JP2005349395A - Method for recycling fluorescent lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance efficiency of a recovery/recycling process and improve quality of recycling materials in recovering and recycling constituent materials of waste fluorescent lamps for reuse, and particularly enhance the recovery efficiency of phosphor and further suppress deterioration in properties of the recycled phosphor. <P>SOLUTION: A recovered waste fluorescent lamp is separated according to the type and product class, and a phosphor layer is separated from the internal face of a glass bulb to separate phosphor from glass and recover them. The recovered phosphor material and glass are recycled for reuse. In this case, in the course of recycling the recovered phosphor, for example, the recovered phosphor is fired in vacuum or in an inert atmosphere to remove mercury contained in the recovered phosphor. The recovered glass is also subjected to the mercury removal treatment. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for regenerating a fluorescent lamp in which a phosphor material, a glass material, or the like is recovered from a waste fluorescent lamp, regenerated and reused.

  In connection with recent depletion of resources and environmental pollution, there is an increasing demand for recycling of electrical products. Among them, electronic functional materials used in various electrical appliances generally use expensive metal materials, so the need to reuse them after being collected (recycled) has been discussed. In addition, attempts are being made to actually collect and reuse.

  For example, since a general fluorescent lamp contains mercury in the lamp, if it is discarded as it is, it may cause environmental pollution. On the other hand, since the life of a fluorescent lamp is based on a decrease in discharge characteristics, the phosphor itself, which is a constituent material of the phosphor film, can be reused as a regenerated phosphor by collecting and regenerating it. Further, the glass material constituting the arc tube (glass bulb) can be reused.

  For this reason, it is possible to collect phosphor materials and glass materials from waste fluorescent lamps, and to recycle them after subjecting them to regeneration treatment and the like. It has been studied as described in Japanese Patent Laid-Open No. 11-513125 (Patent Document 2), and in some cases, recovery and regeneration have been attempted experimentally. In collecting and recycling the phosphor material and the glass material from the waste fluorescent lamp, it is necessary to first peel off the phosphor film from the inner surface of the glass bulb to separate the phosphor material and the glass material.

  Here, even if it is simply a fluorescent lamp, various types and types of fluorescent lamps have been put into practical use according to their applications and functions, and each has its own unique materials and configurations. If fluorescent lamps having different sizes are collected and regenerated at the same time, the collected material may not be reused. In addition, depending on the structure of the fluorescent lamp, there are cases where a specific collection / regeneration process must be performed. If multiple types of fluorescent lamps are processed at the same time, the efficiency of the collection / regeneration work is reduced and the quality of the recycled material It will cause a decrease.

  The occurrence of various problems is also considered regarding specific recovery / regeneration processes of phosphor materials and glass materials. For example, when the fluorescent film is peeled off and collected from the inner surface of the glass bulb, the conventional method has a low efficiency of collecting the phosphor and there is a possibility that impurities such as metal components and foreign substances are mixed.

  Further, since mercury and mercury oxide are attached and mixed in the collected phosphor material, it cannot be used as a regenerated phosphor unless they are removed. Therefore, it has been studied to heat the collected phosphor in the atmosphere at, for example, about 800 ° C. and evaporate mercury by this heat treatment.

  However, there is a problem in that heating in the atmosphere causes thermal degradation of the phosphor itself, and the luminance is greatly reduced when used as a regenerated phosphor. In particular, europium-activated aluminate phosphors and europium-activated halophosphate phosphors used as blue light-emitting components in three-wavelength emission phosphors are susceptible to oxidation of europium (Eu) as an activator. As a result of this Eu oxidation, the luminous efficiency of the blue phosphor is lowered, and furthermore, there is a problem that light emission itself cannot be obtained.

Similarly, since the collected glass material contains or contains mercury, it cannot be used as it is as a recycled glass material. Furthermore, in the rapid start type fluorescent lamp, a tin oxide film (nesa film) is formed on the inner surface of the glass bulb, so if it is reused as it is as a cullet, impurities such as tin are deposited on the glass surface. It will cause. Therefore, a glass bulb having a nesa film cannot be reused as it is.
Japanese National Patent Publication No. 10-500731 Japanese National Patent Publication No. 11-513125

  As described above, in the conventional method for collecting and regenerating a fluorescent lamp, a process corresponding to the type and type of the fluorescent lamp has not been established. When the collection / regeneration process is performed in a state where a plurality of types of fluorescent lamps are mixed, there is a risk that the efficiency of the collection / regeneration work may be reduced or the quality of the recycled material may be reduced.

  Furthermore, since the collected phosphor materials and glass materials contain mercury and the like, they cannot be reused as they are, but the conventional recovery / regeneration process has not necessarily established a mercury removal process, There are concerns that it will cause various problems. For example, when removing mercury from the recovered phosphor, the phosphor (especially the blue light-emitting component in the three-wavelength phosphor) may be thermally deteriorated, resulting in a decrease in luminance when used as a reproduction phosphor. It is regarded as a problem.

  For this reason, there is a strong demand for a method for regenerating a fluorescent lamp that improves the work efficiency and improves the quality of the regenerated phosphor material when recovering and regenerating the phosphor material from the waste fluorescent lamp. In addition, when reusing glass, which is a constituent material of a glass bulb, from a waste fluorescent lamp, there is a demand for a method for regenerating a fluorescent lamp that can suppress deterioration in characteristics of the regenerated glass.

