Preparation method of adsorbent of collecting agent for removing positive ions in phosphorite beneficiation return water

Abstract

The invention relates to a preparation method of an adsorbent for removing a cation collecting agent in phosphorite beneficiation return water, which comprises the following steps of: 1, fully stirring and dissolving a certain amount of acrylamide in water, adding a proper amount of montmorillonite and sodium alginate, and continuously stirring; then sequentially dispersing and dissolving a certain amount of exciting agent and cross-linking agent into the mixture to obtain a mixed solution A; 2, sealing the mixed solution A, and maintaining for a period of time under a hydrothermal condition to obtain a precursor A; and 3, soaking the precursor A in a metal salt solution for a period of time to obtain the adsorbent. Compared with the prior art, the specification of the prepared adsorbent can be flexibly controlled, the adsorbent can be easily separated from water, little sludge is generated in the using process, operation is easy and convenient, and the cation collecting agent in return water can be effectively removed.

Description

Technical Field

[0001] The invention belongs to the technical field of collophanite beneficiation, and in particular relates to a method for preparing an adsorbent for removing a cationic collector in phosphate beneficiation return water. Background Art

[0002] Most of the domestic phosphate resources belong to poor-quality colloidal phosphate. The grinding fineness is high and the flotation agent consumption is large during the beneficiation process, resulting in a large amount of flotation wastewater and a large amount of residual flotation agents. In the gravity flotation beneficiation process, different collectors are used in the dealuminization section and the dealuminization section. The cationic collector used in the dealuminization section remains in the dealuminization return water. After the return water is recycled many times, the return water will be reused in the dealuminization section, which will affect the beneficiation index and flotation foam. The foam in the dealuminization section is sticky, which reduces the concentrate yield, destroys the stability of the entire production process, and leads to a decrease in production efficiency. Therefore, removing the residual cationic collector in the dealuminization section return water before it is reused in the dealuminization section can effectively improve the flotation foam and beneficiation index, which is of great significance to ensure the stable and continuous operation of the process.

[0003] Traditional treatment methods for cationic organic pollutants in water include adsorption, chemical oxidation, enhanced coagulation, biological methods, etc. Among them, the adsorption method has the advantages of simple operation, low cost, less secondary pollution, etc., and has a rapid removal effect on cationic pollutants in water. The surface of montmorillonite is electronegative, and due to its unique interlayer domain structure, montmorillonite has cation exchange properties, which makes it have a certain adsorption effect on cationic pollutants in water. Therefore, montmorillonite can be used as a cheap raw material for adsorbents.

[0004] Patent CN102580682A discloses an adsorbent for simultaneously removing heavy metals and phenolic organic matter from mineral processing wastewater and a preparation method thereof. The method uses a quaternary phosphonium salt cationic surfactant and a chelating agent to modify bentonite, which can remove heavy metals and phenolic organic matter from mineral processing wastewater. However, the adsorbent is powdery and amorphous, and produces a lot of sludge during use.

[0005] Patent CN117181454A discloses a method for treating return water from a collophane refloatation and joint selection process. The method uses montmorillonite as the main treatment agent to remove residual cationic collectors in the return water. However, the method produces a large amount of sludge, and the subsequent sludge discharge work in the return water tank is relatively cumbersome. Summary of the invention

[0006] The present invention aims to solve the problem that the dealuminous return water of residual cationic collector in the re-floatation and combined selection process of collophosphate ore is reused in the de-magnesium stage, resulting in sticky de-magnesium foam and reduced concentrate yield, and proposes a method for preparing an adsorbent for removing cationic collectors from phosphate ore dressing return water.

[0007] The technical solution adopted by the present invention to solve the above-mentioned problems is: A method for preparing an adsorbent for removing a cationic collector from phosphate ore dressing return water comprises the following steps: S1, stirring and dissolving acrylamide and water, adding montmorillonite and sodium alginate, stirring, and then dissolving an activator and a cross-linking agent in the mixture to obtain a mixed solution A; S2, sealing the mixed solution A and performing hydrothermal curing to obtain a precursor A; S3. Soaking the precursor A in a metal salt solution to obtain an adsorbent for the cationic collector.

