A resin dewatering method and dewatering device

Abstract

The present invention provides a resin dehydration method and device. The dehydration method comprises: (1) heating the organic solvent raw material in the organic solvent raw material tank to form organic solvent hot steam; (2) the organic solvent hot steam rises to the resin storage chamber containing the resin, part of the organic solvent hot steam condenses after contacting the resin and performs rinsing exchange with the resin, and the other organic solvent hot steam continues to rise to the condensation unit to form condensate; (3) part of the condensate flows back into the resin storage chamber, flows into the organic solvent raw material tank after contacting the resin; at the same time, part of the condensate flows out of the condensation unit and is collected in a sealed container. The resin dehydration method provided by the present invention can effectively remove moisture from the resin while using a small amount of organic solvent, reduce the consumption of the organic solvent on the resin, and avoid the phenomenon of cracking and structural damage caused by the resin being separated from the liquid infiltration during the dehydration process.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor manufacturing, and in particular relates to a resin dehydration method and a dehydration device. Background Art

[0002] Many high-purity organic solvents are often used in industries such as semiconductors, which require the metal ion content in the organic solvent to reach the ppb or ppt level. In general, resins are used to treat organic solvents to adsorb and remove metal elements in organic solvents. Resins are widely used in industrial production to separate and purify impurities in liquids, such as ion exchange resins and chelating resins. After production, these resins will first be pretreated with acid-base aqueous solutions, and the subsequent regeneration treatment is carried out in aqueous solutions. After treatment, they are generally stored in a water-wet form. In order to meet purity requirements, organic solvents need to have an extremely low water content. When wet resins are used directly to treat organic solvents, a small amount of water will be introduced into them, resulting in unqualified products. Therefore, the resins need to be dehydrated in advance.

[0003] Currently, there are generally two methods for removing water from resins. One is direct drying treatment: drying the resin with air flow at medium to high temperatures. Although this method can achieve the purpose of removing water, the loss of water will cause cracks on the resin surface, damage the resin structure, and affect the performance and life of the resin; the other method is to use the target solvent for direct rinsing, and use a large amount of flowing target solvent to flush the resin to remove the moisture in it. The disadvantage of this method is that the solvent consumption is large, and during the rinsing process, a large amount of ions in the rinsing solvent are exchanged with the resin, which reduces the ion exchange performance of the resin in subsequent formal production. Summary of the invention

[0004] Based on this, the object of the present invention is to provide a resin dehydration method, which can effectively remove moisture from the resin using a small amount of organic solvent, and can avoid the resin from being separated from liquid infiltration during the dehydration process, resulting in cracking and structural damage.

[0005] To achieve the above object, the present invention adopts the following technical solution.

[0006] A resin dehydration method is performed under negative pressure conditions and comprises the following steps: (1) heating an organic solvent raw material in an organic solvent raw material tank to form organic solvent hot steam; (2) the organic solvent hot steam rises from the organic solvent raw material tank to a resin storage chamber containing resin, part of the organic solvent hot steam condenses after contacting the resin and performs rinsing exchange with the resin, and the rest of the organic solvent hot steam continues to rise to a condensation unit above the resin storage chamber to form condensate; (3) part of the condensate flows back into the resin storage chamber, contacts the resin and flows into the organic solvent raw material tank; at the same time, part of the condensate flows out of the condensation unit and is collected in a sealed container.

[0007] In some embodiments, the boiling point of the organic solvent raw material is 120-250°C; preferably, the organic solvent is selected from N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, γ-butyrolactone, cyclohexanone, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, diethylene glycol monobutyl ether, ethylene glycol isopropyl ether, ethylene glycol, and dimethyl sulfoxide.

[0008] In some embodiments, the temperature at which the organic solvent raw material in the organic solvent raw material tank is heated in step (1) is 30 to 100° C.; and / or, the temperature in the condensing unit in step (2) is controlled to be -10 to 20° C.

[0009] In some preferred embodiments, the temperature at which the organic solvent raw material in the organic solvent raw material tank is heated in step (1) is 30-80°C.

[0010] In some preferred embodiments, in step (2), the temperature in the condensing unit is controlled to be -10 to 15°C.

[0011] In some embodiments, the organic solvent raw material is stirred while being heated in step (1); preferably, the stirring speed is 100 to 1200 rpm; more preferably, the stirring speed is 300 to 1000 rpm.

[0012] In some embodiments, the negative pressure is 0-0.1 MPa.

