CN114685700A - Resource method of polytetrafluoroethylene dispersion resin coagulation mother liquor - Google Patents
Resource method of polytetrafluoroethylene dispersion resin coagulation mother liquor Download PDFInfo
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- CN114685700A CN114685700A CN202011560211.2A CN202011560211A CN114685700A CN 114685700 A CN114685700 A CN 114685700A CN 202011560211 A CN202011560211 A CN 202011560211A CN 114685700 A CN114685700 A CN 114685700A
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- polytetrafluoroethylene dispersion
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F6/00—Post-polymerisation treatments
- C08F6/14—Treatment of polymer emulsions
- C08F6/22—Coagulation
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/62—Plastics recycling; Rubber recycling
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- Polymers & Plastics (AREA)
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- Separation, Recovery Or Treatment Of Waste Materials Containing Plastics (AREA)
- Separation Of Suspended Particles By Flocculating Agents (AREA)
Abstract
The invention provides a recycling method of polytetrafluoroethylene dispersion resin coagulation mother liquor, which comprises the following steps: adding electrolyte into the condensed mother liquor, and then mechanically demulsifying, wherein clean inert gas is introduced in the mechanical demulsification process. The invention provides a resource method of polytetrafluoroethylene dispersion resin coagulation mother liquor, which increases the destructive capacity to micelles by adding electrolyte and introducing clean inert gas in the mechanical demulsification process, so that the demulsification is more thorough, and the recovery rate of the residual polytetrafluoroethylene resin in the coagulation mother liquor is improved to more than 95%.
Description
Technical Field
The invention relates to the technical field of fluororesin synthesis, and in particular relates to a recycling method of polytetrafluoroethylene dispersion resin coagulation mother liquor.
Background
The production of Polytetrafluoroethylene (PTFE) dispersion resins generally consists of three parts, polymerization, coagulation, and drying. Specifically, water or other solvents are used as carriers in a high-pressure reaction kettle, a dispersing agent, an initiator and other auxiliary agents are added to react with Tetrafluoroethylene (TFE) monomers, the initiator in the reaction kettle forms free radicals at a certain temperature and performs polymerization reaction of chain initiation, chain growth and chain termination with the monomers, the dispersing agent forms micelles in the carriers, the monomers are endowed with oleophilic property with water, the whole reaction is completed in the micelles, finally, milky PTFE emulsion is obtained in the reaction kettle, the PTFE emulsion is conveyed to a feed liquid storage tank after the reaction is finished, then deionized water is added to dilute the PTFE emulsion from 1.2 to 1.05 in specific gravity, the PTFE emulsion is conveyed to a condensation barrel, the micelles are broken under the action of mechanical stirring, the PTFE micelles are separated to form PTFE resin with a regular shape, and the obtained resin is conveyed to a dryer to be dried and then sold as a commodity.
The mother liquor obtained after the condensation of each ton of polytetrafluoroethylene resin (calculated according to dry materials) is 12 tons, and most enterprises directly discharge the mother liquor as industrial wastewater. However, due to the limitation of the existing polytetrafluoroethylene dispersion resin production process, the coagulation mother liquor contains a small amount of resin and additives (specifically about 0.1% of PTFE, 30ppm of fluorosurfactant and a small amount of paraffin and other additives) added during polymerization, and these substances are discharged along with the coagulation mother liquor, and are hardly naturally degraded in the environment, which is harmful to the environment and causes a certain waste of resources.
At present, few reports adopt the method of adding metal salt to coagulate and demulsify to recover the polytetrafluoroethylene resin in the mother liquor, but the polytetrafluoroethylene resin obtained by the method is a low-end product or has low recovery rate, and the effect is not ideal anyway.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a recycling method of polytetrafluoroethylene dispersion resin coagulation mother liquor, which is used for recycling high value-added components and improving economic benefits.
The invention adopts the following technical scheme:
the invention provides a resource method of polytetrafluoroethylene dispersion resin coagulation mother liquor, which comprises the following steps: adding electrolyte into the condensed mother liquor, and then mechanically demulsifying, wherein clean inert gas is introduced in the mechanical demulsification process.
