JP2008272599A - Method and device for treating fly ash, and method and device for treating waste substances from waste incinerator using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a device for treating fly ash capable of conveniently and efficiently performing treatment and reducing a generated amount of treated waste as well as a running cost without a high-priced chemical and a complicated treatment. <P>SOLUTION: The system that includes a supply section 1 and a carrying-in section 2 that carries the fly ash in, a heating device 3a that performs heating/sintering treatment on the fly ash, and a carrying-out device 5, wherein a fluid containing oxygen is introduced into the device 3a and heating/sintering treatment is performed under an oxidative atmosphere. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a fly ash treatment method and treatment apparatus, and a treatment method and treatment apparatus for waste discharged from a waste incineration facility, and more particularly, a treatment method and treatment for sodium bicarbonate fly ash discharged from a waste incineration facility. The present invention relates to an apparatus, and a method and apparatus for processing waste discharged from a waste incineration facility using the apparatus.

  At present, acid incineration facilities (general waste incinerators, industrial waste incinerators) emit acid gas along with the incineration ash. At this time, the acid gas is often processed using slaked lime or the like, and fly ash (slaked lime fly ash or the like) containing various heavy metals is generated. Previously, these pollutants such as incineration ash and slaked lime fly ash are, for example, (1) cement solidification method, (2) chemical treatment using a chelating agent, (3) stabilization with acid and solvent, etc. They were detoxified and disposed of in managed landfills. Along with the incineration ash, fly ash generated after treating the acid gas is discharged.

  (1) The cement solidification method is a method of solidifying after adding an appropriate amount of cement to the discharge from the incinerator. Specifically, a treatment apparatus using a cement solidification method as shown in FIG. 6 can be mentioned. A rotary heating furnace 102 having a heating means 109 outside; a contaminant introduction device 103 provided upstream of the rotary heating furnace 102; an air supply device 108 for supplying air B1 into the rotary heating furnace 102; A pollutant is rendered harmless by a pollutant purification device comprising a carry-out device 107 provided on the downstream side of the rotary heating furnace 102 and provided with a dust collector 106 at the top. A processing agent supply device 105 is provided in the pollutant introduction device 103 located on the upstream side of the rotary heating furnace 102, and slaked lime, lime, calcium carbonate, baking soda, soda ash, etc. are added to the contaminant from the processing agent supply device 105. A treatment method has been proposed in which the treatment agent C is added to detoxify harmful substances in the cracked gas generated when the pollutants contaminated with dioxins or the like are purified (see, for example, Patent Document 1).

  (2) The chemical treatment method involves adding a suitable amount of a drug (mainly a liquid chelating agent) and performing a detoxification treatment. Specifically, (1-1) Cu content concentration and Pb content concentration in fly ash are measured, and it is necessary to add to fly ash from these measured values and dithiocarbamate group concentration in liquid chelating agent. A method of determining the amount of liquid chelating agent added and immobilizing heavy metals in fly ash (see, for example, Patent Document 2), or (1-2) a salt-forming or complex having a sulfur atom that exhibits a heavy metal immobilizing function It includes one or more heavy metal immobilizing agents having a formable functional group and one or more organic sulfur compounds or oxidizing agents that exhibit a dioxin decomposing function, and these treatments can be performed simultaneously in one agent. An incineration fly ash treatment method (see, for example, Patent Document 3) has been proposed.

  (3) In the acid extraction / sulfide extraction treatment method, water is added to dust to form a slurry, acid is added to extract heavy metals, water and sodium sulfide are further added to insolubilize heavy metal sulfides, and then dehydrated. It is a method to make a cake. Specifically, industrial waste containing toxic heavy metals such as cadmium, zinc, copper, mercury, lead, arsenic, selenium, and nickel, municipal waste incineration ash, soil and sediment, and pollutants such as wastewater, thiosulfuric acid Add the compound or its solution or the waste liquid containing the thiosulfate compound so that the amount of thiosulfate compound is 5 times or more in molar ratio to the heavy metal content in the pollutant, and stirring and mixing at room temperature, or A method for insolubilizing heavy metal elements in pollutants (see, for example, Patent Document 4), characterized by heat treatment at 95 to 120 ° C. for 5 to 36 hours, has been proposed.