[0013] In some embodiments, a distributor is provided in the condensation unit, and the volume ratio of the condensate flowing out in the step (3) to the condensate flowing back is controlled by the distributor to be n, and the value range of n is: 0<n≤0.5.

[0014] In some embodiments, the water removal method further comprises the following steps: (4) detecting the moisture content of the outflowing condensate, and stopping heating when the moisture content reaches a target value;

[0015] The target value is less than or equal to 1 / 2 of the resin moisture content control value.

[0016] In some embodiments, in step (4), the water content of the condensate flowing out after 1 to 4 hours is detected.

[0017] In some embodiments, the resin is an ion exchange resin or a chelating resin.

[0018] The present invention also provides a resin dehydration device, which includes an organic solvent raw material tank, a resin storage chamber and a condensation unit; a heater is arranged inside the organic solvent raw material tank; a filter is arranged at the lower end of the resin storage chamber; a condensate outlet is arranged on the condensation unit, a condenser is arranged inside, and a reflux liquid outlet is arranged below; the condensation unit is connected with the resin storage chamber through the reflux liquid outlet; the organic solvent raw material tank is connected with the resin storage chamber.

[0019] In some embodiments, a stirrer is provided inside the organic solvent raw material tank; and / or,

[0020] The condensing unit is provided with a nitrogen inlet and a vacuum pumping port; and / or,

[0021] The resin storage chamber is detachably connected to the organic solvent raw material tank; preferably, the detachable connection is a threaded connection, a snap connection or a hinge connection; and / or,

[0022] The resin storage chamber is detachably connected to the condensing unit; preferably, the detachable connection is a threaded connection, a snap connection or a hinge connection.

[0023] In some embodiments, the organic solvent raw material tank is provided with an injection port.

[0024] In some embodiments, a distributor is provided in the condensing unit, and the distributor can control the volume ratio of the condensate flowing out and the condensate flowing back in step (3).

[0025] The present invention provides a resin dehydration method, which includes heating an organic solvent in an organic solvent raw material tank, so that when the formed hot steam rises to the surface of the wet resin, it is partially condensed and exchanged with the resin rinse; the hot steam that continues to rise reaches the condensation unit to form a condensate, and part of the condensate reflux liquid is poured into the resin to maintain the wet state of the resin, and at the same time, part of the condensate flows out of the condensation unit to take away the moisture in the resin. The rising hot steam and reflux liquid can prevent the resin from being separated from the liquid infiltration, thereby avoiding the occurrence of resin cracking and structural damage. In the dehydration process, the rinse liquid in contact with the resin is a distillate. Compared with direct rinse with an organic solvent raw material, the ion content that the resin contacts is greatly reduced, avoiding the exchange of a large amount of ions in the rinse solvent with the resin during the rinse process, and reducing the consumption of resin exchange. In addition, the dehydration method is operated under negative pressure conditions. Under negative pressure, the resin expands to a certain extent. At this time, the reflux infiltration of the condensed refluxed organic solvent can take away organic impurities (such as uncrosslinked monomers, etc.) inside the resin pores, which has the effect of cleaning the resin, and avoiding the dissolution of impurities in the resin during subsequent use and contaminating the purified target solvent. In addition, by monitoring the moisture content in the outflowing condensate, the resin dehydration effect can be effectively controlled to ensure that the moisture content in the resin meets the control requirements.

[0026] The dehydration method of the present invention has loose requirements on the quality of the organic solvent raw material used. Even if there is more water in the organic solvent raw material, water can be removed by the principle of distillation during the dehydration process, so low-grade organic solvent can be used as the pretreatment raw material. In addition, the organic solvent in the raw material tank is continuously refluxed during the dehydration process and can be reused. Compared with conventional rinsing, the amount of organic solvent used is saved; at the same time, the organic solvent does not need to be discharged, reducing environmental problems such as organic discharge, which is economical and environmentally friendly.

[0027] The present invention also provides a dehydration device suitable for the dehydration method, which comprises an organic solvent raw material tank, a resin storage chamber and a condensation unit. The dehydration device is simple to operate and highly efficient for dehydrating resin. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of the dewatering method of the present invention; wherein, 1-organic solvent raw material tank; 2-resin storage chamber; 3-condensation unit; 33-control valve; 34-condensate outlet; 36-reflux liquid outlet; Represents the flow direction of hot vapor of organic solution; Represents the flow direction of the condensate.