Among the above-mentioned technical scheme, the stability of micelle can be destroyed in the addition of electrolyte, and inert gas is cut into the microbubble and is attached to the micelle under the effect of mechanical force, becomes more tiny along with constantly cutting to progressively explode and then increased the destructiveness to the micelle, make the breakdown of emulsion more thorough, improved the rate of recovery of surplus resin in the condensation mother liquor. Among them, the clean inert gas may be nitrogen, argon, compressed air, etc., and compressed air is preferably used because it is inexpensive and readily available.
Preferably, the electrolyte is ammonium bicarbonate, and the addition amount of the electrolyte is 0.02-0.08% of the coagulation mother liquor.
Furthermore, the mechanical demulsification mode is a shearing mode, and the rotating speed of a shearing blade is 2000-3000 r/min. Under the repeated action of the electrolyte and the strength shearing force, the stability of the micelles is reduced and the micelles collide with each other, and finally PTFE particles remained in the mother solution and wrapped by the micelles break loose the constraint of the micelles and are separated from the water phase.
After the mechanical demulsification, the particle size of the polytetrafluoroethylene resin in the condensed mother liquor is 15-25 microns.
Compared with the coagulation process comprising two functions of granulation and demulsification in the normal production process, the process of mechanical demulsification is a secondary coagulation process, and the particle size of the resin obtained by mechanical demulsification is 15-25 microns, which is much finer than the particle size of discharged material in the normal production process of 800-1000 microns. It is this high intensity mechanical demulsification that allows the residual resin to be recovered as much as possible, which is not desirable if normal coacervation processes are used.
Further, the resource recycling method also comprises the steps of sequentially carrying out flocculation and air flotation treatment on the material obtained after the mechanical demulsification, and separating to obtain polytetrafluoroethylene resin powder.
PTFE particles obtained by mechanical demulsification are only 15-25 microns, so that the PTFE particles are inconvenient to separate. The invention adopts flocculation and air flotation treatment, and can simply and efficiently separate and obtain the polytetrafluoroethylene resin powder.
Wherein, flocculating agents of polyaluminium chloride and polyacrylamide are preferably added in the flocculation process. The addition of the two flocculating agents is helpful for agglomeration of PTFE particles, and is convenient for subsequent separation. The addition amount of the flocculating agent is preferably 0.001-0.002% by mass of the coagulation mother liquor.
In the air floatation process, the micro bubbles are adsorbed on the agglomerated PTFE particles, and the PTFE particles at the bottom are driven to float to the water surface under the action of buoyancy, so that the separation is convenient.
Further, the resource recycling method also comprises the step of filtering and membrane recycling the liquid obtained after the air flotation treatment to obtain the auxiliary agent and the recyclable water.
After mechanical demulsification, flocculation and air flotation treatment, PTFE in the condensed mother liquor is basically recovered, the residue is little, the fluorine-containing surfactant can be more easily recovered for recycling by adopting filtration and membrane recovery, the devices such as a filter, an ultrafiltration membrane and the like are not easy to block, and meanwhile, recyclable water is obtained, so that the sewage discharge is reduced, and the method has high economic benefit and social benefit.
In the preferred embodiment of the invention, the clear liquid from the air flotation tank is sent to sand filtration, precise filtration and ultrafiltration for removing the micro powder, and the separated micro powder is sold as leftovers;
clear liquid from the filtering system is sent to a nanofiltration membrane system for recycling the fluorine-containing surfactant, the nanofiltration membrane can intercept substances such as the fluorine-containing surfactant with molecular weight more than 150 in the form of concentrated liquid, the concentrated liquid is sent to a distillation system for secondary concentration, and then acidification, layering and rectification are sequentially carried out to finally obtain the high-purity fluorine-containing surfactant for recycling;
and (3) sending the clear liquid separated from the nanofiltration membrane system to a reverse osmosis membrane system for removing micromolecules and anions and cations, collecting the separated concentrated liquid, then uniformly incinerating, and recycling the clear liquid as boiler feed water or raw water of deionized water.
The invention also provides a secondary coagulation barrel, which is internally provided with a plurality of groups of shear type blades and guide plates, wherein the guide plates are horizontally arranged on the inner wall of the secondary coagulation barrel and positioned between two adjacent groups of shear type blades.
