethyldiallylammonium chloride to prevent it from being degraded or inactivated under complex water conditions.

[0016] In the second aspect, the embodiments of the present application provide an application of a flocculant for treating spodumene beneficiation wastewater, wherein the treated wastewater is reused in spodumene beneficiation, and the beneficiation results meet the clean water index.

[0017] In the technical solution of the embodiment of the present application, the prepared flocculant is combined with the wastewater treatment process to solve the problems of low reuse efficiency of mineral processing wastewater and poor wastewater indicators.

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

[0019] S1. Pretreatment of spodumene ore dressing wastewater: After the ore dressing wastewater is naturally settled for 2h, the supernatant is taken, 80 to 120g / t of the flocculant is added to the supernatant, stirred for 10min, and then naturally settled for 30min, the supernatant is taken, and diluted with water by 50% to obtain pretreated wastewater;

[0020] S2. The pre-treated wastewater is reused in the flotation closed-circuit test of spodumene. After the crushed ore is wet-milled, the pre-treated wastewater is added to the pulp concentration of 30-40%. 450-550 g / t of NaOH and 45-55 g / t of CaCl2 are added to the pulp. After stirring for 2 min, 250-350 g / t of sodium oleate and 280-320 g / t of oxidized paraffin soap are added. After stirring for 2 min, the foam is scraped to obtain a spodumene rough concentrate and a rough tailing. 180-220 g / t of Na2CO3 is added to the rough concentrate for fine process 1. 180-220 g / t of Na2CO3 is added to the fine concentrate. ~220g / t Na2CO3 is added to carry out the refinement 2 process, and 80~120g / t Na2CO3 is added to the refinement 2 concentrate to carry out the refinement 3 process to obtain the final spodumene concentrate; 80~120g / t sodium oleate and 80~120g / t oxidized paraffin soap are added to the roughing tailings to carry out the sweep 1 process, and 45~55g / t sodium oleate and 45~55g / t oxidized paraffin soap are added to the sweep 1 tailings to carry out the sweep 2 process to obtain the final tailings, wherein the refinement 1 tailings and the sweep 1 concentrate are returned to the roughing together, the refinement 2 tailings are returned to the refinement 1, the refinement 3 tailings are returned to the refinement 2, and the sweep 2 concentrate is returned to the sweep 1.

[0021] In this embodiment, the spodumene wastewater treatment method is used to improve the spodumene wastewater index and reduce the amount of reagents used.

[0022] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings used in the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 This is a flow chart of spodumene beneficiation wastewater treatment in an embodiment of the present application;

[0025] Figure 2 This is a flow chart of the preparation of spodumene beneficiation wastewater in Example 1 of the present application;

[0026] Figure 3 This is a flow chart of the spodumene beneficiation wastewater reuse and beneficiation in Example 1 of the present application. DETAILED DESCRIPTION

[0027] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0029] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0030] In order to solve the problem that the existing spodumene beneficiation wastewater index is low and the wastewater reuse efficiency is not high, the present application provides a method for preparing a flocculant for treating spodumene beneficiation wastewater and its application. Among them, the present application finds that the alcohol hydroxyl group in fatty acid triethanolamine ester and the quaternary ammonium group in dodecyl trimethyl ammonium chloride can undergo nucleophilic substitution reaction to generate a new quaternary ammonium salt derivative, which, as a strong cationic polyelectrolyte, contains a large number of positively charged cationic quaternary ammonium salt groups, and can interact electrostatically with anionic particles (such as suspended particles, colloidal particles, etc.) in water. As the electrostatic attraction proceeds, its long-chain molecules will bridge between multiple anionic particles to form a "bridging" effect; polyaluminium chloride can give full play to its charge effect and the bridging and coagulation advantages of the newly generated quaternary ammonium salt derivative, and the two molecules form a strong cooperation, further enhancing the flocculation effect and increasing the sedimentation rate; starch, as a natural polymer flocculant, can not only reduce the heavy metal ion content in wastewater, but also help stabilize the molecular structure of dodecyl trimethyl ammonium chloride to prevent it from being degraded or inactivated under complex water conditions. Therefore, the present application uses fatty acid triethanolamine ester, dodecyltrimethylammonium chloride, aluminum chloride, polyacrylamide, starch and water as raw materials to prepare a flocculant for treating spodumene ore dressing wastewater. The flocculant has high efficiency in treating spodumene ore dressing wastewater and good indicators of the treated wastewater through the synergistic effect between different components.

