Recycling method and application of high-purity quartz sand green flotation reagent

Abstract

The invention belongs to the technical field of high-purity quartz sand purification, and relates to a recycling method and application of a high-purity quartz sand green flotation reagent. 2, activating agent recovery: adding NaOH into the wastewater to preferentially hydrolyze Al < 3 + > to generate Al (OH) 3 flocculent precipitate, so as to obtain aluminum-rich precipitate and filtrate I; 3, collecting agent and inhibitor synergistic recovery, wherein an anionic polyelectrolyte recovery agent is added into the filtrate I to generate floccules; then, a hydrophobic modified recycling agent is added to promote the inhibitor-collecting agent compound to be further separated out, and agent-enriched mud and supernate are obtained; 4, reagent regeneration and reuse: adjusting the pH value of the reagent-enriched mud with a dilute acid solution, stirring and dissociating, supplementing a fresh reagent, and directly reusing the reagent in a quartz sand flotation process; according to the method, low treatment and discharge of the flotation wastewater are realized, the reagent cost is greatly reduced (more than 60%), and a key technical support is provided for green and low-cost preparation of the high-purity quartz sand.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high-purity quartz sand purification, and particularly relates to a recycling method of a green flotation reagent for high-purity quartz sand and application thereof. BACKGROUND

[0002] High-purity quartz sand is a key basic material for emerging industries such as high-end semiconductors, photovoltaic solar energy, optical communication and precision optics. Flotation is a key core purification technology for removing associated aluminum minerals (such as feldspar and mica) and iron-containing minerals in high-purity quartz sand. Traditional quartz sand flotation generally uses hydrofluoric acid or sulfuric acid methods. Although these methods are effective, they have problems such as serious environmental pollution, strong corrosion of equipment, and great harm to the health of operators. In recent years, a green flotation reagent system without fluorine and acid has become a research hotspot. This system is usually composed of a collector, an inhibitor and an activator.

[0003] However, if the reagent remaining in the tailings water produced after green flotation is directly discharged, it will still pose a potential threat to the ecological environment of the water body (such as causing water eutrophication and toxicity effects). At the same time, the continuous addition of fresh reagent also increases the production cost. At present, there is little research on the recycling and recycling of flotation reagents, especially for complex and multi-component green reagent systems, and the recycling mechanism is not clear, and there is a lack of efficient and targeted recycling technology.

[0004] Therefore, there is a need for a method that can accurately recycle and recycle green flotation reagents to solve the above technical problems. SUMMARY

[0005] The application aims to recover and recycle cationic collectors, inhibitors and metal ion activators in flotation wastewater based on the synergistic effect of "bridging-flocculation", "hydrogen bond reconstruction-temperature response" and "pH regulation-hydrolysis precipitation".

[0006] The application provides the following technical scheme: a recycling method of a green flotation reagent for high-purity quartz sand, comprising the following steps:

[0007] S1. Flotation wastewater collection: collecting wastewater from the high-purity quartz sand flotation process, and the wastewater contains residual green flotation reagents.

[0008] S2. Activator recovery: adding NaOH solution to the wastewater and stirring to make Al 3+ Preferentially hydrolyze to generate Al(OH) flocculent precipitate, and the Al(OH) flocculent precipitate is allowed to stand, precipitate and filter to obtain an aluminum-rich precipitate and a filtrate I.

[0009] S3. Collector and inhibitor synergistic recovery: an anionic polyelectrolyte collector is added to the filtrate I and stirred to make it fully bridging flocculation, producing flocculation; then a hydrophobically modified collector is added and slowly heated, to promote further precipitation of the inhibitor-collector complex, and then the supernatant is obtained by standing, settling and centrifugal separation.

[0010] S4. Regeneration and reuse of the reagent: the mud-like reagent is stirred and dissociated after adjusting the pH value with a dilute acid solution, and then fresh reagent is added to the initial effective concentration, which is directly used for quartz sand flotation process.

[0011] Preferably, in step S2, the pH value of the NaOH solution is 5.5-6.5.

[0012] Preferably, in step S2, the concentration of the NaOH solution is 5%-20%.

[0013] Preferably, in step S3, the anionic polyelectrolyte collector includes sodium alginate and sodium carboxymethyl cellulose; the hydrophobically modified collector includes alkyl polyglycoside, fatty acid polyoxyethylene ether, sorbitan fatty acid ester and its ethoxylate.

