JPH1012149A - Mercury recovery method for waste fluorescent tubes - Google Patents

Abstract

(57) [Problem] To provide a mercury recovery method for preventing the outflow of mercury from waste material and recovering the mercury when the waste fluorescent tube is disposed. SOLUTION: A waste fluorescent tube is crushed in a closed box, mercury gas and mercury-based waste in the waste fluorescent tube are separated and sorted, and contacted with an aqueous solution of a sulfide treating agent mainly containing active sulfur, It was recovered from mercury gas and mercury-based waste as mercury sulfide compounds that are hardly soluble in water. In addition, mercury gas and mercury-based waste are brought into contact with an aqueous solution in which a plant essential oil having a thiol group is activated, and the water-soluble polymer compound of mercury sulfide, which is hardly soluble in water, is recovered from mercury gas and mercury-based waste. I did it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for recovering mercury from mercury-based waste from a waste fluorescent tube.

[0002]

2. Description of the Related Art At present, fluorescent tubes (fluorescent discharge tubes) are widely used as efficient illumination lamps. The fluorescent tube is coated with a fluorescent substance on the inside of a cylindrical glass tube, and a tungsten double filament electrode with a protective film such as barium oxide formed on both surfaces is attached to both ends. After evacuating the inside of the tube, a small amount of mercury And argon gas. In this fluorescent tube, a current is applied to the filament electrodes at both ends, a voltage is applied between the electrodes to generate a discharge in the tube, ultraviolet rays are emitted from the mercury gas in the tube, and the ultraviolet rays are irradiated on the fluorescent substance applied to the inner wall of the tube to emit light. Let it. Currently, there is no suitable UV-emitting material to replace toxic mercury gas. When the life of the fluorescent tube is exhausted due to a broken filament electrode, etc., harmful mercury remains in the waste fluorescent tube as a gas or adsorbed on the inner wall or fluorescent material, etc., and the waste fluorescent tube is collected and accumulated in large quantities. Or crushing in large quantities will release harmful mercury gas in large quantities. Also, when mercury-based waste is removed by washing, mercury is different from other heavy metals and its hydroxide is considerably soluble in water. Since it cannot be treated as follows, environmental destruction and pollution generation become problems. Conventionally, mercury in fluorescent tubes is of little interest in general because of the small amount of the enclosed amount, and the response of each local government varies, and when waste fluorescent tubes are discharged from homes, they are treated as general non-combustible waste. It is not specifically recognized as secondary pollution of waste. In addition, recovery of mercury gas from a waste fluorescent tube, recovery of mercury adsorbed on a glass tube wall, a fluorescent substance, a filament, and the like, and detoxification of the recovered mercury are not simple and costly, and facilities for processing are limited. Generally, methods for removing mercury in waste gas include a wet oxidation absorption method and a dry adsorption method. In the oxidation absorption method, metallic mercury in waste gas is oxidized with an oxidizing agent, absorbed in a solution containing a water-soluble sulfide, and removed as a hardly water-soluble mercury sulfide precipitate. In this case, if the water-soluble sulfide is excessively added, the mercury sulfide precipitate becomes a water-soluble polysulfide complex, which has a problem that it is dissolved again in water and flows out. Further, the generated mercury sulfide precipitate becomes fine particles, and a coagulant must be used in combination to capture the fine particles and perform solid-liquid separation. Although an organic polymer flocculant is used as a flocculant, mixing processing failure may occur, and solid-liquid separation is not easy. In the dry adsorption method, a method in which an oxidizing agent such as ferric chloride is attached to activated carbon to oxidize and adsorb and remove mercury gas, and a method in which a divalent mercury compound is previously passed through an oxidizing agent and has a thiol group in this state There is a method of adsorbing and removing the chelate resin. In the method of oxidizing and adsorbing mercury gas on activated carbon, it is difficult to desorb the adsorbed mercury. In addition, a method using a chelate resin cannot adsorb non-ionized metal mercury, and a chelate resin having a thiol group is not only expensive, but also unstable to acid, and can absorb adsorbed mercury. When desorbed by an acid and trying to regenerate the chelate resin, the chelate resin is destroyed and mercury cannot be regenerated.

[0003]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a mercury recovery method for recovering mercury and mercury gas flowing out of a waste material when a waste fluorescent tube is disposed.

[0004]

In order to achieve the above object, according to the present invention, waste fluorescent tubes are crushed in a closed box,
Mercury gas and mercury-based waste in waste fluorescent tubes are separated and sorted, and brought into contact with an aqueous solution of a sulfide treatment agent mainly composed of active sulfur to form a mercury sulfide compound that is hardly soluble in water from mercury gas and mercury-based waste. to recover. In addition, mercury gas and mercury-based waste are brought into contact with an aqueous solution in which a plant essential oil having a thiol group is activated, and the water-soluble polymer compound of mercury sulfide, which is hardly soluble in water, is recovered from mercury gas and mercury-based waste. .

