Method and device for regenerating waste ceramic membrane tube for mine water

Abstract

The invention discloses a method and a device for regenerating a waste ceramic membrane tube for mine water. The method comprises the following steps: (1) carrying out surface analysis on the waste ceramic membrane tube through SEM and EDS; (2) heating at high temperature of 500 DEG C, and keeping the temperature for 1 hour; (3) acid pickling is conducted, 1-3% hydrochloric acid or citric acid solution is adopted as acid liquor, and the cleaning time is 30 min; (4) alkali washing, wherein the alkali liquor is a compound cleaning alkali liquor of sodium hydroxide or potassium hydroxide with the mass concentration of 1-3% and sodium citrate with the mass concentration of 1%; and (5) low-pressure large-flow high-speed physical cleaning. According to the invention, thorough regeneration of the waste ceramic membrane tube can be realized, the investment cost can be saved, and high-value recycling of the ceramic membrane tube can be realized.

Description

Technical Field

[0001] The invention belongs to the technical field of cleaning and regeneration of ceramic membranes, and in particular relates to a method and a device for regenerating waste ceramic membrane tubes for mine water. Background Art

[0002] Ceramic membrane is a type of inorganic membrane and belongs to the solid membrane material in membrane separation technology. It is mainly made of inorganic ceramic materials such as aluminum oxide, zirconium oxide, titanium oxide and silicon oxide of different specifications as the support body, and is made by surface coating and high-temperature firing. Commercial ceramic membranes usually have a three-layer structure, which is a porous support layer, a transition layer and a membrane layer. The pore size distribution of the entire membrane gradually decreases from the support layer to the membrane layer, showing an asymmetric distribution. The pore size specifications range from 0.8nm to 1μm, and the filtration accuracy covers microfiltration, ultrafiltration and nanofiltration levels. Depending on the support body, the configuration of ceramic membranes can be divided into three types: flat plate, tubular and multi-channel.

[0003] The ceramic membrane separation process is a fluid separation process in the form of "cross-flow filtration": the raw liquid flows at high speed in the membrane tube, and the clarified permeate containing small molecular components passes through the membrane in a direction perpendicular to it under pressure, while the turbid concentrated liquid containing large molecular components is retained by the membrane, thereby achieving the purpose of separation, concentration and purification of the fluid.

[0004] Ceramic membranes have many advantages, such as high chemical stability, acid resistance, alkali resistance, oxidation resistance, organic solvent resistance, and high temperature resistance; high mechanical strength and good wear resistance; extremely high separation accuracy, up to nano-level filtration; easy to clean, online disinfection or high-temperature sterilization, and reverse flushing. Therefore, ceramic membranes are widely used in food processing, bioengineering, petrochemical, metal smelting, seawater desalination, coking wastewater, mine water treatment and other fields.

[0005] A large amount of mine water is produced during the coal mining process. The mine water not only suspends fine coal powder, but also contains a variety of pollutants, which will cause serious damage to the water environment and ecological environment, and must be effectively managed. On January 1, 2021, Shanxi Province issued the "Shanxi Province Comprehensive Wastewater Discharge Standard" (DB14 / 1928-2019), which clearly requires that the three indicators of COD, ammonia nitrogen and total phosphorus of mine water must meet the Class III standard of surface water environmental quality, and at the same time, the supporting water treatment online monitoring system closely monitors the effluent water quality. The traditional mine water treatment process of "regulating tank + coagulation sedimentation + filtration + ultrafiltration" can basically meet the treatment requirements and meet the discharge standards. However, due to the large changes in the amount of incoming water, and the emulsion will enter the wastewater during the relocation of the underground working face or the coal mining process, resulting in variable water quality, this treatment process has problems such as high reagent costs, large amount of coal slime, and substandard effluent.

[0006] Based on the current status of coal mine water treatment, some mine water treatment stations have introduced tubular ceramic membranes to treat mine wastewater, achieving standard effluent from the regulating tank to the ceramic membrane system. This treatment system has the advantages of simplifying water treatment processes, saving coagulation treatment agents, saving floor space, high degree of automation, and simple operation. However, during the filtration process, the contamination of the ceramic membrane is unavoidable. As the operating time increases, pollutants such as carbon powder, silica, calcium carbonate, and calcium sulfate are easily attached to the membrane surface or exist in the pores. Figure 1 As shown, the permeation flux of the ceramic membrane is significantly attenuated and the membrane cleaning cycle is significantly shortened, the water production capacity is greatly reduced, and the design requirements of mine water treatment are not met.

[0007] At present, mine water stations usually use traditional physical cleaning and chemical cleaning methods to regenerate ceramic membrane tubes. From the current water treatment station operation results, the ceramic membrane tubes have been used for about 2 years. This conventional traditional cleaning method has little effect, which is manifested in the material flux being greatly attenuated and the membrane cleaning cycle being significantly shortened. The main reason is that a dense pollutant layer is formed on the membrane surface or the membrane pores are completely blocked. Figure 1 As shown, traditional physical and chemical cleaning can only restore loose pollutants on the membrane surface, but it is ineffective for ceramic membrane tubes that have formed a dense pollutant layer or the inside of the membrane pores are completely blocked, which makes the ceramic membrane tubes lose their effectiveness. Therefore, the traditional water cleaning method cannot meet the work needs; the treatment station can also choose to replace the ceramic membrane tube, but the ceramic membrane tube is expensive, and replacing the ceramic membrane tube will bring great economic pressure to the enterprise. At the same time, the construction of the ceramic membrane water treatment system itself requires huge investment. In a short period of time, it is necessary to continue to invest a large amount of funds to replace the ceramic membrane tube. The water treatment station will be under heavy financial pressure, so replacing the ceramic membrane tube is not an appropriate method.