[0014] More preferably, when the anionic polyelectrolyte is sodium alginate, the amount of sodium alginate added is 0.8-1.2 equivalents of the total positive charge in the wastewater.

[0015] More preferably, when the hydrophobically modified collector is alkyl polyglycoside, the amount of alkyl polyglycoside added is 0.05%-0.2% of the mass of the wastewater.

[0016] Preferably, in step S3, the temperature range for adding the hydrophobically modified collector and slowly heating is 50-70°C.

[0017] Preferably, in step S4, the pH value is adjusted to 3-4 by a dilute acid solution.

[0018] The application also discloses a method for recycling and recovering green flotation reagents for high-purity quartz sand.

[0019] Recycling principle:

[0020] "Bridge flocculation" recovery principle (for amine collectors): the residual amine cationic collector in the wastewater is associated with each other through van der Waals force through the hydrophobic carbon chain, and the positive polar group (-NH3 +) can be adsorbed on the negatively charged modified starch inhibitor molecular chain by electrostatic action to form a "collector-inhibitor" complex. By adding sodium alginate, the multiple negative groups on its chain can simultaneously electrostatically "bridge" the positive centers in multiple complexes, rapidly forming large flocs, thereby achieving efficient separation from the water body.

[0021] The "hydrogen bond reorganization-temperature response" recovery principle (for inhibitors): The molecular chain of the inhibitor (such as hydroxypropyl starch) in the wastewater contains a large number of hydroxyl groups, which are combined with water molecules in the aqueous solution through hydrogen bonds to dissolve. By adding alkyl polyglycoside and auxiliary precise temperature control, the alkyl polyglycoside can destroy the hydrogen bond network between the inhibitor and the water molecules, and at the same time combine with the hydrophobic modified part of the inhibitor, so that its water solubility decreases sharply, and it is precipitated from water. This process has a temperature-sensitive characteristic, and the controlled precipitation and recovery of the inhibitor can be achieved by adjusting the temperature.

[0022] The "pH regulation-hydrolysis precipitation" recovery principle (for metal ion activators): The metal ion activator (such as Al 3+ , Fe 3+ ) in the wastewater will generate hydroxide precipitate under alkaline conditions. By precisely controlling the pH value, the target metal ion can be selectively precipitated, while other ions remain in the solution, thereby achieving selective recovery and reuse of the activator.

[0023] The beneficial effects of the present application are:

[0024] 1. The present application is green and environmentally friendly, and the present application realizes near-zero pollution discharge of flotation wastewater and recycling of reagents, greatly reducing the pollution of discharged wastewater to the environment, and the whole process is free of secondary pollution.

[0025] 2. The present application is low in cost, and the present application has high recovery efficiency (the comprehensive recovery rate of amine collectors and inhibitors can be more than 75%), which greatly reduces the consumption of fresh reagents and reduces the production cost of high-purity quartz sand.

[0026] 3. The mechanism of the present application is clear, and the present application discloses the internal mechanism of the synergistic recovery of each component in the green flotation reagent system, which provides a theoretical basis for the optimization and precise control of the recovery process, and avoids blindness.

[0027] 4. The effect of the present application is stable, and the reagent recovered by the present application has high activity, and has no negative effect on the flotation indexes (purity, recovery rate) of quartz sand after reuse, and even slightly improves due to the formation of a more efficient "collector-inhibitor" complex structure in the system. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 The present application is a process flow chart of a method for recycling green flotation reagents for high-purity quartz sand and its application. Detailed Implementation

[0029] The related technologies of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0030] like Figure 1 As shown, the recycling method for the high-purity quartz sand green flotation reagent of the present invention includes the following steps:

[0031] Flotation wastewater collection: Collect wastewater from the high-purity quartz sand flotation process, which contains residual green flotation reagents.

[0032] Graded recycling and processing:

[0033] a. Activator recovery: Add NaOH solution to the wastewater, stir the reaction, and control the pH value at 5.5-6.5 to allow Al to... 3+ Preferential hydrolysis produces Al(OH)3 flocculent precipitate. After standing, precipitation, and filtration, aluminum-rich precipitate and filtrate I are obtained.

