JP6943571B2 - Mercury-containing waste treatment equipment and treatment method - Google Patents

Description

The present invention relates to a mercury-containing waste treatment apparatus and a treatment method, and in particular, recycles mercury-containing waste having a high water content, including waste such as a thermometer, a sphygmomanometer, a fluorescent lamp, and a mercury lamp using mercury. With respect to the device and method for doing so.

In recent years, recycling of waste has been promoted. Therefore, in Patent Document 1, the applicant applies a kiln that heats mercury-containing waste such as contaminated soil to volatilize mercury from the waste and a waste discharged from the kiln into a cement manufacturing facility as a cement raw material. We have proposed a treatment device for mercury-containing waste, etc., which is equipped with a supply device for supplying the waste.

Japanese Unexamined Patent Publication No. 2009-21399

Although the invention described in Patent Document 1 is effective, it is difficult or possible to use an externally heated kiln when heat-treating the mercury-containing waste having a high water content. There was a problem that the heat energy and time required for processing increased, and there was room for improvement.

Therefore, the present invention has been made in view of the above-mentioned problems in the prior art, and an object of the present invention is to efficiently recycle mercury-containing waste having a high water content.

In order to achieve the above object, the present invention is a mercury-containing waste treatment device, which is a dryer for drying the mercury-containing waste and volatilizes the mercury contained in the mercury-containing waste discharged from the dryer. An external heat type kiln to be generated, a supply device for supplying the waste discharged from the external heat type kiln as a cement raw material to a cement manufacturing facility, a dust collector for collecting dust from the exhaust gas of the external heat type kiln, and discharge from the dust collector. It is characterized by including a dust circulation path for returning the collected dust to the externally heated kiln.

According to the present invention, by pre-drying the mercury-containing waste having a high water content, the thermal energy and time required for volatilization of mercury contained in the mercury-containing waste can be significantly reduced, and the water content is high. Mercury-containing waste can be efficiently recycled. Further, by returning the dust collecting dust discharged from the dust collector to the external heat type kiln, mercury adhering to the surface of the dust collecting dust can be volatilized and removed, and the mercury removal efficiency can be improved.

The mercury-containing waste treatment apparatus includes a crusher for crushing the mercury-containing waste discharged from the dryer, and the external heat type kiln is included in the mercury-containing waste discharged from the crusher. Mercury can be volatilized. As a result, by pre-crushing the mercury-containing waste having a relatively large particle size, the thermal energy and time required for volatilization of mercury contained in the mercury-containing waste can be significantly reduced, and the treatment efficiency can be improved. Can be done.

The mercury-containing waste treatment device may include a mercury recovery device that recovers mercury contained in the exhaust gas of the dust collector, and an exhaust gas circulation path that returns the exhaust gas from the mercury recovery device to the external heat type kiln. As a result, mercury remaining in the exhaust gas of the dust collector can be recovered.

In the mercury-containing waste treatment apparatus, the heating temperature in the external heat type kiln can be set to 400 ° C. or higher and 600 ° C. or lower, and the heat energy required for the treatment can be kept low by treating the mercury at a relatively low temperature. , Processing cost can be reduced.

Further, the present invention is a method for treating mercury-containing waste, in which the mercury-containing waste is dried, the dried mercury-containing waste is crushed, and the crushed mercury-containing waste is heated by an external heat type kiln. Mercury is volatilized from the mercury-containing waste, the waste in which the mercury is volatilized is supplied to the cement manufacturing facility as a cement raw material, dust is collected from the exhaust gas of the external heat type kiln, and the dust collected dust is turned into the external heat type kiln. It is characterized in that the mercury contained in the exhaust gas of the external heat type kiln after the dust collection is recovered, and the exhaust gas after the mercury recovery is returned to the external heat type kiln. According to the present invention, mercury-containing waste having a high water content, particularly mercury-containing waste having a relatively large particle size, can be efficiently recycled. Further, by collecting dust from the exhaust gas of the external heat type kiln and returning the dust collected dust to the external heat type kiln, mercury adhering to the surface of the dust collected dust can be volatilized and removed, and the mercury removal efficiency can be improved. Can be enhanced. Further, the mercury contained in the exhaust gas of the external heat type kiln after the dust collection can be recovered, and the exhaust gas after the mercury recovery can be returned to the external heat type kiln, and the mercury remaining in the gas after the dust collection can be recovered. can do.

As described above, according to the present invention, mercury-containing waste having a high water content can be efficiently recycled.

It is a flowchart which shows one Embodiment of the mercury-containing waste processing apparatus which concerns on this invention.

Next, a mode for carrying out the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of a mercury-containing waste treatment apparatus (hereinafter referred to as “treatment apparatus”) according to the present invention, in which the treatment apparatus 1 receives a mercury-containing waste W1 having a high water content. A tank 2 for temporary storage, a dryer 3 for drying the mercury-containing waste W1 from the tank 2, a crusher 4 for crushing the mercury-containing waste W2 from the dryer 3, and mercury from the crusher 4. The external heat type kiln 5 that volatilizes mercury and the like contained in the contained waste W3, the high temperature dust collector 7 that collects dust from the exhaust gas G1 of the external heat type kiln 5, and the mercury contained in the exhaust gas G2 of the high temperature dust collector 7 are adsorbed. It is composed of a mercury recovery device 8 for recovery.

A general-purpose dryer 3 can be used, and one using hot air such as incinerator exhaust gas or fired exhaust gas or an air flow of high-temperature gas can be used.

As the crusher 4, a general-purpose crusher such as a ball mill, a rod mill, or a roller mill can be used. Further, the dryer 3 and the crusher 4 may be integrated. If the particle size of the received mercury-containing waste W1 is relatively small, the crusher 4 may not be provided.

