JP4954646B2 - Incineration ash melting equipment - Google Patents

Description

  The present invention relates to an improvement of an incineration ash melting apparatus, and is an incineration ash melting apparatus capable of preventing elution of heavy metals by melting incineration ash of waste containing heavy metals. More specifically, regardless of the furnace atmosphere, it is simple, has low running costs, and is not contained in the waste containing chromium, or the process of burning the waste containing chromium, etc. While reducing harmful hexavalent chromium produced by oxidation to harmless trivalent chromium, melting the incinerated ash while maintaining the form of trivalent chromium, minimizing the hexavalent chromium concentration in the slag, The present invention relates to a melting apparatus for incinerated ash that can surely prevent elution of chromium.

  Incineration ash (incineration residue discharged from the incinerator and waste generated when municipal waste and / or industrial waste and waste such as dewatered cake of sewage sludge are incinerated in the incinerator or incineration ash is melted in the melting furnace Fly ash discharged during the exhaust gas treatment process) occurs, but most of the incinerated ash is landfilled at the final disposal site. However, harmful heavy metals such as lead and cadmium contained in these incineration ash and fly ash, and harmful dioxins, etc. are eluted to the surroundings by the action of rainwater and the like, causing pollution to the environment. It has become a big problem. In recent years, various elution prevention means have been adopted in order to prevent elution of heavy metals contained in incineration ash. In the following, a method for treating incineration ash and fly ash according to a typical conventional example that makes it possible to prevent elution of heavy metals and the like will be introduced.

The thing which concerns on the prior art example 1 is the processing method of the incineration fly ash which generate | occur | produces when incinerating municipal waste and / or industrial waste with an incinerator, or the melting fly ash which generate | occur | produces when incineration fly ash is melted with a melting furnace It is as follows. The molten fly ash or incinerated fly ash is simply referred to as fly ash.
(1) When the measured value of the fly ash pH is 11.0 or higher, the fly ash is heated to 580 ° C. to 800 ° C. to make the treated ash have a pH of 8.5 or higher and lower than 11.0. Is the method.
(2) When the measured value of fly ash pH is less than 8.5, an alkali source is added in advance to make the pH 11.0 or higher, and then the fly ash is heated to 580 ° C. to 800 ° C. This is a fly ash treatment method in which the pH is 8.5 or more and less than 11.0.
(3) When the measured value of the pH of the washed ash is 12.0 or more, the washed ash is heated to 580 ° C. to 800 ° C., and the pH of the treated ash is 8.5 or more and less than 11.8. This is a method for treating fly ash.
(4) If the measured value of the pH of the fly ash washed with water is less than 8.5, an alkali source is added in advance to bring the pH to 12.0 or higher, and then the fly ash is heated to 580 ° C. to 800 ° C. This is a fly ash treatment method in which the pH of the ash is 8.5 or more and less than 11.8.

  That is, the method for treating incinerated fly ash according to the above-mentioned conventional example 1 sets the pH range of fly ash according to the difference between non-washing and water washing pretreatment when measuring fly ash pH, After adjusting the pH, heat treatment is performed at 580 ° C. to 800 ° C. to change the pH range of the treated ash after the overheat treatment, thereby preventing elution of heavy metals in the treated ash and dioxins in the treated ash as well. This is a method for treating fly ash that decomposes at the same time. In addition, in the patent publication according to the conventional example 1, elution of heavy metal components such as Pb, Cd, Zn and Cr is highly dependent on the pH value, and elution of heavy metals such as Pb, Cd, Zn and Cr depending on the pH value. Although it is described that the amount is determined, each example relating to Pb, Cd, Zn as a heavy metal is disclosed in the examples (for example, see Patent Document 1).

In the case of the conventional example 2, the incineration ash is obtained by heating and melting incineration ash such as municipal waste and then obtaining slag with a small amount of elution of heavy metals such as Pb, even by heating and melting at a lower temperature. It is a melt processing method. In this incineration ash melting method, municipal waste is incinerated at a temperature of, for example, about 800 ° C. in a fluidized bed incinerator, the incinerated ash generated by incineration is stored in a storage tank, and then humidified with water at the time of carrying out. Such incinerated ash is supplied to an electric furnace and heated to 1350 ° C. to 1500 ° C. while supplying N ₂ gas which is an inert gas so that the oxygen concentration in the atmosphere in the electric furnace becomes 10% or less. Then, after melting, it is solidified by flowing down into water to form a solidified slag.

Thus, when supplying the N ₂ gas during the melting of the ash to lower the oxygen concentration in the electric furnace, heavy metal oxides melting temperature even at lower temperatures, for example, easily PbO or the like is reduced, in incineration ash Reacts with chlorine (Cl) to form chloride. Since this chloride has a low melting point / boiling point and easily volatilizes, the transfer rate of Pb or the like into the molten slag is lowered. Moreover, since the melting temperature of the incinerated ash is lower, the life of the electric furnace is improved and the energy cost is also reduced, so that the melting cost of the incinerated ash can be made lower (for example, Patent Document 2). reference.).

What concerns the prior art example 3 is a heavy metal elution prevention method of slag. More specifically, when incineration ash containing heavy metal is melted in a melting furnace to produce slag, sulfur in an amount that forms at least an equimolar amount of sulfur with respect to the heavy metal contained in the incineration ash together with the incineration ash. By supplying ore to the melting furnace and generating and stabilizing heavy metal sulfur compounds in the slag generation process, elution of heavy metals during slag disposal is prevented. In addition, the slag produced from the incineration ash of waste contains lead, copper, zinc, and the like as heavy metals in addition to aluminum, silicon, calcium, and the like (see, for example, Patent Document 3). .
Japanese Patent Laid-Open No. 11-192471 JP-A-11-104592 JP 2000-001346 A

  By the way, wastes containing chromium are generated from factories such as the tanned leather industry or the plating industry. In addition, products and equipment containing heavy metals such as chromium are discharged as waste from ordinary households. When such a chromium-containing waste is incinerated in an incinerator, naturally, incineration ash containing chromium is generated. Chromium contained in incineration ash is oxidized to extremely toxic hexavalent chromium. Therefore, when such incineration ash is melted and made into slag, six slags from slag are used to meet the soil environmental standards. It is necessary to prevent elution of valent chromium.