JP 2006-95383 A Japanese Patent Application Laid-Open No. 11-70374 JP 2003-94001 A JP 2003-245632 A

However, the fly ash treatment method as described above may cause the following problems and issues.
(1) In the case of cement solidification, high-priced special cement must be used depending on the heavy metal content in the fly ash. Also, cement purchase costs and solidification equipment are required, and the weight discharged by adding cement. Has the disadvantage of increasing.
(2) In the method using chemical treatment, the cost of purchasing the drug to be added is high, and it is necessary to determine the drug, added water, pH, and kneading time by a preliminary test. Previously, the amount of fly ash generated was relatively small, so this method was often used only for slaked lime fly ash.However, these methods have been improved by increasing the amount of waste and reviewing costs. There was a strong request.
(3) In the acid extraction / sulfide extraction treatment method, since the acid for extraction is added, there are problems such as corrosion, wear, and blockage of equipment. In addition, improvements have been demanded from the viewpoint of post-processing and running costs.

  Therefore, an object of the present invention is to easily and efficiently perform processing without using expensive chemicals or complicated processing in processing of fly ash generated by garbage processing, etc. Disclosed is a fly ash treatment method and treatment apparatus capable of reducing the generation amount of waste and reducing running costs, and a treatment method and treatment apparatus for waste discharged from a waste incineration facility using the same. .

  As a result of intensive research, the present inventors can achieve the above object by the following processing method and processing apparatus for fly ash, and processing method and processing apparatus for waste discharged from waste incineration facilities using the same. As a result, the present invention has been completed.

  The present invention is a method for treating fly ash, wherein the fly ash to be treated is sodium bicarbonate fly ash, which is heated and fired in an oxidizing atmosphere.

  Further, the present invention is a fly ash treatment apparatus having a supply device for carrying fly ash, a heating device for heating and firing the fly ash, and a carry-out device for carrying out the treated fired product. The fly ash to be used is baking soda fly ash, an oxygen-containing fluid is introduced into the heating device, and the heat and baking treatment is performed in an oxidizing atmosphere.

  As described above, in the conventional fly ash treatment method, since various chemicals are used, secondary treatment or several-order treatment is often required. The present inventor appropriately detoxifies heavy metals such as cadmium, mercury and lead by performing a baking treatment in an oxidizing atmosphere under a high temperature condition in the treatment process of sodium bicarbonate fly ash, and the fly ash after the baking treatment ( (Hereinafter referred to as “calcined fly ash”) was found to be able to be reduced to a landfill standard value or less in the environmental standards described later. That is, the present inventors have found that the presence of sodium or a sodium compound contained in sodium bicarbonate fly ash functions to detoxify heavy metals when acid gas is treated with sodium bicarbonate. As a result, in the treatment process of baking soda fly ash, it is possible to carry out treatment simply and efficiently without using expensive chelating agents and other chemicals, and further reduce the amount of waste generated and reduce the running cost. It has become possible to provide a fly ash treatment method and treatment apparatus capable of reducing the amount of ash.

  The present invention is the above fly ash treatment method, characterized in that the firing temperature is in the range of more than 500 ° C. and 1200 ° C. or less.

  In the treatment of sodium bicarbonate fly ash, treatment of heavy metals in the sodium bicarbonate fly ash is particularly important, and it is necessary to simultaneously separate a plurality of heavy metals from the sodium bicarbonate fly ash. Furthermore, the burned fly ash is usually reused as a material such as landfill treatment or cement, and for such burned fly ash, the landfill disposal standard and the soil environment standard are set as environmental standards as described later. Of the heavy metals, especially arsenic, mercury, and lead, it was necessary to study new treatment methods as well as strict environmental standards. In the present invention, it has been found that harmful heavy metals as described later can be rendered harmless by high temperature treatment exceeding 500 ° C. On the other hand, in the treatment of baking soda fly ash, it is preferable to carry out the treatment and transfer in the form of a gas or a solid such as a powder, and it becomes very difficult to handle due to melting of the baking soda fly ash under a temperature condition exceeding 1200 ° C. . From the above verification results, in the baking soda fly ash treatment process, by setting the firing temperature in the range of more than 500 ° C. and 1200 ° C. or less, it is simple and efficient without requiring expensive chemicals or complicated treatments. It has become possible to provide a method for treating fly ash that can be treated.

  The present invention is the above fly ash treatment method, characterized in that the firing time is in the range of 5 minutes to 120 minutes.