[0008] Traditional cleaning methods, such as a cleaning device for tubular ceramic membranes with authorization announcement number CN 109621731 B, clamp the ceramic membrane with a clamp, clean the filter pores of the ceramic membrane with a second high-pressure pipe, and clean the outer wall of the ceramic membrane with a first high-pressure pipe, mainly by high-pressure water cleaning. This is a traditional physical cleaning method that can only restore pollutants on the surface of the ceramic membrane tube, and is ineffective for ceramic membrane tubes that have formed a dense pollutant layer or have completely blocked the inside of the membrane pores, thereby rendering the ceramic membrane tube ineffective.

[0009] For example, in a method for cleaning a ceramic membrane with the authorization announcement number CN 103551043 B, under normal temperature conditions, the ceramic membrane is acid-washed, alkaline-washed, and acid-washed in a single-stage cycle until the membrane assembly is qualified and then changed to water-washing. Ordinary acid-washing, alkaline-washing, and water-washing can only restore loose pollutants on the membrane surface, but are ineffective for ceramic membrane tubes that have formed a dense pollutant layer or have completely blocked the inside of the membrane pores, thereby rendering the ceramic membrane tube ineffective.

[0010] For example, the authorization announcement number is CN 206631443 U is an off-line regeneration device for a ceramic membrane, comprising a device body, a hot air heating furnace, a fan and a ceramic diaphragm supporting platform; the air outlet of the hot air heating furnace is connected to the air inlet of the fan, the air outlet of the fan is connected to the device body and supplies air into the device body, the device body has a built-in cavity and is provided with an opening and closing door, the ceramic diaphragm supporting platform enters and exits the device body through the opening and closing door, and is located at the upper part of the air outlet, and the pollutants of the ceramic diaphragm are removed by heating, but since the flat ceramic membrane assembly includes a ceramic diaphragm and a plug, the plug includes an upper plug and a lower plug, and the plug has a water collecting trough, which is connected to the water outlet pipe, the plug is molded by model casting with glue, heated and cured, and connected with the sealing glue at both ends of the flat ceramic diaphragm to form a whole, so the plug is easily damaged by hot air heating treatment of waste ceramic diaphragms, and the device is mainly used for ceramic diaphragms, and the ceramic membrane tube is a cylindrical ceramic membrane. The pollutants are mainly accumulated in the internal through holes of the ceramic membrane tube. The internal pollutants cannot be completely removed by heating alone, and it is not suitable for the regeneration of waste ceramic membrane tubes.

[0011] Through searching multiple databases, relevant reports on the regeneration technology of waste ceramic membranes only focus on the cleaning and regeneration of ceramic membranes, while there are no relevant reports on the complete regeneration of waste ceramic membranes.

[0012] In order to solve the above technical problems, the present invention proposes a method and device for regenerating waste ceramic membrane tubes for mine water. Summary of the invention

[0013] The purpose of the present invention is to overcome the deficiencies of the prior art and to propose a method and device for regenerating waste ceramic membrane tubes for mine water, which can achieve complete regeneration of waste ceramic membrane tubes, thereby saving investment costs and achieving high-value recycling of ceramic membrane tubes.