By the way, it is described in the said patent document 1 that the elution amount of heavy metals, such as Pb, Cd, Zn, Cr, is determined by pH value. Therefore, it is considered that the elution amount of Cr can be suppressed by adjusting the pH value, but it is possible to reliably prevent the elution of Cr in both Patent Documents 1 and 2 and Patent Documents 2 and 3. No specific Cr elution prevention means that makes it possible to do so is disclosed. Moreover, in order to suppress the elution of Cr from the slag, it is known that the melting furnace is made a reducing atmosphere with less oxygen and the furnace temperature is raised as in Conventional Example 2. However, these methods require the installation of a nitrogen generator and supply of coke into the melting furnace to create a reducing atmosphere, increasing running costs and increasing CO ₂ emissions, which are said to be a global warming effect gas. This is not an effective method in terms of total environmental impact.

  Therefore, the object of the present invention is to reduce the waste in the incineration ash of the heavy metal, particularly chromium-containing waste, without being burdened with environmental burden, regardless of the furnace atmosphere. In the slag, the incinerated ash is melted while maintaining the form of trivalent chromium, while reducing the harmful hexavalent chromium that is contained or produced by oxidation of chromium in the waste to harmless trivalent chromium. It is intended to provide a melting apparatus for incinerated ash in which the concentration of hexavalent chromium is minimized so that elution of hexavalent chromium can be reliably prevented.

In order to solve the above-mentioned problems, the inventors have elucidated the elution mechanism of hexavalent chromium by a laboratory experiment and embodied the present invention after confirming the experiment. More specifically, after converting the sewage sludge into incinerated ash, the conditions are changed by an electric furnace to melt and cool to produce sample slags S _{11 to} S ₁₃ , S _{21 to} S ₂₃ and S _{25 to} S ₂₈ . Based on the results of chemical analysis data (qualitative analysis, quantitative analysis) and physical analysis data (structural analysis, morphological analysis) obtained by analysis, the elution mechanism of hexavalent chromium was elucidated.

First, among the sample slug _{S 11 ~S 13, S 21 ~S} 23 and _S 25 _{to S 28,} the dissolution test of the sample slug _S 11 _{to S 13,} and _S 21 _{to S 23} (ring tell No. 46) and heavy metals The analysis results of the content (annular water tube 127) are shown in Table 1 below. Of the sample slags shown in Table 1, the relationship between the elution amount (mg / L) of hexavalent chromium with respect to the basicity (CaO / SiO ₂ or (CaO + MgO) / SiO ₂ ) of sample slags S _{21 to} S ₂₃ is shown in FIG. 11 as shown. Moreover, the relationship with the total chromium elution amount with respect to the basicity of each sample slag shown in this Table 1 is as showing in FIG. The values below the detection limit of hexavalent chromium and total chromium with respect to basicity are all shown as “0”. The “a method” in the column of the cooling method in Table 1 below indicates a case where 1500 ° C. molten slag is gradually cooled to 1000 ° C. over about 30 minutes, and then 1000 ° C. slag is rapidly cooled by water cooling. The “b method” indicates a case where a molten slag of 1500 ° C. is rapidly cooled by water cooling, and the same applies to Tables 2 and 3 below.

11 and 12, it can be seen that the elution amount of hexavalent chromium and the elution amount of total chromium increase as the basicity increases. Further, according to the dissolution results of the sample slug S ₁₁ to S _13, even though basicity is 1 or less, hexavalent chromium is eluted. In particular, the elution amount of hexavalent chromium in the sample slag S ₁₃ exceeds the soil environment standard value (0.05 mg / L), which can be considered to be caused by the cooling rate of the molten slag.

The relationship between the eluate pH of sample slags S _{21 to} S ₂₃ and the elution amount of hexavalent chromium is shown in FIG. 13, and the eluate pH and the conversion rate of eluated chromium to hexavalent chromium (hexavalent chromium in the eluate / elution). The relationship of the total chromium in the liquid is shown in FIG. FIG. 15 shows the relationship between the basicity of sample slags S _{21 to} S ₂₃ and the eluate pH, and FIG. 16 shows the relationship between Ca elution rate and eluate pH. FIG. 13 shows that the elution amount of hexavalent chromium increases as the eluate pH increases. From FIG. 14, when the eluate pH increases, the chromium eluted in the test solution is oxidized and converted to hexavalent chromium. It can be seen that the tendency to Further, FIG. 15 shows that the eluate pH tends to increase as the basicity increases, and FIG. 16 shows that the eluate pH tends to increase as the Ca elution rate increases.

スラグの骨格を構成するＳｉの溶出率と全クロムの溶出率の関係を図１７に示し、スラグの骨格を構成するＣａの溶出率と全クロムの溶出率の関係を図１８に示し、また塩基度とＳｉ，Ｃａの溶出率の関係を図１９に示す。なお、溶出率とは、溶出液中濃度／スラグ中濃度で表されるパラメータのことである。これら図１７乃至１９から、スラグの骨格を構成する主要成分であるＳｉ，Ｃａの溶出率が高くなるにつれて、全クロムの溶出率も高くなる傾向があることが分かる。このことは、スラグ表面で水溶液と接触しているＳｉ，Ｃａが溶出することにより、スラグマトリックス中に取込まれていたクロムが溶出するということを示すものである。また、塩基度とＳｉ，Ｃａの溶出率にも相関関係が認められ、塩基度が高くなるとＳｉ，Ｃａの溶出率も高くなることが分かる。 Table 2 shows the composition analysis results in the test solution and the composition analysis results of the molten slag.

FIG. 17 shows the relationship between the dissolution rate of Si constituting the slag skeleton and the dissolution rate of all chromium, and FIG. 18 shows the relationship between the dissolution rate of Ca and the dissolution rate of all chromium, constituting the slag skeleton. FIG. 19 shows the relationship between the temperature and the elution rate of Si and Ca. The dissolution rate is a parameter represented by the concentration in the eluate / the concentration in the slag. 17 to 19, it can be seen that the elution rate of all chromium tends to increase as the elution rate of Si and Ca, which are the main components constituting the slag skeleton, increases. This indicates that chromium and silicon incorporated in the slag matrix are eluted by elution of Si and Ca in contact with the aqueous solution on the slag surface. Moreover, a correlation is recognized also in basicity and the elution rate of Si, Ca, and it turns out that the elution rate of Si and Ca becomes high when basicity becomes high.

When comparing samples slag _S 11 _{to S 13} and the sample slug _S 21 _{to S 23,} even though towards the sample slug _S 11 _{to S 13} is lower basicity than the sample slug _S 21 _{~S 23,} Si, Ca The elution rate of is high. This indicates that the water resistance of the slag surface is weaker in the sample slags S _{11 to} S ₁₃ , and from this, the rapid cooling of the molten slag from the high temperature region is important for the glassy formation of the slag surface. I understand that there is. As described in paragraph [0012] above, the cooling process of the sample slags S _{11 to} S _{13 includes} a cooling process from 1500 ° C. to 1000 ° C. over about 30 minutes. On the other hand, the sample slug _S 21 _{to S 23} are quenched from 1500 ° C. by water-cooling, the sample slug _S 11 _{to S 13} rigid glassy compared to is formed (provided that basicity 1 below).