[0031] On the one hand, the present application embodiment provides a method for preparing a flocculant for treating spodumene ore dressing wastewater, comprising the following steps:

[0032] S1. The fatty acid triethanolamine ester, dodecyltrimethylammonium chloride, polyaluminium chloride, polyacrylamide, starch and water are sequentially mixed and stirred to obtain a mixed solution;

[0033] S2. Acid is added to the mixed solution to adjust the pH value to neutral, thereby obtaining a spodumene beneficiation wastewater treatment flocculant.

[0034] In the technical scheme of the embodiment of the present application, fatty acid triethanolamine ester, dodecyltrimethylammonium chloride, polyaluminum chloride, polyacrylamide, starch, and water are mixed in sequence, stirred, and acid is added to adjust the pH value to neutral to obtain a spodumene ore dressing wastewater treatment flocculant. Among them, fatty acid triethanolamine ester and dodecyl trimethyl ammonium chloride are the main flocculation components. The alcohol hydroxyl group in fatty acid triethanolamine ester and the quaternary ammonium group in dodecyl trimethyl ammonium chloride can undergo 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, which can interact electrostatically with anionic particles in water (such as suspended particles, colloidal particles, etc.). As the electrostatic attraction proceeds, its long-chain molecules will bridge between multiple anionic particles to form a "bridging" effect; polyaluminum chloride can give full play to its charge effect and the bridging and coagulation advantages of the newly generated quaternary ammonium salt derivatives, and a strong cooperation is formed between the molecules of the two, further enhancing the flocculation effect and increasing the sedimentation rate; starch, as a natural polymer flocculant, can not only reduce the content of heavy metal ions in wastewater, but also help stabilize the molecular structure of dodecyl trimethyl ammonium chloride to prevent it from being degraded or inactivated under complex water conditions. Through the synergistic effect between different components of the flocculant, a spodumene beneficiation wastewater flocculant 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 min.

[0036] In the technical solution of the embodiment of the present application, by mixing the components in a specific ratio at a specific temperature, the components can fully react with each other to achieve a synergistic effect.

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

[0038] In the technical solution of the embodiment of the present application, the newly generated quaternary ammonium salt derivative will be hydrolyzed into a quaternary ammonium base under alkaline conditions, so acid needs to be added to neutralize the pH of the solution to neutral or weak acidity.

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

[0040] In the technical solution of the embodiment of the present application, starch, as a natural polymer flocculant, can not only reduce the content of heavy metal ions in wastewater, but also help stabilize the molecular structure of polydimethyldiallylammonium chloride to prevent it from degradation or inactivation under complex water conditions.

[0041] In the second aspect, the embodiments of the present application provide an application of a flocculant for treating spodumene beneficiation wastewater, wherein the treated wastewater is reused in spodumene beneficiation, and the beneficiation results meet the clean water index.

[0042] In the technical solution of the embodiment of the present application, the prepared flocculant is combined with the wastewater treatment process to solve the problems of low reuse efficiency of mineral processing wastewater and poor wastewater indicators.

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

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

[0045] S2. The pre-treated wastewater is reused in the closed-circuit flotation test of spodumene, the crushed ore is wet-ground, the pre-treated wastewater is added to the pulp concentration of 30-40%, 450-550 g / t of NaOH and 45-55 g / t of CaCl2 are added to the pulp, stirred for 2 min, 250-350 g / t of sodium oleate and 280-320 g / t of oxidized paraffin soap are added, stirred for 2 min, and the foam is scraped to obtain a spodumene rough concentrate and a rough tailing, 200 g / t of Na2CO3 is added to the rough concentrate for a refined process, and 200 g / t of Na2CO3 is added to the refined concentrate. 00g / t of Na2CO3 is added to the roughing tailings for the fine 2 process, and 100g / t of Na2CO3 is added to the fine 2 concentrate for the fine 3 process to obtain the final spodumene concentrate; 80-120g / t of sodium oleate and 80-120g / t of oxidized paraffin soap are added to the roughing tailings for the sweep 1 process, and 45-55g / t of sodium oleate and 45-55g / t of oxidized paraffin soap are added to the sweep 1 tailings for the sweep 2 process to obtain the final tailings, wherein the fine 1 tailings and the sweep 1 concentrate are returned to the roughing together, the fine 2 tailings are returned to the fine 1, the fine 3 tailings are returned to the fine 2, and the sweep 2 concentrate is returned to the sweep 1.

