JP2009213999A - Apparatus and method of treating mercury-containing waste - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To recycle mercury-containing wastes of contaminated soil, incineration ash or the like inexpensively with simple operation. <P>SOLUTION: The treatment apparatus 1 or the like is equipped with: an external heating type kiln 4 for heating the contaminated soil S1 to volatilize mercury; and a conveying apparatus 9 for conveying the clarified soil S2 discharged from the kiln to a cement manufacturing facility. The apparatus may be provided with a filter 6, on which a catalyst for decomposing and removing VOC and odorous components incorporated in the waste gas G1 is carried, by blowing adsorptive powder of aluminum, zinc, copper, etc., into waste gas G1 of the kiln to form amalgam, separating and removing the amalgam together with chlorine incorporated in the dust in the waste gas G1. The external heating type kiln is used and also the kiln waste gas is circulated, thus the harmful substance being not separated and decomposed in the filter can be treated by the filter again, thereby efficiently removing the harmful gas. As a result, the harmful substance does not discharge outside during the normal operation, so that there is no possibility of environmental pollution. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a processing apparatus and a processing method for mercury-containing waste, and more particularly to an apparatus and a method for recycling mercury-containing waste such as contaminated soil and incinerated ash.

  Soil contaminated with mercury is obliged to take measures such as containment and purification. Therefore, re-elution is suppressed by fixing the contaminated soil in the soil using a chelating agent or the like or containing it in situ. In addition, the contaminated soil is excavated and removed, and then transported to a managed final disposal site, and then backfilled with healthy soil.

  However, the in-situ treatment cannot completely rule out the possibility of future re-elution, and the treatment at the managed final disposal site has the problem of depletion of the final disposal site and the removal of contaminated soil. It takes a lot of cost to bring in healthy soil.

  Therefore, for example, in Patent Document 1, a substance containing chlorine and soil containing heavy metal are mixed, and the moisture content inside the heating device is set to 0% by mass of the mass of the solid non-heated material excluding moisture. As described above, a method for recycling heavy metal-containing soil in which heavy metal is volatilized and separated by heat treatment at a temperature of 700 ° C. or higher and 1600 ° C. or lower while being controlled to be less than 2.0% by mass has been proposed.

In addition, although not related to recycling, Patent Document 2 discloses that about 1 to 97% carbon, hydroxylated water is used to remove mercury from high-temperature and high-humidity gas discharged from contaminated soil treatment equipment and the like. calcium about 1-97% cupric impregnated carbon about 1-97%, and KI ₃ adsorbing powder containing about 1-60% impregnated carbon, and mercury removal method using adsorption chloride powder is described .

Japanese Patent No. 3910132 Special table 2003-523281 gazette

  However, in the method for recycling heavy metal-containing soil described in Patent Document 1, it is necessary to adopt a chlorination volatilization method and to set the inside of the heating device for heavy metal-containing soil to a high temperature atmosphere of 700 ° C. or higher and 1600 ° C. or lower. There is a problem that a large amount of heat energy is required for soil treatment, and the treatment cost increases. Prior to the heat treatment, ceramic products are manufactured by molding or granulating a mixture of a chlorine-containing substance and heavy metal-containing soil. However, many operations are required for the manufacture.

  Further, by using the adsorbed powder described in Patent Document 2, it is possible to remove mercury from a high-temperature and high-humidity gas discharged from a contaminated soil treatment apparatus and containing mercury. There is no mention of the use of soil after removal of wastewater and the recycling of mercury-contaminated soil.

  Therefore, the present invention has been made in view of the problems in the above-described conventional technology, and is intended to recycle mercury-containing waste such as contaminated soil and incinerated ash at low cost and with simple operation. Objective.

  In order to achieve the above object, the present invention is an apparatus for treating mercury-containing waste, comprising a kiln that heats mercury-containing waste and volatilizes mercury from the mercury-containing waste, and waste discharged from the kiln. And a supply device for supplying an article as a cement raw material to a cement manufacturing facility.