サンプルスラグの溶融温度と六価クロムの溶出量の関係を図２０に示し、サンプルスラグの溶融温度と六価クロムの濃度の関係を図２１に示し、そしてサンプルスラグの溶融温度とＳｉ，Ｃａ溶出率の関係を図２２に示す。これら図２０乃至２２から、以下のことが分かる。
（１）溶融温度が１４００℃以上になると、六価クロムの溶出は確認されない。
（２）溶融温度によるスラグ中の六価クロムの濃度は１３００℃で若干高くなっているものの、その差は極僅かであり、殆ど相違がない。
（３）スラグの主要構成要素のＳｉの溶出率については溶融温度による顕著な相違が認められないが、Ｃａの溶出率は溶融温度が低温になるにつれて高くなっており、溶融温度が１３００℃ではスラグ表面に耐水性が劣る部位があると考えることができる。 Further, for the sample slug _{S 27} that ash was obtained by melting at 1300 ° C., the sample slug _{S 28} obtained by melting at 1400 ° C., and the sample slug _{S 21} obtained by melting at 1500 ° C., molten The relationship between temperature and elution amount of hexavalent chromium was investigated. The analysis results of these sample slags S ₂₇ , S ₂₈ and S ₂₁ are as shown in Table 3 below.

The relationship between the melting temperature of sample slag and the elution amount of hexavalent chromium is shown in FIG. 20, the relationship between the melting temperature of sample slag and the concentration of hexavalent chromium is shown in FIG. 21, and the melting temperature of sample slag and elution of Si and Ca The relationship between rates is shown in FIG. 20 to 22, the following can be understood.
(1) When the melting temperature is 1400 ° C. or higher, elution of hexavalent chromium is not confirmed.
(2) Although the concentration of hexavalent chromium in the slag due to the melting temperature is slightly higher at 1300 ° C., the difference is very slight and there is almost no difference.
(3) Regarding the elution rate of Si as the main component of the slag, no remarkable difference is observed depending on the melting temperature, but the elution rate of Ca increases as the melting temperature decreases, and the melting temperature is 1300 ° C. It can be considered that there is a portion having poor water resistance on the slag surface.

Moreover, it is confirmed by XRD inspection that Cr ₂ O ₃ is present in the sample slag S ₂₁ (melting temperature; 1500 ° C.) and the sample slag S ₂₈ (melting temperature; 1400 ° C.), and in the sample slag S ₂₇ It was confirmed that a composite oxide of calcium, silica, and chromium called Ca ₃ Cr ₂ (SiO ₄ ) was present.

From the above, it can be understood that the following may be performed in order to prevent elution of hexavalent chromium from the molten slag of incinerated ash.
(1) Increase the water resistance of the slag surface so that skeletal elements do not elute from the slag.
a. Reduce the basicity to 1 or less and reduce the number of silica network blocking points.
b. The molten slag is rapidly cooled to keep the silica in a glass state and to contain chromium in a highly water-resistant glass body.
(2) The eluate pH is not shifted to the alkali side.
The basicity is set to 1 or less, the molten slag is rapidly cooled to contain chromium in a highly water-resistant glass body, and the elution of Ca from the slag is suppressed.
(3) In order to reduce the content of hexavalent chromium in the slag, hexavalent chromium is reduced at a high temperature.
(4) Since hexavalent chromium is unstable at a high temperature such as the melting temperature (1400 ° C.), the temperature in the melting furnace is maintained at a high temperature.

The present invention is embodied by the above laboratory experiment and the result of the experiment. Therefore, the gist of the means adopted by the melting apparatus for incinerated ash according to claim 1 of the present invention is the waste supply apparatus and the waste disposal apparatus. An incinerator for incinerating waste supplied from an incinerator, a cyclone for collecting incineration ash in exhaust gas discharged from the incinerator, and an incineration ash supplied from the cyclone via an incineration ash supply unit A melting furnace that melts the molten slag, a water cooling device that quenches the molten slag discharged from the slag discharge port, a basicity measuring device that measures the basicity of the incinerated ash, and the incineration Any one of a chromium concentration measuring device for measuring the chrome concentration of ash and the waste supply device or the incinerator is provided with a base so that the basicity of the incinerated ash is 0.6 to 1.0. Supply degree adjusting agent And Motodo adjusting agent supply device, to any one of the waste feed device or the incinerator, and chromium concentration adjusting agent supply device for supplying the chromium concentration adjusting agent, in the exhaust gas discharged from the cyclone It is characterized by comprising a dust collector that further collects fly ash and a chimney that releases the exhaust gas discharged from the dust collector and from which fly ash has been removed to the atmosphere.

Fei gist of means melter ash is adopted according to claim 2 of the present invention, the melting apparatus of ash according to claim 1, in which the melting furnace before Symbol dust collector, which is collected by a dust collector It is characterized by comprising a transport device for supplying ash to the incineration ash supply device.

The gist of the means adopted by the incinerator ash melting apparatus according to claim 3 of the present invention is as follows: a waste supply apparatus, an incinerator for incinerating waste supplied from the waste supply apparatus, and an exhaust from the incinerator Ash supply device for supplying the incinerated ash to the melting furnace, a basicity measuring device for measuring the basicity of the incinerated ash, a chromium concentration measuring device for measuring the chromium concentration of the incinerated ash, and the waste supply Basicity for supplying basicity adjusting agent to any one of the apparatus, the incinerator or the incinerator so that the basicity of the incinerated ash discharged from the incinerator is 0.6 to 1.0 A chrome concentration adjusting agent supply device for supplying a chrome concentration adjusting agent and an incineration ash supplied from the incineration ash supply device to any one of the adjusting agent supply device, the waste supply device or the incinerator. Melting furnace to be melted and the position below this melting furnace Provided and is characterized in that it consists of a water-cooling apparatus for rapidly cooling the molten slag discharged from the slag discharge port.

The gist of the means adopted by the melting apparatus for incineration ash according to claim 4 of the present invention is a hopper for receiving incineration ash , an incineration ash supply apparatus, a basicity measurement apparatus for measuring the basicity of the incineration ash, and A chromium concentration measuring device for measuring the chromium concentration of the incinerated ash, and a basicity adjusting agent supply device for supplying a basicity adjusting agent to the hopper so that the basicity of the incinerated ash is 0.6 to 1.0. A chromium concentration adjusting agent supplying device for supplying a chromium concentration adjusting agent, a melting furnace for melting the incinerated ash supplied from the incineration ash supplying device, and a lower position of the melting furnace, and discharged from a slag discharge port And a water cooling device for rapidly cooling the molten slag.