Preferably, the distance between each group of shear blades is 400-600 mm, and the diameter of the shear blades is 400-500 mm.
The secondary coagulation tank can be applied to the method for recycling the polytetrafluoroethylene dispersion resin coagulation mother liquor.
The invention provides a resource method of polytetrafluoroethylene dispersion resin coagulation mother liquor, which increases the destructive capacity to micelles by adding electrolyte and introducing inert gas in the mechanical demulsification process, so that the demulsification is more thorough, and the recovery rate of the residual polytetrafluoroethylene resin in the coagulation mother liquor is improved to more than 95%.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.
FIG. 1 is a process flow diagram of a recycling method of coagulation mother liquor of polytetrafluoroethylene dispersion resin provided in the example of the invention;
fig. 2 is a schematic structural diagram of a secondary coagulation barrel in an embodiment of the present invention.
Detailed Description
The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention. The examples do not show the specific techniques or conditions, according to the technical or conditions described in the literature in the field, or according to the product specifications. The reagents or instruments used are conventional products available from regular distributors, not indicated by the manufacturer.
Example 1
The embodiment provides a recycling method of polytetrafluoroethylene dispersion resin coagulation mother liquor, a process flow diagram of which is shown in fig. 1, and the method comprises the following specific steps:
1000 kg of coagulation mother liquor with 0.1 percent of PTFE content is collected, 500 g of ammonium bicarbonate is added and mixed evenly, the rotating speed of a secondary coagulation barrel is set to 3000 r/min, then the coagulation mother liquor which is mixed evenly is continuously added into the secondary coagulation barrel by a centrifugal pump at the speed of 1000L/h,at the same time, the second coagulation tank is charged with 300Nm3Compressed air of 0.6MPa is introduced at a speed of h.
The material continuously discharged from the secondary coagulation barrel was sent to a flocculation tank, 5 g each of PAC and PAM was added to the flocculation tank, stirred for 30 minutes and then allowed to stand for 1 hour.
The material from the flocculation tank is fed into an air flotation tank according to the speed of 600Nm3Introducing 0.1Mpa compressed air into the air flotation tank at a flow rate of/h, bubbling for 20 minutes, standing for 10 minutes, scooping out the PTFE material floating on the air flotation tank, and conveying to an oven for drying. 965 g of dry PTFE (sold as raw material for raw tape) were obtained with a 96.5% recovery.
And (4) sending the clear liquid from the air flotation tank to sand filtration, precise filtration and ultrafiltration for removing micro powder, and selling the separated micro powder as leftovers.
And sending the clear liquid from the filtering system to a nanofiltration membrane system for recovering the fluorine-containing surfactant. The nanofiltration membrane can intercept substances such as the fluorine-containing surfactant with molecular weight more than 150 in the form of concentrated solution, the concentrated solution is sent to a distillation system for secondary concentration, and the high-purity fluorine-containing surfactant is obtained through acidification, layering and rectification in sequence and is recycled.
And (3) sending the clear liquid separated from the nanofiltration membrane system to a reverse osmosis membrane system to remove small molecules and anions and cations, and collecting the separated concentrated solution and then uniformly incinerating. The clear liquid can be used as raw water of boiler feed water or deionized water for recycling.
The schematic structure and material inlet and outlet of the secondary coagulation barrel in this embodiment are shown in fig. 2. Wherein, the secondary is coagulated bucket inside and is equipped with guide plate and shear type blade, and the guide plate level sets up on the both sides inner wall of secondary is coagulated the bucket and is located between two sets of adjacent shear type blades, and shear type blade is provided with the multiunit, and each is organized interval 500mm, and shear type blade diameter is about 450 mm.
Example 2
The embodiment provides a recycling method of polytetrafluoroethylene dispersion resin coagulation mother liquor, which comprises the following specific steps:
collect 1000 kilogramsAdding 500 g of ammonium bicarbonate into a coagulation mother liquor containing 0.1% of PTFE, uniformly mixing, setting the rotation speed of a secondary coagulation barrel at 2000 r/min, continuously adding the uniformly mixed coagulation mother liquor into the secondary coagulation barrel at 1000L/h by a centrifugal pump, and simultaneously adding 300Nm of the uniformly mixed coagulation mother liquor into the secondary coagulation barrel3Compressed air of 0.6MPa is introduced at a speed of h.
