A polarizing plate recycling system

Abstract

The utility model relates to a kind of polaroid recycling system, including alcoholysis reaction unit, solid-liquid separation unit, acidification oxidation reaction unit, extraction unit and separation unit, alcoholysis reaction unit is connected with solid-liquid separation unit, and the liquid phase export of solid-liquid separation unit is connected with acidification oxidation reaction unit, acidification oxidation reaction unit is connected with extraction unit, and the extraction phase of extraction unit is connected with separation unit. Polaroid is depolymerized by alcoholysis reaction unit, iodine ion is converted into iodine element by acidification oxidation reaction unit, and extraction and separation purification are carried out to iodine element by extraction unit and separation unit, and the whole recycling system reaction is mild, non-toxic byproduct, which realizes the recycling of iodine resources, improves economic benefits, and reduces environmental pollution.

Description

Technical Field

[0001] This utility model relates to the field of resource recycling and processing technology, and in particular to a polarizer recycling and processing system. Background Technology

[0002] With the widespread use of consumer electronics such as LCD monitors and large-screen TVs, a large amount of waste polarizing film is generated every year. This type of waste not only contains a large amount of high molecular polymers, such as cellulose triacetate and polyvinyl alcohol, but also contains a high-value-added element—iodine.

[0003] As a strategically scarce resource, the global annual production of iodine is approximately 30,000 tons, mainly concentrated in regions such as Chile and Japan. China, as the world's largest producer of LCD panels, generates over 100,000 tons of waste polarizer film annually. However, current methods for processing polarizer film, including pyrolysis, incineration, physical crushing, and chemical dissolution, cannot achieve efficient and green recycling of iodine, resulting in both economic losses and exacerbating environmental pollution.

[0004] Based on the above-mentioned technical problems, this application proposes a polarizer recycling and processing system. Utility Model Content

[0005] The purpose of this invention is to provide a polarizer recycling system to solve the technical problems mentioned in the background art. This purpose is achieved through the following technical solution: A polarizer recycling system includes an alcoholysis reaction unit, a solid-liquid separation unit, an acidification and oxidation reaction unit, an extraction unit, and a separation unit. The alcoholysis reaction unit is connected to the solid-liquid separation unit, the liquid phase outlet of the solid-liquid separation unit is connected to the acidification and oxidation reaction unit, the acidification and oxidation reaction unit is connected to the extraction unit, and the extract phase of the extraction unit is connected to the separation unit.

[0006] Furthermore, the alcoholysis reaction unit includes an alcoholysis reaction vessel, with a feed inlet at the top and a discharge outlet at the bottom. A temperature control jacket is installed on the outside of the alcoholysis reaction vessel, and a stirring mechanism, a temperature sensor, and a pressure sensor are installed inside the alcoholysis reaction vessel.

[0007] Furthermore, the solid-liquid separation unit is a continuous belt filter or a centrifugal separator.

[0008] Furthermore, the acidification and oxidation reaction unit includes an acidification and oxidation reaction vessel, with an inlet at the top and an outlet at the bottom. A temperature control jacket is installed on the outside of the acidification and oxidation reaction vessel, and a stirring mechanism, a temperature sensor, a pressure sensor, and a pH sensor are installed inside the acidification and oxidation reaction vessel.

[0009] Furthermore, an observation window is provided on the acidification and oxidation reaction vessel.

[0010] Furthermore, the extraction unit includes an extraction tower, the top of which has an extractant inlet and a raffinate outlet, the raffinate outlet being higher than the extractant inlet, the bottom of which has a mixed liquid inlet and an extractant outlet, the extractant outlet being lower than the mixed liquid inlet, and a stirring mechanism is provided inside the extraction tower.

[0011] Furthermore, the separation unit includes a distillation column, the bottom of which is equipped with a heating mechanism, a temperature sensor, and a pressure sensor, and the top of which is provided with an exhaust port and a condenser.

[0012] Furthermore, the front end of the alcoholysis reaction unit also includes a pretreatment unit, which includes a crusher and a dryer.

[0013] The technical solutions provided in this application have at least the following technical effects or advantages: The polarizer is depolymerized through an alcoholysis reaction unit, iodide ions are converted into elemental iodine through an acidification and oxidation reaction unit, and the elemental iodine is extracted and purified through an extraction and separation unit. The entire recovery system is mild and produces no toxic byproducts, which not only realizes the recycling of iodine resources and improves economic benefits, but also reduces environmental pollution. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the polarizer recycling system according to an embodiment of this application.