In the melting apparatus for incineration ash according to claims 1 to 4 of the present invention, when the incineration ash discharged from the incinerator is supplied to the melting furnace, the basicity of the incineration ash becomes 0.6 to 1.0. The incineration ash in which the basicity adjusting agent is supplied to any one of the waste supply device and the incinerator is supplied to the melting furnace. And the molten slag of the incinerated ash melted in this melting furnace is rapidly cooled by a water cooling device. Therefore, according to the melting apparatus for incineration ash according to claims 1 to 4 of the present invention, while reducing the harmful hexavalent chromium in the incineration ash to harmless trivalent chromium, the form of trivalent chromium is maintained. By melting the incinerated ash, the hexavalent chromium concentration in the slag can be minimized and the elution of hexavalent crumb can be reliably prevented, so that the elution of hexavalent chromium into the environment can be further reduced. Moreover, since the surface of the slag is formed of glass having excellent water resistance, the elution of hexavalent chromium from the slag body can be effectively suppressed.

  According to the incinerator ash melting apparatus according to claim 2 of the present invention, the fly ash collected by the dust collector is melted again in the melting furnace, thereby reducing the total amount of fly ash to be landfilled at the final disposal site. It is possible to transfer heavy metals such as hexavalent chromium and lead contained in fly ash to slag, and to reduce the elution of heavy metals such as hexavalent chromium to the environment as much as possible. it can.

  According to the melting apparatus for incineration ash according to claim 3 of the present invention, the incineration ash discharged from the incinerator (incineration residue discharged from the incinerator, the boiler, the temperature reducing tower, the exhaust gas treatment process of the dust collector, etc.) Ash) is reduced to harmless trivalent chromium while reducing the harmful hexavalent chromium in the incineration ash, while maintaining the form of trivalent chromium to minimize the hexavalent chromium concentration in the slag. Since elution of hexavalent crumb can be reliably prevented, elution of hexavalent chromium into the environment can be further reduced. Further, in the incineration ash melting device according to claims 3 and 4 of the present invention, the incineration ash is supplied from the incineration ash supply device. Therefore, according to the incinerator ash melting apparatus according to claims 3 and 4 of the present invention, not only the incinerated ash discharged from the incinerator of the specific facility equipped with the melting furnace as ancillary equipment, but also the garbage not equipped with the melting furnace. The general-purpose effect that the incineration ash discharged from the incineration facility can be received and melted can be obtained.

  Hereinafter, an incinerator ash melting apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings. First, an incineration ash melting apparatus according to Embodiment 1 of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a block diagram showing a processing flow of the waste.

_Reference sign F _m1 shown in FIG. 1 is an incineration ash melting apparatus according to Embodiment 1 of the present invention. Melter F _m1 of the incineration ash, waste K _m containing chromium is supplied via a waste feed device 1 comprises a incinerator 3 to incinerate the supplied waste K _m. The exhaust gas discharged from the incinerator 3 through the duct 3a is introduced into the cyclone 4, and the incinerated ash separated and collected from the exhaust gas by the cyclone 4 is supplied to the melting furnace 5 through the incinerator ash supply device 4a. It has come to be.

The incinerator 3 is connected to a regulator supply line from the regulator supply device 2, and the basicity of the incineration ash generated by the combustion of the waste K _{m in} the incinerator 3 is 0.6 to 1.0. The basicity adjusting agent is supplied so that it becomes. Further, when the chromium content of the ash resulting from the incineration of waste _{K m} by the incinerator 3 is greater than 20000 mg / kg, chromium concentration 90000mg / kg or less, preferably to a predetermined concentration below 60000mg / kg Thus, a chromium concentration adjusting agent is supplied. Moreover, you may supply a chromium density | concentration regulator so that the melt flow temperature of incineration ash may become 1200-1400 degreeC depending on the case. These basicity adjusters and chromium concentration adjusters are slaked lime, quicklime, silica sand, dolomite and magnesium oxide, and one or more of these are supplied from the adjuster supply device 2.

The supply amount of the basicity adjusting agent and chromium concentration adjusting agent to be supplied to the incinerator 3, the production of the melter F _m1, as well as incineration actually waste K _m, periodically ash during operation The basicity and the chromium concentration are examined and determined based on the test results. Moreover, the melt flow temperature of waste and incinerated ash was measured based on JIS M8801 "Ash melting characteristics test".

  The combustion exhaust gas from which the incineration ash has been removed by the cyclone 4 is introduced into the secondary combustion device 7, and after the unburned gas such as carbon monoxide in the combustion exhaust gas is combusted by the secondary combustion device 7, the temperature reducing tower 8. To be introduced. The exhaust gas reduced in temperature by the temperature reducing tower 8 is introduced into a bag filter 9 which is a dust collector. The fly ash in the exhaust gas is collected by the bag filter 9 and the exhaust gas from which the fly ash has been removed is discharged from the chimney 10. Released into the atmosphere.

  On the other hand, it is supplied to the melting furnace 5 through the incineration ash supply device 4a, and the basicity is adjusted to 0.6 to 1.0 by supplying the basicity adjusting agent and the chromium concentration adjusting agent, and the chromium concentration is 20000 mg. / Kg or less, or the incinerated ash adjusted to have a melt flow temperature of 1200 ° C. to 1400 ° C. is melted at a temperature of 1350 ° C. to 1500 ° C. to form molten slag. The molten slag flows down from the slag discharge port 5a provided at the lower part of the melting furnace 5 into the water cooling device 6 provided below the slag discharge port 5a, and is rapidly cooled by the cooling water in the water cooling device 6. It is comprised so that.

  The high-temperature exhaust gas discharged from the melting furnace 5 is introduced into the secondary combustion device 7 through a duct 5b. Although not shown in the drawing, the water cooling device 6 is provided with a cooling circulation line equipped with a cooler, and the temperature of the cooling water in the water cooling device 6 is maintained at, for example, 50 ° C. to 80 ° C. It is configured. In the case of the first embodiment, the basicity adjusting agent and the chromium concentration adjusting agent are configured to be supplied to the incinerator 3 as described above. This is because the basicity adjusting agent and the chromium concentration adjusting agent are supplied to the incinerator 3 so that the incineration ash, the basicity adjusting agent and the chromium concentration adjusting agent are uniformly mixed by the turbulent mixing of the exhaust gas in the incinerator 3. Because it is done. However, as shown by a broken line in FIG. 1, even if the waste is supplied to the waste supply device 1 or the incineration ash supply device 4a, the same effect as that supplied to the incinerator 3 can be obtained.