[0029] Figure 2This is a schematic diagram of the structure of a resin dehydration device used in a specific embodiment of the present invention; wherein, 1-organic solvent raw material tank; 2-resin storage chamber; 3-condensation unit; 11-inlet; 12-heater; 13-agitator; 21-filter; 31-nitrogen inlet; 32-vacuum exhaust port; 33-control valve; 34-condensate outlet; 35-condenser; 36-reflux liquid outlet.

[0030] Figure 3 This is a result diagram of the surface properties of the ion exchange resin after rinsing and dehydration under a scanning electron microscope (SEM) in Example 1.

[0031] Figure 4 This is a result diagram of the surface properties of the ion exchange resin after rinsing and dehydration in Comparative Example 1, observed using a scanning electron microscope. DETAILED DESCRIPTION

[0032] The experimental methods in the following examples of the present invention, where no specific conditions are specified, are usually carried out under conventional conditions or under conditions recommended by the manufacturers. The various commonly used chemical reagents used in the examples are all commercially available products.

[0033] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0034] The terms "including" and "having" and any variations thereof of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, device, product or equipment comprising a series of steps is not limited to the listed steps or modules, but may optionally include steps not listed, or may optionally include other steps inherent to these processes, methods, products or equipment.

[0035] The present embodiment provides a resin dehydration method, which is performed under negative pressure conditions and includes the following steps: (1) heating the organic solvent raw material in the organic solvent raw material tank to form organic solvent hot steam; (2) the organic solvent hot steam rises from the organic solvent raw material tank to the resin storage chamber containing the resin, and part of the organic solvent hot steam condenses after contacting the resin and performs rinsing exchange with the resin, while the other organic solvent hot steam continues to rise to the condensation unit above the resin storage chamber to form condensate; (3) part of the condensate flows back into the resin storage chamber, contacts the resin and flows into the organic solvent raw material tank; at the same time, part of the condensate flows out of the condensation unit and is collected in a sealed container. The schematic diagram of the principle of the dehydration method is shown in the figure. Figure 1 shown.

[0036] In the dehydration method, after condensate is formed in the condensation unit, part of the condensate is controlled to flow out. On the one hand, this is because the condensate will take away water while flowing out. As the amount of condensate flowing out increases, the water content in the subsequent condensate will become less and less. On the other hand, it is convenient to collect the outflowing condensate at any time and monitor its water content, so as to achieve effective control of the resin dehydration effect and ensure that the water content in the resin meets the control requirements.

[0037] Another embodiment of the present invention provides a resin dehydration device, which includes an organic solvent raw material tank, a resin storage chamber and a condensation unit; a heater is provided inside the organic solvent raw material tank; a filter is provided at the lower end of the resin storage chamber; a condensate outlet is provided on the condensation unit, a condenser is provided inside, and a reflux liquid outlet is provided below; the condensation unit is connected to the resin storage chamber through the reflux liquid outlet; the organic solvent raw material tank is connected to the resin storage chamber.

[0038] In some embodiments, an agitator is provided inside the organic solvent raw material tank; a nitrogen inlet and a vacuum pumping port are provided on the condensation unit; and a distributor is provided in the condensation unit, and the distributor can control the volume ratio of the condensate flowing out in step (3) to the condensate flowing back.

[0039] Another embodiment of the present invention provides a resin dehydration method, which uses the above-mentioned resin dehydration device to dehydrate, and the resin dehydration method includes the following steps: (1) first loading the resin to be dehydrated into the resin storage chamber, and adding the organic solvent raw material into the organic solvent raw material tank, and then connecting the two ends of the resin storage chamber to the organic solvent raw material tank and the condensation unit respectively; (2) closing the control valve of the condensate outlet, and depressurizing the dehydration device through the nitrogen inlet and the vacuum pumping port; (3) turning on the heater and the agitator, and turning on the condenser at the same time; (4) when the condensate is formed, opening the condensate outlet; part of the condensate flows back into the resin storage chamber, and flows into the organic solvent raw material tank after contacting the resin; at the same time, part of the condensate flows out of the condensation unit and is collected in a sealed container.

[0040] In some preferred embodiments, the resin dehydration method further comprises the following steps: (5) detecting the moisture content of the outflowing condensate, and stopping heating when the moisture content reaches a target value.

[0041] In some more preferred embodiments, the resin dehydration method comprises the following steps: (5) detecting the moisture content of the condensate flowing out after 1 to 4 hours, and stopping heating when the moisture content reaches the target value.

