JPS61263687A - Apparatus for treating dry cell containing mercury - Google Patents

Abstract

PURPOSE:To recover and reutilize mercury by crushing and heating a spent mercury-contg. dry cell, cooling the obtained mercury vapor, sending the dry- distilled gas to a spray tower to remove a trace of mercury and then removing the remaining trace amt. of mercury with the final treating device. CONSTITUTION:A mercury-contg. dry cell is crushed by a crusher 1, the crushed material is heated in an external-heating dry distillation furnace 2 at a temp. above the b.p. of mercury, the gaseous distillate discharged from the furnace 2 is cooled by a condenser 3 to condense the mercury vapor and the condensed mercury is recovered a mercury recovery vessel 4. The trace amt. of mercury in the waste gas from the vessel 4 and suspended dust are removed in a spray tower 6, small amts. of impurities and moisture are separated from the waste gas from the tower 6 by a cushion tank 81 in the final treating part 8, then the minor amt. of remaining mercury which has not been removed in the tower 6 and hydrocarbons in the waste gas are adsorbed and removed by the activated carbon and silica gel in a packed tower 84 and the waste gas after passing through the tower 84 is discharged to the atmosphere from a waste gas stack 85.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a processing device for mercury-containing dry batteries.

[Conventional technology]

1 for button type mercury batteries and cylindrical alkaline manganese batteries.
Each piece contains 90.2 to 1.7 grams of mercury.
Currently, in Japan, the total amount of mercury in the approximately 2 billion waste dry batteries that are consumed annually exceeds 50) tons, and used mercury-containing dry batteries are attracting attention as a new source of pollution, and the national and local governments are collecting them.・I am having trouble processing it.

The method for collecting used mercury-containing dry batteries is as follows:
The amount of mercury-containing batteries has been reduced as more and more measures are being taken to separate and collect them, such as bringing used batteries to stores when purchasing new batteries, and battery manufacturers installing collection boxes specifically for mercury-containing batteries at stores that sell mercury batteries. On the other hand, methods for disposing of used batteries that have been collected separately include: ■ Storing them in drums in a warehouse, etc.; ■ Packing them in concrete; ■ Dumping them underground in a landfill, etc. together with general waste; ■ With general waste. Processes such as incineration are being carried out.

[Problem that the invention seeks to solve]

However, with the conventional processing technology for used mercury-containing dry batteries as described above, depending on the method of (2) and (2), for example, the amount of collection increases day by day. There is a risk of air pollution with the method (2) and (2), and they are far from being a drastic treatment measure for used mercury-containing batteries. Therefore, if the current situation continues, the amount of mercury released into the environment will definitely continue to increase. When considering the possibility that large amounts of water and silver can be transformed into highly toxic organic mercury by bacteria and heat, and the risk of complex contamination with other pollutants, we need to take a more drastic approach to treating used mercury-containing dry batteries. It is clear that there is a need for the development of processing technology. Furthermore, with the conventional processing techniques mentioned above, the mercury in batteries was dumped without being recovered at all, but it is now possible to establish a processing technology that can recover relatively expensive mercury in a recyclable form. This is also desired from the standpoint of effective use of resources.

This invention was made in view of the above circumstances, and its purpose is to provide a processing device for mercury-containing dry batteries that is capable of recovering and recycling mercury and that can process mercury-containing dry batteries at high speed.

[Means for solving problems]

In order to solve the above problems, the present invention provides a pulverizer for pulverizing mercury-containing dry batteries, an external heat carbonization furnace for heating the pulverized product pulverized by the pulverizer at a temperature higher than the boiling point of mercury, The carbonization gas discharged from this carbonization furnace is cooled,
A condenser that condenses mercury vapor, a mercury recovery tank that recovers the condensed mercury, a spray tower that removes trace amounts of mercury and suspended dust from the waste gas discharged from the mercury recovery tank, and a spray tower that removes the waste gas from the spray tower. A guard tank that separates minute amounts of impurities and moisture from gas, a packed tower filled with activated carbon that adsorbs and removes trace amounts of residual mercury that could not be removed by the spray tower, and silica gel that adsorbs and removes hydrocarbons in waste gas. The present invention provides a treatment device for a mercury-containing dry battery, comprising: and a final treatment section comprising a waste gas chimney that discharges the waste gas that has passed through the packed tower into the atmosphere.

[For production]

In the mercury-containing dry battery processing apparatus of the present invention having the above configuration, the collected used mercury-containing dry batteries are appropriately crushed by a crusher, and the crushed product is put into an external heating type carbonization furnace and heated. .

This temperature is considerably higher than the boiling point of mercury (375°C), and the mercury used in dry batteries, mainly in the form of mercury oxide, is thermally decomposed into mercury vapor, and other components are also ashed by combustion or thermal decomposition. and becomes carbonized gas. The ash is deposited in the hearth and the carbonized gas containing mercury vapor is sent to the condenser. Furthermore, when dry batteries are crushed as in the present invention, the processing time in a carbonization furnace or combustion furnace is shortened to one-fifth to one-sixth compared to when the batteries are not crushed, and therefore the processing time of the entire device is also reduced. will be significantly shortened.

