Amphoteric polyacrylamide flocculant for tailing treatment and preparation method thereof

Abstract

The invention discloses an amphoteric polyacrylamide flocculant for tailing treatment and a preparation method thereof, and belongs to the technical field of flocculant processing, the amphoteric polyacrylamide flocculant comprises the following raw materials by weight: 300 parts of a main material, 100 parts of an anionic monomer, 60 parts of a cationic monomer, 1 part of an initiator, and 1 part of an auxiliary agent. The main material is acrylamide, and the water is deionized water. The anionic monomer is any one of acrylic acid, methacrylic acid and 2-acrylamide-2-methylpropanesulfonic acid. The cationic monomer is any one of acryloyloxyethyl trimethyl ammonium chloride, methacryloyloxyethyl trimethyl ammonium chloride and dimethyl diallyl ammonium chloride. The initiator is any one of a thermal initiator, a cationic initiator and a reduction initiator, and the thermal initiator comprises ammonium persulfate and potassium persulfate. The cationic initiator is set to be azobis (isobutylamidine hydrochloride), and the reduction initiator is set to be sodium hydrogen sulfite.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of flocculants, and particularly relates to an amphoteric polyacrylamide flocculant for tailing treatment and a preparation method thereof. BACKGROUND

[0002] In the ore dressing operation, the flocculation process is often used for solid-liquid separation. If not treated by flocculation, the sedimentation efficiency is very low, and the sedimentation efficiency can be greatly improved by using flocculation concentration, and the flocculation concentration has the advantages of effectively removing suspended solids in supernatant, efficiently accelerating the sedimentation speed of particles, etc., and is widely used in the ore dressing operation. The operation efficiency is related to the cost of the whole solid-liquid separation process, the recovery rate of useful minerals, the utilization of backwater, and green discharge. In order to strengthen the concentration of ore pulp and the clarification of water in the ore dressing plant, and improve the hydraulic transportation concentration of tailings and the utilization rate of backwater, many ore dressing plants at home and abroad use flocculants to strengthen the sedimentation and concentration of tailings.

[0003] Another application of the flocculant in the ore dressing operation is the selective flocculation process of micro-fine particle ore. The process is to make the nearly colloidal suspension fully dispersed by using a dispersant, and then to flocculate the target mineral particles and other dispersed phases of gangue by using a flocculant to separate and settle.

[0004] In the prior art, the preparation method of the amphoteric polyacrylamide flocculant is very complicated, and at the same time, the viscosity of the prepared amphoteric polyacrylamide colloid is large, the resilience is poor, and it is difficult to granulate and form.

[0005] Therefore, in view of the above situation, it is urgent to design and produce an amphoteric polyacrylamide flocculant for tailing treatment and a preparation method thereof to meet the actual needs. SUMMARY

[0006] The purpose of the present application is to provide an amphoteric polyacrylamide flocculant for tailing treatment and a preparation method thereof to solve the problems in the background art.

[0007] To achieve the above-mentioned purpose, the present application provides the following technical scheme: an amphoteric polyacrylamide flocculant for tailing treatment, comprising main material, anionic monomer, cationic monomer, initiator and additive, and the weight mass fraction of each raw material is: 300-400 parts of main material, 100-160 parts of anionic monomer, 60-80 parts of cationic monomer, and 1-3 parts of initiator.

[0008] As a preferred embodiment, the main material is set as acrylamide, and the water is set as deionized water.

[0009] As a preferred embodiment, the anionic monomer is set as any one of acrylic acid, methacrylic acid and 2-acrylamide-2-methylpropane sulfonic acid.

[0010] As a preferred embodiment, the cationic monomer is set as any one of acryloyloxyethyl trimethyl ammonium chloride, methacryloyloxyethyl trimethyl ammonium chloride, dimethyl diallyl ammonium chloride.

[0011] As a preferred embodiment, the initiator is set as any one of thermal initiator, cationic initiator and reducing initiator, the thermal initiator includes ammonium persulfate, potassium persulfate.