[0034] b. Synergistic recovery of collector and inhibitor: Sodium alginate was added to filtrate I and stirred to fully bridge and flocculate it, producing a large amount of flocculent material; then alkyl polysaccharide was added and the temperature was slowly raised to 50-70°C to promote further precipitation of the inhibitor-collector complex. After standing, settling, and centrifugation, mud and supernatant enriched with the agent were obtained.

[0035] Reagent regeneration and reuse: The sludge of enriched reagent obtained in step b is adjusted to pH 3-4 with a small amount of dilute acid solution, stirred to dissociate, and then a small amount of fresh reagent is added to bring it to the initial effective concentration, and it is directly reused in the quartz sand flotation process.

[0036] Furthermore, the amount of sodium alginate added is 0.8-1.2 equivalents of the expected total positive charge in the wastewater.

[0037] Furthermore, the amount of the alkyl polysaccharide added is 0.05%-0.2% of the wastewater mass.

[0038] Example

[0039] Example 1:

[0040] This embodiment verifies the recovery effect of the core recovery process of the present invention on typical pharmaceutical formulations.

[0041] Take 1 ton of quartz sand with feldspar and mica as main impurities, prepare the slurry with concentration of 65%, and carry out flotation. 1000g of hydroxypropyl starch is added as depressor while stirring, and 400g of aluminum chloride hexahydrate is added as activator. 200g of dodecylamine is used as collector. After flotation, all tailings water is collected, and the total volume is about 1.2m 3 . The analysis shows that the residual reagent concentration is: dodecylamine 18mg / L, hydroxypropyl starch 85mg / L, and Al 3+ 30mg / L.

[0042] 10% NaOH solution is added to the wastewater, and the pH is adjusted to 6.0 slowly under stirring for 30 minutes, and the precipitate is settled for 2 hours. Filtration is carried out to obtain Al(OH)3 filter residue and filtrate. 60g of sodium alginate is added to the filtrate, and fast stirring is carried out for 10 minutes. Then 1800g of alkyl polyglycoside is added, and slow stirring and heating to 60°C are carried out for 1 hour. Centrifugal separation is carried out to obtain mud rich in reagents. The mud is adjusted to pH 3.5 with dilute hydrochloric acid, and stirring is carried out to dissociate and form a uniform slurry.

[0043] Effect evaluation:

[0044] Chemical analysis shows that the recovery rate of dodecylamine is 89%, the recovery rate of hydroxypropyl starch is 86%, and the recovery rate of aluminum ions is >95%. The regenerated reagent slurry is supplemented with a small amount of fresh reagent to the initial concentration, and is used for flotation of the next batch of quartz sand with the same grade. The results show that the concentrate SiO2 grade reaches 99.99%, which has no significant difference from using all new reagents, and the flotation selectivity is good.

[0045] Example 2:

[0046] This example verifies the applicability of the present application to another common depressant, dextrin.

[0047] Take 1 ton of quartz sand with feldspar and mica as main impurities, prepare the slurry with concentration of 65%, and carry out flotation. 1000g of hydroxypropyl starch is added as depressor while stirring, and 400g of aluminum chloride hexahydrate is added as activator. 200g of dodecylamine is used as collector. After flotation, all tailings water is collected, and the total volume is about 1.2m 3 .

[0048] 10% NaOH solution is added to the wastewater, and the pH is adjusted to 6.0 slowly under stirring for 30 minutes, and the precipitate is settled for 2 hours. Filtration is carried out to obtain Al(OH)3 filter residue and filtrate. 60g of sodium alginate is added to the filtrate, and fast stirring is carried out for 10 minutes. Then 1800g of alkyl polyglycoside is added, and slow stirring and heating to 60°C are carried out for 1 hour. Centrifugal separation is carried out to obtain mud rich in reagents. The mud is adjusted to pH 3.5 with dilute hydrochloric acid, and stirring is carried out to dissociate and form a uniform slurry.

[0049] Effect evaluation: the residual dextrin concentration in the wastewater was about 100 mg / L. The recovery rate of dextrin reached 84%, indicating that the "hydrogen bond reconstitution-temperature response" mechanism described in the application had universality for different types of starch-based inhibitors.

[0050] Example 3:

[0051] This example verified the recovery effect of the application on more efficient ether amine collectors.