[0014] To achieve the above objectives, the present invention proposes the following technical solutions: A method for regenerating waste ceramic membrane tubes for mine water comprises the following steps: ① Conduct surface analysis on waste ceramic membrane tubes; By analyzing the surface of waste ceramic membrane tubes, a basic method for membrane tube treatment is provided; specifically, the surface pollutants of ceramic membrane tubes are analyzed by SEM and EDS; SEM, the full name of which is scanning electron microscope, uses the interaction between electrons and matter to obtain information on various physical and chemical properties of the sample itself, such as morphology, composition, crystal structure, electronic structure, and internal electric or magnetic fields, etc. EDS, the full name of which is energy dispersive spectrometer, is used to analyze the types and contents of the elements in the micro-region of the material, and is used in conjunction with a scanning electron microscope and a transmission electron microscope; ② High temperature heating; Since the surface of the waste ceramic membrane tubes used for mine water is covered with a dense carbon layer, the hydrophobic carbon layer has a weak interaction with water, which will effectively prevent the cleaning effect of forward washing, acid washing, alkaline washing, oxidants, and backwashing on the ceramic membrane tubes; First, put the ceramic membrane tube into a tube furnace, heat it up to 100°C at a rate of 5°C / min, and keep it warm for 30 minutes to prevent excessive water vapor from damaging the microporous skeleton of the ceramic membrane tube; Then, the temperature was raised to 500°C at 10°C / min and the holding time was 1h; In particular, when heating up and cooling down at the end of calcination, the speed should not be too fast to prevent permanent damage to the ceramic membrane tube; the optimal calcination temperature is 500℃. Too high a temperature will cause the ceramic membrane tube to turn red, and the red ceramic membrane tube is not easy to clean; after the dense carbon is removed, the pollutants on the surface of the ceramic membrane tube are mainly inorganic oxide SiO2 and a small amount of carbon, which can be easily scrubbed off; ③ Pickling; The specific method of pickling is as follows: the acid solution uses 1~3% hydrochloric acid or citric acid solution, and the cleaning time is 30 minutes. After pickling, inorganic sediments such as Fe(OH)3, CaCO3 or Mg(OH)2 on the surface of the waste ceramic membrane tube will be effectively removed. After pickling, softened water should be added to rinse the ceramic membrane tube until it becomes neutral; If the concentration of inorganic sediment on the surface of mine water is very low, and there is no accumulation of inorganic sediment such as CaCO3 or Mg(OH)2 on the surface of the ceramic membrane tube, there is no need for acid washing; ④ Alkaline washing; Specifically, the alkali washing method is as follows: the alkali solution uses a compound cleaning alkali solution with a mass concentration of 1-3% sodium hydroxide or potassium hydroxide and 1% sodium citrate. Since SiO2 is deposited on the surface of the ceramic membrane tube, the ceramic membrane tube that has been heated at high temperature is cooled and then placed in the cleaning alkali solution. At the same time, an aeration device is used to aerate the cleaning alkali solution. The alkali washing time is 45 minutes. The main purpose of the alkaline washing process is to promote the partial dissolution of colloidal silica and promote the effective removal of colloidal silica. After the alkaline washing is completed, softened water should be added to rinse the ceramic membrane tube until it reaches neutral. ⑤ Low pressure, large flow and high speed physical cleaning; Softened water is used as the cleaning fluid, the outlet pressure of the cleaning circulation pump is 0.2~0.4 MPa, and the flow range of the circulation pump is 2~3m 3 / min, high-speed cleaning of the ceramic membrane tube surface after alkali washing or acid washing, the cycle cleaning time is 30min; The purpose of high-speed physical cleaning is to remove some loose and large-particle pollutants that are difficult to remove. The low-pressure and high-flow cleaning technology can effectively remove pollutants that remain on the membrane surface; ⑥ When the outer surface or end of the ceramic membrane tube is not clean, ultrasonic cavitation technology can be used to clean the ceramic membrane tube, but ultrasonic cavitation technology has no effect on the pollutants inside the ceramic membrane tube. According to the actual pollution of the membrane tube and related test characteristics, the above steps 2-6 can be selectively used to adjust the regeneration steps of the target waste ceramic membrane tube.

[0015] The content disclosed in the present invention also includes a waste ceramic membrane tube regeneration device for mine water, including a high-temperature calcination tube furnace, an acid washing device, an alkali washing device, and a cleaning circulation pump; wherein the high-temperature calcination tube furnace includes an air intake device, a heating device, and an exhaust device, wherein the heating device is a furnace structure as a whole, and a furnace tube is arranged on the periphery, one end of the furnace tube is connected to the air intake device, and the other end of the furnace tube is connected to the exhaust device, and the internal space of the furnace tube increases the gas circulation space; The heating device is provided with a heating element, and the heating device is connected to the air intake device and the exhaust device respectively; The air intake device is connected to the inside of the furnace tube, and the air intake device includes an air intake port, an air intake valve and a pressure gauge; the air intake port is arranged at one end of the air intake device, the air intake valve is used to adjust the gas intake amount at the air intake port, and the pressure gauge is used to detect the air pressure value at the air intake port; The exhaust device comprises an exhaust port and an exhaust valve, wherein the exhaust port is arranged at the other end of the furnace tube, and the exhaust valve is arranged at the exhaust port; A heat insulation layer is arranged on the top of the heating device, and a handle is arranged on the heat insulation layer; An automatic control display screen, an indicator light and a manual switch are arranged at the bottom of the heating device.

[0016] During high-temperature heating, the ceramic membrane tube is placed inside the heating device, and the air intake device delivers a suitable volume of gas into the heating device and controls the air intake pressure; the gas pressure is maintained during the heating process, and exhaust can be performed through the exhaust device as needed; The alkali washing device comprises a sewage collecting tank, an alkali washer, an alkali washing water tank and an aeration fan; a mud discharge bucket is arranged below the alkali washer, the mud discharge bucket is connected to the sewage collecting tank through a pipeline, and a sewage pump is arranged on the pipeline; an alkali washing liquid inlet is arranged above the alkali washer, the alkali washing water tank is connected to the alkali washing liquid inlet through a pipeline, and an alkali washing pump is arranged on the pipeline; an aeration plate is arranged inside the alkali washer, and the aeration plate is connected to an external aeration fan through an air pipe; During alkali cleaning, the used ceramic membrane tube is hung inside the alkali cleaning device, and the aeration plate is placed under the ceramic membrane tube. The alkali cleaning liquid enters the alkali cleaning device from the alkali cleaning water tank, and the aeration fan draws air or gas into the aeration plate, so that the air or gas is forced into the alkali cleaning liquid; After the ceramic membrane tube is fully alkaline washed, the sewage pump will pump the sludge from the sludge hopper into the sewage collecting tank for further treatment.

[0017] The beneficial effects of the present invention are: The present invention obtains a targeted method for membrane tube treatment by performing surface analysis on waste ceramic membrane tubes, and then sequentially performs high-temperature heating, acid washing, alkali washing, and low-pressure, high-flow, and high-speed physical cleaning to remove dense surface carbon, remove inorganic precipitates on the membrane tube surface, partially dissolve colloidal silicon, and remove some loose, large-particle pollutants that are difficult to remove. Through the above steps, pollutants on the surface and inside of the waste ceramic membrane tubes can be removed to achieve complete regeneration of the waste ceramic membrane tubes.