[0042] Specifically, the resin dehydration method comprises the following steps: (1) firstly loading the resin to be dehydrated into a resin storage chamber, and adding the target organic solvent into an organic solvent raw material tank, and then connecting the two ends of the resin storage chamber to the organic solvent raw material tank and the condensation unit respectively; (2) extracting the gas in the device through a vacuum exhaust port, and then introducing nitrogen into the dehydration device through a nitrogen inlet, and then exhausting the gas through a vacuum exhaust port, and repeating the operation for 2 to 3 times, and finally closing the condensate outlet, and decompressing the dehydration device through the vacuum exhaust port to make the pressure in the device 0 to 0.1 MPa; (3) turning on the agitator to start stirring, and at the same time turning on the heater and condenser and adjusting them to a suitable temperature; (4) when the condensate is formed, opening the condensate outlet; part of the condensate flows back into the resin storage chamber, and after contacting with the resin, flows into the organic solvent raw material tank; at the same time, part of the condensate flows out of the condensation unit and is collected in a sealed container; (5) detecting the moisture content of the condensate flowing out after 1 to 4 hours, and stopping heating when the moisture content reaches the target value.

[0043] The dewatering method and dewatering device of the present invention can be applied to the dewatering of various resins, including but not limited to ion exchange resins and chelating resins.

[0044] The following describes the invention in conjunction with specific embodiments.

[0045] In the following embodiments, the structure of the water removal device used in the water removal method is as follows: Figure 2 As shown: the dehydration device includes an organic solvent raw material tank 1, a resin storage chamber 2 and a condensation unit 3; the organic solvent raw material tank 1 is provided with an injection port 11, and a heater 12 and an agitator 13 are arranged inside; a filter screen 21 is arranged at the lower end of the resin storage chamber 2, and the pore size of the filter screen 21 is smaller than the particle size of the resin to be dehydrated, which can prevent the resin in the resin storage chamber 2 from falling into the organic solvent raw material tank 1, and the hot steam generated in the organic solvent raw material tank 1 can enter the resin storage chamber 2 through the filter screen 21; a nitrogen inlet 31 and a vacuum suction port 32 are arranged above the condensation unit 3, a condensate outlet 34 with a control valve 33 is arranged on the side, a condenser 35 is arranged inside, and a reflux liquid outlet 36 is arranged below; the condensation unit 3 is connected with the resin storage chamber 2 through the reflux liquid outlet 36; the organic solvent raw material tank 1 is connected with the resin storage chamber 2.

[0046] Example 1

[0047] This embodiment provides a resin dehydration method, which specifically includes the following steps:

[0048] Fill the resin storage chamber 2 with 500ml of ion exchange resin, and then connect the two ends of the resin storage chamber 2 to the organic solvent raw material tank 1 and the condensation unit 3 respectively to form a dewatering device; first fill 2L of N-methylpyrrolidone (water content 100ppm) into the organic solvent raw material tank 1 from the injection port 11, then extract the gas in the device through the vacuum exhaust port 32, then introduce nitrogen into the dewatering device through the nitrogen inlet 31, and then exhaust gas through the vacuum exhaust port 32, and repeat this operation 2-3 times; close the control valve 33 of the condensate outlet 34, and decompress the dewatering device through the vacuum exhaust port 32 until the pressure in the device is 0.01MPa, turn on the agitator 13, control the speed to 600rpm, and turn on the heater 12 (heated to 60℃) and the condenser 35 (temperature set to 0℃) at the same time. When the hot steam formed in the organic solvent raw material tank 1 rises to the surface of the wet resin through the filter screen 21, it is partially condensed and exchanged with the resin rinse; the hot steam that continues to rise reaches the condensation unit 3. When condensate begins to form in the condensation unit 3, the control valve 33 of the condensate outlet 34 is opened. After the condensate is formed, part of the condensate is poured into the resin through the reflux outlet 36 to keep the resin wet; at the same time, part of the condensate flows out of the condensation unit 3 through the condensate outlet 34; the condensate flowing out is controlled by the distributor in the condensation unit 3: the reflux condensate = 0.2 (volume ratio). The moisture value of the condensate flowing out after 1 hour is detected. When the moisture value is less than or equal to 250ppm, the heating is stopped, and nitrogen is filled in to remove the ion exchange resin.