  In the baking soda fly ash treatment, the firing time is an important indicator as the firing condition, together with the oxygen atmosphere condition and the firing temperature. In other words, when the firing time is short, there is a possibility that the inside of the fly ash is not sufficiently fired and cannot be rendered harmless, while if too much time is taken for the firing treatment, the processing time of the entire process becomes excessive, Energy efficiency is degraded. From the verification results of the present inventors, in the treatment process of sodium bicarbonate fly ash, by providing the firing time in the range of 5 to 120 minutes, a method for treating fly ash that can be simply and efficiently treated is provided. It became possible.

  The present invention is the above fly ash treatment device, wherein the heating device is one of a screw type, a kiln type, a tunnel kiln type, a roller hearth type, a batch furnace, or a combination thereof.

  In the high-temperature treatment of sodium bicarbonate fly ash, a heating device capable of even diffusion of sodium bicarbonate fly ash and rapid preheating, firing and cooling is preferable. Moreover, in this invention, in order to form an oxidizing atmosphere, the heating apparatus in which an oxygen-containing fluid (for example, heating air) and baking soda fly ash can be directly contacted is preferable. Specifically, any of screw type, kiln type, tunnel kiln type, roller hearth type, batch furnace, or a combination of these is a heating device having such a function, ensuring an appropriate firing temperature, simple and efficient. In addition, baking soda fly ash can be processed. Moreover, in an external heating type, direct heat exchange with the baking soda fly ash by heated air is attained, and it is more preferable.

  The present invention relates to a method for treating waste discharged from a waste incineration facility, wherein the acid gas discharged from the waste incineration facility and separated from the incineration ash is subjected to primary treatment with sodium bicarbonate, and the sodium bicarbonate produced by the primary treatment. The fly ash is subjected to secondary treatment using the above treatment method or treatment apparatus.

  Further, the present invention is an introduction path for introducing acid gas discharged from a waste incineration facility, a primary treatment section for reacting acid gas connected to the introduction path, a baking soda supply section for supplying sodium bicarbonate to the primary treatment section, A waste treatment apparatus having a fly ash carry-out path for carrying out the baking soda fly ash generated in the primary processing section, wherein the baking soda fly ash is secondarily treated using the treatment method or the treatment apparatus. And

  As described above, the present inventor has demonstrated that the baking treatment in an oxidizing atmosphere under a high temperature condition is a very simple and effective means in the baking soda fly ash treatment process. At the same time, the present inventors have found that the presence of sodium or sodium compound contained in sodium bicarbonate fly ash functions to detoxify heavy metals. That is, the present inventors have found that by treating acid gas with sodium bicarbonate, the generated sodium bicarbonate fly ash can be made harmless easily and efficiently. The present invention applies such knowledge in the treatment of emissions from a waste incineration facility. The acid gas is primarily treated with baking soda, and the resulting baking soda fly ash is treated with the above-described method for treating fly ash. To provide a simple and efficient method and apparatus for treating waste from a waste incineration facility by appropriately detoxifying waste containing various heavy metals by performing secondary treatment using a treatment apparatus. Became possible.

  As described above, according to the present invention, it is possible to perform processing simply and efficiently without requiring expensive chemicals or complicated processing, and further, the generation amount of processed waste can be reduced and the running cost can be reduced. It became possible to provide a treatment method and treatment apparatus for sodium bicarbonate fly ash that can be reduced. In addition, by using such a baking soda fly ash treatment method and treatment equipment for the treatment of sodium bicarbonate fly ash generated using baking soda in the primary treatment of waste from the incineration facility, the conventional method can be used. The ability to detoxify cadmium, mercury, lead, etc. contained in difficult emissions is further improved, and a simple and efficient method and apparatus for treating waste from waste incineration facilities can be provided. It became.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The baking soda fly ash treatment apparatus according to the present invention (hereinafter referred to as “the present apparatus”)
(1) Supply device for carrying sodium bicarbonate fly ash,
(2) A heating device that performs baking treatment of baking soda fly ash,
(3) It consists of a carrying-out device for carrying out the treated fired fly ash, wherein an oxygen-containing fluid is introduced into the heating device, and the baking soda fly ash is heated and fired in an oxidizing atmosphere.