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the accompanying drawings, attached tables and chemical formulas. FIG. 1 is a configuration diagram of a recovery equipment based on a method for recovering mercury from a waste fluorescent tube according to the present invention, which comprises a fluorescent tube crushing device 1, a suction pump device 2, a glass recovery device 3, and a mercury recovery device 4. They are sequentially connected by piping 11. The fluorescent tube crushing apparatus 1 is provided with an airtight box 5, a cylindrical inlet 6 into which waste fluorescent tubes are inserted one by one, and a ceiling inlet 7 on the ceiling. A crushing machine 8 provided with crushing blades rotated by an electric motor 21 at an upper portion of the box body 5, and a mercury-based waste such as a glass powder or a fluorescent substance adsorbing mercury gas while leaving a terminal portion and a large glass piece below the crushing machine. Is provided. The metal pieces and large glass pieces remaining on the wire mesh 9 are discharged from the discharge port 10 as necessary. Inlet 6, ceiling inlet 7 and outlet 10
Each is provided with a lid that can be opened and closed, and the lid is closed so that mercury-based waste such as mercury gas and fluorescent substance does not leak during crushing. A waste gas containing mercury gas and mercury-based wastes such as glass particles and fluorescent substances pass through the wire netting 9, and are passed through a pipe 11 a by a blower 12 to form an airtight chamber of a suction pump device 2 provided at an upper portion of the glass recovery device 3. 13 side.

[0006] The other end of the pipe 11a passes through a filter 14 in an airtight chamber 13 to remove foreign substances such as glass particles and dust. The remaining waste gas and mercury-based waste such as fluorescent substances are pressurized by the suction pump device 2 and discharged to the mercury recovery device 4 through the pipe 11b. Foreign substances such as glass particles and dust removed by the filter 14 are periodically accumulated in the glass collection device 3 by opening the glass discharge port 15. The mercury recovery apparatus 4 has a casing formed airtight, a processing tank 16 is provided below the inside thereof, and the other end of the pipe 11 b is inserted near the bottom of the processing tank 16. The processing tank 16 is filled with the processing liquid 22, and the pipe 11b
Is buried in the processing liquid 22. Mercury recovery device 4
The pipe 11c is connected to the pipe 11a through the on-off valve 17 from the upper part of the housing. As the treatment liquid 22, an aqueous solution of a sulfide treatment agent mainly composed of active sulfur or an aqueous solution obtained by activating a plant essential oil having a thiol group with a surfactant is used.

[0007] With the above construction, a waste fluorescent tube is introduced from the fluorescent tube inlet 6 and crushed by a crusher 8, metal and large pieces of glass such as electrodes are removed by a wire mesh 9, and fine glass particles and mercury are removed. Mercury-based waste such as fluorescent substances that have absorbed
Waste gas containing argon gas and mercury gas is sent out to the pipe 11 a by the blower 12, sucked by the suction pump device 2, and the airtight chamber 1 provided at the upper part of the glass recovery device 3.
Send to 3. In the airtight chamber 13, foreign matter such as glass particles and dust is separated by the filter 14 and collected by the glass collection device 3. The waste gas containing the mercury gas and the fluorescent substance is sent to the mercury recovery device 4 through the pipe 11b, and is jetted into the processing liquid 22 filled in the processing tank 16.

[0008] As shown in the following chemical formula 1, a plant essential oil having a thiol group can produce a plant essential oil having a thiol group by reacting the plant essential oil with hydrogen sulfide or sulfide. Chemical formula 1 Plant essential oil with thiol group

Embedded image By ejecting a waste gas containing mercury gas or a fluorescent substance into the treatment liquid 22, the mercury particles adsorbed on the mercury gas or the fluorescent substance are adsorbed on the treatment liquid 22 of a plant essential oil having a thiol group, and As shown in the chemical formula 2, the organic polymer thiol sulfide becomes coarse particles and precipitates in the treatment liquid 22, and the mercury in the waste gas is recovered. Processing liquid 2 in processing tank 16
After passing through the pipe 2 and removing water, gas, and mercury particles, the open / close valve 17 is opened, and the pipe 11c is returned to the pipe 11a.
As a result, it is possible to return to the hermetic chamber 13 and reliably remove mercury gas and mercury particles. Formula 2 Mercury gas and mercury particles are adsorbed on plant essential oils with thiol groups

Embedded image As described above, mercury gas released when the waste fluorescent tube is crushed or a fluorescent substance adsorbing mercury is blown into the treatment liquid 22 of the plant essential oil agent having a thiol group, or
By passing through a filter impregnated with water, mercury can be recovered as a mercury sulfide polymer compound that is hardly soluble in water. Further, with respect to the plant essential oil having a thiol group, mercury can be eliminated by acid and mercury can be recycled as mercury oxide.