  The present invention has been made to cope with such problems, and in collecting, recycling, and reusing the constituent materials of waste fluorescent lamps, the efficiency of the recovery / regeneration process and the improvement of the quality of the recycled materials are improved. It aims at providing the reproduction | regenerating method of the implement | achieved fluorescent lamp. In addition, in the individual recovery and regeneration processes for phosphor materials and glass materials, a method for regenerating a fluorescent lamp that makes it possible to suppress the deterioration of the properties of the regenerated phosphor and the regenerated glass, and to increase the efficiency of phosphor recovery. The purpose is to provide.

  The method for regenerating a fluorescent lamp according to the present invention includes a step of recovering a phosphor material from a waste fluorescent lamp and a step of recovering the recovered phosphor material as described in claim 1. In the process of regenerating the collected phosphor material, the phosphor material is baked in a vacuum, in a reducing atmosphere or in an inert atmosphere, and mercury contained in the phosphor material is removed. It is characterized by that.

  In this way, the recovered phosphor material is baked in vacuum, in a reducing atmosphere or in an inert atmosphere to remove mercury contained in the phosphor material, thereby deteriorating characteristics due to oxidation of the phosphor material. Can be suppressed. In particular, the divalent europium activated aluminate phosphor and the divalent europium activated halophosphate phosphor contained as a blue light emitting component in the three-wavelength light emitting phosphor have a lower emission efficiency due to the oxidation of europium, Furthermore, there is a problem that light emission itself cannot be obtained. However, it is possible to significantly suppress deterioration of the characteristics of the blue phosphor by firing in a vacuum, a reducing atmosphere, or an inert atmosphere. Furthermore, according to such firing, since the firing temperature itself required for removing mercury can be lowered, thermal deterioration of the phosphor material can be suppressed. As a result, it is possible to obtain a regenerated phosphor maintaining its characteristics with good reproducibility.

  In this fluorescent lamp regeneration method, the recovered phosphor material is preferably fired in the vacuum, in a reducing atmosphere or in an inert atmosphere after being fired in the air in advance. That is, since it contains organic impurities in the phosphor, after firing and removing this organic matter in the air, the phosphor material is baked in a vacuum, reducing atmosphere or inert atmosphere to remove mercury. It is preferable to do. As a result, it is possible to more reliably obtain a regenerated phosphor that is less contaminated with impurities and foreign matters.

  Furthermore, as described in claim 3, in addition to the step of firing the collected phosphor material, a step of washing the phosphor material after firing or before firing with an acid solution, an alkali solution, an alkali halide solution, or the like It is also effective to implement. Similarly, as described in claim 4, it is also effective to classify the recovered phosphor material and to redisperse the fired phosphor material. By these, it becomes possible to further improve the characteristics of the regenerated phosphor.

  In the method for regenerating a fluorescent lamp according to the present invention, as described in claim 5, the electrode portions at both ends of the waste fluorescent lamp are separated from the electrode position of the glass bulb by 10 mm or more inside, and the tube of the waste fluorescent lamp It is preferable to cut from a position of 100 mm or less from the end and collect the phosphor material from the inner surface of the glass bulb after the cutting. As a result, it is possible to collect the phosphors having deteriorated characteristics existing in the end colored region and the like, and it is possible to further improve the characteristics of the reproduction phosphor.

  As described above, according to the method for regenerating a fluorescent lamp of the present invention, it is possible to efficiently recover and regenerate a regenerated phosphor or a regenerated glass from a waste fluorescent lamp without deteriorating its characteristics. Accordingly, it is possible to greatly increase the usability of the regenerated phosphor and the regenerated glass.

  Hereinafter, modes for carrying out the present invention will be described.

  FIG. 1 is a process diagram showing a recovery and recycling process of a waste fluorescent lamp according to an embodiment of the present invention. First, waste fluorescent lamps to be regenerated (used fluorescent lamps, defective fluorescent lamps, etc.) are collected (step 101). Here, it is assumed that the collected waste fluorescent lamp includes various types or types of fluorescent lamps.

  As a typical fluorescent lamp, for example, as shown in FIG. 2, there is a three-wavelength fluorescent lamp 3 in which a fluorescent film 2 containing a three-wavelength fluorescent substance is formed on the inner surface of a glass bulb 1. Three-wavelength phosphors are generally blue phosphors such as divalent europium activated aluminate phosphors and divalent europium activated halophosphate phosphors, and trivalent europium activated yttrium oxide fluorescence. And phosphors in which red phosphors such as trivalent europium-activated yttrium oxysulfide phosphors and rare earth green phosphors are appropriately mixed are used.

  Of these, the blue phosphor is particularly susceptible to degradation during the regeneration process, so it is important to suppress the degradation of the characteristics of the blue light-emitting phosphor. Alternatively, it is also conceivable to remove only the blue light-emitting phosphor whose characteristics are likely to deteriorate during the regeneration process and to use a new phosphor for the blue light-emitting component (blue phosphor).