[0008] In the step S1, the mass ratio of acrylamide: water: montmorillonite: sodium alginate is 1.5-5: 100: 4-10: 0.25-0.9.

[0009] The montmorillonite is one of calcium-based montmorillonite and sodium-based montmorillonite.

[0010] In the step S1, the mass ratio of activator: acrylamide: cross-linking agent is 0.3-0.45:4:0.5-1.

[0011] In the step S1, the activator includes one of potassium persulfate and N-vinyl-2-pyrrolidone.

[0012] In step S1, the cross-linking agent includes one of N,N-methylenebisacrylamide and benzoyl peroxide.

[0013] In step S2, the hydrothermal temperature is 60-70° C., and the reaction time is 8-12 hours.

[0014] In step S3, the metal salt is one or more of calcium chloride, barium chloride, calcium nitrate or barium nitrate.

[0015] The concentration of the metal salt solution in step S3 is 2-4 wt %, and the mass ratio is precursor A:metal salt solution=1:1.7-2.

[0016] The soaking time in step S3 is 4 to 8 hours.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention aims at the problem that the cationic collectors remaining in the dealuminization return water of the collophanite beneficiation process are reused in the demagnesization flotation, which causes the flotation foam in the demagnesization stage to become sticky and the concentrate index to decrease. An adsorbent is prepared to remove the cationic collectors in the return water. This invention can obtain adsorbents of different specifications by curing the mixed solution A in different molds. At the same time, the adsorbent is easy to separate from water, produces less sludge during use, is easy to operate, and can effectively remove the cationic collectors in the return water.

[0018] 2. The present invention proposes a method for preparing an adsorbent for removing cationic collectors from phosphate ore dressing return water. The method shapes and solidifies montmorillonite into an adsorbent with a certain strength. At the same time, different molds can be used to prepare adsorbents of various specifications according to needs. The adsorbent is easy to separate from water, produces less sludge during use, is easy to operate, and can effectively remove cationic collectors from return water.

[0019] 3. The present invention uses calcium chloride or barium chloride to soak. On the one hand, it increases the mechanical strength of the solid adsorbent, which is convenient for separation from the dealuminized return water. The adsorbent selectively adsorbs dodecylamine, which reduces the discharge of sludge in the dealuminized return water. On the other hand, during soaking, Ca 2+ and Ba 2+ The combination with sodium alginate strengthens the support of the porous structure of the adsorbent, increases the effective contact area between the adsorbent and the dealuminized return water, and improves the adsorption rate of the flotation agent. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a physical picture of the adsorbent in Example 1. DETAILED DESCRIPTION

[0021] In order to better understand the present invention, the content of the present invention is further described below in conjunction with the examples and comparative examples, but the present invention is not limited to the following examples. The following examples are not specifically described, and the reagents used are commercially available chemical reagents or industrial products. The return water in the following examples is taken from the dealuminized return water (pH value 4.6) of a ore dressing plant in Yichang.

[0022] The dealuminized return water contains flotation reagent CH3 (CH2) to be removed 11 NH2, Composition and content of main substances in dealuminized return water: Mg 2+ The content is 1267mg / L, Ca 2+ The content is 894mg / L, SO4 2- The content is 1886mg / L, PO4 3- The content is 3510mg / L.

[0023] The flotation reagent is a cationic amine collector, dodecylamine, with the molecular formula CH3(CH2) 11 NH2, the present invention can also be applied to the adsorption and removal of other organic amine cationic collectors. The content of the flotation reagent is characterized by the total organic carbon TOC measurement value of 42.1 mg / L.

[0024] Calcium montmorillonite was purchased from Lingshou County Zhongshi Hengda Mineral Products Processing Plant; Molecular formula: Ca x (H2O)4(Al 2-x Mg0.5 x ) (Si4O 10 )(OH)2;0 <x<2。

[0025] Sodium montmorillonite was purchased from Lingshou County Zhongshi Hengda Mineral Products Processing Plant; molecular formula: Na x (H2O)4(Al 2-x Mg x ) (Si4O 10 )(OH)2;0 <x<2。

[0026] The molecular formula of sodium alginate is (C6H7NaO6) m ; m is a positive integer.