[0049] After rinsing and dehydrating, take 200ml of the ion exchange resin and place it in the ion exchange column. Pass 2L of raw material N-methylpyrrolidone (water content 100ppm) through the column for exchange. Test the water content of the product to verify the dehydration effect (water content control value: ≤500ppm). Take another small amount of the ion exchange resin after rinsing and dehydrating, blow off the surface solvent, and observe the surface properties by scanning electron microscopy.

[0050] Example 2

[0051] This embodiment provides a resin dehydration method, which specifically includes the following steps:

[0052] Fill the resin storage chamber 2 with 500ml of ion exchange resin, and then connect the two ends of the resin storage chamber 2 to the organic solvent raw material tank 1 and the condensation unit 3 respectively to form a dewatering device; first fill 2L of propylene glycol methyl ether acetate (water content 180ppm) into the organic solvent raw material tank 1 from the injection port 11, then extract the gas in the device through the vacuum exhaust port 32, then introduce nitrogen into the dewatering device through the nitrogen inlet 31, and then exhaust through the vacuum exhaust port 32, and repeat the operation 2-3 times; close the control valve 33 of the condensate outlet 34, and decompress the dewatering device through the vacuum exhaust port 32 until the pressure in the device is 0.05MPa, turn on the agitator 13, control the speed to 600rpm, and turn on the heater 12 (heated to 40℃) and the condenser 35 (temperature set to -10℃) at the same time. When the hot steam formed in the organic solvent raw material tank 1 rises to the surface of the wet resin through the filter screen 21, it is partially condensed and exchanged with the resin rinse; the hot steam that continues to rise reaches the condensation unit 3. When condensate begins to form in the condensation unit 3, the control valve 33 of the condensate outlet 34 is opened. After the condensate is formed, part of the condensate is poured into the resin through the reflux outlet 36 to keep the resin wet; at the same time, part of the condensate flows out of the condensation unit 3 through the condensate outlet 34; the condensate flowing out is controlled by the distributor in the condensation unit 3: the reflux condensate = 0.4 (volume ratio). The moisture value of the condensate flowing out after 3 hours is detected. When the moisture value is less than or equal to 250ppm, the heating is stopped, and nitrogen is filled in to remove the ion exchange resin.

[0053] After rinsing and dehydrating, take 200 ml of the ion exchange resin and place it in the ion exchange column. Pass 2L of raw material propylene glycol methyl ether acetate (water content 180ppm) through the column for exchange. Test the water content of the product to verify the infiltration and dehydration effect (water content control value: ≤500ppm).

[0054] Example 3

[0055] This embodiment provides a resin dehydration method, which specifically includes the following steps:

[0056] Fill the resin storage chamber 2 with 500ml of ion exchange resin, and then connect the two ends of the resin storage chamber 2 to the organic solvent raw material tank 1 and the condensation unit 3 respectively to form a dewatering device; first fill the organic solvent raw material tank 1 with 2L of γ-butyrolactone (water content 100ppm) from the injection port 11, then extract the gas in the device through the vacuum exhaust port 32, then introduce nitrogen into the dewatering device through the nitrogen inlet 31, and then exhaust the gas through the vacuum exhaust port 32, and repeat this operation 2-3 times; close the control valve 33 of the condensate outlet 34, and decompress the dewatering device through the vacuum exhaust port 32 until the pressure in the device is 0.1MPa, turn on the agitator 13, control the speed to 600rpm, and turn on the heater 12 (heated to 80℃) and the condenser 35 (temperature set to 10℃) at the same time. When the hot steam formed in the organic solvent raw material tank 1 rises to the surface of the wet resin through the filter 21, it is partially condensed and exchanged with the resin rinse; the hot steam that continues to rise reaches the condensation unit 3. When condensate begins to form in the condensation unit 3, the control valve 33 of the condensate outlet 34 is opened. After the condensate is formed, part of the condensate pours into the resin through the reflux outlet 36 to keep the resin wet; at the same time, part of the condensate flows out of the condensation unit 3 through the condensate outlet 34; the condensate flowing out is controlled by the distributor in the condensation unit 3: the reflux condensate = 0.5 (volume ratio). The moisture value of the condensate flowing out after 2.5 hours is detected. When the moisture value is less than or equal to 100ppm, the heating is stopped, and nitrogen is filled in to remove the ion exchange resin.