  According to the present invention, the mercury-containing waste is heated by the kiln to volatilize mercury from the mercury-containing waste, and the waste discharged from the kiln is supplied to the cement manufacturing facility as a cement raw material. The contained waste can be recycled at a low cost and with a simple operation.

  In the mercury-containing waste treatment apparatus, the exhaust gas of the kiln may be provided with a blowing device that blows one or more adsorbed powders selected from the group consisting of aluminum, zinc, and copper, and adsorbs aluminum or the like from the blowing device. Volatilized mercury can be adsorbed by blowing powder.

  In the mercury-containing waste treatment apparatus, a filter in which a catalyst capable of decomposing VOC (Volatile Organic Compounds) or / and odor components contained in the exhaust gas of the kiln is supported after the blowing apparatus Can be provided. Thereby, VOC generated when the mercury is volatilized and / or odor components can be decomposed and rendered harmless.

  The mercury-containing waste treatment apparatus may include a blowing device for blowing caustic soda and / or slaked lime into the exhaust gas of the kiln. Thereby, desulfurization of the kiln exhaust gas can be performed.

  In the mercury-containing waste treatment apparatus, an ammonia addition device for adding ammonia to the exhaust gas of the kiln can be provided, and the denitration of the kiln exhaust gas can be performed with the ammonia added by the ammonia addition device. At this time, the amount of ammonia added to the kiln exhaust gas can be adjusted according to the NOx concentration of the kiln exhaust gas.

  In the mercury-containing waste treatment apparatus, the heating temperature in the kiln can be 250 ° C. or more and 800 ° C. or less, and mercury can be treated at a relatively low temperature, so that the thermal energy required for the treatment is kept low. , Processing costs can be reduced.

  In the mercury-containing waste treatment apparatus, the exhaust gas temperature of the kiln can be set to 150 ° C. or more and 500 ° C. or less, thereby separating and removing mercury and chlorine contained in the exhaust gas, and decomposing and removing VOC and odor components. Can be performed efficiently.

  In the mercury-containing waste treatment apparatus, the kiln can be an externally heated kiln, and by using an externally heated kiln, exhaust gas from the externally heated kiln and combustion used for heating the externally heated kiln The gases can be processed separately and can be processed in a manner suitable for each gas.

  In the mercury-containing waste treatment apparatus, the exhaust gas from the external heat kiln is blown through the blower and the filter through which one or more adsorbed powders selected from the group consisting of aluminum, zinc and copper are blown. There can be a route back to the thermal kiln. As a result, harmful substances that have not been separated or decomposed by the filter can be treated again by the filter, and the harmful substances can be efficiently removed. During normal operation, harmful substances such as mercury volatilized from the contaminated soil can be removed. It is possible to provide a processing apparatus in which no substances are discharged to the outside and there is no risk of environmental pollution.

  The present invention also relates to a method for treating mercury-containing waste, wherein the mercury-containing waste is heated to volatilize mercury from the mercury-containing waste, and the waste from which mercury has volatilized is used as a cement raw material in a cement manufacturing facility. It is characterized by supplying. According to the present invention, similar to the above-described invention, mercury-containing waste can be recycled at a low cost and with a simple operation.

  In the method for treating mercury-containing waste, the mercury in the gas may be removed by blowing one or more adsorbed powders selected from the group consisting of aluminum, zinc and copper into the gas containing volatilized mercury. it can.

  Moreover, in the said processing method of mercury containing waste, the blowing amount of this adsorption powder can be adjusted according to the mercury concentration in the gas after blowing the said adsorption powder.

  As described above, according to the present invention, mercury-containing waste such as contaminated soil and incinerated ash can be recycled at a low cost with a simple operation.