Hereinafter, the operation mode of the incinerator ash melting apparatus F _{m1 according to} the first embodiment of the present invention will be described. Waste K _m from the waste supply device 1 is supplied to the incinerator 3 are incinerated in the incinerator 3, the generated exhaust gas is introduced into the cyclone 4 through the duct 3a. The exhaust gas introduced into the cyclone 4 and the incineration ash contained in the exhaust gas are separated by the cyclone 4, and the exhaust gas from which the incineration ash has been removed is the secondary combustion device 7, the temperature reducing tower 8, and the bag filter 9. After that, it is emitted from the chimney 10 into the atmosphere.

Wherein with the waste feed device basicity adjusting agent from the adjustment agent supply device 2 with waste K _m supplied from 1 to incinerator 3 are supplied, the chromium concentration adjusting agent as needed is supplied, and basicity Since the chromium concentration is adjusted, it is separated by the cyclone 4 and the basicity of the collected incineration ash is 0.6 to 1.0, and the chromium concentration is 90000 mg / kg or less, The predetermined concentration is preferably 60000 mg / kg or less. Incineration ash having such basicity and chromium concentration is supplied to the melting furnace 5 and melted at a temperature of 1350 ° C. to 1500 ° C. in the melting furnace 5 to form molten slag.

  The molten slag flows down along the furnace inner wall of the melting furnace 5 toward the slag discharge port 5a and is dropped from the slag discharge port 5a into the water cooling device 6 for rapidly cooling the molten slag. It is rapidly cooled by water and solidified to form solidified slag. High-temperature exhaust gas generated from the melting furnace 5 due to melting of the incineration ash is discharged into the atmosphere together with the combustion exhaust gas discharged from the fluidized bed incinerator 2 from the chimney 10 through the temperature reducing tower 8 and the bag filter 9. . Further, high-temperature exhaust gas discharged from the melting furnace 5 passes through the secondary combustion chamber 7, the temperature reducing tower 8, and the bag filter 9, and is released into the atmosphere from the chimney 10 together with the exhaust gas discharged from the incinerator 3. .

As described above, in the incineration ash melting apparatus F _{m1 according} to Embodiment 1 of the present invention, the basicity of the incineration ash is adjusted to be 0.6 to 1.0, and the temperature is 1350 ° C. to 1500 ° C. Since it is melted and rapidly cooled by the cooling water in the water cooling device 6 from a temperature of 1350 ° C. to 1500 ° C., the surface of the slag is formed of glass having excellent water resistance. Therefore, according to the melting apparatus 1 for incineration ash according to Embodiment 1 of the present invention, while reducing the harmful hexavalent chromium in the incineration ash to harmless trivalent chromium, the form of trivalent chromium is maintained. By melting the incinerated ash, the hexavalent chromium concentration in the slag is minimized, and there is an effect that the elution of hexavalent chromium can be surely prevented.

In addition, in the incineration ash melting apparatus F _{m1 according} to Embodiment 1 of the present invention, when the chromium content of the waste K _m is high and the chromium concentration of the incineration ash exceeds 20000 mg / kg, as described above, The chromium concentration is adjusted to a predetermined concentration of 90000 mg / kg or less, preferably 60000 mg / kg or less. Therefore, the incineration ash can be reliably melted at a temperature of 1500 ° C. or less. Therefore, according to the incinerator ash melting apparatus F _m1 according to the first embodiment of the present invention, an increase in the operating temperature of the melting furnace 5 can be suppressed, and the refractory (refractory bricks) constituting the inner wall of the melting furnace 5 can be suppressed. ) Can be extended, so that it can greatly contribute to the reduction of running costs of the incinerator ash melting device F _m1 , the reduction of waste incineration and melting treatment costs, and the prevention of global warming. Effects can be obtained.

In addition, in the incineration ash melting apparatus F _{m1 according to the} first embodiment of the present invention, the chromium content of the waste K _m tends to be high, and the melting temperature of the incineration ash tends to be high. Therefore, a chromium concentration adjusting agent may be supplied to adjust the melt flow temperature of the incineration ash so that the melt flow temperature of the incineration ash becomes 1200 ° C to 1400 ° C. As a result, the incineration ash can be reliably melted at a temperature of 1500 ° C. or less, and the slag in which the incineration ash is melted does not solidify even in the vicinity of the slag discharge port 5a where the ambient temperature is low. Therefore, according to the incinerated ash melting device F _m1 according to the first embodiment of the present invention, the slag can be stably discharged from the slag discharge port 5a, and the slag discharge port 5a is blocked by the solidification of the slag. Therefore, stable operation of the incinerated ash melting device _Fm1 can be continued for a long period of time.

  The melting apparatus for incineration ash according to the second embodiment of the present invention is denoted by the same reference numerals as those in the first embodiment while referring to FIG. 2 of the block diagram showing the waste processing flow. The differences will be described below.

  That is, as is well understood in the comparison between FIG. 2 according to the second embodiment of the present invention and FIG. 1 according to the first embodiment, the second embodiment of the present invention is different from the first embodiment. The place where the bag filter 9 and the incinerated ash supply device 4a are communicated with each other via a fly ash air transfer device 9a which is a transfer device, and the fly ash collected by the bag filter 9 is connected to the fly ash air transfer device 9a. It is in the place where it was made the structure which supplies to the melting furnace 5 via.

Therefore, according to the incineration ash melting device _Fm2 according to the second embodiment, the fly ash collected by the bag filter 9 is transferred from the incineration ash supply device 4a to the melting furnace 5 through the fly ash air transfer device. since the point of supply is only different, in addition to the effect equivalent to the melter F _m1 of ash according to the first embodiment is obtained, melting furnace fly ash is captured in a bag filter 9 again 5 can be melted, reducing the total amount of fly ash landfilled at the final disposal site, and reducing the elution of heavy metals such as hexavalent chromium into the environment as much as possible. is there.

  An incineration ash melting apparatus according to Embodiment 3 of the present invention will be described with reference to FIG. 3 of a block diagram showing a waste processing flow.