[0057] After rinsing and dehydrating, 200 ml of the ion exchange resin is placed in an ion exchange column, and 2 L of raw material γ-butyrolactone (water content 100 ppm) is passed through the column for exchange. The water content of the product is tested to verify the infiltration and dehydration effect (water content control value: ≤200 ppm).

[0058] Example 4

[0059] This embodiment provides a resin dehydration method, which specifically includes the following steps:

[0060] Fill chelating resin 500ml in resin storage chamber 2, then resin storage chamber 2 is connected with organic solvent raw material tank 1 and condensation unit 3 respectively, form dewatering device; First, fill technical grade N-Methylpyrrolidone 2L (water content 1700ppm) into organic solvent raw material tank 1 from injection port 11, then extract the gas in the device through vacuum pumping port 32, then pass nitrogen into dewatering device through nitrogen inlet 31, then exhaust through vacuum pumping port 32, so cycle 2-3 times operation; Close the control valve 33 of condensate outlet 34, decompress the dewatering device through vacuum pumping port 32, decompress to the pressure in the device is 0MPa, turn on agitator 13, speed control is 600rpm, turn on heater 12 (heated to 90 ℃) and condenser 35 (temperature is set to 20 ℃) ​​simultaneously. When the hot steam formed in organic solvent raw material tank 1 rises to the wet resin surface through filter screen 21, part condensation is exchanged with resin rinse; The hot steam that continues to rise arrives condensation unit 3. When condensate begins to form in the condensation unit 3, the control valve 33 of the condensate outlet 34 is opened. After the condensate is formed, part of the condensate pours into the resin through the reflux outlet 36 to keep the resin wet; at the same time, part of the condensate flows out of the condensation unit 3 through the condensate outlet 34; the condensate flowing out is controlled by the distributor in the condensation unit 3: the reflux condensate = 0.2 (volume ratio). The moisture value of the condensate flowing out after 4 hours is detected. When the moisture value is less than or equal to 250ppm, the heating is stopped, and nitrogen is filled in to remove the ion exchange resin.

[0061] After rinsing and dehydrating, take 200 ml of the chelating resin and place it in an ion exchange column. Pass 2L of raw material N-methylpyrrolidone (water content 100ppm) through the column for exchange. Test the water content of the product to verify the infiltration and dehydration effect (water content control value: ≤500ppm).

[0062] Comparative Example 1

[0063] This comparative example provides a resin dehydration method, which specifically comprises the following steps:

[0064] Take 200ml of ion exchange resin and spread it in a glass culture dish, put it in an oven, dry it at 50℃ for 4h, take 200ml of the dried ion exchange resin and put it in an ion exchange column, exchange it with 2L of raw material N-methylpyrrolidone (water content 100ppm) through the column, test the water content of the product to verify the infiltration and water removal effect (water content index: ≤500ppm). Take a small amount of dried resin and observe the surface properties by scanning electron microscopy.

[0065] Comparative Example 2

[0066] This comparative example provides a resin dehydration method, which specifically comprises the following steps:

[0067] The ion exchange column was filled with 500 ml of ion exchange resin, and 5 L of raw material N-methylpyrrolidone (water content 100 ppm) was passed through the ion exchange column for water rinsing. 200 ml of the rinsed ion exchange resin was placed in the ion exchange column, and 2 L of raw material N-methylpyrrolidone (water content 100 ppm) was passed through the column for exchange. The water content of the product was tested to verify the rinsing and water removal effect (water content index: ≤500 ppm).

[0068] Comparative Example 3

[0069] This comparative example provides a resin dehydration method, which specifically comprises the following steps:

[0070] 500 ml of ion exchange resin was placed in a container, and 5 L of raw material N-methylpyrrolidone (water content 100 ppm) was poured into the container to seal and soak the resin for rinsing. The soaking time was 1 day. 200 ml of the rinsed ion exchange resin was placed in an ion exchange column, and 2 L of raw material N-methylpyrrolidone (water content 100 ppm) was passed through the column for exchange. The moisture content of the product was tested to verify the infiltration and water removal effect (moisture content index: ≤500 ppm).