[0018] By adopting the above scheme, the present invention can realize the complete regeneration of waste ceramic membrane tubes, which can not only save investment costs, but also realize the high-value recycling of ceramic membrane tubes; it has important progressiveness and significant economic significance for the research on the regeneration technology of ceramic membrane tubes. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0020] Figure 1 This is a real picture of the waste ceramic membrane tube.

[0021] Figure 2 This is a schematic diagram of the effect of calcination temperature on the outer surface of the ceramic membrane tube, where a-500℃, b-600℃, and c-700℃.

[0022] Figure 3 This is a schematic diagram of the effect of calcination temperature on the inner surface of the ceramic membrane tube, where a-500℃, b-600℃, and c-700℃.

[0023] Figure 4 This is the internal analysis diagram of waste ceramic membrane tubes used for coal mine water, where a-SEM analysis results, b- EDS analysis results, and c- EDS element analysis data.

[0024] Figure 5 This is the analysis diagram of the ceramic membrane tube after high-temperature heating and pickling, where a-SEM analysis results, b- EDS analysis results, c- EDS element analysis data.

[0025] Figure 6 This is the surface SEM image of the recycled waste ceramic membrane tube.

[0026] Figure 7 It is a structural schematic diagram of a high temperature calcination tube furnace.

[0027] Figure 8It is a structural schematic diagram of a ceramic membrane tube alkali washing device.

[0028] Fig. 9 It is a graph of experimental data of each embodiment.

[0029] Fig.10 This is a comparison chart of experimental data of each experimental reference group Figure 7-8 Among them, 1-air inlet, 2-air inlet valve, 3-pressure gauge, 4-insulation layer, 5-handle, 6-heating element, 7-furnace tube, 8-exhaust valve, 9-exhaust port, 10-automatic control display screen, 11-indicator light, 12-manual switch, 13-sewage collecting tank, 14-ceramic membrane tube, 15-mud bucket, 16-sewage pump, 17-alkali washing pump, 18-alkali washing water tank, 19-aeration fan. Implementation

[0030] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0031] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0032] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0033] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0034] like Figure 2As shown, when the high temperature heating temperature is 600℃ and 700℃, the outer surface of the ceramic membrane tube has turned red, and it is even redder at 700℃, which will affect the cleaning effect. However, at 500℃, the outer surface color of the ceramic membrane tube is normal and will not affect the cleaning effect.

[0035] like Figure 3 As shown, when the high temperature heating temperature is 600℃ and 700℃, the inner surface of the ceramic membrane tube has turned red, and it is even redder at 700℃, which will affect the cleaning effect. However, at 500℃, the color of the inner surface of the ceramic membrane tube is normal and will not affect the cleaning effect.

[0036] like Figure 4 and 5 As shown in the figure, when the waste ceramic membrane tube is not regenerated, the surface is almost completely covered by pollutants, and except for the three elements of O, Al and Si, the others are impurity elements, and the proportion of other impurity elements is as high as 18.8%. After the waste ceramic membrane tube is heated at high temperature and pickled, Figure 5 In the SEM analysis picture, particles of the ceramic membrane itself can be seen, indicating that the pollutants on the surface of the ceramic membrane have been basically cleaned up. At the same time, calculations show that the proportion of impurity elements has dropped to 5.61%, which has reached the standard for reuse.

[0037] like Figure 6 As shown, the surface SEM images of the regenerated waste ceramic membrane tubes are compared Figure 5 The surface SEM image in is closer to that of the new ceramic membrane tube.

[0038] First embodiment: A method for regenerating waste ceramic membrane tubes for mine water, specifically, firstly analyzing the pollutants on the surface of the ceramic membrane tubes by SEM and EDS, and then determining the method for treating the membrane tubes, and more specifically, determining the specific regeneration method according to the component analysis of the pollutants on the surface of the ceramic membrane tubes, such as the temperature and insulation time of high-temperature heating, the components and time of acid washing liquid and alkaline washing liquid, the pressure and time of physical cleaning, etc.; First, high-temperature heating is performed, that is, the waste ceramic membrane tube is placed in a high-temperature calcination tube furnace. The waste ceramic membrane tube is 1178 mm long, the outer diameter is 25 mm, the inner diameter is 3.5 mm, and the high-temperature calcination tube furnace is 1400 mm long. The exhaust hole of the high-temperature calcination tube furnace is opened, and the temperature is raised to 100 ° C at a rate of 5 ° C / min through the temperature control device, and the temperature is kept for 30 minutes; then the temperature is raised to 500 ° C at a rate of 10 ° C / min, and the heat preservation time is 1 hour. After the heat preservation is completed, the high-temperature calcination tube furnace is cooled to room temperature at a rate of 10 ° C / min; Then pickling, i.e. preparing 3% hydrochloric acid solution as cleaning acid; the cleaning time is 30 minutes; The next step is to perform alkaline washing, that is, prepare sodium hydroxide with a mass concentration of 3% and sodium citrate with a mass concentration of 1% as a compound cleaning alkali solution, put the calcined ceramic membrane tube into the cleaning alkali solution, and use an aeration device to aerate the cleaning alkali solution at the same time. The alkaline washing time is 45 minutes.

