Method and device for separating and recovering mercury

Abstract

The invention relates to a method and device for separating and recovering mercury. By cutting off both ends of a lamp tube of a waste fluorescent lamp and peeling off a phosphor film formed on the inner surface of the lamp tube, phosphor powder containing mercury is recovered. Adding an organic reducing agent to the recovered phosphor powder and heating it to perform dry heating reduction treatment to vaporize and separate mercury from the phosphor powder. This vaporized mercury is condensed and recovered.

Description

technical field [0001] The invention relates to a method for separating and recovering mercury and a device for separating and recovering mercury, in particular to a technique for separating and recovering mercury contained in a fluorescent material of a fluorescent lamp from a fluorescent material. Background technique [0002] Generally, mercury, a harmful substance, is recovered when disposing of end-of-life fluorescent lamps and defective fluorescent lamps generated during the manufacturing process, etc. (hereinafter referred to as "waste fluorescent lamps"). The recovered mercury is reused after removing impurities and the like contained therein. [0003] At present, as a method of separating and recovering mercury enclosed in waste fluorescent lamps, especially mercury contained in phosphor powders of waste fluorescent lamps, from phosphor powders (fluorescent substances), it is known that phosphor powders recovered from waste fluorescent lamps A wet mercury separatio...

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Problems solved by technology

[0006] However, in the above-mentioned existing wet mercury separation and recovery method, there is a so-called part of the phosphor powder dissolved in the aqueous solution containing active sulfur, the crystal structure of the phosphor is destroyed and changed, and the properties such as brightness deteriorate, making it impossible to recycle. After the phosphor powder problem

[0007] In addition, in general, wet mercury separation and recovery methods also have the problem of requiring special equipment for waste water treatment of used aqueous solutions and higher recovery costs compared to dry mercury separation and recovery methods.

[0008] On the other hand, adopt existing dry use separation and recovery method, there is following problem, promptly when the mercury form that contains in phosphor powder is metallic mercury and oxidized mercury, can fully separate and recover mercury from phosphor powder, However, since the form of mercury contained in the phosphor powder in waste fluorescent lamps at the end of its life becomes an amalgam that reacts with emitters (electron emitting substances) and phosphor components, mercury is difficult to thermally decompose and cannot be removed from the phosphor powder. Fully separate and recover mercury

Therefore, although it is conceivable to raise the temperature during the heat treatment, in this case, the temperature during the heat treatment is too high, and the thermal deterioration of the phosphor powder is remarkable, and as a result, the characteristics such as brightness deteriorate, and it cannot be reused. Problems with Treated Phosphor Powders

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