  Next, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an embodiment of a processing apparatus for mercury-containing waste (hereinafter referred to as “processing apparatus”) according to the present invention. This processing apparatus 1 is roughly divided into mercury-containing contamination received by a hopper 2. The soil supply device 3 that supplies soil (hereinafter referred to as “contaminated soil”) S1 to the external heating kiln 4 and the mercury or the like contained in the contaminated soil S1 from the soil supply device 3 Adsorption powder such as aluminum is blown into the external heat kiln 4 that volatilizes by combustion heat and the exhaust gas G1 of the external heat kiln 4 to separate and remove mercury and chlorine contained in the exhaust gas G1, and to decompose and remove VOC and odor components. Filter 6 with catalyst, heat exchanger 7 for exchanging the air supplied from fan 11 with combustion gas G2 used for heating externally heated kiln 4, and purified soil discharged from externally heated kiln 4 A cooler 8 for cooling the S2, composed purification soil S2, which is discharged from the cooler 8 by a conveying device 9 or the like for transporting the cement manufacturing facility.

  The external heat kiln 4 is a rotary kiln, and is supplied with contaminated soil S1 from the soil supply device 3 inside, and is heated from the outside via the burner 5, thereby containing mercury contained in the contaminated soil S1, Volatilizes chlorine, VOC and odor components. The internal temperature of the external heating kiln 4 is adjusted to 250 ° C. or higher and 800 ° C. or lower, and the temperature of the exhaust gas G1 is adjusted to 150 ° C. or higher and 500 ° C. or lower.

  The filter with catalyst 6 is an amalgam formed by supporting a titanium / vanadium catalyst by blowing an adsorbent powder such as aluminum, zinc and copper into the exhaust gas G1 of the external heating kiln 4 and blowing the adsorbed powder. And the function of both a filter that separates and removes chlorine contained in the dust in the exhaust gas G1 and decomposes and removes VOC and odor components contained in the exhaust gas G1.

  The heat exchanger 7 bleeds the combustion gas G2 (about 400 ° C.) after heating the externally heated kiln 4, raises the temperature of the atmosphere supplied from the fan 11 by the combustion gas G2, and burns the combustion air (about 180 ° C.) and this combustion air is supplied to the burner 5.

  The cooler 8 is provided to cool the purified soil S2 from which harmful substances such as mercury have been volatilized and removed by the external heating kiln 4, and is provided outside the inner cylinder through which the purified soil S2 passes, And an outer cylinder through which cooling water circulates.

  The transport device 9 is provided to supply the purified soil S2 discharged from the cooler 8 to a cement production facility (not shown) as a cement raw material R. For example, a cement raw material is supplied to a raw material hopper attached to a cement raw material crushing mill. Carry R.

  The fan 10 is provided in order to return the exhaust gas G <b> 1 after the harmful substances are removed by the catalyst filter 6 to the external heating kiln 4.

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

  Contaminated soil S1 received from a factory site or the like is stored in the hopper 2. The external heating kiln 4 is heated by the combustion heat generated by burning the fuel with the burner 5, and the internal temperature of the external heating kiln 4 is maintained at 250 ° C. or higher and 800 ° C. or lower. Is supplied with contaminated soil S1.

  In the external heat kiln 4, mercury, chlorine, VOC and odor components contained in the contaminated soil S1 are volatilized, and the volatilized mercury forms amalgam by adsorbed powder such as aluminum blown from the filter 6 with catalyst, The amalgam is separated by the filter 6 with catalyst. Moreover, although chlorine contained in the contaminated soil S1 is contained in dust as KCl or the like, this dust is also removed by the filter with catalyst 6. Furthermore, VOC and odor components contained in the exhaust gas G1 are also separated and removed by the titanium / vanadium catalyst. The separated dust containing amalgam, KCl and the like is periodically discharged out of the system. On the other hand, the exhaust gas G1 from which the harmful substances have been removed is returned to the external heating kiln 4 by the fan 10, and thereafter circulates in the gas flow path including the external heating kiln 4. If the amount of gas circulating through the gas flow path including the external heat kiln 4 becomes excessive, a part of the gas is exhausted outside the system.

  The purified soil S2 from which mercury or the like has been removed is supplied to the cooler 8 from the external heating kiln 4 and cooled, and then is transferred to the raw material hopper attached to the cement raw material crushing mill of the cement manufacturing facility by the conveying device 9 It is conveyed as R and used for cement firing.