[0052] Take 1 ton of quartz sand with feldspar and mica as main impurities, prepare a slurry with a concentration of 65%, and carry out flotation. While stirring, add 1000g of hydroxypropyl starch as depressor, 400g of aluminum chloride hexahydrate as activator. 150g of ether amine as collector. After flotation, collect all the tailings water, the total volume is about 1.2m 3 .

[0053] Add 10% NaOH solution to the wastewater, slowly stir to adjust the pH to 6.0, react for 30 minutes, and stand for 2 hours. Filter to obtain Al(OH)3 filter residue and filtrate. Add 60g of sodium alginate to the filtrate, stir quickly for 10 minutes. Then add 1800g of alkyl polyglycoside, slowly stir and heat to 60℃, keep for 1 hour. Centrifugal separation to obtain rich reagent mud. Adjust the pH of the mud to 3.5 with dilute hydrochloric acid, stir to dissociate, and form a uniform slurry.

[0054] Effect evaluation:

[0055] The residual ether amine concentration in the wastewater was about 12 mg / L. The recovery rate of ether amine reached 91%. Due to the better water solubility and dispersibility of ether amine, its "bridging-flocculation" efficiency with the recovery agent A is higher. It proves that this method has good adaptability to different cationic amine collectors.

[0056] Example 4:

[0057] This example verified that the recovery agent A could use other anionic polyelectrolytes, such as sodium carboxymethyl cellulose (CMC-Na).

[0058] Take 1 ton of quartz sand with feldspar and mica as main impurities, prepare a slurry with a concentration of 65%, and carry out flotation. While stirring, add 1000g of hydroxypropyl starch as depressor, 400g of aluminum chloride hexahydrate as activator. 150g of ether amine as collector. After flotation, collect all the tailings water, the total volume is about 1.2m 3 . Analysis showed that the residual reagent concentration was: dodecylamine 18 mg / L, hydroxypropyl starch 85 mg / L, and Al 3+ 30 mg / L.

[0059] To the wastewater, 10% NaOH solution was added, and the pH was adjusted to 6.0 under slow stirring for 30 minutes, and then the mixture was allowed to stand for 2 hours for precipitation. Filtration was performed to obtain Al(OH)3 filter residue and filtrate. To the filtrate, 55 g of sodium carboxymethyl cellulose was added, and the mixture was stirred rapidly for 10 minutes. Then, 1800 g of alkyl polyglycoside was added, and the mixture was stirred slowly and heated to 60°C for 1 hour. Centrifugal separation was performed to obtain a rich medicament mud. The mud was adjusted to pH 3.5 with dilute hydrochloric acid, and the mixture was stirred to dissociate to form a uniform slurry.

[0060] Effect evaluation:

[0061] The recovery rates of dodecylamine and hydroxypropyl starch were 87% and 85%, respectively, which was comparable to the effect of using sodium alginate. This indicated that the selection of the recovery agent A had flexibility, and any substance that could form anionic polyelectrolyte chain in water could achieve the bridging flocculation function.

[0062] Example 5:

[0063] Two groups of the same experimental raw materials were prepared, and each group had 10 batches. One ton of quartz sand was taken from each batch, and a slurry with a concentration of 65% was prepared for the flotation process. While stirring, 1000 g of hydroxypropyl starch was added as an inhibitor, 400 g of aluminum chloride hexahydrate was added as an activator, and 200 g of dodecylamine was added as a collector. After the flotation was completed, all the tailings wastewater was collected.

[0064] Experimental group: To the wastewater, 10% NaOH solution was added, and the pH was adjusted to 6.0 under slow stirring for 30 minutes, and then the mixture was allowed to stand for 2 hours for precipitation. Filtration was performed to obtain Al(OH)3 filter residue and filtrate. To the filtrate, 60 g of sodium alginate was added, and the mixture was stirred rapidly for 10 minutes. Then, 1800 g of alkyl polyglycoside was added, and the mixture was stirred slowly and heated to 60°C for 1 hour. Centrifugal separation was performed to obtain a rich medicament mud. The mud was adjusted to pH 3.5 with dilute hydrochloric acid, and the mixture was stirred to dissociate to form a uniform slurry. After the recovery of the medicament, it was reused in the flotation process of the next batch, and the flotation experiment was continuously performed for 5 batches.