[0027] Example 1 A method for preparing an adsorbent for removing cationic collectors from phosphate ore dressing return water.

[0028] 1) After 4g of acrylamide is fully stirred and dissolved in 100g of water, 10g of calcium montmorillonite and 0.6g of sodium alginate are added and stirred continuously. Then 0.4g of potassium persulfate activator and 0.8g of N,N-methylenebisacrylamide are dispersed and dissolved in the above mixture in sequence to obtain mixed solution A; 2) Seal the mixed solution A and maintain it at 60°C for 12 hours to obtain precursor A; 3) Precursor A was placed in a 3 wt% calcium chloride aqueous solution with a mass of 200 g and soaked for 8 h to obtain the adsorbent, such as Figure 1 shown.

[0029] Take 1L of dealuminated return water in a conical flask, add 10g of the adsorbent, and shake for 1h to obtain the treated return water. After treatment with the adsorbent, the flotation reagent content decreased from 42.13mg / L to 9.62mg / L, and the flotation reagent removal rate reached 77.17%, see Table 1.

[0030] Example 2 A method for preparing an adsorbent for removing cationic collectors from phosphate ore dressing return water.

[0031] 1) After 4g of acrylamide is fully stirred and dissolved in 100g of water, 8g of sodium montmorillonite and 0.5g of sodium alginate are added and stirred continuously. Then 0.35g of potassium persulfate activator and 0.7g of N,N-methylenebisacrylamide are dispersed and dissolved in the above mixture in sequence to obtain mixed solution A; 2) Seal the mixed solution A and maintain it at 70°C for 12 hours to obtain precursor A; 3) The precursor A was placed in a 3 wt % calcium chloride aqueous solution with a mass of 200 g and soaked for 8 hours to obtain the adsorbent.

[0032] 1L of dealuminated return water was taken into a conical flask, 10g of the adsorbent was added, and the treated return water was obtained after shaking for 1h. After treatment with the adsorbent, the content of flotation reagent in the return water decreased from 42.13mg / L to 6.55mg / L. Compared with Example 1, the use of sodium montmorillonite as the main adsorbent had a better removal effect on the cationic collector in the return water, and the removal rate reached 84.45%, as shown in Table 1.

[0033] Example 3 A method for preparing an adsorbent for removing cationic collectors from phosphate ore dressing return water.

[0034] 1) After 4g of acrylamide is fully stirred and dissolved in 100g of water, 8g of sodium montmorillonite and 0.8g of sodium alginate are added and stirred continuously. Then 0.35g of potassium persulfate activator and 0.7g of N,N-methylenebisacrylamide are dispersed and dissolved in the above mixture in sequence to obtain mixed solution A; 2) Seal the mixed solution A and maintain it at 70°C for 12 hours to obtain precursor A; 3) The precursor A was placed in a 3 wt % calcium chloride aqueous solution with a mass of 200 g and soaked for 8 hours to obtain the adsorbent.

[0035] Take 1L of dealuminated return water in a conical flask, add 10g of the adsorbent, and shake for 1h to obtain the treated return water. After treatment with the adsorbent, the flotation reagent content in the return water decreased from 42.13mg / L to 7.97m / L. Compared with Example 2, the removal effect of the adsorbent was slightly reduced by appropriately increasing the content of sodium alginate, and the removal rate was 81.08%. At the same time, the mechanical strength of the adsorbent can be enhanced, which is more conducive to industrial application, as shown in Table 1.

[0036] Example 4 A method for preparing an adsorbent for removing cationic collectors from phosphate ore dressing return water.