[0012] As a preferred embodiment, the cationic initiator is set as azobisdimethylaminoformamide hydrochloride, and the reducing initiator is set as sodium bisulfite.

[0013] As a preferred embodiment, the auxiliary agent includes EDTA, urea and deionized water, the EDTA is a metal chelating agent for preventing polymerization inhibition, the urea is a chain transfer agent for adjusting molecular weight, and the deionized water is used as a solvent.

[0014] A preparation method of an amphoteric polyacrylamide flocculant for tailings treatment, comprising the following steps:

[0015] Step one, batching and dissolving: acrylamide, anionic monomer and cationic monomer are added into deionized water in proportion, stirred and dissolved, the anionic monomer is neutralized by a NaOH solution, and the total monomer concentration is adjusted to 20%-40%;

[0016] Step two, oxygen removal and temperature adjustment: nitrogen is introduced into the solution to remove oxygen, and the temperature of the reaction kettle is controlled at 20-60℃;

[0017] Step three, initiation of polymerization: the initiator is added, the reaction kettle is sealed after uniform stirring, the polymerization reaction lasts for 4-8 hours, and the system gradually forms a gel-like product;

[0018] Step four, post-treatment: the gel-like product is cut into small pieces, granulated, dried and crushed to obtain solid APAM powder, and the molecular weight can be controlled by adjusting the amount of initiator and the monomer concentration.

[0019] As a preferred embodiment, the total monomer concentration in the batching and dissolving step is adjusted: too high is easy to crosslink, and too low is easy to cause low molecular weight, the nitrogen introduction time in the oxygen removal and temperature adjustment step is set to 30-60 minutes to avoid oxidation of free radicals, and the temperature control of the reaction kettle is because low temperature is beneficial to the generation of high molecular weight products.

[0020] As a preferred embodiment, the initiation of polymerization step is exothermic, and temperature control is required to prevent explosive polymerization, and the drying operation in the post-treatment step is vacuum drying at 60-80℃.

[0021] Compared with the prior art, the technical effects and advantages of the present application are:

[0022] The amphoteric polyacrylamide flocculant for tailings treatment and the preparation method, the anion and cation groups on the molecular chain can respectively neutralize the negative charge and positive charge (such as some metal oxide particles) on the surface of tailings particles, reduce the electrostatic repulsion between particles, and promote the aggregation of the particles;

[0023] The amphoteric polyacrylamide flocculant for tailings treatment and the preparation method, the long molecular chain can be adsorbed on the surfaces of multiple tailings particles through van der Waals force, hydrogen bond and the like, to form a three-dimensional bridging structure of "particle-polymer-particle", connect the fine particles into large flocs, and accelerate the sedimentation. When the dosage is high, the molecular chains are intertwined to form a network structure, which wraps the dispersed tailings particles like a "fishing net", and promotes the common sedimentation of the tailings particles.

[0024] The amphoteric polyacrylamide flocculant for tailings treatment and the preparation method, the synergistic effect of the anion and cation groups makes it not easy to be salting out in high-salt tailings water (such as containing a large amount of Ca 2+ , Mg 2+ ), and can maintain stable flocculation performance in the pH range of 3-11, solving the problem of poor effect of single cation or anion PAM under extreme pH.

[0025] The amphoteric polyacrylamide flocculant for tailings treatment and the preparation method can adapt to complex water quality. The pH value of tailings wastewater often fluctuates due to the type of ore (such as acid mine wastewater, alkaline tailings slurry). APAM is not affected by the severe change of pH, while cationic PAM is easy to fail under strong acidic conditions, and anionic PAM has a decreased flocculation effect under strong alkaline conditions

[0026] The amphoteric polyacrylamide flocculant for tailings treatment and the preparation method has strong anti-interference ability. High-concentration electrolytes (such as metal ions, sulfates) in tailings water can interfere with the charge balance of single-ion PAM, while the amphoteric groups of APAM can offset the ion interference through charge adjustment to maintain the flocculation activity.