<One Embodiment of the Apparatus (First Configuration Example)>
FIG. 1 shows a schematic overall configuration of a processing apparatus using an external heating type rotary kiln type heating apparatus as a first configuration example of the present apparatus. Sodium bicarbonate fly ash supplied from the supply unit 1 and carried into the heating device 3a by the carry-in unit 2 (which together with the supply unit 1 constitutes a “supply device”) is supplied from the external heat supply device 4 in the heating device 3a. A heating and baking process is performed in an oxidizing atmosphere by contacting countercurrently with heated air (corresponding to “oxygen-containing fluid”) supplied to the heating device 3a. The fired fly ash produced by the firing treatment is transferred to the ash pit 6 after being cooled by the carry-out device 5 and delivered from the device to be used as a valuable material. On the other hand, the heated air subjected to the heating and firing is discharged from the heating device 3a by the blower 7, and is subjected to a cleaning process (for example, a detoxification process such as adsorption of evaporated organic substances or metal compounds). In this way, by forming an oxidizing atmosphere in the heating device 3a and baking baking soda fly ash under high temperature conditions, it is easy and efficient to use baking soda fly ash without expensive chemicals or complicated treatment. Detoxification treatment can be performed.

  Here, the baking soda fly ash which is a to-be-processed object contains a plurality of heavy metals. Specifically, the composition of incinerated ash and dust includes heavy metals as exemplified in Table 2 in addition to the main components as exemplified in Table 1. Regarding heavy metals, as shown in Table 2, environmental standards are included. As landfill disposal standards and soil environmental standards are established.

Specifically, the composition of sodium bicarbonate fly ash is exemplified as shown in Table 3 below, and it is necessary to separate arsenic, mercury, lead and selenium.

The heating device 3a is preferably configured so that it can directly contact the fly ash with heated air and form an oxidizing atmosphere. Specifically, the screw type, kiln type, tunnel kiln type, roller Any of a hearth type, a batch furnace, or a combination thereof may be mentioned. It has an internal volume of about 5 to ³⁰ m ³ and can be fired while always forming a fresh oxidizing atmosphere by contacting the heated air while flowing or stirring (diffusing) the fly ash. . The heating apparatus is advantageous in that uniform heating can be performed on an object to be processed, and a highly efficient firing process can be performed. In addition, since such a heating device does not require a particularly difficult sealing structure or the like if leakage of fly ash can be prevented, the complexity of the device or the costs associated therewith can be reduced. Note that both the internal heat type and the external heat type can be applied to the heating device, but for the external heat type such as this device, direct heat exchange with the fly ash by the heated air is possible, and heating is performed. It is preferable in that it has high efficiency and has a more excellent firing function.

  As the oxygen-containing fluid, air that can be easily obtained and processed is used in the present apparatus. However, the oxygen-containing fluid is not limited to this as long as it can form an oxidizing atmosphere under high temperature conditions. It is also possible to use the generated waste heat.

  As the heat source of the heated air, electricity, kerosene, heavy oil, gas, or the like can be used, and in-facility waste heat can also be used. It is also possible to improve energy efficiency by reusing the exhausted air after the cleaning process.

  As the firing conditions, as a result of the verification of the present invention, (1) heating air supply amount (or ratio to fly ash supply amount), (2) firing temperature, and (3) firing time are important indicators. The inventors have found that an excellent baking treatment is performed by setting the following range.

(1) Supply amount of heated air (or ratio with supply amount of fly ash)
When the supply amount of fly ash is about 50 to 200 kg / hr, the heating air supply rate is preferably 0.01 to 10 m / sec. If it is 0.01 m / sec or less, the air agitating function is lowered and the oxidizing atmosphere on the surface of the fly ash particles is lowered. If it is 10 m / sec or more, the fly ash becomes a flow of heated air. There is a risk of being caught and mixed in the discharge flow and discharged. In addition, the oxygen concentration for forming the “oxidizing atmosphere” in the present invention is sufficient if it is 2% or more, and can be ensured by the supply amount of the air. By oxidizing atmosphere, detoxification of heavy metals such as lead can be achieved. However, excessive oxygen supply (for example, supply of high-concentration oxygen) may cause trivalent chromium to be hexavalent, and from the viewpoint of operability such as securing an oxygen supply source, it is also necessary to form an oxidizing atmosphere. Is preferably supplied with air.