[0037] 1) After 4g of acrylamide is fully stirred and dissolved in 100g of water, 8g of sodium montmorillonite and 0.5g of sodium alginate are added and stirred continuously. Then 0.35g of potassium persulfate activator and 0.7g of N,N-methylenebisacrylamide are dispersed and dissolved in the above mixture in sequence to obtain mixed solution A; 2) Seal the mixed solution A and maintain it at 70°C for 12 hours to obtain precursor A; 3) The precursor A was placed in a 4 wt % barium chloride aqueous solution with a mass of 200 g and soaked for 8 hours to obtain the adsorbent.

[0038] Take 1L of dealuminated return water in a conical flask, add 10g of the adsorbent, and shake for 1h to obtain the treated return water. After treatment with the adsorbent, the content of flotation reagent in the return water decreased from 42.13mg / L to 7.44 m / L. The removal rate was 82.34%. Compared with Example 1, the use of calcium chloride as an enhancer had a slightly worse removal effect on the cationic collector in the return water, and the removal rate reached 77.17%, as shown in Table 1.

[0039] Example 5 The difference between this embodiment and embodiment 2 is that in step 3), the precursor A is placed in a 4wt% calcium nitrate aqueous solution with a mass of 200 g and immersed for 4 hours to obtain the adsorbent.

[0040] The other operating steps are exactly the same as those in Example 2. The experimental results are shown in Table 1.

[0041] Example 6 The difference between this embodiment and embodiment 2 is that in step 3), the precursor A is immersed in a 200 g 4 wt % barium nitrate aqueous solution for 4 hours to obtain the adsorbent.

[0042] The other operating steps are exactly the same as those in Example 2. The experimental results are shown in Table 1.

[0043] Comparative Example 1 Compared with Example 2, the difference is that there is no step 2), and the adsorbent is not solidified. Take 1L of return water in a conical flask, add 10g of the unsolidified adsorbent, and shake for 1h to obtain the treated return water. The flotation agent content in the return water decreases from 42.13mg / L to 24.84mg / L, and the flotation agent removal rate is 41.04%, indicating that the unsolidified adsorbent has a poor adsorption effect on the flotation agent. At the same time, the sludge generated in the return water after use is more than that in Example 2, as shown in Table 1.

[0044] Comparative Example 2 Compared with Example 2, the difference is that there is no step 3), and the mechanical strength of the adsorbent obtained is lower than that of Example 2. Take 1L of backwater in a conical flask, add 10g of the adsorbent, and shake for 1h to obtain the treated backwater. The flotation agent content in the backwater decreases from 42.13mg / L to 16.71mg / L, and the flotation agent removal rate is 60.34%. At the same time, the sludge generated by the backwater after use is more than that in Example 2, as shown in Table 1.

[0045] Comparative Example 3 Compared with Example 2, the difference is that the sodium montmorillonite in step 1) is replaced by kaolinite. 1L of return water is taken into a conical flask, 10g of the adsorbent is added, and after shaking for 1h, the treated return water is obtained. The flotation agent content in the return water decreases from 42.13mg / L to 18.38mg / L, and the flotation agent removal rate is 56.37%, indicating that kaolinite has a worse adsorption capacity for flotation agents than montmorillonite, as shown in Table 1.

[0046] Comparative Example 4 Compared with Example 2, the difference is that the calcium salt in step 3) is calcium acetate, and the obtained adsorbent has lower mechanical strength than Example 2. Take 1L of return water in a conical flask, add 10g of the adsorbent, and shake for 1h to obtain the treated return water. The flotation agent content in the return water decreases from 42.13mg / L to 16.45mg / L, and the flotation agent removal rate is 60.95%. At the same time, the sludge generated by the return water after use is more than that in Example 2, as shown in Table 1.