  In addition, although illustration was abbreviate | omitted, in the said processing apparatus 1, the blowing apparatus which blows in caustic soda and slaked lime to the waste gas G1 of the external heating kiln 4 may be provided, and you may make it desulfurize the waste gas G1. Further, an ammonia addition device for adding ammonia to the exhaust gas G1 can be provided, and the exhaust gas G1 can be denitrated with the added ammonia.

  As described above, according to the present invention, the contaminated soil S1 is heated by the external heating kiln 4 to volatilize mercury and the like, and the purified soil S2 discharged from the external heating kiln 4 is used as the cement raw material R in the cement manufacturing facility. Therefore, the contaminated soil S1 can be recycled at a low cost and with a simple operation.

  Further, since the contaminated soil S1 is heated by the external heat kiln 4 and the exhaust gas G1 is returned to the external heat kiln 4 through the fan 10 and circulated, it is not separated or decomposed in the filter 6 with catalyst. Hazardous substances can also be processed again in the filter with catalyst 6 and can be removed efficiently, and during normal operation, such harmful substances are not discharged to the outside, which may cause environmental pollution. There is no.

  In the above embodiment, the case where contaminated soil is treated using the present invention has been described. However, in addition to contaminated soil, the present invention is applied to recycling waste containing mercury such as incinerated ash. You can also

  Moreover, in the said embodiment, although the case where the external heating kiln 4 was used in volatilizing mercury etc. was illustrated, it replaced with the external heating kiln 4 and used the internal heating kiln, By combining them, purified soil S2 from which mercury or the like has been removed can be obtained and used as cement raw material R.

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

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Processing apparatus 2 Hopper 3 Soil supply apparatus 4 External heat kiln 5 Burner 6 Filter with catalyst 7 Heat exchanger 8 Cooler 9 Conveyance apparatus 10-12 Fan

Claims (12)

A kiln for heating mercury-containing waste to volatilize mercury from the mercury-containing waste;
An apparatus for treating mercury-containing waste, comprising: a supply device for supplying waste discharged from the kiln as a cement raw material to a cement manufacturing facility.   The apparatus for treating mercury-containing waste according to claim 1, further comprising a blowing device for blowing one or more adsorbed powders selected from the group consisting of aluminum, zinc, and copper into the exhaust gas of the kiln.   The mercury-containing waste treatment apparatus according to claim 2, further comprising a filter supporting a catalyst capable of decomposing a VOC or / and an odor component contained in the exhaust gas of the kiln at a subsequent stage of the blowing device. .   The mercury-containing waste treatment apparatus according to claim 1, 2 or 3, further comprising a blowing device for blowing caustic soda and / or slaked lime into the exhaust gas of the kiln.   The apparatus for treating mercury-containing waste according to any one of claims 1 to 4, further comprising an ammonia addition device for adding ammonia to the exhaust gas of the kiln.   The apparatus for treating mercury-containing waste according to any one of claims 1 to 5, wherein a heating temperature of the mercury-containing waste in the kiln is 250 ° C or higher and 800 ° C or lower.   The apparatus for treating mercury-containing waste according to any one of claims 1 to 6, wherein an exhaust gas temperature of the kiln is 150 ° C or higher and 500 ° C or lower.   The mercury-containing waste treatment apparatus according to any one of claims 1 to 7, wherein the kiln is an external heat kiln.   Having a route for returning the exhaust gas from the external heat kiln to the external heat kiln through the blowing device for blowing one or more adsorbed powders selected from the group consisting of the aluminum, zinc and copper, and the filter. The apparatus for treating mercury-containing waste according to claim 8, Heating the mercury-containing waste to volatilize mercury from the mercury-containing waste,
A method for treating mercury-containing waste, characterized by supplying waste from which mercury has volatilized as cement raw material to a cement production facility.   The mercury in the gas according to claim 10, wherein mercury in the gas is removed by blowing one or more adsorbed powders selected from the group consisting of aluminum, zinc and copper into the gas containing volatilized mercury. Treatment method for waste contained.   The method for treating mercury-containing waste according to claim 11, wherein the amount of the adsorbed powder blown is adjusted according to the concentration of mercury in the gas after the adsorbed powder is blown.

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