Specific examples of the blue phosphor used in the three-wavelength emission fluorescent lamp include a general formula: a (M, Eu) O.bAl ₂ O ₃ (wherein M is at least 1 selected from Mg, Ca, Sr and Ba). A and b are numbers satisfying a> 0, b> 0, 0.2 ≦ a / b ≦ 1.5 (the same shall apply hereinafter), and a divalent europium activated aluminate substantially represented by: Examples thereof include a salt phosphor and a divalent europium activated halophosphate phosphor substantially represented by the general formula: (M, Eu) ₁₀ (PO ₄ ) ₆ · Cl ₂ .

  However, it is conceivable that the waste fluorescent lamps to be regenerated include not only the above-described three-wavelength emission fluorescent lamps but also fluorescent lamps using, for example, a halophosphate phosphor alone. In addition, three-wavelength fluorescent lamps are also available in daylight color type and daylight white type, and the phosphor materials used are different. It is desirable that waste fluorescent lamps of different types or varieties are treated according to their constituent materials (for example, phosphor materials).

  Further, the three-wavelength fluorescent lamp includes a general fluorescent lamp (FL) and a rapid start type fluorescent lamp (FLR), which have different glass bulb configurations. Even in such a case, it is desirable to perform processing according to the configuration of each glass bulb.

  Therefore, the collected waste fluorescent lamps are sorted according to their types and varieties (step 102). In the waste fluorescent lamp separation step, for example, the phosphor material used in the fluorescent lamp is separated, and further, FL and FLR are separated. As a method of separating the phosphor material, for example, a light source that emits ultraviolet light having a wavelength of 365 nm or less is arranged outside the glass bulb, and the phosphor is excited by irradiating the waste fluorescent lamp with ultraviolet light from this light source. A method for identifying and discriminating lamp types is mentioned. According to such a method (step), automatic separation of waste fluorescent lamps is possible. For example, ultraviolet light having a wavelength of 300 nm passes through a glass bulb and excites a fluorescent film formed on the inner surface thereof. Since the blue phosphor in the fluorescent film emits light by such ultraviolet excitation, the emission spectrum is detected to distinguish the types of waste fluorescent lamps, for example, the three-wavelength fluorescent lamp and the halophosphate phosphor alone. And the daylight color type and the daylight white type among the three-wavelength fluorescent lamps.

  However, in the separation process using ultraviolet rays with a wavelength of 300 nm as described above, it is difficult to separate light bulb color fluorescent lamps with a small amount of blue phosphor added, and green and red color lamps (single color lamps) emit light. Since it is difficult, it is difficult to separate from a three-wavelength light emitting fluorescent lamp and further to individual lamps. In such a case, after cutting the bulb end of a waste fluorescent lamp, which will be described later, for example, an ultraviolet lamp that emits ultraviolet light having a wavelength of 254 nm is inserted into the glass bulb, and the fluorescent lamp is placed in the glass bulb. By making the body emit light, the types of waste fluorescent lamps can be separated.

  Specifically, the fluorescent film is irradiated with a phosphor having a wavelength of 254 nm from an ultraviolet lamp (for example, a pen-type ultraviolet lamp) disposed in the glass bulb, and light emission from the fluorescent film is detected on the outer surface side of the glass bulb. . Then, by detecting the emission spectrum from this phosphor film (e.g. the emission spectrum of B, G, R and calcium halophosphate phosphor) and specifying the type of phosphor, a fluorescent lamp with less blue phosphor added Even so, it is possible to sort the types and types of waste fluorescent lamps. For detection of the emission spectrum, for example, an instantaneous spectroscopic system using a CCD camera can be used.

  Further, the three-wavelength fluorescent lamp is classified into a general fluorescent lamp (FL) and a rapid start type fluorescent lamp (FLR). That is, when the waste fluorescent lamp is a rapid start type, a tin oxide film exists as a nesa film on the inner surface of the glass bulb. After removing this tin oxide film separately, the glass bulb is reused as a glass raw material (cullet). Since it is necessary to use, rapid start type fluorescent lamps are separated from general fluorescent lamps.

  The separation process of the rapid start type waste fluorescent lamp is, for example, (1) recognizing an identification mark such as a mark printed on the lamp or a product name by image processing, and separating based on the recognition result, or (2 ) The resistance value of the glass bulb can be measured based on, for example, a method of measuring the resistance value from the outside of the bulb and sorting based on the measurement result of the resistance value.

  Here, in the above method (1), there is a possibility that the identification accuracy by the image processing may be lowered when the valve end portion is blackened due to deterioration with time or the identification mark itself disappears. On the other hand, according to the method (2) of measuring the resistance value of the glass bulb, it is possible to more reliably sort the rapid start type waste fluorescent lamp. Specifically, the resistance value near the center of the glass bulb is measured, and when this measurement result is below a predetermined resistance value, a rapid start type fluorescent lamp, that is, a tin oxide film exists as a Nesa film. Therefore, it can be determined that the fluorescent lamp has a low resistance of the glass bulb due to the tin oxide film.

  The measurement of the resistance value of the glass bulb is not limited to non-destructive measurement from the outside of the bulb. For example, the resistance value of the inner surface of the glass bulb after separating the phosphor is directly measured, or the glass bulb is crushed. Various methods such as measuring the resistance value can be employed. However, in consideration of the ease of the post-process, it is preferable to measure in advance from the outside of the valve in a nondestructive manner. In addition, the rapid start type fluorescent lamp is not limited to the measurement of resistance value, but the inner surface of the glass bulb can be detected from the current, voltage, phase shift, etc. by bringing a conductive terminal closer to the outer surface of the lamp and applying a high frequency voltage to it. It can also be determined whether or not a tin oxide film is present.