The symbol F _m3 shown in FIG. 3 is an incinerator ash melting device, and the melting device F _m3 is supplied with waste K _m containing chromium through the waste supply device 21 and supplied waste K _m. The incinerator 23 which incinerates is provided. Incineration residues waste K _m generated in the incinerator 23 are supplied to the ash supply unit 24. The incinerator 23 is connected to a regulator supply line from a regulator supply device 22, and the basicity of the incineration ash is 0.6 to 1.0 through this regulator supply line. When the adjusting agent is supplied, and when the chromium concentration of the incineration ash exceeds 20000 mg / kg, the chromium concentration adjusting agent is supplied so that the predetermined concentration is 90000 mg / kg or less, preferably 60000 mg / kg or less. It has come to be. Or you may supply a chromium concentration regulator so that the melt flow temperature of incineration ash may become 1200-1400 degreeC instead of chromium concentration. The supply amount of the waste K _m of supplying basicity adjusting agent and a chromium concentration adjusting agent is determined by the same means as in the first embodiment.

  The exhaust gas discharged from the incinerator 23 is recovered by the boiler 27 at the rear stage of the incinerator 23, and the exhaust gas after the heat recovery is introduced into the temperature reducing tower 28. The exhaust gas whose temperature has been reduced by the temperature reducing tower 28 is introduced into the bag filter 29, the fly ash in the exhaust gas is collected by the bag filter 29, and the exhaust gas from which the fly ash has been removed is discharged from the chimney 30 into the atmosphere. It has become so. Further, the incineration ash supply device 24 communicates with the fly ash air transfer device 29a from the boiler 27, the temperature reducing tower 28, and the bag filter 29. In addition to the incineration residue discharged from the incinerator 23, The fly ash discharged from the boiler 27, the fly ash discharged from the temperature reducing tower 28, and the fly ash collected by the bag filter 29 are all supplied to the incineration ash supply device 24.

  On the other hand, it is supplied to the melting furnace 25 through the incineration ash supply device 24 so that the basicity becomes 0.6 to 1.0 by supplying the basicity adjusting agent and the chromium concentration adjusting agent, and the chromium concentration is 90000 mg / day. The incineration ash adjusted to a predetermined concentration of kg or less, preferably 60000 mg / kg or less, or an incineration ash melting temperature of 1200 ° C to 1400 ° C is melted at a temperature of 1350 ° C to 1500 ° C. It becomes molten slag. The molten slag flows from a slag discharge port 25a provided in the lower part of the melting furnace 25 to a water cooling device 26 provided below the slag discharge port 25a, and is discharged to the water cooling device 26. It is configured to be rapidly cooled with cooling water. The high-temperature exhaust gas generated from the melting furnace 25 due to melting of the incineration ash is introduced into the temperature reducing tower 28 through the duct 25b, and exhausted from the incinerator 23 through the bag filter 29. At the same time, it is discharged from the chimney 30 into the atmosphere.

  In addition, as shown with an imaginary line in FIG. 3, you may comprise so that the high temperature waste gas which generate | occur | produces from the melting furnace 25 may be discharge | released from the said chimney 30 through the temperature-reduction tower and bag filter which provided separately. Furthermore, in the case of the third embodiment, the basicity adjusting agent and the chromium concentration adjusting agent are configured to be supplied to the incinerator 23 as described above, but as shown by a broken line in FIG. Alternatively, the waste may be supplied to the waste supply device 21 or the depreciated ash supply device 24.

The incineration ash melting device F _{m3 according} to the third embodiment and the incineration ash melting devices F _m1 and F _{m2 according to the first} and second embodiments are greatly different in equipment arrangement configuration. However, as is well understood in the comparison between FIG. 3 according to the third embodiment and FIGS. 1 and 2 according to the first and second embodiments, the incineration ash with adjusted basicity and chromium concentration is melted. The point that the molten slag is melted in the furnace 25 at a temperature of 1350 ° C. to 1500 ° C., and flows down from the slag discharge port 25a of the melting furnace 25 and is rapidly cooled by the cooling water in the water cooling device 26 is the first embodiment. , 2 is exactly the same.

Therefore, according to the incineration ash melting apparatus _Fm3 according to the third embodiment, the incineration residue generated from the incinerator 23, the boiler 27, the temperature reducing tower 28, and the fly ash discharged from the bag filter 29 are melted. Since it can be melted again in the furnace 25, it is possible to reduce the total amount of fly ash landfilled at the final disposal site and to prevent elution of heavy metals such as hexavalent chromium and lead in the fly ash into the environment. it can.

In addition, in the incineration ash melting device F _{m3 according to the} third embodiment, the incineration ash composed of the incineration residue and fly ash supplied to the melting furnace 25 is supplied to the incineration ash supply device 24. Therefore, according to the incinerator ash melting apparatus _Fm3 according to the third embodiment, incineration residues, boilers, temperature reduction towers, bag filters, and other exhaust gases generated from the incinerator of a specific facility equipped with a melting furnace as ancillary equipment To obtain a general-purpose effect that not only fly ash discharged in the treatment process but also incineration ash of waste generated by incinerators of other incinerators that do not have a melting furnace can be received and melted. Can do.

  A melting apparatus for incineration ash according to Embodiment 4 of the present invention will be described with reference to FIG. 4 of a block diagram showing a processing flow of the incineration ash.

The reference symbol F _m4 shown in FIG. 4 is an incinerator ash melting device. The melting device F _m4 includes a hopper 31 that receives incinerated ash containing generated chrome incinerated in an incinerator (not shown), and incineration. An incineration ash supply device 33 for supplying ash to the melting furnace 34 is provided. The hopper 31 communicates with a regulator supply line from a regulator supply device 32, and the basicity regulator is supplied so that the basicity of the incineration ash is 0.6 to 1.0. When the chromium concentration exceeds 20000 mg / kg, the chromium concentration is 90,000 mg / kg or less, preferably 60000 mg / kg or less, or the incinerated ash has a melting temperature of 1200 ° C. to 1400 ° C. Thus, the chromium concentration adjusting agent is supplied.

  Then, the incineration ash whose basicity and chromium concentration are adjusted is configured to be introduced into the melting furnace 34 from the incineration ash supply device 33. The supply amount of the basicity adjusting agent and the chromium concentration adjusting agent to the incinerated ash is the same as in the first to third embodiments described above, by measuring the basicity and the chromium concentration of the incinerated ash with a fluorescent X-ray analyzer, The measured basicity of the incinerated ash and the measured value of the chromium concentration, or the melt flow temperature of the incinerated ash is determined by the measured value measured by JIS M8801 “Ash melting characteristics test”.