(2) Firing temperature The firing temperature is preferably in the range of more than 500 ° C and 1200 ° C or less, more preferably 550 ° C or more and 650 ° C or less. Of the heavy metals exemplified in Table 3 above, for cadmium and hexavalent chromium, the amount contained in the baking soda fly ash to be treated was substantially below the environmental standard, and no special treatment was required. Further, it has been demonstrated that arsenic, mercury, selenium, and the like can be rendered harmless under an oxidizing atmosphere at a high temperature exceeding 500 ° C. as will be described later. Further, the same is true for lead, but in the verification process of the present invention, it was found that when heated in an oxidizing atmosphere, lead (II) oxide is formed and detoxified by a reaction presumed to be PbCl ₂ → PbO. . That is, since lead chloride has solubility at room temperature (for example, 1.08 g / 100 g water at 25 ° C.), it causes lead elution, while lead chloride has a melting point of 501 ° C. (boiling point is 950 ° C.). For this reason, the dissolved lead chloride is thought to be replaced by chlorine and oxygen to become lead oxide. This is supported by the fact that the elution value of lead decreases with increasing temperature.
On the other hand, in the transport unit 2, the unloading device 5 and the ash pit 6, the fired fly ash is preferably in the form of a solid such as powder, and as exemplified in Table 1 above, The melt of ash can form a melt, making it very difficult to handle. Therefore, the firing temperature can be easily and efficiently performed by setting the firing temperature in the range of more than 500 ° C. and 1200 ° C. or less.

  (3) The firing time is preferably in the range of 5 minutes to 120 minutes, more preferably in the range of 15 minutes to 45 minutes. When the time is less than 5 minutes, there is a possibility that lead arsenic or the like cannot be sufficiently rendered harmless because the inside of the fly ash is not sufficiently fired. Baking exceeding 120 minutes results in excessive processing time and deterioration of energy efficiency, so that the processing can be performed efficiently by setting the range from 5 minutes to 120 minutes. Specific demonstration results will be described later.

  In addition, the heat and baking treatment as described above can reduce the scattering of fly ash powder, improve handling, and reduce the weight of the burned fly ash by about 10%. Can be reduced by 10%.

<Another configuration example of the present apparatus (second configuration example)>
FIG. 2 shows a schematic overall configuration of a processing apparatus using an internal heating type rotary kiln type heating apparatus as a second configuration example of the present apparatus. The basic configuration is the same as that of the first configuration example, but is characterized in that an internal heating type rotary kiln type heating device 3b using a burner 8 is used instead of an external heating type that supplies heated air from the outside.

  In the heating device 3b, external air can be sucked and supplied from the fly ash supply unit 1 by the blower 7, and heated to 500 ° C. or more and 1200 ° C. or less by the burner 8 to form desired fired fly ash. The arrangement and quantity of the burners 8 can be arbitrarily set according to the type and supply amount of fly ash to be supplied, and highly versatile temperature control or temperature distribution control can be performed. The internal heating type heating device 3b is excellent in that there is little energy loss and high energy efficiency, and when the object to be processed is in a warmed state, the preheating can be further utilized. Further, since there is no need to provide heating equipment outside, the apparatus can be made smaller and more compact.

<Other configuration example of the present apparatus (third configuration example)>
FIG. 3 shows a schematic overall configuration of a processing apparatus using an internally heated roller hearth type heating device 3c as a third configuration example of the present apparatus. The basic configuration is the same as that of the second configuration example, except that a roller hearth type heating device 3c is used instead of the rotary kiln type. This is a continuous firing furnace in which fly ash from the supply unit 1 is poured into a container 31 and conveyed by a roller conveyor 32. The container 31 and the roller conveyor 32 are preferably made of a material having heat resistance and corrosion resistance, such as stainless steel (SUS) and ceramics.

  The roller hearth type heating device 3c is a heating device that is optimal for high-speed heating and uniform heating. In other words, since radiation heating from all directions of the roller conveyor 32 is possible, it becomes easy to obtain a uniform temperature distribution, and the conveyance speed can be controlled by adjusting the rotation speed of the roller conveyor 32. Therefore, it has an excellent function of enabling high-speed conveyance, and it is possible to ensure efficient processing and high energy efficiency.

<Other configuration example of the present apparatus (fourth configuration example)>
FIG. 4 shows a schematic overall configuration of a processing apparatus using a batch furnace 3d as a heating apparatus as a fourth configuration example of the present apparatus. It can be fired by supplying fly ash to the plurality of containers 33 arranged inside the batch furnace 3d and heating the entire batch furnace 3d. As shown by the broken line in FIG. 4, it is possible to supply heated air from the external heat supply device 4, which is highly versatile as a stationary heating device, depending on the type of fly ash, the processing amount, or the processing conditions. Processing can be performed batchwise.