[0027] The amphoteric polyacrylamide flocculant for tailings treatment and the preparation method has excellent floc characteristics. The generated flocs have large density, high strength, and are not easy to break, which can quickly settle, reduce the moisture content of filter cake, and reduce the energy consumption of subsequent dewatering (such as filter pressing and centrifugation).

[0028] The amphoteric polyacrylamide flocculant for tailings treatment and the preparation method has multifunctionality. In addition to flocculation, it also has certain filtering aid and sludge conditioning effects, which can improve the stripping performance of tailings filter cake and improve the filtering efficiency. DETAILED DESCRIPTION

[0029] In the following description, numerous specific details are set forth to provide a more thorough understanding of the present application. However, it will be apparent to one of skill in the art that the present application can be practiced without one or more of these specific details. In other instances, well-known features have not been described in order to avoid obscuring the present application.

[0030] Embodiment one

[0031] The present application provides a kind of amphoteric polyacrylamide flocculants for tailings processing, including main material, anionic monomer, cationic monomer, initiator, auxiliary, and the weight mass fraction of each raw material is as follows: main material 300 parts, anionic monomer 100 parts, cationic monomer 60 parts, initiator 1 part.

[0032] Main material is set to acrylamide, and water is set to deionized water.

[0033] Anionic monomer is set to any one of acrylic acid, methacrylic acid, 2-acrylamide-2-methylpropane sulfonic acid.

[0034] Cationic monomer is set to any one of acryloyloxyethyl trimethyl ammonium chloride, methacryloyloxyethyl trimethyl ammonium chloride, dimethyl diallyl ammonium chloride.

[0035] Initiator is set to any one of thermal initiator, cationic initiator and reducing initiator, and thermal initiator includes ammonium persulfate, potassium persulfate.

[0036] Cationic initiator is set to azobisdimethylaminoform hydrochloride, and reducing initiator is set to sodium bisulfite.

[0037] Auxiliary includes EDTA, urea, deionized water, EDTA is metal chelating agent, for preventing polymerization obstruction, urea is chain transfer agent, for adjusting molecular weight, and deionized water is used as solvent.

[0038] A preparation method of amphoteric polyacrylamide flocculants for tailings processing, comprising the following steps:

[0039] Step one, batching and dissolving: acrylamide, anionic monomer, cationic monomer are added to deionized water in proportion, stirring and dissolving, neutralizing anionic monomer with NaOH solution, adjusting total monomer concentration to 20%-40%;

[0040] Step two, oxygen removal and temperature adjustment: nitrogen is introduced into the solution to remove oxygen, and the temperature of the reaction kettle is controlled at 20-60 DEG C;

[0041] Step three, initiation polymerization: after adding initiator, the reaction kettle is sealed after uniform stirring, and the polymerization reaction lasts for 4-8 hours, and the system gradually forms gel-like product;

[0042] Step four, post-processing: cut the gel product into small pieces, granulation, drying, crushing, get solid APAM powder, the molecular weight can be controlled by adjusting the amount of initiator, monomer concentration.

[0043] Adjust the total monomer concentration in the batching and dissolving step: too high is easy to crosslink, too low is easy to cause low molecular weight, the nitrogen gas inlet time in the oxygen removal and cooling step is set to 30-60 minutes, which is used to avoid the oxidation of free radicals, the temperature control of the reaction kettle is because low temperature is beneficial to generate high molecular weight products.

[0044] The reaction of the initiation polymerization step is exothermic, and temperature control is needed to prevent explosive polymerization, and the drying operation in the post-processing step is vacuum drying at 60-80 DEG C.

[0045] Example two

[0046] The application provides a kind of for tailings processing ampholyte polyacrylamide flocculants, including main material, anionic monomer, cationic monomer, initiator, auxiliary, each raw material weight mass fraction proportion is as follows: main material 400 parts, anionic monomer 160 parts, cationic monomer 80 parts, initiator 3 parts.