The external heating type kiln 5 is a cylindrical rotary type kiln, which burns fuel from the outside of the kiln with a burner to add heat, or heats the inside of the kiln with hot air introduced from the outside. The internal temperature of the external heat type kiln 5 is adjusted to 400 ° C. or higher and 600 ° C. or lower, and the temperature of the exhaust gas G1 is adjusted to 150 ° C. or higher and 500 ° C. or lower.

As the high-temperature dust collector 7, one having a filter made of a plurality of rod-shaped ceramic tubes can be used, and one having a heat resistance of at least 500 ° C., which is the upper limit of the temperature of the exhaust gas G1, is used.

The mercury recovery device 8 can use an activated carbon adsorption tower or the like that adsorbs and recovers mercury using activated carbon or the like, and the activated carbon used is subjected to a sulfur imposition treatment adjusted for mercury adsorption. Activated carbon is suitable. A fan (not shown) for blowing cooling air for lowering the temperature of the gas G2 to a temperature at which gas can pass through the activated carbon (for example, about 100 ° C.) is provided in the front stage of the mercury recovery device 8. A mercury recovery device other than the activated carbon adsorption tower may be used.

Next, the operation of the processing device 1 having the above configuration will be described with reference to the drawings.

For example, mercury-containing waste having a water content of about 20% or more and 85% or less is received and temporarily stored in the tank 2. The mercury-containing waste W1 is supplied from the tank 2 to the dryer 3 and dried until the water content becomes, for example, about 10% or less. Further, the dried mercury-containing waste W2 is supplied to the crusher 4 to be pulverized to a desired particle size.

The temperature inside the externally heated kiln 5 is maintained at 400 ° C. or higher and 600 ° C. or lower, and the crushed mercury-containing waste W3 is supplied from the crusher 4. In the external heating type kiln 5, mercury contained in the mercury-containing waste W3 volatilizes. The exhaust gas G1 of the external heat type kiln 5 is introduced into the high temperature dust collector 7, and the dust D contained in the exhaust gas G1 is returned to the external heat type kiln 5. As a result, even if mercury is attached to the dust D, it can be volatilized and removed by the external heating type kiln 5.

The volatile mercury contained in the exhaust gas G2 of the high-temperature dust collector 7 is recovered by the mercury recovery device 8, and the exhaust gas G3 after the mercury recovery is returned to the external heat type kiln 5.

The waste W4 from which mercury has been removed is supplied from an externally heated kiln 5 to a cooler (not shown) or the like to be cooled, and then used as a cement raw material in a raw material hopper or the like attached to a cement raw material crushing mill of a cement manufacturing facility. It is transported and used for cement firing.

Although not shown, the treatment device 1 may be provided with a blowing device for blowing caustic soda or slaked lime into the exhaust gas G2 of the high-temperature dust collector 7 to desulfurize the exhaust gas G2. Further, it is also possible to provide an ammonia adding device for adding ammonia to the exhaust gas G2 and denitrate the exhaust gas G2 with the added ammonia.

As described above, according to the present invention, in order to recycle the mercury-containing waste having a high water content, the mercury-containing waste is heated by the external heat type kiln 5 in order to be dried in advance in the dryer 3, and mercury is generated. The heat energy and time required for volatilizing such substances can be significantly reduced, and the processing efficiency can be improved. Further, even when the particle size of the mercury-containing waste is relatively large, the processing efficiency can be further improved because it is crushed by the crusher 4.

Further, since the mercury-containing waste W3 is heated by the external heat type kiln 5 and the exhaust gas G3 is returned to the external heat type kiln 5 and circulated, mercury is efficiently discharged even when mercury remains in the exhaust gas G3. It can be removed and it is possible to prevent mercury from being discharged to the outside of the system.

1 Treatment device 2 Tank 3 Dryer 4 Crusher 5 External heat type kiln 7 High temperature dust collector 8 Mercury recovery device D Dust G1 to G3 Exhaust gas W1 to W3 Mercury-containing waste W4 Waste

Claims (5)

A dryer that dries mercury-containing waste,
An externally heated kiln that volatilizes mercury contained in mercury-containing waste discharged from the dryer,
A supply device that supplies the waste discharged from the externally heated kiln to the cement manufacturing equipment as a cement raw material , and
A dust collector that collects dust from the exhaust gas of the externally heated kiln,
A mercury-containing waste treatment apparatus comprising a dust circulation path for returning dust collected from the dust collector to the externally heated kiln. A crusher for crushing mercury-containing waste discharged from the dryer is provided.
The mercury-containing waste treatment apparatus according to claim 1, wherein the external heat-type kiln volatilizes mercury contained in the mercury-containing waste discharged from the crusher. A mercury recovery device that recovers mercury contained in the exhaust gas of the dust collector,
The mercury-containing waste treatment device according to claim 1 or 2 , further comprising an exhaust gas circulation path for returning the exhaust gas from the mercury recovery device to the external heat type kiln. The mercury-containing waste treatment apparatus according to any one of claims 1 to 3 , wherein the heating temperature of the mercury-containing waste in the externally heated kiln is 400 ° C. or higher and 600 ° C. or lower. Dry the mercury-containing waste and
Crush the dried mercury-containing waste and
The crushed mercury-containing waste is heated with an external heating kiln to volatilize mercury from the mercury-containing waste.
Waste mercury has evaporated supplied as raw material for cement in the cement manufacturing facility,
Dust is collected from the exhaust gas of the external heat type kiln,
Return the dust collector to the external heating kiln,
A method for treating mercury-containing waste, which comprises recovering mercury contained in the exhaust gas of the externally heated kiln after dust collection and returning the exhaust gas after recovering the mercury to the externally heated kiln.

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