[0016] Attached reference numerals: 1. Crusher; 2. Dryer; 3. Alcohololysis reaction unit; 4. Solid-liquid separation unit; 5. Acidification and oxidation reaction unit; 6. Extraction unit; 7. Separation unit; 8. Condenser. Detailed Implementation

[0017] To further illustrate the technical means and effects adopted by this utility model in order to achieve the intended utility model purpose, the following detailed description of the specific implementation methods, structure, features and effects of this utility model is provided in conjunction with the accompanying drawings and preferred embodiments.

[0018] like Figure 1The illustrated polarizer recycling system includes a crusher 1, a dryer 2, an alcoholysis reaction unit 3, a solid-liquid separation unit 4, an acidification and oxidation reaction unit 5, an extraction unit 6, and a separation unit 7. The crusher 1 processes waste polarizer film into fragments with a particle size of 2-5 mm. The dryer 2 dries and dehydrates the crushed polarizer film fragments. Crushing and drying the waste polarizer film improves the efficiency of the subsequent alcoholysis reaction.

[0019] The alcoholysis reaction unit 3 includes an alcoholysis reaction vessel, which is made of stainless steel. The top of the vessel has an inlet for adding dried polarizer fragments and the alcoholysis reaction solvent. The bottom of the vessel has an outlet for discharging the solid-liquid mixture after the alcoholysis reaction. This mixture is then sent to a solid-liquid separation unit 4 for solid-liquid separation. The solid-liquid separation unit 4 is either a continuous belt filter or a centrifuge.

[0020] The alcoholysis reactor is equipped with a temperature control jacket on its exterior. This jacket is used to heat the materials inside the reactor. Inside the reactor are a stirring mechanism, temperature sensors, and pressure sensors. The stirring mechanism agitates the materials to improve the efficiency of the alcoholysis reaction. The temperature and pressure sensors monitor the reaction temperature and pressure to ensure the safe and stable operation of the alcoholysis reaction.

[0021] During production, dried polarizing film fragments and an ethylene glycol-water mixture are fed into the alcoholysis reactor through the inlet. The mass ratio of polarizing film:ethylene glycol:water is 1:5:10. The materials are heated to 80±2℃ and reacted under atmospheric pressure and stirring for 2.5~3 hours. Under the synergistic effect of ethylene glycol and water, the polyvinyl alcohol base in the polarizing film hydrolyzes, releasing iodide ions into the solution, and cellulose triacetate precipitates out. The solid-liquid separation unit 4 separates the solid-liquid mixture after the alcoholysis reaction to obtain a liquid phase containing iodide ions and a solid phase containing cellulose triacetate.

[0022] The acidification and oxidation reaction unit 5 includes an acidification and oxidation reaction vessel, which is made of stainless steel. The top of the vessel has an inlet for adding the liquid phase after solid-liquid separation, sulfuric acid, and hydrogen peroxide solution. The bottom of the vessel has an outlet for discharging the products from the acidification and oxidation reaction.

[0023] The acidification oxidation reaction vessel is equipped with a temperature control jacket on its exterior, which is used to heat the materials inside the vessel. Inside the vessel are a stirring mechanism, a temperature sensor, and a pressure sensor. The stirring mechanism agitates the materials to improve the efficiency of the acidification oxidation reaction. The temperature and pressure sensors monitor the reaction temperature and pressure to ensure the safe and stable operation of the reaction. A pH sensor automatically monitors the pH value within the vessel. Preferably, the vessel has a transparent observation window for easy observation of the reaction process.

[0024] During operation, the liquid phase after solid-liquid separation is added into the acidification oxidation reactor through the feed inlet. Dilute sulfuric acid is added dropwise to adjust the pH to 2.5-3. Under stirring conditions, 30% hydrogen peroxide solution is added in batches to oxidize iodide ions to obtain elemental iodine. The solution in the acidification oxidation reactor gradually changes from colorless to light brown and dark brown, and finally tends to stabilize, indicating that the oxidation reaction is complete.

[0025] Extraction unit 6 includes an extraction tower. The top of the extraction tower has an extractant inlet and a raffinate outlet, with the raffinate outlet higher than the extractant inlet. The bottom of the extraction tower has a mixed solution inlet and an extractant outlet, with the extractant outlet lower than the mixed solution inlet. A stirring mechanism is installed inside the extraction tower to agitate the solution, promoting contact between the extractant and the mixed solution and improving the extraction efficiency.