[0046] In the technical solution of the embodiment of the present application, the spodumene wastewater treatment method is used to improve the spodumene wastewater index and reduce the amount of reagents used.

[0047] Some specific embodiments are listed below. It should be noted that the embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used without specifying the manufacturer are all conventional products that can be obtained commercially.

[0048] Example 1

[0049] This embodiment provides a preparation method and application of a flocculant for treating spodumene ore dressing wastewater, which specifically comprises the following steps:

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

[0051] 2. Preparation process of spodumene beneficiation wastewater: Figure 2 As shown, the raw ore is crushed to -2mm, and then the crushed ore is wet-ground. 1000g / t Na2CO3 is added during grinding, and the grinding fineness is -0.074mm, accounting for 72%. Water is added until the pulp concentration is 30%; then 500g / t NaOH and 50g / t CaCl2 are added, and after stirring for 2min, 300g / t sodium oleate and 300g / t oxidized paraffin soap (i.e. 731) are added, and after stirring for 2min, the foam is scraped to obtain spodumene coarse concentrate and tailings. After standing for 10min, the upper suspension is taken as mineral processing wastewater;

[0052] 3. Pretreatment process of spodumene beneficiation wastewater: Figure 1 As shown, after the prepared ore dressing wastewater is naturally settled for 2 hours, the supernatant is taken, 15 mg / L flocculant is added to the supernatant, stirred for 10 minutes, and then naturally settled for 30 minutes, the supernatant is taken, and diluted with clean water by 50%, thus obtaining the pretreated wastewater;

[0053] 4. The pre-treated wastewater is reused in the closed-circuit flotation test of spodumene. The test process is as follows: Figure 3As shown, the raw ore is crushed to -2mm, and then the crushed ore is wet-ground. 1000g / t Na2CO3 is added during grinding, and the grinding fineness is -0.074mm, accounting for 72%. Water is added until the pulp 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. After stirring for 2 minutes, the foam is scraped to obtain spodumene rough concentrate and rough tailings. 200g / t Na2CO3 is added to the rough concentrate for fine 1 process, 200g / t Na2CO3 is added to the fine 1 concentrate for fine 2 process, and 100g / t is added to the fine 2 concentrate. Na2CO3 is used for the refining 3 process to obtain the final spodumene concentrate; 100g / t sodium oleate and 100g / t oxidized paraffin soap (i.e. 731) are added to the roughing tailings for the sweep 1 process, and 50g / t sodium oleate and 50g / t oxidized paraffin soap (i.e. 731) are added to the sweep 1 tailings for the sweep 2 process to obtain the final tailings, wherein the refine 1 tailings and the sweep 1 concentrate are returned to the roughing together, the refine 2 tailings are returned to the refine 1, the refine 3 tailings are returned to the refine 2, and the sweep 2 concentrate is returned to the sweep 1.

[0054] In this embodiment, the spodumene concentrate index finally obtained by the closed-circuit test and the water quality analysis of the wastewater obtained by the pretreatment were analyzed, and the results are shown in Table 1 and Table 2 respectively.

[0055] Table 1 Test results of pre-treated wastewater components in Examples 1 to 2 and Comparative Examples 1 to 4

[0056]

[0057]

[0058] Table 2 Spodumene concentrate indexes finally obtained from closed circuit tests in Examples 1 to 2 and Comparative Examples 1 to 4

[0059]

[0060] It can be seen from the test results in Table 1 that COD, SS, and Ca in the pretreated wastewater in Example 1 2+ Mg 2+ The contents were 32mg / L, 44mg / L, 33.75mg / L and 4.77mg / L respectively. Compared with the untreated wastewater, the Ca 2+ The content dropped significantly, COD, SS, Mg 2+ The content was significantly reduced and the water quality was significantly improved.

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

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

[0063] Examples 2 to 3 and Comparative Examples 1 to 2 respectively provide a method for preparing a flocculant for treating spodumene ore dressing wastewater and its application. Compared with Example 1, the difference is that in the preparation of the flocculant in step 1, the stirring temperatures are 80°C, 100°C, 20°C, and 150°C, respectively. The other steps are roughly the same as those in Example 1 and will not be repeated here.