  The waste fluorescent lamp whose type and variety are found by the above-described sorting process is then separated into a phosphor material and a glass material, and each is recovered as a recycling material. In separating and collecting the phosphor material from the waste fluorescent lamp, first, as shown in FIG. 2, the bulb end portion 1a including the base 4 of the prepared waste fluorescent lamp 3 is cut.

  Here, since the bulb end 1a is often colored blackish brown and the electrode material may be scattered, the phosphor present in such a portion has reduced brightness and reflectance. doing. Therefore, it is preferable to cut the glass bulb 1 from the position Y in the range of 10 mm or more inward from the electrode position X and 100 mm or less from the tube end of the waste fluorescent lamp 3, instead of simply cutting from the portion of the base 4. . Thereby, the characteristics of the regenerated phosphor can be further improved.

  If the bulb end is not colored black-brown, or if the colored substance can be removed in a later step even if it is colored black-brown, it is cut near the end of the glass bulb 1 and then the subsequent step is performed. You may make it send.

  Next, the phosphor film 2 is peeled off from the inner surface of the glass bulb 1 cut at both ends 1a and 1a, whereby the phosphor material and the glass material are separated and recovered from the waste fluorescent lamp as a regenerating material (step 104). . This separation step is performed so as to collect the phosphor material and the glass material for each lamp type, based on the result of the waste fluorescent lamp separation step. For example, regarding the phosphor material, a three-wavelength light emitting phosphor, a calcium halophosphate phosphor, and the like are individually collected.

  For collecting the phosphor material from the waste fluorescent lamp, for example, high-pressure air is blown onto the inner surface of the glass bulb to peel off the fluorescent film, or the fluorescent film is peeled off by vacuum suction. However, with such a peeling method, it is difficult to completely recover the fluorescent film from the inner surface of the glass bulb, and impurities (such as metal components) and foreign substances are mixed, resulting in the characteristics of the regenerated phosphor (luminance characteristics, etc.). There is a risk that it will fall.

  Therefore, as shown in FIG. 3, it is preferable to collect the phosphor material by spraying the liquid 6 applied with pressure from the nozzle 5 or the like to the inner surface of the glass bulb 1. The phosphor material is collected in the collection container 7 together with the liquid 6. In this way, the liquid 6 applied with pressure to the fluorescent film 2 formed on the inner surface of the glass bulb 1 is sprayed, and the fluorescent film 2 is peeled off by the pressure of the liquid 6, thereby suppressing the entry of impurities and foreign matters. Thus, the phosphor recovery efficiency can be increased.

As the liquid sprayed on the fluorescent film 2, water, an acid solution, an alkaline solution, or the like is used. The water may be either cold water or hot water. As the acid solution, an aqueous solution having a pH of 6 or less containing at least one selected from nitric acid, hydrochloric acid and acetic acid is used. As the alkaline solution, an aqueous solution of NaOH or Ca (OH) _{2 having} pH = 8 or more is used. Since these acid solutions and alkali solutions have a function of dissolving the binder in the phosphor film 2, the phosphor recovery efficiency can be further enhanced. In order to obtain such an effect, it is particularly preferable to spray an acid solution onto the fluorescent film 2.

  Further, when the fluorescent film 2 is peeled off with the liquid 6, it is also effective to spray the liquid 6 while changing the pressure in a pulse shape, for example. Such pressure fluctuations effectively act on the peeling of the fluorescent film 2. Furthermore, the fluorescent film 2 remaining on the inner surface of the glass bulb 1 after the spraying process of the liquid 6 may be mechanically peeled off using a brush, sandblast, or the like. By using both the liquid pressure and the mechanical force, it becomes possible to further increase the phosphor recovery efficiency. In some cases, only mechanical peeling can be applied.

  The above-described phosphor material separation / recovery step is performed for each type and type of waste fluorescent lamp based on the result of the above-described sorting step. That is, by performing a separation step according to the type and type of waste fluorescent lamp, the phosphor is collected for each specific phosphor (for example, a three-wavelength emission phosphor and a calcium halophosphate phosphor).

  In this way, the phosphor material (collected phosphor) collected for each type is subjected to a regeneration process (105) after being subjected to various processes such as washing and drying as necessary. The regeneration process is performed according to the type of the recovered phosphor, such as the three-wavelength phosphor 106 and the other phosphor (for example, calcium halophosphate phosphor) 107. For example, when the recovered phosphor is subjected to a water washing treatment, it is also effective to classify it using a water sieve or the like. This is effective for removing foreign substances. Further, physical / mechanical separation / removal treatment of impurities and foreign matters other than classification, such as filtration, may be performed.

  In the recovery process of the recovered phosphor, first, a mercury removal step (step 108) contained in the recovered phosphor is performed. Examples of the method for removing mercury include a floating sorting method, a pickling treatment, and a heat treatment method. In the floating selection method, the recovered phosphor is added to a dispersion medium such as city water, pure water, or water adjusted to weak acidity, and the recovered phosphor is dispersed while slowly stirring. Then, impurities such as mercury and scattered matter from the emitter and foreign matters such as glass dust are separated from the phosphor, and only the phosphor having a low specific gravity is gradually overflowed and collected. The pickling treatment means that the phosphor and glass cullet are washed and dried with an acid solution such as dilute nitric acid or acetic acid. The acid solution may be hydrochloric acid, sulfuric acid or oxalic acid having a low concentration.