FIG. 2 is a structural view of another recovery apparatus for performing the mercury recovery method of the present invention. The recovery apparatus includes a fluorescent tube crushing apparatus 1, a suction pump apparatus 2, a glass recovery apparatus 3, an ultrasonic spray apparatus 18, and a waste tank 19. The pipes 11a, 11b and 11c are sequentially connected. The waste fluorescent tube is crushed by the crusher 8 to remove metal pieces such as terminals and large glass pieces.
Mercury gas and mercury gas-adsorbed glass particles and fluorescent materials
It is sucked by the suction pump device 2 through the pipe 11a. At this time, the ultrasonic spray device 18 is filled with an aqueous solution obtained by activating a plant essential oil having a thiol group, and the aqueous solution is atomized by the ultrasonic spray device 18 to form a pipe 11c.
And is injected into the pipe 11a by the three-way valve 20.
The injection of this liquid is performed by adsorbing mercury gas and mercury particles into the flow of the mercury gas and the glass particles and the fluorescent substance that have exited the fluorescent tube crushing device 1 and passing through a filter (not shown) of the suction pump device 2. The foreign matter such as glass particles and dust is removed, and the spray adsorbing the mercury particles is condensed.
Run down and collect.

[0010]

EXAMPLES The effects of preventing elution and recovery of mercury discharged from a waste fluorescent tube according to the present invention will be described in detail with reference to the following examples. Example 1 Sulfide treating agent mainly composed of active sulfur (for example, RHF; Redu
Table 1 shows the results of the treatment of mercury contained in waste fluorescent tubes using se Harmless Flyash). A certain amount of the fluorescent paint in the waste fluorescent tube was shaken for 6 hours and filtered with a filter to prepare a sample solution according to the test method of the Environment Agency Notification No. 13, and the elution amount of mercury was assayed by the reduced vaporization atomic absorption method.

[Table 1] As is clear from Table 1, the effect of suppressing the elution of mercury is confirmed by the addition of a sulfide treatment agent (RHF) mainly composed of active sulfur.

Example 2 Table 2 shows the results of treating mercury contained in a waste fluorescent tube using a plant essential oil having a thiol group. In this mercury treatment, a certain amount of the fluorescent paint of the waste fluorescent tube is determined by the Environment Agency Notification No. 13 test method.
After shaking for 6 hours, the solution was filtered through a filter to prepare a sample solution, and the amount of mercury eluted was assayed by reduced vaporization atomic absorption spectrometry.

[Table 2] As is clear from Table 2, the effect of suppressing the elution of mercury by adding a plant essential oil having a thiol group is confirmed.

[0012]

As described above, according to the present invention, mercury gas or mercury-based waste flowing out in accordance with the crushing treatment of a waste fluorescent tube can be converted to an aqueous solution of a sulfide treatment agent mainly containing active sulfur or a thiol group. By contacting with an aqueous solution of a plant essential oil, it absorbs as a hardly soluble mercury sulfide compound in water, prevents its dissipation, and can avoid secondary pollution to the natural environment due to release of a large amount of mercury. . Further, mercury can be reused by desorbing mercury from an aqueous solution of a plant essential oil having a thiol group into which mercury has been taken in with an acid.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a recovery facility based on a method for recovering mercury from a waste fluorescent tube according to the present invention.

FIG. 2 is a configuration diagram of another recovery apparatus that performs the mercury recovery method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fluorescent tube crushing device 2 Suction pump device 3 Glass recovery device 4 Mercury recovery device 5 Box 6 Input port 7 Ceiling input port 8 Crusher 9 Wire net 10 Outlet 11 Pipe 12 Blower 13 Airtight room 14 Filter 15 Glass outlet 16 Treatment tank 17 On-off valve 18 Ultrasonic spray device 19 Waste tank 20 Three-way valve 21 Motor 22 Treatment liquid

 ──────────────────────────────────────────────────続 き Continuation of the front page (71) Applicant 396005298 Iseishi Shokai Co., Ltd. 5-27-2 Nishikamata, Ota-ku, Tokyo (71) Applicant 396005313 Kanki Limited company 2-1-11-1 Yoshino-cho, Omiya-shi, Saitama ( 72) Inventor Tsuneaki Tsuru 4-23-9 Toyomakita, Nerima-ku, Tokyo Inside Biomedic Laboratory Co., Ltd.

Claims (2)

[Claims] 1. A waste fluorescent tube is crushed in a closed box, mercury gas and mercury-based waste in the waste fluorescent tube are separated and sorted, and contacted with an aqueous solution of a sulfide treating agent mainly containing active sulfur. And mercury gas and mercury-based waste are collected as mercury sulfide compounds that are hardly soluble in water. 2. A mercury sulfide polymer that is hardly soluble in water from mercury gas and mercury-based waste by bringing the mercury gas and mercury-based waste into contact with an aqueous solution in which a plant essential oil having a thiol group is activated. The method for recovering mercury according to claim 1, which is recovered as a compound.