[0064] Comparative Example 3

[0065] This comparative example provides a preparation method and application of a flocculant for treating spodumene ore dressing wastewater. Compared with Example 1, the difference is that in the preparation of the flocculant in step 1, no acid is added to adjust the pH value. The other steps are roughly the same as those in Example 1 and will not be repeated here.

[0066] Comparative Example 4

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

[0068] The spodumene concentrate indicators finally obtained by analyzing the closed-circuit tests in Examples 1 to 2 and Comparative Examples 1 to 4 and the water quality analysis of the wastewater obtained by the pretreatment were performed, and the results are shown in Tables 3 and 4, respectively.

[0069] Table 3 Test results of pre-treated wastewater components in Examples 2 to 3 and Comparative Examples 1 to 4

[0070] Example / Comparative Example COD(mg / L) SS(mg / L) <![CDATA[Ca 2+ (mg / L)]]> <![CDATA[Mg 2+ (mg / L)]]> Shimizu 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 Spodumene concentrate indexes finally obtained from closed circuit tests in Examples 2 to 3 and Comparative Examples 1 to 4

[0072]

[0073]

[0074] It can be seen from the test results of Examples 2 to 3 in Table 3 and Table 4 that in the preparation of the flocculant, when the stirring temperature is 80 to 100° C., the content of impurity elements in the pretreated wastewater is greatly reduced, the prepared flocculant wastewater treatment effect is good, and the flotation result of the flocculant in the spodumene flotation is close to that of clean water; it can be seen from the test results of Comparative Examples 1 to 2 in Table 1 that 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 result in Example 1, and the flotation concentrate grade and recovery rate of the flotation concentrate in the spodumene flotation are reduced. This is because when the stirring temperature is lower than 80° C., the nucleophilic substitution reaction of fatty acid triethanolamine ester and dodecyltrimethylammonium chloride is insufficient, and when the stirring temperature is higher than 100° C., the newly generated quaternary ammonium salt derivative will undergo thermal decomposition, the bond energy between the nitrogen atom and the hydrogen and carbon atoms in the quaternary ammonium salt molecule is weak, and the intermolecular force is weakened when the temperature is too high, resulting in a change in the molecular structure. It can be seen from the test results of Comparative Example 3 that in the preparation of the flocculant, no acid was added to adjust the pH value of the flocculant to neutrality, resulting in the content of impurity elements in the pretreated wastewater being higher than the test results in Example 1, and the flotation concentrate grade and recovery rate in the spodumene flotation were both reduced. This is because the quaternary ammonium salt derivative newly generated by the nucleophilic substitution reaction of fatty acid triethanolamine ester and dodecyltrimethylammonium chloride will hydrolyze into quaternary ammonium base under alkaline conditions, so acid needs to be added to neutralize the solution pH to neutral or weak acid. It can be seen from the test results of Comparative Example 4 that when fatty acid triethanolamine 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 flotation concentrate grade and recovery rate in the spodumene flotation were both reduced.

[0075] In summary, the present application provides a method for preparing a flocculant for treating spodumene beneficiation wastewater and its application. Among them, the present application finds that the alcohol hydroxyl group in fatty acid triethanolamine ester and the quaternary ammonium group in dodecyl trimethyl ammonium chloride can undergo nucleophilic substitution reaction to generate a new quaternary ammonium salt derivative, which, as a strong cationic polyelectrolyte, contains a large number of positively charged cationic quaternary ammonium salt groups, and can interact electrostatically with anionic particles (such as suspended particles, colloidal particles, etc.) in water. As the electrostatic attraction proceeds, its long-chain molecules will bridge between multiple anionic particles to form a "bridging" effect; polyaluminium chloride can give full play to its charge effect and the bridging and coagulation advantages of the newly generated quaternary ammonium salt derivatives, and the two molecules form a strong cooperation, further enhancing the flocculation effect and increasing the sedimentation rate; starch, as a natural polymer flocculant, can not only reduce the heavy metal ion content in wastewater, but also help stabilize the molecular structure of dodecyl trimethyl ammonium chloride to prevent it from being degraded or inactivated under complex water conditions. Therefore, the present application uses fatty acid triethanolamine ester, dodecyltrimethylammonium chloride, aluminum chloride, polyacrylamide, starch and water as raw materials to prepare a flocculant for treating spodumene ore dressing wastewater, which solves the problem that the existing spodumene ore dressing wastewater has low indicators and low wastewater reuse efficiency.