In the condenser, the carbonized gas is cooled and the mercury vapor is condensed and liquefied, most of which is recovered in the mercury recovery tank. The carbonized gas (waste gas) treated in the mercury recovery tank is sent to a spray tower to remove trace amounts of mercury and suspended dust.
Furthermore, water is separated in the buffer tank of the final treatment equipment, and trace amounts of residual mercury and hydrocarbons are removed through the activated carbon layer and silica gel layer of the packed tower, and then the waste gas is completely purified. The waste gas is released into the atmosphere from the chimney.

〔Example〕

An embodiment of the mercury-containing dry cell processing apparatus according to the present invention includes a crusher 11. External heat carbonization furnace 2, condenser 3, mercury recovery tank 4, first blower 5, spray tower 6, second blower 7,
and a final processing section 8.

Used mercury-containing dry batteries collected from mercury battery dealers, etc. in various places are properly crushed in a crusher 1, and then transferred to an external heat carbonization furnace 2.
The boiling point of mercury (37
5°C). During this heating, an appropriate amount of dry air is supplied to the carbonization furnace 2 from an air intake port 22 filled with silica gel under the control of a solenoid valve 23.

Further, the carbonization furnace 2 is equipped with a water pipe 24 along the outer wall of the furnace for obtaining hot water using combustion waste heat. In addition,
Reference numerals 25 and 26 indicate an in-furnace pressure needle and an in-furnace thermometer, respectively.

The mercury oxide in the crushed material introduced into the furnace is decomposed by heating and generates mercury vapor. In addition, other components such as zinc become residue or floating dust by melting or combustion. Carbonization furnace 2 containing these mercury vapors and suspended dust
The carbonized gas or waste gas is drawn by the first blower 5 and cooled while passing through the condenser 3, condenses, becomes liquefied mercury, and is recovered by the mercury recovery tank 4. In this mercury recovery tank 4, about 75 to 80 percent of the mercury components in the pulverized material fed into the carbonization furnace 2 is recovered and recycled. and sent to the spray tower 6. As shown in FIG. 2, the spray tower 6 has a circulation tank 61 containing a sodium sulfide solution at the bottom, and a circulation pump 62 sends the sodium sulfide solution to a large number of spray nozzles 64 provided in a tower section 63. It is sprayed onto the rising waste gas to cause trace amounts of mercury in the waste gas to react with sodium sulfide and remove it as mercury sulfide. Further, most of the suspended dust is also removed by this spray tower 6.

The waste gas treated in the spray tower 6 is sent to the final treatment section 8 by the second blower 7.・The second blower 7 is the third
As shown in the figure, the control pressure balance of the main pipe line 71 and the entire processing apparatus is adjusted. The bypass line 72 is controlled by a bypass valve 73. Note that the reference numeral 74 indicates a main pipe flow valve, and 75 and 76 indicate a blower fan and its drive motor, respectively.

As shown in FIG. 4, the final processing section 8 includes a buffer tank 81 containing a buffer solution for separating minute amounts of impurities and moisture from the waste gas from the spray tower 6, and a silica gel 8 for spray removal.
3, and a waste gas chimney 85 that discharges the waste gas treated in the packed tower 84 into the atmosphere. The ingredients have been almost completely removed and the product has been sufficiently purified to the point that it will not pollute the environment.

〔Effect of the invention〕

According to this invention, it is possible to process a large amount of used mercury-containing dry batteries at high speed, and it is also possible to recycle the mercury.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of a mercury-containing dry cell processing apparatus according to the present invention, FIG. 2 is a schematic cross-sectional view of the spray tower of the above embodiment, and FIG. 3 is a configuration of the second blower of the above embodiment. 4 are schematic cross-sectional views of the final processing section. 1... Pulverizer, 2... External heating carbonization furnace, 3... Condenser, 4... Mercury recovery tank, 6... Spray tower, 8
...Final processing section, 81...Buffer tank, 84...
Packed tower, 85...waste gas chimney

Claims (2)

[Claims] (1) A pulverizer that crushes mercury-containing dry batteries, an external heating carbonization furnace that heats the pulverized material by this pulverizer at a temperature higher than the boiling point of mercury, and a cooling carbonization gas discharged from this carbonization furnace. A condenser that condenses mercury vapor, a mercury recovery tank that recovers the condensed mercury, a spray tower that removes trace amounts of mercury and suspended dust from the waste gas discharged from the mercury recovery tank, and A buffer tank that separates minute amounts of impurities and water from the waste gas, a packed tower filled with activated carbon that adsorbs and removes trace amounts of residual mercury that could not be removed by the spray tower, and silica gel that adsorbs and removes hydrocarbons in the waste gas. , and a final treatment section consisting of a waste gas chimney that discharges the waste gas that has passed through the packed tower into the atmosphere. (2) The external heating type carbonization furnace is equipped with a dry air supply device for supplying dry air into the furnace, and the spray tower and the buffer tank of the final treatment section have a bypass pipe that is opened and closed by a surus valve. 2. The mercury-containing dry cell processing apparatus according to claim 1, wherein the mercury-containing dry battery processing apparatus is connected by a blower provided therein.