[0047] Main material is set to acrylamide, and water is set to deionized water.

[0048] Anionic monomer is set to any one of acrylic acid, methacrylic acid, 2-acrylamide-2-methylpropane sulfonic acid.

[0049] Cationic monomer is set to any one of acryloyloxyethyl trimethyl ammonium chloride, methacryloyloxyethyl trimethyl ammonium chloride and dimethyl diallyl ammonium chloride.

[0050] Initiator is set to any one of thermal initiator, cationic initiator and reducing initiator, and the thermal initiator includes ammonium persulfate and potassium persulfate.

[0051] Cationic initiator is set to azobisdimethylaminoformamidine hydrochloride, and reducing initiator is set to sodium bisulfite.

[0052] Auxiliary includes EDTA, urea and deionized water, EDTA is a metal chelating agent, which is used to prevent polymerization obstruction, urea is a chain transfer agent, which is used to adjust molecular weight, and deionized water is used as a solvent.

[0053] A preparation method of an ampholyte polyacrylamide flocculant for tailings treatment, comprising the following steps:

[0054] Step one, batching and dissolving: acrylamide, anionic monomer and cationic monomer are added to deionized water in proportion, stirring and dissolving, neutralizing anionic monomer with NaOH solution, and adjusting the total monomer concentration to 20%-40%;

[0055] Step two, oxygen removal and temperature adjustment: nitrogen is introduced into the solution to remove oxygen, and the temperature of the reaction kettle is controlled at 20-60℃;

[0056] Step three, initiation of polymerization: after stirring evenly, the reaction kettle is sealed, and the polymerization reaction lasts for 4-8 hours, and the system gradually forms a gel-like product;

[0057] Step four, post-processing: the gel-like product is cut into small pieces, granulated, dried, and crushed to obtain solid APAM powder, and the molecular weight can be controlled by adjusting the amount of initiator and monomer concentration.

[0058] The total monomer concentration in the dosing and dissolving step is adjusted: too high is easy to crosslink, and too low is easy to cause low molecular weight, the nitrogen introduction time in the oxygen removal and cooling step is set to 30-60 minutes, which is used to avoid the oxidation of free radicals, and the temperature control of the reaction kettle is because low temperature is beneficial to the generation of high molecular weight products.

[0059] The initiation of polymerization step is exothermic, and temperature control is needed to prevent explosive polymerization, and the drying operation in the post-processing step is vacuum drying at 60-80℃.

[0060] Example three

[0061] The application provides an amphoteric polyacrylamide flocculant for tailings treatment, which comprises main materials, anionic monomers, cationic monomers, an initiator and an additive, and the weight mass fraction of each raw material is as follows: 350 parts of main materials, 130 parts of anionic monomers, 70 parts of cationic monomers and 2 parts of initiator.

[0062] The main material is set as acrylamide, and the water is set as deionized water.

[0063] The anionic monomer is set as any one of acrylate, methacrylic acid, 2-acrylamide-2-methylpropane sulfonic acid.

[0064] The cationic monomer is set as any one of acryloyloxyethyl trimethyl ammonium chloride, methacryloyloxyethyl trimethyl ammonium chloride and dimethyl diallyl ammonium chloride.

[0065] The initiator is set as any one of a thermal initiator, a cationic initiator and a reducing initiator, the thermal initiator comprises ammonium persulfate and potassium persulfate.

[0066] The cationic initiator is set as azobisdimethylaminoformamidine hydrochloride, and the reducing initiator is set as sodium bisulfite.

[0067] The additive comprises EDTA, urea and deionized water, the EDTA is a metal chelating agent and is used for preventing polymerization obstruction, the urea is a chain transfer agent and is used for adjusting the molecular weight, and the deionized water is used as a solvent.