  Although it is possible to remove a certain amount of mercury from the recovered phosphor only by the above-described floating sorting method, it is preferable to use a firing method together in order to increase the mercury removal rate. The removal of mercury from the recovered phosphor can be performed only by a firing method. The firing method is carried out by firing the recovered phosphor in a firing furnace, and this makes it possible to more reliably remove mercury mixed in the recovered phosphor. In addition, organic substances contained in the recovered phosphor, such as the binder component of the fluorescent film, can also be removed.

  The above heat treatment step may be performed in any atmosphere such as air, vacuum, reducing atmosphere, inert atmosphere, etc., but when performed in air, the heating temperature is 400 ° C. or less, For example, it is preferable to set it as 100-300 degreeC. Although it is possible to remove mercury only by heating in the atmosphere, there is a risk that the mercury removal rate may be insufficient if it is heated to 400 ° C or less, so in other vacuum or reducing atmospheres. It is preferable to perform the heat treatment step in combination with baking in an inert atmosphere or the like.

  Heating the recovered phosphor in the air is effective for removing organic substances such as a binder component. If the temperature at this time is too high, the characteristics of the recovered phosphor deteriorate, so the heating temperature is preferably 400 ° C. or lower. Moreover, since the organic substance removal efficiency decreases even if the firing temperature is too low, the firing temperature is preferably 100 ° C. or higher. The heating in the atmosphere can be omitted if the organic substance can be sufficiently removed when, for example, the liquid is sprayed on the fluorescent film to be peeled off. It is also possible to carry out organic substance removal in a cleaning process described later.

  When the recovered phosphor is fired in vacuum, in a reducing atmosphere, or in an inert atmosphere, it is possible to perform firing at a temperature exceeding 600 ° C, but this suppresses thermal deterioration of the phosphor. It is preferable to carry out at a temperature in the range of 400 to 600 ° C. The recovered phosphor is baked in vacuum, in a reducing atmosphere, or in an inert atmosphere to remove mercury. If the firing temperature exceeds 600 ° C, the phosphor is thermally deteriorated. On the other hand, if the temperature is lower than 400 ° C., the mercury removal efficiency decreases.

  As described above, the recovered phosphor is baked in a vacuum, in a reducing atmosphere, in an inert atmosphere, or the like to remove mercury, whereby deterioration in characteristics due to phosphor oxidation or the like can be suppressed. In particular, the emission efficiency of the blue phosphor (the divalent Eu-activated aluminate phosphor and the divalent Eu-activated halophosphate phosphor described above) contained in the three-wavelength phosphor is reduced. Non-light emission can be significantly suppressed. Furthermore, by firing in a vacuum or in an inert atmosphere, the firing temperature itself required for removing mercury can be lowered, so that thermal deterioration of the phosphor can be suppressed. As a result, it is possible to obtain a regenerated phosphor maintaining its characteristics with good reproducibility.

The specific firing atmosphere of the recovered phosphor is preferably a vacuum atmosphere of 10 Pa or less, a reducing atmosphere using a forming gas (N ₂ + H ₂ ), or an inert gas atmosphere such as Ar or He. If the atmospheric pressure when applying a vacuum atmosphere exceeds 10 Pa, the phosphor may be oxidized. Of the above-mentioned atmospheres, a reducing atmosphere using a forming gas is particularly effective in suppressing phosphor oxidation.

  Note that the various conditions of the above-described firing process are mainly based on the assumption of the three-wavelength light-emitting phosphor 106, and other phosphors (for example, calcium halophosphate phosphor) 107 are at a temperature of 1000 ° C. or less. Mercury is removed by firing. Phosphors 107 other than the three-wavelength light emitting phosphor after firing are reused or discarded as the treated phosphor 109.

  By performing the firing treatment step as described above, a regenerated phosphor that can be reused in a three-wavelength fluorescent lamp can be obtained. Further, the phosphor can be obtained with an acid solution, an alkali solution, an alkali halide solution, or the like. Is preferably washed. By using the firing treatment step and the cleaning treatment step in combination, the characteristics of the regenerated phosphor can be further improved.

As the acid solution used for the cleaning treatment, an aqueous solution having a pH of 6 or less containing at least one selected from nitric acid, hydrochloric acid and acetic acid is used. Further, as the alkaline solution, an aqueous solution such as NaOH or Ca (OH) _{2 having} pH = 8 or more is used. In addition, use a solution of hypochlorite such as sodium hypochlorite or potassium hypochlorite, or a solution of periodic acid compounds such as ammonium periodate or potassium periodate (alkali halide). May be. These are particularly effective for removing organic substances.

  The acid solution is effective not only for removing organic substances but also for dissolving and removing blue phosphors. According to the baking process described above, although the deterioration of the blue phosphor can be suppressed, the blue phosphor is easily deteriorated as compared with other red phosphors and green phosphors. Therefore, only the blue phosphor is dissolved and removed by acid cleaning, and a new blue phosphor is added to the removed portion to improve the emission characteristics and the like. A mixture of new phosphors).