[0071] The test results of the water removal effects of the above embodiments and comparative examples are shown in Table 1:

[0072] Table 1

[0073]

[0074]

[0075] The above results show that the dewatering method of the present invention (Examples 1 to 4) can meet the corresponding rinsing and dewatering requirements, the consumption of organic solvent raw materials for rinsing pretreatment is not large, and the quality requirements of the organic solvent raw materials used are loose. For example, the raw material used in the dewatering method of Example 4 is 2L of industrial-grade N-methylpyrrolidone, and its water content is 1700ppm, but it can also meet the rinsing and dewatering requirements for the resin. In addition, the dewatering method of the present invention can avoid the occurrence of structural damage such as drying, cracking, and breakage after the resin is rinsed and dewatered. Take the surface properties of the resin after the dewatering treatment of Example 1 as an example ( Figure 3 ). Comparative Example 1 directly uses drying to remove water without consuming the treatment liquid. Although it can meet the corresponding rinse and water removal requirements, the resin surface is damaged and rough, causing certain damage to the resin structure ( Figure 4 ). The dehydration methods of Comparative Examples 2 and 3 not only consume a large amount of organic solvent raw materials, but also fail to meet the corresponding index requirements for rinsing.

[0076] In summary, the dewatering method of the present invention can effectively remove moisture from the resin while using a small amount of organic solvent, can meet the corresponding rinsing and dewatering requirements, and can avoid the phenomenon of cracking and structural damage caused by the resin being separated from the liquid infiltration during the dewatering process.

[0077] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0078] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A resin dewatering method, characterized in that: The dewatering method is carried out under negative pressure conditions and comprises the following steps: (1) heating the organic solvent raw material in the organic solvent raw material tank to form organic solvent hot steam; (2) the organic solvent hot steam rises from the organic solvent raw material tank to the resin storage chamber containing the resin, part of the organic solvent hot steam condenses after contacting the resin and performs rinsing exchange with the resin, and the rest of the organic solvent hot steam continues to rise to the condensation unit above the resin storage chamber to form condensate; (3) part of the condensate flows back into the resin storage chamber, contacts the resin and flows into the organic solvent raw material tank; at the same time, part of the condensate flows out of the condensation unit and is collected in a sealed container; the boiling point of the organic solvent raw material is 120-250°C; the temperature at which the organic solvent raw material in the organic solvent raw material tank is heated in step (1) is 30-100°C; the negative pressure is 0-0.1MPa.

2. The resin dehydration method according to claim 1, characterized in that: The organic solvent is selected from N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, γ-butyrolactone, cyclohexanone, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, diethylene glycol monobutyl ether, ethylene glycol isopropyl ether, ethylene glycol, and dimethyl sulfoxide.

3. The resin dewatering method according to claim 1, characterized in that: In the step (2), the temperature in the condensing unit is controlled to be -10~20°C.

4. The resin dewatering method according to claim 1, characterized in that: In the step (1), the organic solvent raw material is heated and stirred at the same time.

5. The resin dewatering method according to claim 4, characterized in that: The stirring speed is 100-1200 rpm.

6. The resin dewatering method according to claim 1, characterized in that: The condensing unit is provided with a distributor, and the volume ratio of the condensate flowing out and the condensate flowing back in the step (3) is controlled by the distributor to be n, and the value range of n is: 0<n≤0.

5.

7. The resin dewatering method according to claim 1, characterized in that: The dewatering method further comprises the following steps: (4) detecting the moisture content of the outflowing condensate, and stopping heating when the moisture content reaches a target value; The target value is less than or equal to 1 / 2 of the resin moisture content control value.

8. The resin dewatering method according to claim 7, characterized in that: In the step (4), the moisture content of the condensate flowing out after 1 to 4 hours is detected.

9. The resin dewatering method according to any one of claims 1 to 8, characterized in that: The resin is an ion exchange resin or a chelating resin.

10. The resin dewatering method according to claim 1, characterized in that: The method uses a resin dehydration device, which includes an organic solvent raw material tank, a resin storage chamber and a condensation unit; a heater is arranged inside the organic solvent raw material tank; a filter is arranged at the lower end of the resin storage chamber; a condensate outlet is arranged on the condensation unit, a condenser is arranged inside, and a reflux liquid outlet is arranged below; the condensation unit is connected with the resin storage chamber through the reflux liquid outlet; the organic solvent raw material tank is connected with the resin storage chamber.

11. The resin dewatering method according to claim 10, characterized in that: A stirrer is provided inside the organic solvent raw material tank; The condensing unit is provided with a nitrogen inlet and a vacuum pumping port; The resin storage chamber is detachably connected to the organic solvent raw material tank; The resin storage chamber is detachably connected to the condensing unit.

12. The resin dewatering method according to claim 11, characterized in that: The detachable connection is a threaded connection, a snap connection or a hinge connection.

Images