[0039] After the alkaline cleaning is completed, physical cleaning is carried out, that is, softened water is used as the cleaning liquid, the outlet pressure of the cleaning circulation pump is 0.2~0.4 MPa, and the flow range of the circulation pump is 2~3 m 3 / min, the surface of the ceramic membrane tube after alkali washing is cleaned at high speed, and the cycle cleaning time is 30min.

[0040] Through measurement, the pure water flux of the new ceramic membrane tube can reach 800 L / m 2 h, the pure water flux of the waste ceramic membrane tube is 10~30 L / m 2 h; After the waste ceramic membrane tube is successfully regenerated, the pure water flux of the regenerated ceramic membrane tube can reach 700 L / m 2 h, the pure water flux reaches more than 87.5% of the new ceramic membrane tube.

[0041] Second embodiment: A method for regenerating waste ceramic membrane tubes for mine water, specifically, firstly analyzing the pollutants on the surface of the ceramic membrane tubes by SEM and EDS, and then determining the method for treating the membrane tubes; First, high-temperature heating is performed, that is, the waste ceramic membrane tube is placed in a high-temperature calcination tube furnace. The waste ceramic membrane tube is 1178 mm long, the outer diameter is 25 mm, the inner diameter is 3.5 mm, and the high-temperature calcination tube furnace is 1400 mm long. The exhaust hole of the tube furnace is opened, and the temperature is raised to 100 °C at a rate of 5 °C / min through the temperature control device, and the temperature is kept for 30 minutes; then the temperature is raised to 600 °C at a rate of 10 °C / min, and the heat preservation time is 1 hour; after the heat preservation is completed, the tube furnace is cooled to room temperature at a rate of 10 °C / min; Then pickling, i.e. preparing 3% hydrochloric acid solution as cleaning acid; the cleaning time is 30 minutes; Next, alkali washing is performed, that is, sodium hydroxide with a mass concentration of 3% and sodium citrate with a mass concentration of 1% are prepared as a compound cleaning alkali solution, and the calcined ceramic membrane tube is placed in the cleaning alkali solution, and the cleaning alkali solution is aerated by an aeration device, and the alkali washing time is 45 minutes; After the alkaline cleaning is completed, softened water is used as the cleaning liquid, the outlet pressure of the cleaning circulation pump is 0.2~0.4 MPa, and the flow range of the circulation pump is 2~3 m 3 / min, the surface of the ceramic membrane tube after alkali washing is cleaned at high speed, and the cycle cleaning time is 30min.

[0042] Through measurement, the pure water flux of the new ceramic membrane tube can reach 800 L / m 2 h, the pure water flux of the waste ceramic membrane tube is 10~30 L / m 2 h; After the waste ceramic membrane tube is successfully regenerated, the pure water flux of the regenerated ceramic membrane tube can reach 560 L / m 2 h, the pure water flux reaches more than 70% of the new ceramic membrane tube. In addition, the red color of the inner tube and the outer wall of the ceramic membrane tube after regeneration is difficult to remove and does not affect normal use.

[0043] Third embodiment: A method for regenerating waste ceramic membrane tubes for mine water, specifically, firstly analyzing the pollutants on the surface of the ceramic membrane tubes by SEM and EDS, and then determining the method for treating the membrane tubes; First, high-temperature heating is performed, that is, the waste ceramic membrane tube is placed in a high-temperature calcination tube furnace. The waste ceramic membrane tube is 1178 mm long, the outer diameter is 25 mm, the inner diameter is 3.5 mm, and the high-temperature calcination tube furnace is 1400 mm long. The exhaust hole of the tube furnace is opened, and the temperature is raised to 100 °C at a rate of 5 °C / min through the temperature control device, and the temperature is kept for 30 minutes; then the temperature is raised to 600 °C at a rate of 10 °C / min, and the heat preservation time is 1 hour; after the heat preservation is completed, the tube furnace is cooled to room temperature at a rate of 10 °C / min; Then pickling, i.e. preparing 3% citric acid solution as the cleaning acid; the cleaning time is 30 minutes; Next, alkali washing is performed, that is, sodium hydroxide with a mass concentration of 3% and sodium citrate with a mass concentration of 1% are prepared as a compound cleaning alkali solution, and the calcined ceramic membrane tube is placed in the cleaning alkali solution, and the cleaning alkali solution is aerated by an aeration device, and the alkali washing time is 45 minutes; After the alkaline cleaning is completed, softened water is used as the cleaning liquid, the outlet pressure of the cleaning circulation pump is 0.2~0.4 MPa, and the flow range of the circulation pump is 2~3 m 3 / min, the surface of the ceramic membrane tube after alkali washing is cleaned at high speed, and the cycle cleaning time is 30min.

[0044] Through measurement, the pure water flux of the new ceramic membrane tube can reach 800 L / m 2 h, the pure water flux of the waste ceramic membrane tube is 10~30 L / m 2 h; After the waste ceramic membrane tube is successfully regenerated, the pure water flux of the regenerated ceramic membrane tube can reach 710 L / m 2 h, the pure water flux reaches more than 88.75% of that of the new ceramic membrane tube. In addition, the red color of the inner tube and the outer wall of the ceramic membrane tube after regeneration is difficult to remove and does not affect normal use.