  The batch furnace 3d can be sized and configured according to the installation conditions, including the size of the container 33, and can be made compact. When the external heat supply device 4 is not used, a sealing structure is possible, and a higher airtight atmosphere can be formed.

<Example>
Among the above processing apparatuses, a demonstration experiment was conducted on the first configuration example shown in FIG. 1 using baking soda fly ash as an object to be processed.

[Example 1]
(1) Experimental conditions (1-1) A baking baking treatment was performed using baking soda fly ash having a heavy metal composition shown in the column of 25 ° C. in Table 4 below.
(1-2) The supply amount of fly ash was 5 kg / hr, and the supply rate of heated air was 1 m / sec.
(1-3) The firing temperature was varied from room temperature (25 ° C.) to 850 ° C., and the composition of heavy metals in the fired fly ash was measured.
(1-4) The firing time was based on 25 minutes.

(2) Result About the baking fly ash produced by processing baking soda fly ash, it resulted in having a heavy metal composition as shown in the following table 4. It can be seen that when the temperature exceeds 500 ° C., the landfill disposal standard is also cleared for cadmium and lead.

[Example 2]
(1) Experimental conditions (1-1) Heat baking treatment was performed using baking soda fly ash having the heavy metal composition shown in Table 5 below.
(1-2) The supply amount of fly ash was 5 kg / hr, and the supply rate of heated air was 1 m / sec.
(1-3) The firing temperature was 600 ° C.
(1-4) The firing time was changed, and the composition of heavy metals in the fired fly ash was measured.

(2) Result About the baking fly ash produced by processing baking soda fly ash, it became a result which has a heavy metal composition as shown in Table 5 below. In the firing time of 5 minutes or more, it was found that cadmium and lead also cleared the landfill disposal standard. Cadmium and arsenic could be further reduced at a firing time of 15 minutes or longer.

<Comparative example>
Among the above-described processing apparatuses, a demonstration experiment was conducted on the first configuration example shown in FIG. 1 using slaked lime fly ash as an object to be processed.

（１−２）飛灰の供給量を５ｋｇ／ｈｒとし、加熱空気の供給速度を１ｍ／ｓｅｃとした。
（１−３）焼成温度８００℃および８５０℃において、焼成飛灰中の重金属の組成を測定した。
（１−４）焼成時間は、２５分を基準とした。 (1) Experimental conditions (1-1) Tests were performed using slaked lime fly ash having the composition shown in Table 6 below. It is necessary to detoxify cadmium, arsenic or lead.

(1-2) The supply amount of fly ash was 5 kg / hr, and the supply rate of heated air was 1 m / sec.
(1-3) The composition of heavy metals in the fired fly ash was measured at firing temperatures of 800 ° C. and 850 ° C.
(1-4) The firing time was based on 25 minutes.

(2) Result About the baked fly ash produced by processing slaked lime fly ash, it resulted in having a heavy metal composition as shown in Table 7 below. When the firing temperature was raised, lead decreased, while chromium elution increased, making it difficult for both to meet the landfill disposal standards.

  All of the above processing methods are capable of firing baking soda fly ash containing heavy metals under high temperature conditions in an oxidizing atmosphere. Therefore, by performing efficient separation of heavy metals, a very excellent fly ash treatment apparatus. Can be configured. That is, by the treatment apparatus of the present invention, sodium bicarbonate fly ash, slaked lime fly ash, and the like generated in a waste incineration facility or the like can be efficiently processed to a level below the environmental standard with minimum energy.

<Emissions processing equipment from waste incineration facilities according to the present invention>
An apparatus for treating waste from a waste incineration facility according to the present invention (hereinafter referred to as “the present waste treatment apparatus”)
(A) an introduction path for introducing acid gas discharged from a waste incineration facility;
(B) a primary processing unit that is connected to the introduction path and reacts with acid gas;
(C) a baking soda supplying unit for supplying baking soda to the primary processing unit,
(D) It has a fly ash carry-out path for carrying out the baking soda fly ash generated in the primary processing section, and the baking soda fly ash is subjected to secondary treatment using the above treatment method or treatment apparatus.