[0026] During operation, carbon tetrachloride extractant is fed into the extraction tower through the extractant inlet, while the acidified and oxidized mixture is pumped into the extraction tower through the mixed liquid inlet. Because the density of the extractant is greater than that of the mixed liquid, the extractant moves downwards within the extraction tower, while the mixed liquid moves upwards, resulting in the transfer of elemental iodine through contact within the tower. The extracted phase containing elemental iodine is purple and sinks to the bottom of the extraction tower, exiting through the extractant phase outlet. The raffinate phase is a white, gelatinous substance that floats to the top of the extraction tower and is exiting through the raffinate phase outlet.

[0027] Separation unit 7 includes a distillation column. The extract phase obtained from extraction unit 6 is fed into the distillation column. A heating mechanism, a temperature sensor, and a pressure sensor are installed at the bottom of the distillation column. The heating mechanism heats the extract phase inside the column, and the temperature sensor monitors the temperature of the extract phase to ensure effective separation. The pressure sensor monitors the pressure inside the distillation column to ensure safe operation. An exhaust port is located at the top of the distillation column, and a condenser is installed at the exhaust port.

[0028] During operation, the extract phase in the distillation column is heated, and the fraction in the 76-77℃ range is collected through a condenser, with the remaining solid being elemental iodine. The principle is as follows: carbon tetrachloride has a boiling point of 76.8℃, while iodine sublimates when heated to around 77℃ under normal pressure. By controlling the temperature, carbon tetrachloride can be evaporated and then condensed for recovery, while the iodine remains in the distillation apparatus due to sublimation.

[0029] The polarizer is depolymerized through an alcoholysis reaction unit, iodide ions are converted into elemental iodine through an acidification and oxidation reaction unit, and the elemental iodine is extracted and purified through an extraction and separation unit. The entire recovery system is mild and produces no toxic byproducts, which not only realizes the recycling of iodine resources and improves economic benefits, but also reduces environmental pollution.

[0030] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A polarizing sheet recycling system characterized by comprising: It includes an alcoholysis reaction unit, a solid-liquid separation unit, an acidification and oxidation reaction unit, an extraction unit, and a separation unit. The alcoholysis reaction unit is connected to the solid-liquid separation unit, the liquid phase outlet of the solid-liquid separation unit is connected to the acidification and oxidation reaction unit, the acidification and oxidation reaction unit is connected to the extraction unit, and the extract phase of the extraction unit is connected to the separation unit.

2. The polarizer recycling system according to claim 1, characterized in that, The alcoholysis reaction unit includes an alcoholysis reaction vessel, with a feed inlet at the top and a discharge outlet at the bottom. A temperature control jacket is installed on the outside of the alcoholysis reaction vessel, and a stirring mechanism, a temperature sensor, and a pressure sensor are installed inside the alcoholysis reaction vessel.

3. The polarizer recycling system according to claim 1, characterized in that, The solid-liquid separation unit is a continuous belt filter or a centrifugal separator.

4. The polarizer recycling system according to claim 1, characterized in that, The acidification and oxidation reaction unit includes an acidification and oxidation reaction vessel. The top of the acidification and oxidation reaction vessel has a feed inlet, and the bottom of the acidification and oxidation reaction vessel has a discharge outlet. A temperature control jacket is provided on the outside of the acidification and oxidation reaction vessel. A stirring mechanism, a temperature sensor, a pressure sensor, and a pH sensor are provided inside the acidification and oxidation reaction vessel.

5. The polarizer recycling system according to claim 4, characterized in that, The acidification and oxidation reaction vessel is equipped with an observation window.

6. The polarizer recycling system according to claim 1, characterized in that, The extraction unit includes an extraction tower. The top of the extraction tower has an extractant inlet and a raffinate outlet, with the raffinate outlet being higher than the extractant inlet. The bottom of the extraction tower has a mixed liquid inlet and an extractant outlet, with the extractant outlet being lower than the mixed liquid inlet. A stirring mechanism is provided inside the extraction tower.

7. The polarizer recycling system of claim 1, wherein The separation unit includes a distillation column, the bottom of which is equipped with a heating mechanism, a temperature sensor, and a pressure sensor, and the top of which is provided with an exhaust port and a condenser.

8. The polarizer recycling system according to claim 1, characterized in that, The front end of the alcoholysis reaction unit also includes a pretreatment unit, which includes a crusher and a dryer.

Images