[0065] Control group: The flotation experiment was continuously performed for 5 batches using quartz sand of the same source and grade and exactly the same fresh medicament formula, but the wastewater after the flotation was not treated for recovery, and completely new medicament was added for the next round of flotation.

[0066] Statistics: The total amount of medicament consumed in each experimental group was calculated, the grade of the quartz sand in each batch of concentrate was detected, and the water quality of the wastewater discharged in each group was detected.

[0067] Result statistics:

[0068] Medicament consumption: The flotation experiment was continuously performed for 5 batches. The total consumption of medicament in the experimental group was only about 20% of that in the control group.

[0069] Concentrate quality: After 5 batches, the SiO2 grade of the concentrate in the experimental group was stable at more than 99.99%. Due to the interference of the accumulated impurity ions and residual reagents in the wastewater, the concentrate grade of the control group fluctuated in the 4th and 5th batches, and decreased to 99.97%-99.98%.

[0070] Wastewater properties: The COD value of the supernatant finally discharged by the experimental group was less than 50 mg / L, and the total aluminum content was less than 0.5 mg / L, which could meet the discharge standard. The COD of the wastewater in the control group was as high as more than 300 mg / L, and the total aluminum content was more than 25 mg / L, which must be subjected to deep treatment before being discharged.

[0071] Conclusion: The comparative experiment fully proves the great advantages of the present application in continuously stabilizing product quality, greatly reducing production cost and realizing green and clean production.

[0072] Example 6

[0073] On the basis of the recovery method determined in Example 1, the addition ratio of the key recovery agents (recovery agent A: sodium alginate and recovery agent B: alkyl polysaccharide) was systematically adjusted to determine the best process parameters for achieving the best recovery effect (taking the comprehensive recovery rate of dodecylamine and hydroxypropyl starch as the index).

[0074] As in Example 1, 1 m 3 of wastewater was taken from the same batch of quartz sand after flotation. 3+ The water quality was stable and contained residual dodecylamine (15±1 mg / L), hydroxypropyl starch (80±5 mg / L) and Al

[0075] Using the single factor variable method, the addition amount of recovery agents A and B was changed in turn under the premise that all other conditions (pH, temperature, stirring time) were fixed. The reagent recovery operation was carried out, and finally centrifugal separation was carried out. The reagent content in the mud was analyzed, and the recovery rate was calculated.

[0076] First part: fixing the amount of recovery agent B, optimizing the amount of recovery agent A

[0077] Fixed conditions: the addition amount of alkyl polysaccharide is 1.5 kg (i.e. 0.15% of the mass of wastewater), and the temperature is 60°C.

[0078] Variable: the addition amount of sodium alginate, which is expressed as the equivalent ratio of its total positive charge in wastewater, as shown in Table 1.

[0079] Table 1

[0080]

[0081] Analysis and Conclusion: When the equivalent ratio of Recovery Agent A increases from 0.5 to 1.0, the overall recovery rate increases significantly, because sufficient anionic polyelectrolyte ensures sufficient "electrical bridging" effect. When the equivalent ratio exceeds 1.0, the recovery rate no longer increases or even decreases slightly, possibly because excess sodium alginate leads to colloidal protection or makes the flocs too dispersed. Therefore, the optimal equivalent ratio of Recovery Agent A is determined to be 1.0.

[0082] Second Part: Fixing the Optimal Recovery Agent A Dosage and Optimizing the Recovery Agent B Dosage

[0083] Fixed Conditions: Sodium Alginate Equivalent Ratio is 1.0, Temperature is 60°C.

[0084] Variable: The addition amount of alkyl polyglycoside is expressed as a percentage of wastewater mass, as shown in Table 2.

[0085] Table 2

[0086]

[0087] Analysis and Conclusion: The addition amount of Recovery Agent B significantly affects the "hydrogen bond reconstruction-temperature response" process. When the amount is insufficient, the inhibition is not complete and the recovery rate is low; when the amount is excessive, the system is too viscous, which affects the aggregation of flocs and the subsequent solid-liquid separation efficiency. Therefore, the optimal addition amount of Recovery Agent B is determined to be 0.15% of the wastewater mass.