[0045] Fourth embodiment: A method for regenerating waste ceramic membrane tubes for mine water, specifically, firstly analyzing the pollutants on the surface of the ceramic membrane tubes by SEM and EDS, and then determining the method for treating the membrane tubes; First, high-temperature heating is performed, that is, the waste ceramic membrane tube is placed in a high-temperature calcination tube furnace. The waste ceramic membrane tube is 1178 mm long, the outer diameter is 25 mm, the inner diameter is 3.5 mm, and the high-temperature calcination tube furnace is 1400 mm long. The exhaust hole of the high-temperature calcination tube furnace is opened, and the temperature is raised to 100 ° C at a rate of 5 ° C / min through the temperature control device, and the temperature is kept for 30 minutes; then the temperature is raised to 500 ° C at a rate of 10 ° C / min, and the heat preservation time is 1 hour. After the heat preservation is completed, the high-temperature calcination tube furnace is cooled to room temperature at a rate of 10 ° C / min; Then pickling, i.e. preparing 3% hydrochloric acid solution as cleaning acid; the cleaning time is 35 minutes; The next step is to perform alkaline washing, that is, prepare sodium hydroxide with a mass concentration of 3% and sodium citrate with a mass concentration of 1% as a compound cleaning alkali solution, put the calcined ceramic membrane tube into the cleaning alkali solution, and use an aeration device to aerate the cleaning alkali solution at the same time. The alkaline washing time is 45 minutes.

[0046] After the alkaline cleaning is completed, physical cleaning is carried out, that is, softened water is used as the cleaning liquid, the outlet pressure of the cleaning circulation pump is 0.2~0.4 MPa, and the flow range of the circulation pump is 2~3 m 3 / min, the surface of the ceramic membrane tube after alkali washing is cleaned at high speed, and the cycle cleaning time is 30min.

[0047] Through measurement, the pure water flux of the new ceramic membrane tube can reach 800 L / m 2 h, the pure water flux of the waste ceramic membrane tube is 10~30 L / m 2 h; After the waste ceramic membrane tube is successfully regenerated, the pure water flux of the regenerated ceramic membrane tube can reach 730 L / m 2 h, the pure water flux reaches more than 91.25% of the new ceramic membrane tube.

[0048] Fifth embodiment: A method for regenerating waste ceramic membrane tubes for mine water, specifically, firstly analyzing the pollutants on the surface of the ceramic membrane tubes by SEM and EDS, and then determining the method for treating the membrane tubes; First, high-temperature heating is performed, that is, the waste ceramic membrane tube is placed in a high-temperature calcination tube furnace. The waste ceramic membrane tube is 1178 mm long, the outer diameter is 25 mm, the inner diameter is 3.5 mm, and the high-temperature calcination tube furnace is 1400 mm long. The exhaust hole of the high-temperature calcination tube furnace is opened, and the temperature is raised to 100 ° C at a rate of 5 ° C / min through the temperature control device, and the temperature is kept for 30 minutes; then the temperature is raised to 500 ° C at a rate of 10 ° C / min, and the heat preservation time is 1 hour. After the heat preservation is completed, the high-temperature calcination tube furnace is cooled to room temperature at a rate of 10 ° C / min; Then pickling, i.e. preparing 3% hydrochloric acid solution as cleaning acid; the cleaning time is 30 minutes; The next step is to perform alkaline washing, that is, prepare sodium hydroxide with a mass concentration of 2% and sodium citrate with a mass concentration of 1% as a compound cleaning alkali solution, put the calcined ceramic membrane tube into the cleaning alkali solution, and use an aeration device to aerate the cleaning alkali solution at the same time. The alkaline washing time is 45 minutes.

[0049] After the alkaline cleaning is completed, physical cleaning is carried out, that is, softened water is used as the cleaning liquid, the outlet pressure of the cleaning circulation pump is 0.2~0.4 MPa, and the flow range of the circulation pump is 2~3 m 3 / min, the surface of the ceramic membrane tube after alkali washing is cleaned at high speed, and the cycle cleaning time is 30min.

[0050] Through measurement, the pure water flux of the new ceramic membrane tube can reach 800 L / m 2 h, the pure water flux of the waste ceramic membrane tube is 10~30 L / m 2 h; After the waste ceramic membrane tube is successfully regenerated, the pure water flux of the regenerated ceramic membrane tube can reach 690 L / m 2 h, the pure water flux reaches more than 86.25% of the new ceramic membrane tube.

[0051] Sixth embodiment: A method for regenerating waste ceramic membrane tubes for mine water, specifically, firstly analyzing the pollutants on the surface of the ceramic membrane tubes by SEM and EDS, and then determining the method for treating the membrane tubes; First, high-temperature heating is performed, that is, the waste ceramic membrane tube is placed in a high-temperature calcination tube furnace. The waste ceramic membrane tube is 1178 mm long, the outer diameter is 25 mm, the inner diameter is 3.5 mm, and the high-temperature calcination tube furnace is 1400 mm long. The exhaust hole of the high-temperature calcination tube furnace is opened, and the temperature is raised to 100 ° C at a rate of 5 ° C / min through the temperature control device, and the temperature is kept for 30 minutes; then the temperature is raised to 500 ° C at a rate of 10 ° C / min, and the heat preservation time is 1 hour. After the heat preservation is completed, the high-temperature calcination tube furnace is cooled to room temperature at a rate of 10 ° C / min; Then pickling, i.e. preparing 3% hydrochloric acid solution as cleaning acid; the cleaning time is 30 minutes; The next step is to perform alkaline washing, that is, prepare sodium hydroxide with a mass concentration of 1% and sodium citrate with a mass concentration of 1% as a compound cleaning alkali solution, put the calcined ceramic membrane tube into the cleaning alkali solution, and use an aeration device to aerate the cleaning alkali solution at the same time. The alkaline washing time is 45 minutes.