  A specific configuration of the present waste treatment apparatus is illustrated in FIG. Out of the discharge from the waste incineration facility 11, the exhaust gas is introduced into the primary processing unit 13 via the heating pipe 12 (corresponding to an “introduction path”). A baking soda supply unit 14 is connected to the primary processing unit 13, and a predetermined amount of baking soda is supplied corresponding to the introduced exhaust gas flow rate. Baking soda fly ash generated by reaction in the primary processing unit 13 is introduced into the supply unit 1 of the processing apparatus 10 through the fly ash carry-out path 15 and is heated and fired in the processing apparatus 10.

Here, the acidic gas that is the object to be treated includes a part of the compound of a plurality of heavy metals as described above and soot containing these. In the case where the amount of sodium bicarbonate fly ash produced in the first configuration example is about 100 kg / hr, the amount of exhaust gas introduced into the primary processing unit 13 is 41000 m ³ N / hr, and the corresponding amount of sodium bicarbonate supplied is 40 kg / hr.

As described above, the present waste treatment apparatus is used in the fly ash treatment process.
(1) The presence of sodium or sodium compounds contained in sodium bicarbonate fly ash functions to detoxify heavy metals. (2) On the contrary, the acid gas is treated with sodium bicarbonate without using slaked lime. By using the fact that it is preferable to generate baking soda fly ash, acid gas is primarily treated with baking soda, and the resulting sodium bicarbonate fly ash is secondarily treated using the above fly ash treatment method and treatment apparatus. It has been proved that it is a very simple and effective means that can appropriately detoxify effluents containing various heavy metals.

As described above, the embodiment of the present invention has been described by taking the baking soda fly ash from the waste incineration facility as an example of the treatment object, but the objects to which the present invention can be applied are limited to these. It may be various slag, for example, copper slag generated during copper refining, or molten fly ash from a melting furnace. That is, the present invention can be applied to a technical field in which wastes or primary treated products that are likely to be eluted with heavy metals are processed into highly safe useful materials.

Explanatory drawing which shows the schematic whole structure of the processing apparatus (1st structural example) which concerns on this invention. Explanatory drawing which shows the structure of a 2nd structural example. Explanatory drawing which shows the structure of a 3rd structural example. Explanatory drawing which shows the structure of a 4th structural example. Explanatory drawing which shows schematic structure of the processing apparatus of the waste material from the waste incineration facility which concerns on this invention Explanatory drawing which shows the contaminant introduction apparatus which concerns on a prior art

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Supply part 2 Carry-in part 3a, 3b, 3c, 3d Heating apparatus 4 External heat supply apparatus 5 Carry-out apparatus 6 Ash pit 7 Blower 8 Burner

Claims (7)

  A fly ash treatment method, wherein the fly ash to be treated is baking soda fly ash, which is heated and fired in an oxidizing atmosphere.   The method for treating fly ash according to claim 1, wherein the firing temperature is in the range of more than 500 ° C and 1200 ° C or less.   The method for treating fly ash according to claim 1 or 2, wherein the firing time is in the range of 5 minutes to 120 minutes.   A fly ash treatment apparatus having a supply device for carrying fly ash, a heating device for heating and firing the fly ash, and a carry-out device for carrying out the treated fired product, wherein the fly ash to be treated is treated with sodium bicarbonate. A fly ash treatment apparatus, wherein fly ash is used, an oxygen-containing fluid is introduced into the heating apparatus, and a heat firing process is performed in an oxidizing atmosphere.   The fly ash treatment apparatus according to claim 4, wherein any one of a screw type, a kiln type, a tunnel kiln type, a roller hearth type, a batch furnace, or a combination thereof is used as the heating device.   The acidic gas discharged from the waste incineration facility and separated from the incineration ash is primarily treated with baking soda, and the baking soda fly ash generated by the primary treatment is treated with claims 1 to 3 or claims 4 to 5. A method for treating waste from a waste incineration facility, wherein the secondary treatment is performed using the processing apparatus according to claim 1.   Generated in the introduction path for introducing the acid gas discharged from the waste incineration facility, the primary treatment section connected to the introduction path for reacting the acid gas, the baking soda supply section for supplying sodium bicarbonate to the primary treatment section, and the primary treatment section A waste treatment apparatus having a fly ash carry-out path for carrying out the burned sodium bicarbonate fly ash, wherein the sodium bicarbonate fly ash is treated using the treatment method according to claims 1 to 3 or the treatment apparatus according to claims 4 to 5. Waste treatment equipment from waste incineration facilities characterized by secondary treatment.

Images