[0068] A preparation method of an amphoteric polyacrylamide flocculant for tailings treatment, comprising the following steps:

[0069] Step one, batching and dissolving: acrylamide, anionic monomer, cationic monomer are added to deionized water in proportion, stirred and dissolved, the anionic monomer is neutralized with NaOH solution, and the total monomer concentration is adjusted to 20%-40%;

[0070] Step two, oxygen removal and temperature adjustment: nitrogen is introduced into the solution to remove oxygen, and the temperature of the reaction kettle is controlled at 20-60 DEG C;

[0071] Step three, initiation of polymerization: the initiator is added, the reaction kettle is sealed after uniform stirring, the polymerization reaction lasts for 4-8 hours, and the system gradually forms a gel-like product;

[0072] Step four, post-processing: the gel-like product is cut into small pieces, granulated, dried and crushed to obtain solid APAM powder, and the molecular weight can be controlled by adjusting the amount of initiator and monomer concentration.

[0073] The total monomer concentration in the batching and dissolving step is adjusted: too high is easy to crosslink, too low is easy to cause low molecular weight, the nitrogen gas is introduced for 30-60 minutes in the oxygen removal and temperature reduction step, which is used to avoid the oxidation of free radicals, and the temperature of the reaction kettle is controlled because low temperature is beneficial to the generation of high molecular weight products.

[0074] The initiation polymerization step is exothermic, and temperature control is required to prevent explosive polymerization, and the drying operation in the post-processing step is vacuum drying at 60-80 DEG C.

[0075] Comparative example

[0076] The application provides an amphoteric polyacrylamide flocculant for tailings treatment, which comprises main materials, anionic monomers, cationic monomers, an initiator and an auxiliary agent, and the weight mass fraction of each raw material is as follows: 200 parts of main materials, 60 parts of anionic monomers, 20 parts of cationic monomers and 8 parts of the initiator.

[0077] The main material is acrylamide, and the water is deionized water.

[0078] The anionic monomer is any one of acrylate, methacrylic acid, 2-acrylamide-2-methylpropane sulfonic acid.

[0079] The cationic monomer is any one of acryloyloxyethyl trimethyl ammonium chloride, methacryloyloxyethyl trimethyl ammonium chloride and dimethyl diallyl ammonium chloride.

[0080] The initiator is any one of a thermal initiator, a cationic initiator and a reducing initiator, and the thermal initiator comprises ammonium persulfate and potassium persulfate.

[0081] The cationic initiator is set as azobisdimethylamidinium hydrochloride, and the reducing initiator is set as sodium bisulfite.

[0082] The auxiliary agent includes EDTA, urea, and deionized water, the EDTA is a metal chelating agent, used for preventing polymerization from being hindered, the urea is a chain transfer agent, used for adjusting the molecular weight, and the deionized water is used as a solvent.

[0083] A preparation method of an amphoteric polyacrylamide flocculant for tailing treatment, comprising the following steps:

[0084] Step one, proportioning and dissolving: acrylamide, anionic monomer and cationic monomer are added into deionized water in proportion, stirring and dissolving, neutralizing the anionic monomer with NaOH solution, and adjusting the total monomer concentration to 20%-40%;

[0085] Step two, oxygen removal and temperature adjustment: nitrogen is introduced into the solution to remove oxygen, and the temperature of the reaction kettle is controlled at 20-60 DEG C;

[0086] Step three, initiating polymerization: the initiator is added, the reaction kettle is sealed after uniform stirring, the polymerization reaction lasts for 4-8 hours, and the system gradually forms a gel-like product;

[0087] Step four, post-treatment: the gel-like product is cut into small pieces, granulated, dried and crushed to obtain solid APAM powder, and the molecular weight can be controlled by adjusting the amount of initiator and the monomer concentration.

[0088] In the proportioning and dissolving step, the total monomer concentration is adjusted: too high is easy to crosslink, and too low is easy to cause low molecular weight; the nitrogen introduction time in the oxygen removal and temperature reduction step is set to 30-60 minutes, for avoiding the oxidation of free radicals; and the temperature of the reaction kettle is controlled because low temperature is beneficial to generating high molecular weight products.