The material continuously discharged from the secondary coagulation bucket is sent to a flocculation tank, 5 g of PAC and PAM are added into the flocculation tank respectively, and the mixture is stirred for 30 minutes and then stands for 1 hour.
The material from the flocculation tank is fed into an air flotation tank according to the speed of 600Nm3Introducing 0.1Mpa compressed air into the air flotation tank at a flow rate of/h, bubbling for 20 minutes, standing for 10 minutes, scooping out the PTFE material floating on the air flotation tank, and conveying to an oven for drying. 850 g of dry PTFE was obtained with a recovery of 85%.
And (4) sending the clear liquid from the air flotation tank to sand filtration, precision filtration and ultrafiltration for removing micro powder, and selling the separated micro powder as leftovers.
And sending the clear liquid from the filtering system to a nanofiltration membrane system for recovering the fluorine-containing surfactant. The nanofiltration membrane can intercept substances such as the fluorine-containing surfactant with molecular weight more than 150 in the form of concentrated solution, the concentrated solution is sent to a distillation system for secondary concentration, and the high-purity fluorine-containing surfactant is obtained through acidification, layering and rectification in sequence and is recycled.
And (3) sending the clear liquid separated from the nanofiltration membrane system to a reverse osmosis membrane system to remove small molecules and anions and cations, and collecting the separated concentrated solution and then uniformly incinerating. The clear liquid can be used as raw water of boiler feed water or deionized water for recycling.
Comparative example 1
This comparative example provides a method for recycling a polytetrafluoroethylene dispersion resin coagulation mother liquor, which is different from example 1 in that compressed air is not introduced into the secondary coagulation tank.
As a result, 610 g of a dried PTFE material was obtained. The recovery rate was 61%.
Comparative example 2
The comparative example provides a recycling method of polytetrafluoroethylene dispersion resin coagulation mother liquor, which is different from the example 1 in that the secondary coagulation barrel is a coagulation barrel used in a normal production process.
As a result, 50 g of a dried PTFE material was obtained. The recovery rate was 5%. It can be seen that only a small amount of recovered material can be obtained after the secondary coagulation by the normal process.
Although the invention has been described in detail hereinabove with respect to a general description and specific embodiments thereof, it will be apparent to those skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.
Claims (10)
1. A resource method of polytetrafluoroethylene dispersion resin coagulation mother liquor is characterized by comprising the following steps: adding electrolyte into the condensed mother liquor, and then mechanically demulsifying, wherein clean inert gas is introduced in the mechanical demulsification process.
2. The method as claimed in claim 1, wherein the electrolyte is ammonium bicarbonate in an amount of 0.02-0.08% of the coagulation mother liquor.
3. The method as claimed in claim 1 or 2, wherein the mechanical demulsification is performed by shearing, and the rotation speed of the shearing blade is 2000-3000 rpm.
4. The method as claimed in any one of claims 1 to 3, wherein the particle size of the PTFE resin in the coagulation mother liquor after the mechanical demulsification is 15 to 25 μm.
5. The recycling method of polytetrafluoroethylene dispersion resin coagulation mother liquor according to any one of claims 1 to 4, wherein the recycling method further comprises subjecting the material obtained after mechanical demulsification to flocculation and air flotation treatment in sequence, and separating to obtain polytetrafluoroethylene resin powder.
6. A resource utilization method of polytetrafluoroethylene dispersion resin coagulation mother liquor according to claim 5, characterized in that flocculating agents polyaluminium chloride and polyacrylamide are added in the flocculation process.
7. The recycling method of the coagulation mother liquor of polytetrafluoroethylene dispersion resin according to claim 5, further comprising filtering and membrane recovery of the liquid obtained after said air flotation treatment to obtain an auxiliary and recyclable water.
8. The secondary coagulation barrel is characterized in that a plurality of groups of shear type blades and guide plates are arranged inside the secondary coagulation barrel, and the guide plates are horizontally arranged on the inner wall of the secondary coagulation barrel and positioned between two adjacent groups of shear type blades.