[0052] After the alkaline cleaning is completed, physical cleaning is carried out, that is, softened water is used as the cleaning liquid, the outlet pressure of the cleaning circulation pump is 0.2~0.4 MPa, and the flow range of the circulation pump is 2~3 m 3 / min, the surface of the ceramic membrane tube after alkali washing is cleaned at high speed, and the cycle cleaning time is 30min.

[0053] Through measurement, the pure water flux of the new ceramic membrane tube can reach 800 L / m 2 h, the pure water flux of the waste ceramic membrane tube is 10~30 L / m 2 h; After the waste ceramic membrane tube is successfully regenerated, the pure water flux of the regenerated ceramic membrane tube can reach 660 L / m 2 h, the pure water flux reaches more than 82.5% of the new ceramic membrane tube.

[0054] Seventh embodiment: A method for regenerating waste ceramic membrane tubes for mine water, specifically, firstly analyzing the pollutants on the surface of the ceramic membrane tubes by SEM and EDS, and then determining the method for treating the membrane tubes; First, high-temperature heating is performed, that is, the waste ceramic membrane tube is placed in a high-temperature calcination tube furnace. The waste ceramic membrane tube is 1178 mm long, the outer diameter is 25 mm, the inner diameter is 3.5 mm, and the high-temperature calcination tube furnace is 1400 mm long. The exhaust hole of the high-temperature calcination tube furnace is opened, and the temperature is raised to 100 ° C at a rate of 5 ° C / min through the temperature control device, and the temperature is kept for 30 minutes; then the temperature is raised to 500 ° C at a rate of 10 ° C / min, and the heat preservation time is 1 hour. After the heat preservation is completed, the high-temperature calcination tube furnace is cooled to room temperature at a rate of 10 ° C / min; Then pickling, i.e. preparing 3% hydrochloric acid solution as cleaning acid; the cleaning time is 30 minutes; The next step is to perform alkaline washing, that is, prepare sodium hydroxide with a mass concentration of 3% and sodium citrate with a mass concentration of 1% as a compound cleaning alkali solution, put the calcined ceramic membrane tube into the cleaning alkali solution, and use an aeration device to aerate the cleaning alkali solution at the same time. The alkaline washing time is 48 minutes.

[0055] After the alkaline cleaning is completed, physical cleaning is carried out, that is, softened water is used as the cleaning liquid, the outlet pressure of the cleaning circulation pump is 0.2~0.4 MPa, and the flow range of the circulation pump is 2~3 m3 / min, the surface of the ceramic membrane tube after alkali washing is cleaned at high speed, and the cycle cleaning time is 30min.

[0056] Through measurement, the pure water flux of the new ceramic membrane tube can reach 800 L / m 2 h, the pure water flux of the waste ceramic membrane tube is 10~30 L / m 2 h; After the waste ceramic membrane tube is successfully regenerated, the pure water flux of the regenerated ceramic membrane tube can reach 720 L / m 2 h, the pure water flux reaches more than 90% of the new ceramic membrane tube.

[0057] Eighth embodiment: A method for regenerating waste ceramic membrane tubes for mine water, specifically, firstly analyzing the pollutants on the surface of the ceramic membrane tubes by SEM and EDS, and then determining the method for treating the membrane tubes; First, high-temperature heating is performed, that is, the waste ceramic membrane tube is placed in a high-temperature calcination tube furnace. The waste ceramic membrane tube is 1178 mm long, the outer diameter is 25 mm, the inner diameter is 3.5 mm, and the high-temperature calcination tube furnace is 1400 mm long. The exhaust hole of the high-temperature calcination tube furnace is opened, and the temperature is raised to 100 ° C at a rate of 5 ° C / min through the temperature control device, and the temperature is kept for 30 minutes; then the temperature is raised to 500 ° C at a rate of 10 ° C / min, and the heat preservation time is 1 hour. After the heat preservation is completed, the high-temperature calcination tube furnace is cooled to room temperature at a rate of 10 ° C / min; Then pickling, i.e. preparing 3% hydrochloric acid solution as cleaning acid; the cleaning time is 30 minutes; The next step is to perform alkaline washing, that is, prepare sodium hydroxide with a mass concentration of 3% and sodium citrate with a mass concentration of 1% as a compound cleaning alkali solution, put the calcined ceramic membrane tube into the cleaning alkali solution, and use an aeration device to aerate the cleaning alkali solution at the same time. The alkaline washing time is 45 minutes.

[0058] After the alkaline cleaning is completed, physical cleaning is carried out, that is, softened water is used as the cleaning liquid, the outlet pressure of the cleaning circulation pump is 0.2~0.4 MPa, and the flow range of the circulation pump is 2~3 m 3 / min, the surface of the ceramic membrane tube after alkali washing is cleaned at high speed, and the cycle cleaning time is 40min.

[0059] Through measurement, the pure water flux of the new ceramic membrane tube can reach 800 L / m 2 h, the pure water flux of the waste ceramic membrane tube is 10~30 L / m 2 h; After the waste ceramic membrane tube is successfully regenerated, the pure water flux of the regenerated ceramic membrane tube can reach 715 L / m 2h, the pure water flux reaches more than 89.38% of the new ceramic membrane tube.