  In the case of performing the cleaning process, ultrasonic cleaning or the like can be combined. The ultrasonic cleaning may be performed using warm water or the like. This cleaning process is not limited to being performed after the firing process, and the above-described firing process may be performed after the recovered phosphor is washed.

  Thereafter, a powdered regenerated phosphor (regenerated three-wavelength) is obtained by subjecting the phosphor subjected to the above-described floating sorting process, firing process, and if necessary, washing process with acid or alkali to water washing process or drying process. A light emitting phosphor 110) is obtained. In this stage, coarse particles such as agglomerates may be included, and therefore it is preferable to perform a redispersion process using a ball mill or the like as necessary.

  The regenerated phosphor powder (for example, the regenerated three-wavelength light emitting phosphor powder 110) obtained through the recovery process and the regeneration process as described above is mixed with a new phosphor as necessary (process 111), and then a fluorescent lamp. Is reused as a fluorescent film forming material (step 112). The mixing ratio of the regenerated phosphor and the new phosphor is not particularly limited, but is set to include, for example, the regenerated phosphor in a range of 1 to 100%. When importance is attached to the regenerated phosphor, the ratio is preferably in the range of 50 to 100%.

  Then, according to the recovery and regeneration process as described above, since the phosphor is efficiently recovered in the recovery process, it is possible to recover nearly 100% of the phosphor from the waste fluorescent lamp, and thus the phosphor. It is possible to greatly increase the reuse rate. In addition, the recycled phosphor prevents impurities and foreign matter from being collected during collection, and also suppresses the deterioration of characteristics associated with the firing process. Therefore, when this is reused in a fluorescent lamp, performance degradation (decrease in brightness, etc.) ). Thus, according to the present invention, a high-performance regenerated phosphor powder can be obtained efficiently and reliably.

  In addition, the glass material from which the phosphor material has been separated in the separation and recovery step 104 described above, that is, the glass bulb, is reused as cullet (glass raw material) after being crushed. Since mercury or the like causes defects, it is reused after the regeneration process (113). In particular, when the waste fluorescent lamp is of a rapid start type, a tin oxide film is present as a nesa film on the inner surface of the glass bulb, and thus it is necessary to recycle it after performing a regeneration process corresponding thereto.

  For this reason, the glass material regeneration process is also performed according to the type of fluorescent lamp, such as a general fluorescent lamp (FL) 114 and a rapid start type fluorescent lamp (FLR) 115. The glass material 114 collected from the general fluorescent lamp (FL) is subjected to mercury removal processing (step 116). Mercury removal treatment from glass materials is, for example, (1) immersing the collected glass bulb in a nitric acid solution after crushing, (2) heating the collected glass bulb to a temperature of about 500 ° C. Is implemented.

  According to the immersion treatment (1) in the nitric acid solution, mercury adhering to or contained in the glass bulb dissolves into the nitric acid, so that the mercury can be satisfactorily removed from the collected glass material. The nitric acid solution may be heated as necessary. The glass material that has been treated with nitric acid can have, for example, an elution amount of mercury of 0.005 g / L (liter) or less. Further, mercury dissolved in nitric acid can be recovered as mercury vapor by reducing it with, for example, tin chloride and further vaporizing it. Further, mercury can be favorably removed from the recovered glass material by the heat treatment of (2).

  In this way, when the recovered glass material is reused as cullet by removing mercury from the glass material (glass bulb constituent material) generated in the recycling process of the waste fluorescent lamp, impurities such as poor deposition of impurities Since generation | occurrence | production can be suppressed, the significant quality improvement of a recycled glass material can be achieved. That is, the recycled glass material can be reused (117) satisfactorily.

  Further, the glass material 115 collected from the rapid start type fluorescent lamp (FLR) is subjected to a removal process of the tin oxide film (nesa film) from the inner surface of the glass bulb (step 118). The glass bulb from which the tin oxide film has been removed is reused (117) as cullet (glass raw material) after being crushed in the same manner as the glass material generated from the general fluorescent lamp (FL).

  For example, (1) the recovered glass bulb is heat-treated in a reducing atmosphere to remove the tin oxide film, and (2) the recovered glass bulb is subjected to acid treatment or alkali treatment. Then, the tin oxide film is dissolved and removed. The heat treatment in a reducing atmosphere may be performed by, for example, heating the inner surface of the collected glass bulb with a reducing flame (for example, a hydrogen burner flame).

  The removal of the tin oxide film by acid treatment or alkali treatment is performed using, for example, hydrofluoric acid, hydrochloric acid, sulfuric acid, sodium hydroxide solution, magnesium hydroxide solution, or the like. In particular, according to the treatment with hydrofluoric acid, even a part of the glass bulb can be dissolved, so that the tin oxide film can be more reliably removed. In addition, a protective film made of alumina, zinc oxide, titanium oxide, or the like attached to glass can be removed well.

  In addition, when processing using an acid solution such as hydrochloric acid or sulfuric acid, or an alkaline solution such as a sodium hydroxide solution or a magnesium hydroxide solution, these processing solutions are heated to about 180 to 200 ° C. and, for example, about 120 kPa. It is preferable to process the glass bulb pieces pulverized in a pressurized atmosphere. According to such treatment, the tin oxide film and the protective film can be removed satisfactorily. Furthermore, the evaporation and scattering of the acid solution and the alkaline solution can also be suppressed.