[0076] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A method for preparing a flocculant for treating spodumene ore dressing wastewater, characterized in that: The steps include: S1. The fatty acid triethanolamine ester, dodecyltrimethylammonium chloride, polyaluminium chloride, polyacrylamide, starch and water are sequentially mixed and stirred to obtain a mixed solution; S2. Acid is added to the mixed solution to adjust the pH value to neutral, thereby obtaining a spodumene beneficiation wastewater treatment flocculant.

2. The method for preparing a flocculant for treating spodumene ore dressing wastewater according to claim 1, wherein: In the mixed solution, the mass percentages of fatty acid triethanolamine ester, dodecyltrimethylammonium chloride, polyaluminium 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 a flocculant for treating spodumene ore dressing wastewater according to claim 1, wherein: In step S1, the stirring temperature is 80-100°C.

4. The method for preparing a flocculant for treating spodumene ore dressing wastewater according to claim 1, wherein: In step S1, the stirring time is 30 minutes.

5. The method for preparing a flocculant for treating spodumene ore dressing wastewater according to claim 1, wherein: In step S2, the acid is oxalic acid or sulfuric acid.

6. The method for preparing a flocculant for treating spodumene ore dressing wastewater according to claim 1, wherein: In step S1, the starch is corn starch, wheat starch or potato starch.

7. Use of a flocculant for treating spodumene ore dressing wastewater obtained by the preparation method according to any one of claims 1 to 6, characterized in that: The treated wastewater is recycled for spodumene beneficiation, and the beneficiation result reaches the clean water index.

8. The use of a flocculant for treating spodumene ore dressing wastewater according to claim 7, characterized in that: The process of recycling the treated wastewater for spodumene beneficiation comprises the following steps: S1. Pretreatment of spodumene ore dressing wastewater: After the ore dressing wastewater is naturally settled for 2h, the supernatant is taken, 80 to 120g / t of the flocculant is added to the supernatant, stirred for 10min, and then naturally settled for 30min, the supernatant is taken, and diluted with water by 50% to obtain pretreated wastewater; S2. The pre-treated wastewater is reused in a closed-circuit flotation test of spodumene: After the crushed ore is wet-milled, the pre-treated wastewater is added to a pulp concentration of 30 to 40%, and a spodumene rough concentrate and rough tailings are obtained after roughing operation; The spodumene rough concentrate is subjected to a beneficiation operation to obtain a final spodumene concentrate; and the rougher tailings are subjected to a scavenging operation to obtain a final tailings.

9. The use of a flocculant for treating spodumene ore dressing wastewater according to claim 8, characterized in that: The roughing operation includes: adding an inhibitor to the ore pulp, stirring for 2 minutes, adding a collector 1, stirring for 2 minutes, scraping bubbles, and obtaining spodumene rough concentrate and tailings; the inhibitor includes 450-550 g / t of NaOH and 45-55 g / t of CaCl2, and the collector 1 includes 250-350 g / t of sodium oleate and 280-320 g / t of oxidized paraffin soap.

10. The use of a flocculant for treating spodumene ore dressing wastewater according to claim 8, characterized in that: The concentrating operation includes: adding 180-220 g / t of Na2CO3 to the rough concentrate for concentrating process 1, adding 180-220 g / t of Na2CO3 to the concentrate 1 for concentrating process 2, adding 80-120 g / t of Na2CO3 to the concentrate 2 for concentrating process 3 to obtain the final spodumene concentrate; the scavenging operation includes: adding collector 2 to the rough tailings for scavenging process 1, adding collector 2 to the rough tailings for scavenging process 2, adding collector 2 to the concentrate 2 for scavenging process 3, adding collector 2 to the rough tailings for scavenging process 1 ... Collector 3 is added to tailings 1 to carry out sweep 2 process to obtain final tailings; wherein, tailings 1 and sweep 1 concentrate are returned to roughing together, tailings 2 are returned to fine 1, tailings 3 are returned to fine 2, and sweep 2 concentrate is returned to sweep 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 45-55 g / t of oxidized paraffin soap.

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