  The high-temperature exhaust gas discharged from the melting furnace 34 is introduced into a temperature reducing tower 36, and the exhaust gas reduced in temperature by the temperature reducing tower 36 is introduced into a bag filter 37. The exhaust gas from which the fly ash has been removed is discharged from the chimney 38 into the atmosphere. On the other hand, it is supplied to the melting furnace 34 via the incineration ash supply device 33 so that the basicity becomes 0.6 to 1.0 by supplying the basicity adjusting agent and the chromium concentration adjusting agent, and the chromium concentration is 90000 mg / day. Incinerated ash adjusted to a predetermined concentration of not more than kg, preferably not more than 60000 mg / kg is melted at a temperature of 1350 ° C. to 1500 ° C. to form molten slag. The molten slag is discharged from a slag discharge port 34a provided in the lower part of the melting furnace 34 to a water cooling device 35 provided below the slag discharge port 34a, and is rapidly cooled by the cooling water in the water cooling device 35. It is configured.

The melting apparatus of ash according to the melter F _m4 and Embodiments 1 to 2 above the ash according to the fourth embodiment, the device configuration is greatly different. However, the incinerated ash with adjusted basicity and chromium concentration is melted in the melting furnace 34 at a temperature of 1350 ° C. to 1500 ° C., and the molten slag discharged from the slag discharge port 34a of the melting furnace 34 is contained in the water cooling device 35. The point of rapid cooling with cooling water is exactly the same as in the first to third embodiments.

Therefore, according to the incineration ash melting apparatus _Fm4 according to the fourth embodiment, the incineration ash supplied from the incineration ash supply apparatus 34 is reduced to harmful hexavalent chromium in the incineration ash to harmless trivalent chromium. However, by melting while maintaining the form of trivalent chromium, the concentration of hexavalent chromium in the slag can be minimized and elution of hexavalent chromium can be reliably prevented. In addition, in the case of the incineration ash melting device F _{m4 according to} the fourth embodiment, the incineration ash generated from another incinerator or the like is supplied to the hopper 31. Therefore, according to the incinerator ash melting apparatus _Fm4 according to the fourth embodiment, in the same manner as in the third embodiment, the incineration residue and boiler generated from the incinerator of a specific facility provided with a melting furnace as ancillary equipment In addition to the fly ash discharged in the exhaust gas treatment process such as a temperature-decreasing tower and a bag filter, a general-purpose effect is obtained in which incineration ash generated in a waste incineration facility not equipped with a melting furnace can be received and melted. be able to.

  An incineration ash melting apparatus according to Embodiment 5 of the present invention will be described with reference to FIG. 5 of a block diagram showing the waste processing flow.

_Reference numeral F _m5 shown in FIG. 5 is an incinerator ash melting device. The melting device F _m5 is supplied with waste K _m via the waste supply device 41 and gasifies the supplied incineration ash by high-temperature heating. A gasification furnace 43 is provided. The waste supply device 41 communicates with the adjustment agent supply line from the adjustment agent supply device 42 so that the basicity of ash in the cracked gas generated in the gasification furnace 43 is 0.6 to 1.0. When the basicity adjusting agent is supplied and the chromium concentration of ash exceeds 20000 mg / kg, the chromium concentration is such that the chromium concentration of ash is a predetermined concentration of 90000 mg / kg or less, preferably 60000 mg / kg or less. It is comprised so that a regulator may be supplied. Or you may be comprised so that a chromium concentration regulator may be supplied so that the melt flow temperature of ash may become 1200 to 1400 degreeC. The pyrolysis gas containing ash generated in the gasification furnace 43 is introduced into the melting furnace 44 via a duct 43a.

The high-temperature exhaust gas discharged from the melting furnace 44 is introduced into the temperature reducing tower 47 after the heat is recovered by the boiler 46 at the rear stage of the melting furnace 44. Then, the exhaust gas reduced in temperature by the temperature reducing tower 47 is introduced into the bag filter 48, and fly ash in the exhaust gas is collected by the bag filter 48, and the exhaust gas from which the fly ash has been removed is discharged from the chimney 49 into the atmosphere. To be released.
On the other hand, introduced into the melting furnace 44 through the duct 43a so that the basicity becomes 0.6 to 1.0 by supplying the basicity adjusting agent and the chromium concentration adjusting agent, and the chromium concentration is 90000 mg / kg or less. Preferably, the ash adjusted to a predetermined concentration of 60000 mg / kg or less or so that the melt flow temperature of ash is 1200 ° C. to 1400 ° C. is melted at a temperature of 1350 ° C. to 1500 ° C. to form molten slag. The molten slag is discharged from a slag discharge port 44a provided in the lower portion of the melting furnace 44 to a water cooling device 45 provided below the slag discharge port 44a, and is rapidly cooled by the cooling water in the water cooling device 45. It is configured.

The incineration ash melting apparatus F _{m5 according} to the fifth embodiment and the incineration ash melting apparatus according to the first to fourth embodiments are greatly different in equipment configuration. However, the ash adjusted in basicity and chromium concentration is melted in the swirl type melting furnace 44 at a temperature of 1350 ° C. to 1500 ° C., and the molten slag discharged from the slag discharge port 44a of the swirl type melting furnace 44 is cooled with water. The point of rapid cooling with the cooling water in 45 is exactly the same as in the first to fourth embodiments.

In the incineration ash melting apparatus _{Fm5 according to the} fifth embodiment, while reducing the ash supplied from the gasification furnace 43 through the duct 43a, harmful hexavalent chromium in the ash is reduced to harmless trivalent chromium. By melting while maintaining the form of trivalent chromium, the concentration of hexavalent chromium in the slag can be minimized, and elution of hexavalent chromium can be reliably prevented. Therefore, according to the incinerated ash melting device F _m5 according to the fifth embodiment, substantially the same effects as those of the first to fourth embodiments can be obtained.

  In the above first to fifth embodiments, the general incinerator for incinerating waste and the incinerator ash melting device including the gasification furnace have been described. Many types of furnaces such as incinerators, bubble fluidized bed incinerators, stoker furnaces, kiln furnaces and the like can be used. Further, as the melting furnace, a swirling melting furnace, a plasma melting furnace, a burner melting furnace, an electric melting furnace, an arc melting furnace, or a shaft melting furnace can be used. Therefore, the form of the present invention is not limited by the above embodiment. Further, in the fifth embodiment, the incineration ash melting apparatus in which the gasification furnace and the melting furnace are separated has been described. However, the present invention is not limited thereto, and a direct melting furnace in which the gasification furnace and the melting furnace are integrated may be used. Moreover, the melting temperature of the ash in Embodiment 1 thru | or 5 above all means the average temperature of melting furnace upper part temperature, melting furnace middle part temperature, and melting furnace lower part temperature.

  In addition, in the first to fifth embodiments described above, the incinerator ash melting device provided with the bag filter as the dust collector has been described. However, the present invention is not limited thereto, and for example, a dust collector such as an electric dust collector can be used. Needless to say. In the first to fifth embodiments described above, the incineration ash melting device provided with the fly ash air transfer device as the fly ash transfer device has been described. However, the present invention is not limited thereto, and for example, a conveyor type fly ash air transfer device is provided. It goes without saying that it can be used.