[0060] In summary, the experimental data are as follows Fig. 9 As shown: Through the above scheme, except for the second embodiment, the pure water flux of the regenerated ceramic membrane in other embodiments reaches 660 L / m 2 h, the recovery degree is more than 82.5%. The regenerated ceramic membrane can be reused, and the recovery degree is 80% compared with the new ceramic membrane tube, which can be called complete regeneration. The service life is more than 90% of the new ceramic membrane tube and can be put into use again.

[0061] At the same time Fig.10 As shown, under the same conditions, heating only, acid washing only, alkali washing only, physical washing only, acid washing + alkali washing, acid washing + alkali washing + physical washing and the regeneration method of the present invention were carried out. The first 6 groups were the reference groups, and a total of 7 groups of experiments were conducted. Fig.10 From the data shown, it can be seen that, except for the regeneration method in the present invention, the recovery degree of pure water flux of the waste ceramic membrane tubes after treatment by other cleaning methods is less than 70%, which is far less than the recovery degree of the regeneration method in the present invention.

[0062] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for regenerating waste ceramic membrane tubes for mine water, characterized in that: The following steps are involved: ① Surface analysis of waste ceramic membrane tubes; ② High temperature heating; ③ Pickling; ④Alkaline washing; ⑤Low pressure, large flow and high speed physical cleaning.

2. A method for regenerating waste ceramic membrane tubes for mine water according to claim 1, characterized in that: Step 1 specifically involves analyzing the contaminants on the surface of the ceramic membrane tube by means of SEM and EDS.

3. A method for regenerating waste ceramic membrane tubes for mine water according to claim 1, characterized in that: Step 2 specifically includes first placing the ceramic membrane tube into a tubular furnace, heating it to 100-110°C at a rate of 4-6°C / min, and keeping it warm for 25-35 minutes; then heating it to 490-510°C at a rate of 9-11°C / min, and keeping it warm for 1-1.2 hours.

4. A method for regenerating waste ceramic membrane tubes for mine water according to claim 1, characterized in that: Step 3 specifically uses 1-3% hydrochloric acid or citric acid solution for 26-34 minutes. After acid washing, softened water is added to rinse the ceramic membrane tube until it becomes neutral.

5. The method for regenerating waste ceramic membrane tubes for mine water according to claim 1, characterized in that: Step 4 specifically uses a compound cleaning alkali solution with a mass concentration of 1-3% sodium hydroxide or potassium hydroxide and 1% sodium citrate. After the ceramic membrane tube is cooled after high-temperature heating, it is placed in the cleaning alkali solution, and an aeration device is used to aerate the cleaning alkali solution. The alkali washing time is 42-48 minutes. After the alkali washing is completed, softened water is added to rinse the ceramic membrane tube until it is neutral.

6. A method for regenerating waste ceramic membrane tubes for mine water according to claim 1, characterized in that: Step 5 specifically uses softened water as the cleaning liquid, the outlet pressure of the cleaning circulation pump is 0.2~0.4 MPa, and the flow range of the circulation pump is 2~3 m 3 / min, the surface of the ceramic membrane tube after alkali washing or acid washing is cleaned at high speed, and the cycle cleaning time is 30~40min.

7. The method for regenerating waste ceramic membrane tubes for mine water according to claim 1, characterized in that: The method also includes step 6, when the outer surface or the tube end of the ceramic membrane tube is not clean, the ceramic membrane tube is cleaned by ultrasonic cavitation technology.

8. A method for regenerating waste ceramic membrane tubes for mine water according to claim 7, characterized in that: According to the actual contamination situation of the membrane tube and relevant test characteristics, the above steps 2-6 can be selectively used to adjust the regeneration steps of the target waste ceramic membrane tube.

9. A regeneration device for regenerating waste ceramic membrane tubes by using the regeneration method described in any one of claims 1 to 8, comprising a high-temperature calcination tube furnace, an acid washing device, an alkali washing device, and a cleaning circulation pump; characterized in that: The high-temperature calcining tubular furnace includes an air intake device, a heating device, and an exhaust device. The heating device is a furnace-type structure as a whole, and a furnace tube is arranged on the periphery. One end of the furnace tube is connected to the air intake device, and the other end of the furnace tube is connected to the exhaust device. A heating element is arranged on the heating device, and the heating device is respectively connected to the air intake device and the exhaust device. The air intake device is connected to the inside of the furnace tube, and the air intake device includes an air inlet, an air inlet valve and a pressure gauge, and the air inlet is arranged at one end of the air intake device. The exhaust device includes an exhaust port and an exhaust valve, and the exhaust port is arranged at the other end of the furnace tube. An insulation layer is arranged on the top of the heating device, and a handle is arranged on the insulation layer. An automatic control display screen, an indicator light and a manual switch are arranged at the bottom of the heating device.

10. The regeneration device according to claim 9, characterized in that: The alkali washing device comprises a sewage collecting tank, an alkali washer, an alkali washing water tank and an aeration fan; a sludge discharge bucket is arranged below the alkali washer, the sludge discharge bucket is connected to the sewage collecting tank through a pipeline, and a sewage pump is arranged on the pipeline; an alkali washing liquid inlet is arranged above the alkali washer, the alkali washing water tank is connected to the alkali washing liquid inlet through a pipeline, and an alkali washing pump is arranged on the pipeline; an aeration plate is arranged inside the alkali washer, and the aeration plate is connected to an external aeration fan through an air pipe.

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