9. The secondary agglomeration drum of claim 8, wherein the pitch between the shear blade sets is 400-600 mm, and the shear blade diameter is 400-500 mm.
10. Use of the secondary coagulation tank according to claim 8 or 9 in a method for recycling a coagulation mother liquor of polytetrafluoroethylene dispersion resin according to any one of claims 1 to 7.
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Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000317214A (en) * | 1999-05-12 | 2000-11-21 | Japan Organo Co Ltd | Flocculating and settling device |
| JP2006094840A (en) * | 2004-09-30 | 2006-04-13 | Makita Corp | Hedge trimmer and shear blade assembly used therefor |
| JP2010248323A (en) * | 2009-04-13 | 2010-11-04 | Unimatec Co Ltd | Method for recovering polymer particle |
| CN102249362A (en) * | 2011-07-13 | 2011-11-23 | 山东东岳高分子材料有限公司 | Method for processing industrial wastewater of polytetrafluoroethylene dispersion resins |
| CN102453166A (en) * | 2010-11-01 | 2012-05-16 | 中化蓝天集团有限公司 | Post-processing method for aqueous polymer emulsion |
| CN103432932A (en) * | 2013-09-03 | 2013-12-11 | 上海化工研究院 | Device and method for enriching and separating fluorine-containing polymer emulsion |
| CN104583135A (en) * | 2012-08-17 | 2015-04-29 | 纳幕尔杜邦公司 | Treating wastewater by ultrafiltration in fluoropolymer resin manufacture |
| CN204365163U (en) * | 2014-12-01 | 2015-06-03 | 天津凯耀科技发展有限公司 | High shear force Y type homogenizing valve |
| WO2016142315A1 (en) * | 2015-03-09 | 2016-09-15 | Rhodia Operations | Process for preparing oxysulphide and fluorinated compounds |
| CN106317265A (en) * | 2015-06-26 | 2017-01-11 | 中昊晨光化工研究院有限公司 | Agglomeration method of polytetrafluoroethylene dispersed resin |
-
2020
- 2020-12-25 CN CN202011560211.2A patent/CN114685700B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000317214A (en) * | 1999-05-12 | 2000-11-21 | Japan Organo Co Ltd | Flocculating and settling device |
| JP2006094840A (en) * | 2004-09-30 | 2006-04-13 | Makita Corp | Hedge trimmer and shear blade assembly used therefor |
| JP2010248323A (en) * | 2009-04-13 | 2010-11-04 | Unimatec Co Ltd | Method for recovering polymer particle |
| CN102453166A (en) * | 2010-11-01 | 2012-05-16 | 中化蓝天集团有限公司 | Post-processing method for aqueous polymer emulsion |
| CN102249362A (en) * | 2011-07-13 | 2011-11-23 | 山东东岳高分子材料有限公司 | Method for processing industrial wastewater of polytetrafluoroethylene dispersion resins |
| CN104583135A (en) * | 2012-08-17 | 2015-04-29 | 纳幕尔杜邦公司 | Treating wastewater by ultrafiltration in fluoropolymer resin manufacture |
| CN103432932A (en) * | 2013-09-03 | 2013-12-11 | 上海化工研究院 | Device and method for enriching and separating fluorine-containing polymer emulsion |
| CN204365163U (en) * | 2014-12-01 | 2015-06-03 | 天津凯耀科技发展有限公司 | High shear force Y type homogenizing valve |
| WO2016142315A1 (en) * | 2015-03-09 | 2016-09-15 | Rhodia Operations | Process for preparing oxysulphide and fluorinated compounds |
| CN106317265A (en) * | 2015-06-26 | 2017-01-11 | 中昊晨光化工研究院有限公司 | Agglomeration method of polytetrafluoroethylene dispersed resin |
Non-Patent Citations (2)
| Title |
|---|
| CONWAY, K 等: "Gas-liquid-solid operation of a vortex-ingesting stirred tank reactor", 《CHEMICAL ENGINEERING RESEARCH & DESIGN》 * |
| 熊正为 等: "电解法处理电镀含镍浓缩废液的试验研究", 《工业水处理》 * |
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