[0089] The initiation polymerization step is exothermic, and temperature control is needed to prevent explosive polymerization; and the drying operation in the post-treatment step is vacuum drying at 60-80 DEG C.

[0090] Through comprehensive comparison of multiple experiments, the effects of example one, example two and example three are better than that of the control example, and in example one, example two and example three, the effect of example three is better than that of example one and example two.

[0091] The above merely illustrates the preferred embodiments of the present application, but the protection scope of the present application is not limited to this, any skilled person in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. An amphoteric polyacrylamide flocculant for tailings treatment, characterized in that: It includes main material, anionic monomer, cationic monomer, initiator and auxiliary agent, and the weight and mass proportion of each raw material is: 300-400 parts of main material, 100-160 parts of anionic monomer, 60-80 parts of cationic monomer and 1-3 parts of initiator.

2. The amphoteric polyacrylamide flocculant for tailings treatment according to claim 1, characterized in that: The main ingredient is acrylamide, and the water is deionized water.

3. The amphoteric polyacrylamide flocculant for tailings treatment according to claim 1, characterized in that: The anionic monomer is any one of acrylic acid, methacrylic acid, and 2-acrylamide-2-methylpropanesulfonic acid.

4. The amphoteric polyacrylamide flocculant for tailings treatment according to claim 1, characterized in that: The cationic monomer is any one of acryloyloxyethyl trimethyl ammonium chloride, methacryloyloxyethyl trimethyl ammonium chloride, and dimethyl diallyl ammonium chloride.

5. The amphoteric polyacrylamide flocculant for tailings treatment according to claim 1, characterized in that: The initiator is configured as any one of a thermal initiator, a cationic initiator, and a reduction initiator, and the thermal initiator includes ammonium persulfate and potassium persulfate.

6. The amphoteric polyacrylamide flocculant for tailings treatment according to claim 1, characterized in that: The cationic initiator is azobisisobutyramidine hydrochloride, and the reduction initiator is sodium bisulfite.

7. The amphoteric polyacrylamide flocculant for tailings treatment according to claim 1, characterized in that: The auxiliary agent includes EDTA, urea and deionized water. The EDTA is a metal chelating agent used to prevent polymerization from being hindered. The urea is a chain transfer agent used to adjust the molecular weight. The deionized water is used as a solvent.

8. A method for preparing the amphoteric polyacrylamide flocculant for tailings treatment according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step 1: Ingredients and dissolution: Add acrylamide, anionic monomer, and cationic monomer to deionized water in proportion, stir to dissolve, neutralize the anionic monomer with NaOH solution, and adjust the total monomer concentration to 20%-40%; Step 2: Deoxygenation and temperature adjustment: nitrogen is introduced into the solution to remove oxygen and the temperature of the reactor is controlled at 20-60°C; Step 3: Initiate polymerization: Add initiator, stir evenly and seal the reactor. Continue the polymerization for 4-8 hours until a gel-like product is gradually formed. Step 4: Post-processing: Cut the gel-like product into small pieces, granulate, dry and grind to obtain solid APAM powder. The molecular weight can be controlled by adjusting the initiator dosage and monomer concentration.

9. The method for preparing an amphoteric polyacrylamide flocculant for tailings treatment according to claim 8, characterized in that: The total monomer concentration is adjusted in the batching and dissolving steps: too high a concentration is prone to cross-linking, while too low a concentration is prone to low molecular weight. The nitrogen introduction time in the deoxygenation and cooling steps is set to 30-60 minutes to prevent free radicals from being oxidized. The temperature of the reactor is controlled because low temperature is conducive to the generation of high molecular weight products.

10. The method for preparing an amphoteric polyacrylamide flocculant for tailings treatment according to claim 8, characterized in that: The polymerization initiation step is exothermic and requires temperature control to prevent explosion. The drying operation in the post-treatment step is vacuum drying at 60-80°C.