  Further, by performing the removal treatment of the tin oxide film as described above, mercury attached to or contained in the glass bulb can also be removed. However, the mercury removal processing step 116 may be performed separately as necessary.

  As described above, the glass material 115 collected from the rapid start type fluorescent lamp (FLR) can be reused as well as the glass material 114 collected from the general fluorescent lamp (FL). This is used to improve the reuse efficiency of the glass material.

  Next, specific examples of the present invention and evaluation results thereof will be described.

Example 1

  First, a phosphor was collected from a used fluorescent lamp (three-wavelength emission type fluorescent lamp), washed with water to remove impurities, and then placed in a vacuum furnace and heat-treated in a vacuum of 10 Pa or less. The heat treatment was performed under conditions of 550 ° C. × 3 hours.

  When a fluorescent lamp was produced using the obtained regenerated phosphor, a luminous flux of 96% was obtained compared to a fluorescent lamp using a new phosphor, and it had sufficient performance as a recycled phosphor. Was confirmed.

  In addition, the amount of residual mercury was 0.005 mg / L or less in terms of elution value, satisfying the standards for industrial waste. Thus, it was confirmed that mercury was also sufficiently removed.

Example 2

  The phosphor was recovered from the used fluorescent lamp (three-wavelength emission type fluorescent lamp), washed with water to remove impurities, and then placed in a nitrogen atmosphere furnace and heat-treated. The heat treatment was performed under conditions of 600 ° C. × 5 hours.

  When a fluorescent lamp was produced using the obtained regenerated phosphor, a luminous flux of 94% was obtained compared to a fluorescent lamp using a new phosphor, and it had sufficient performance as a recycled phosphor. Was confirmed.

  In addition, the amount of residual mercury was 0.005 mg / L or less in terms of elution value, satisfying the standards for industrial waste. Thus, it was confirmed that mercury was also sufficiently removed.

Example 3

The phosphor is recovered from the used fluorescent lamp (three-wavelength emission type fluorescent lamp), washed with water to remove impurities, and then put into a firing furnace, and a forming gas (N ₂ : 97% + H ₂ : 3%) is used. Heat treatment was performed while flowing. The treatment conditions were 550 ° C. × 3 hours.

  When a fluorescent lamp was manufactured using the obtained regenerated phosphor, a luminous flux of 95% was obtained compared to a fluorescent lamp using a new phosphor, and it had sufficient performance as a recycled phosphor. Was confirmed.

  In addition, the amount of residual mercury was 0.005 mg / L or less in terms of elution value, satisfying the standards for industrial waste. Thus, it was confirmed that mercury was also sufficiently removed.

Example 4

  After collecting the phosphor from the used fluorescent lamp (three-wavelength emission type fluorescent lamp) and washing it with water to remove impurities, it was first put in a firing furnace and heat-treated in the atmosphere. The heat treatment conditions at this time were 450 ° C. × 2 hours. Organic substances were removed by baking in the atmosphere. Subsequently, it heat-processed in the vacuum of 10 Pa or less in the vacuum furnace. The heat treatment conditions at this time were 550 ° C. × 3 hours.

  When a fluorescent lamp was produced using the obtained regenerated phosphor, a luminous flux of 97% was obtained compared to a fluorescent lamp using a new phosphor, and it had sufficient performance as a recycled phosphor. Was confirmed.

  In addition, the amount of residual mercury was 0.005 mg / L or less in terms of elution value, satisfying the standards for industrial waste. Thus, it was confirmed that mercury was also sufficiently removed.

Example 5

The phosphor is recovered from the used fluorescent lamp (three-wavelength emission type fluorescent lamp), washed with water to remove impurities, and then put into a firing furnace, and a forming gas (N ₂ : 97% + H ₂ : 3%) is used. Heat treatment was performed while flowing. The heat treatment conditions were 550 ° C. × 3 hours. Next, the fired phosphor was put into an aqueous nitric acid solution or an aqueous acetic acid solution for washing treatment. Thereafter, ultrasonic cleaning was performed in 40 ° C. warm water, and further, filtration, water washing, and drying were performed to obtain regenerated phosphors.

  The amount of residual mercury and the reflectance of the obtained regenerated phosphor were measured. Phosphors put into nitric acid aqueous solution after heat treatment have a residual mercury amount below the detection limit and reflectivity of 98%, and phosphors put into acetic acid aqueous solution after heat treatment have a residual mercury amount below the detection limit and reflectivity 95%. The phosphor subjected only to the heat treatment had a mercury content of 0.03 mg / g and a reflectance of 93%. The reflectance is a relative value when the reflectance of the new phosphor is 100.

  As a comparison with the present invention, when the amount of residual mercury and the reflectance of the regenerated phosphor subjected only to washing with water were measured, the amount of residual mercury was 0.08 mg / g and the reflectance was 90%. The untreated recovered phosphor had a residual mercury content of 0.26 mg / g and a reflectance of 85%.

Example 6

  The phosphor was recovered from the used fluorescent lamp (three-wavelength emission type fluorescent lamp), and 20 g of this phosphor was put into a container containing 2 L of water, and stirred slowly to such an extent that the phosphor did not precipitate. Then, the phosphor was collected while overflowing about 400 mL / min of water, filtered and dried.