[0047] Table 1 Backwater indicators before and after treatment Flotation reagent content before treatment (mg / L) Flotation reagent content after treatment (mg / L) Flotation agent removal rate (%) Adsorbent mechanical strength (MPa) Return sludge volume g / L Example 1 42.13 9.62 77.17 0.56 1.23 Example 2 42.13 6.55 84.45 0.52 1.31 Example 3 42.13 7.97 81.08 0.72 1.37 Example 4 42.13 7.44 82.34 0.54 1.25 Example 5 42.13 6.23 85.21 0.53 1.06 Example 6 42.13 6.82 83.81 0.51 1.12 Comparative Example 1 42.13 24.84 41.04 - 6.47 Comparative Example 2 42.13 16.71 60.34 0.12 3.79 Comparative Example 3 42.13 18.38 56.37 0.45 1.89 Comparative Example 4 42.13 16.45 60.95 0.31 2.65 Adsorbents such as Figure 1 As shown above, in summary, the present invention proposes a method for preparing an adsorbent for removing cationic collectors in phosphate ore dressing return water, which takes montmorillonite as the main body and solidifies it to obtain an adsorbent, which can remove the cationic collectors in the return water without causing secondary pollution to the water.

[0048] In the method provided by the present invention, the specifications of the adsorbent can be flexibly adjusted by changing the mold. At the same time, the adsorbent is easy to separate from water, produces less sludge during use, is easy to operate, and can effectively remove the cationic collector in the return water.

[0049] Calcium montmorillonite, sodium montmorillonite and sodium alginate can all be purchased from the existing market. The models selected in this application are for the convenience of description, but not for limiting this application. The embodiments described above are only preferred embodiments of the present invention, rather than all embodiments. It is pointed out here that based on the embodiments in the present invention, all modifications, improvements or equivalent substitutions made by ordinary technicians in this field without departing from the core concept of the present invention belong to the protection scope of the present invention.

Claims

1. A method for preparing an adsorbent for removing cationic collectors from phosphate ore dressing return water, characterized in that: The steps include: S1, stirring and dissolving acrylamide and water, adding montmorillonite and sodium alginate, stirring, and then dissolving an activator and a cross-linking agent in the mixture to obtain a mixed solution A; S2, sealing the mixed solution A and performing hydrothermal curing to obtain a precursor A; S3. Soaking the precursor A in a metal salt solution to obtain an adsorbent for the cationic collector.

2. The method for preparing an adsorbent for removing cationic collectors from phosphate ore dressing return water according to claim 1, characterized in that: In the step S1, the mass ratio of acrylamide: water: montmorillonite: sodium alginate is 1.5-5: 100: 4-10: 0.25-0.

9.

3. The method for preparing an adsorbent for removing cationic collectors from phosphate ore dressing return water according to claim 1, characterized in that: The montmorillonite is one of calcium-based montmorillonite and sodium-based montmorillonite.

4. The method for preparing an adsorbent for removing cationic collectors from phosphate ore dressing return water according to claim 1, characterized in that: In the step S1, the mass ratio of activator: acrylamide: cross-linking agent is 0.3-0.45:4:0.5-1.

5. The method for preparing an adsorbent for removing cationic collectors from phosphate ore dressing return water according to claim 1, characterized in that: In the step S1, the activator includes one of potassium persulfate and N-vinyl-2-pyrrolidone.

6. The method for preparing an adsorbent for removing cationic collectors from phosphate ore dressing return water according to claim 1, characterized in that: In step S1, the cross-linking agent includes one of N,N-methylenebisacrylamide and benzoyl peroxide.

7. The method for preparing an adsorbent for removing cationic collectors from phosphate ore dressing return water according to claim 1, characterized in that: In step S2, the hydrothermal temperature is 60-70° C., and the reaction time is 8-12 hours.

8. The method for preparing an adsorbent for removing cationic collectors from phosphate ore dressing return water according to claim 1, characterized in that: In step S3, the metal salt is one or more of calcium chloride, barium chloride, calcium nitrate or barium nitrate.

9. The method for preparing an adsorbent for removing cationic collectors from phosphate ore dressing return water according to claim 1, characterized in that: The concentration of the metal salt solution in step S3 is 2-4 wt %, and the mass ratio is precursor A:metal salt solution=1:1.7-2.

10. The method for preparing an adsorbent for removing cationic collectors from phosphate ore dressing return water according to claim 1, characterized in that: The soaking time in step S3 is 4 to 8 hours.

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