[0088] Verification Experiment

[0089] Using the optimal ratio determined above: Recovery Agent A equivalent ratio 1.0 and Recovery Agent B addition amount 0.15%, other conditions are the same as in Example 1. Three repeated experiments were conducted, with an average dodecylamine recovery rate of 92.0% and an average hydroxypropyl starch recovery rate of 89.5%, and the overall recovery rate stabilized at 90.7%. The flocs formed rapidly and densely, with excellent settling and separation performance, and the supernatant was clear.

[0090] Conclusion: This example determines the optimal ratio of the two key recovery agents in the recovery method of the present invention through systematic ratio adjustment experiments. The optimal addition amount of sodium alginate is 1.0 equivalent ratio of the total positive charge in the wastewater. The optimal addition amount of alkyl polyglycoside is 0.15% of the wastewater mass.

[0091] Under these optimized parameters, the overall recovery rate of the green flotation reagent system can reach more than 90%, providing precise process control basis for the stable and efficient economic and environmental benefits of the present invention in industrial application.

[0092] In conclusion, the application illustrates the synergistic recycling mechanism of the multi-component medicament system, overcomes the technical bottleneck that green flotation medicament cannot be recycled, realizes low treatment discharge of flotation wastewater and significant reduction (more than 60%) of medicament cost, and provides key technical support for green and low-cost preparation of high-purity quartz sand.

[0093] It should be emphasized that the above is only the preferred embodiment of the present application, and does not limit the present application in any form. Any simple modification, equivalent change and modification of the above embodiment according to the technical essence of the present application still belongs to the scope of the technical solution of the present application.

Claims

1. A method for recycling green floatation reagents of high purity quartz sand, characterized by, The method comprises the following steps: S1. collecting waste water from a high-purity quartz sand flotation process, the waste water containing residual green flotation reagents; S2. Activator recovery: NaOH solution is added to the waste water and the reaction is stirred to make Al 3+ The Al(OH)3floc is allowed to stand, precipitate and filter to obtain an aluminum-rich precipitate and filtrate I. S3. synergistic recovery of collectors and depressants: adding an anionic polyelectrolyte recovery agent to the filtrate I and stirring to fully bridge flocculation, producing flocculation; then adding a hydrophobically modified recovery agent and slowly increasing the temperature, promoting further precipitation of the depressant-collector complex, standing, settling, and centrifugal separation, to obtain a mud-like material rich in reagents and a supernatant; S4. reagent regeneration and reuse: adjusting the pH of the mud-like material rich in reagents with a dilute acid solution, stirring to dissociate, then supplementing fresh reagents to the initial effective concentration, and directly reusing the reagents in the quartz sand flotation process.

2. The method of recycling green floatation reagents of high purity quartz sand according to claim 1, characterized in that, In the step S2, the pH of the NaOH solution is 5.5-6.

5.

3. The method of recycling green floatation reagents of high purity quartz sand according to claim 1, characterized in that, In the step S2, the concentration of the NaOH solution is 5%-20%.

4. The method of recycling green floatation reagents of high purity quartz sand according to claim 1, characterized in that, In the step S3, the anionic polyelectrolyte recovery agent includes sodium alginate and sodium carboxymethyl cellulose; the hydrophobically modified recovery agent includes alkyl polyglycoside, fatty acid polyoxyethylene ether, sorbitan fatty acid ester, and ethoxylates thereof.

5. The method of recycling green float reagents of high purity quartz sand according to claim 4, characterized in that, When the anionic polyelectrolyte is sodium alginate, the amount of sodium alginate added is 0.8-1.2 equivalents of the total positive charge in the waste water.

6. The method of recycling green float reagents of high purity quartz sand according to claim 4, characterized in that, When the hydrophobically modified recovery agent is alkyl polyglycoside, the amount of alkyl polyglycoside added is 0.05%-0.2% of the mass of the waste water.

7. The method of recycling green floatation reagents of high purity quartz sand according to claim 1, characterized in that, In the step S3, the temperature range for adding the hydrophobically modified recovery agent and slowly increasing the temperature is 50-70°C.

8. The method of recycling green floatation reagents of high purity quartz sand according to claim 1, characterized in that, In the step S4, the dilute acid solution adjusts the pH to 3-4.

9. Use of a method for recycling of green float reagents for high purity quartz sand, characterized in that, The application is used for high-purity quartz sand purification.

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