  When the amount of residual mercury in the obtained regenerated phosphor was measured, the amount of residual mercury was about 1/5 or less compared with the recovered phosphor not subjected to the floating sorting method. This satisfies the elution value of 0.005 mg / L or less.

Example 7

  Both ends of the used fluorescent lamp (three-wavelength emission type fluorescent lamp) were cut. Water, dilute nitric acid, or dilute acetic acid was sprayed onto the inner surface of the glass bulb from which both ends were cut, and the respective phosphors were collected. When each of these recovered phosphors was used to produce a fluorescent lamp, the phosphor recovered with water was 80% of the fluorescent lamp using a new phosphor, and 90% of the phosphor recovered with dilute nitric acid was diluted. The phosphor recovered with acetic acid was 85%.

  In this example, in order to see the difference in the luminous flux due to the difference in the recovery conditions, a fluorescent lamp was produced using the recovery phosphor, but by carrying out the regeneration process as shown in Examples 1 to 5, It is clear that the luminous flux is further improved in each case. In all cases, the phosphor recovery rate showed a good value.

Example 8

  Both ends of the used fluorescent lamp (three-wavelength emission type fluorescent lamp) were cut. At this time, a glass bulb with a cutting position of 15 mm and 5 mm from the electrode position was prepared. The phosphors were collected from each of them, and further subjected to a regeneration process, and then the luminance and reflectance of each were measured. As a result, the phosphor recovered from the glass bulb cut at 15 mm from the electrode position had a luminance of 90% and a reflectance of 95%. On the other hand, the sample cut at 5 mm from the electrode position had a luminance of 88% and a reflectance of 90%. These values are relative values when the new phosphor is 100.

Example 9

  A glass bulb was recovered from the used fluorescent lamp (FL), and the glass bulb was crushed and then immersed in a nitric acid solution. Further, mercury was reduced with tin chloride while heating, and mercury vapor was recovered. When the residual mercury content of the glass material after the immersion treatment in the nitric acid solution was measured, the elution value was less than 0.005 mg / L.

Example 10

  After collecting the glass bulb from the used fluorescent lamp (FL) and crushing the glass bulb, it is heated in the atmosphere under conditions of 500 ° C x 10 minutes (Sample 1) and 500 ° C x 60 minutes (Sample 2). Processed. The elution value of mercury from the non-heat-treated glass material was 0.1 mg / L, whereas both the heat-treated sample 1 and sample 2 had a mercury elution value of 0.005 mg / L. It was the following.

Example 11

  A glass bulb was recovered from a used rapid start type fluorescent lamp (FLR), and the glass bulb was crushed and then heat-treated in a reducing atmosphere at 500 ° C. for 60 minutes. When the state of the glass material after the heat treatment was confirmed, it was confirmed that the tin oxide film was well removed.

Example 12

  A glass bulb was recovered from a used rapid start type fluorescent lamp (FLR), and the glass bulb was crushed and then immersed in hydrofluoric acid solutions having various concentrations to remove the tin oxide film. The concentration of the hydrofluoric acid solution was 5%, 1%, 0.5%, and 0.07%, and the immersion time in each was 10 seconds, 3 minutes, 5 minutes, and 2 hours. It was confirmed that the tin oxide film and the protective film were satisfactorily removed under any treatment condition.

It is process drawing which shows the collection | recovery and regeneration process of the waste fluorescent lamp by one Embodiment of this invention. It is a figure which shows typically the cutting state of the valve | bulb edge part in the collection | recovery process of the waste fluorescent lamp of this invention. It is a figure which shows typically an example of the isolation | separation collection method of the fluorescent material in the collection | recovery process of the waste fluorescent lamp of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Glass bulb 1a ... Valve end part 2 ... Fluorescent film 3 ... Fluorescent lamp (waste fluorescent lamp)
4 ... Base 5 ... Nozzle 6 ... Liquid under pressure

Claims (5)

  In a method for regenerating a fluorescent lamp comprising a step of recovering a phosphor material from a waste fluorescent lamp and a step of regenerating the recovered phosphor material, in the process of regenerating the recovered phosphor material, A method for regenerating a fluorescent lamp, comprising a step of removing mercury contained in the phosphor material by baking in a vacuum, a reducing atmosphere or an inert atmosphere.   2. The method for regenerating a fluorescent lamp according to claim 1, further comprising a step of firing the recovered phosphor material in the air, followed by firing in the vacuum, a reducing atmosphere, or an inert atmosphere. .   3. The method according to claim 1, further comprising a step of washing the phosphor material after firing or before firing with an acid solution, an alkali solution, or an alkali halide solution in addition to the phosphor material firing step. To regenerate fluorescent lamps.   4. The method for regenerating a fluorescent lamp according to claim 1, further comprising a step of classifying the phosphor material and redispersing the phosphor material after firing.   The electrode parts at both ends of the waste fluorescent lamp are cut away from the electrode position of the glass bulb by 10 mm or more and from the position of 100 mm or less from the tube end of the waste fluorescent lamp. The method for regenerating a fluorescent lamp according to any one of claims 1 to 4, wherein the phosphor material is collected.

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