  By the way, in the melting apparatus of the incineration ash which concerns on the above embodiment, the case where a heavy metal was chromium was demonstrated as an example. However, the technical idea of the present invention can be applied not only to chromium but also to, for example, lead, arsenic, selenium, mercury and the like. . In addition, design changes and the like within a range that does not depart from the technical idea of the present invention can be freely made. Therefore, the present invention is not limited to the embodiment according to the above embodiment.

Hereinafter, the Example which melt | dissolved the incineration ash of the dry cake of sludge using a turning type melting furnace is described.
300 kg of sludge dry cake containing a high concentration of all chromium was sampled and supplied to a fluidized bed incinerator (inner diameter; 200 mmφ) for complete combustion at an air ratio of 1.3 or higher. Ashes were collected in a cyclone.

The basicity is adjusted by adding 0.3 kg of SiO ₂ as a basicity adjusting agent to 1 kg of the collected incinerated ash, and the incineration ash having an adjusted basicity is turned into a rotary melting furnace (inner diameter: 200 mmφ) at 10 kg / h. And melted at a melting temperature of 1450 ° C. or higher (upper melting furnace: 1529 ° C., middle melting furnace: 1547 ° C., lower melting furnace: 1470 ° C.) and rapidly cooled by water cooling Nine sample slags were obtained. The relationship between the basicity of the sample slag thus obtained and the hexavalent chromium elution amount is as shown in FIG. 6, and the relationship between the basicity of the sample slag and the hexavalent chromium content is as shown in FIG. . According to FIG. 6, the basicity of slag is 0.7-0.9, and it can be seen that the detected amount of hexavalent chromium is below the detection limit (<0.02 mg / L). Further, according to FIG. 7, the hexavalent chromium contained in the incinerated ash is also below the detection limit, and even in a weakly oxidizing atmosphere that is an in-furnace atmosphere of a swirl type melting furnace, It can be seen that the chromium is reduced.

  In addition, from the viewpoint of the elution amount of hexavalent chromium from the slag, the chromium limit concentration in the slag preferred for safety was investigated. The relationship between the total chromium concentration in the slag, the slag basicity, and the elution amount of hexavalent chromium is as shown in FIG. According to FIG. 8, most of the elution amount of hexavalent chromium is below the detection limit until the total chromium concentration in the slag is up to 90000 mg / kg. Therefore, if the total chromium concentration in the slag is set to 90000 mg / kg or less, it is considered that there is no problem with respect to the elution amount of hexavalent chromium.

  In addition, the melting characteristics of incinerated ash with respect to the total chromium concentration were investigated. The relationship between the total chromium concentration in the incineration ash and the melting temperature of the incineration ash is as shown in FIG. 9, and the relationship between the total chromium concentration in the incineration ash and the melt temperature of the incineration ash is as shown in FIG. . According to these FIGS. 9 and 10, the melting temperature and the melting temperature of the incinerated ash are increased as the total chromium concentration is increased.

  From the above, in FIG. 8, the elution of hexavalent chromium is not a problem when the total chromium concentration is 90000 mg / kg or less, but according to FIG. 10, when the total chromium concentration is 90000 mg / kg or less, the melting temperature of the incineration ash is About 1400 ° C. Even if the melt flow temperature of the incineration ash is 1400 ° C., the melting temperature becomes 1450 ° C. or higher, so that the incineration ash is melted into slag, but the slag solidifies in the vicinity of the slag discharge port. As a result, the slag is not properly discharged from the slag discharge port, and stable operation of the melting apparatus is hindered over a long period of time. In order to avoid this, a large amount of a combustant is required to increase the ambient temperature of the slag discharge port, the running cost is increased, the CO2 emission as a global warming effect gas is increased, and the refractory is increased. It is not realistic because it will accelerate wear and tear. Therefore, it is preferable to set the total chromium concentration in the slag to 60000 mg / kg or less in consideration of fluctuations in the properties of the incineration ash so that the melt flow temperature of the incineration ash becomes 1200 ° C to 1400 ° C.

  Furthermore, considering the durability of the refractory lining the melting furnace and the slag discharge stability in the vicinity of the slag discharge port, if the chromium concentration in the incinerated ash is set to 20000 mg / kg or less, the average temperature in the furnace of the melting furnace is 1400. Since both ℃ -1500 ℃ and slag discharge port ambient temperature will sufficiently satisfy + 100 ℃ or more of the melting temperature of incineration ash, the incineration ash can be reliably melted while reducing running costs I understand. The melting temperatures of the above incinerated ash all mean the average of the melting furnace upper temperature, the melting furnace middle temperature, and the melting furnace lower temperature.

It is a block diagram which concerns on Embodiment 1 of this invention and shows the processing flow of the waste of the melting apparatus of incineration ash. It is a block diagram which concerns on Embodiment 2 of this invention and shows the processing flow of the waste of the melting apparatus of incineration ash. It is a block diagram which concerns on Embodiment 3 of this invention and shows the processing flow of the waste of the melting apparatus of incineration ash. It is a block diagram which concerns on Embodiment 4 of this invention and shows the processing flow of the incineration ash of the melting apparatus of incineration ash. It is a block diagram which concerns on Embodiment 5 of this invention and shows the processing flow of the waste of the melting apparatus of incineration ash. It is a figure which concerns on the Example of this invention and shows the relationship between the basicity of slag and the hexavalent chromium elution amount. It is a figure which concerns on the Example of this invention and shows the relationship between the basicity of slag, and hexavalent chromium content. It is a figure which concerns on the Example of this invention and shows the relationship between the total chromium density | concentration in slag, and the elution amount of hexavalent chromium. It is a figure which concerns on the Example of this invention and shows the relationship between the total chromium density | concentration in incineration ash, and the melting temperature of incineration ash. It is a figure which concerns on the Example of this invention and shows the relationship between the total chromium density | concentration in incineration ash, and the melt flow temperature of incineration ash. Relates to laboratory experiments were conducted in order to implement the present invention, is a diagram showing the relationship between the amount of elution of hexavalent chromium to the nucleotide of the sample slug _{S 11 ~S 13 (mg / L} ). Relates to laboratory experiments were conducted in order to implement the present invention, is a diagram showing the relationship between the amount of elution of total chromium to the nucleotide of the sample slug _{S 11 ~S 13, S 21 ~S} 23 (mg / L). It is a figure which shows the relationship between the eluate pH and the elution amount of hexavalent chromium in the laboratory experiment implemented in order to embody this invention. The figure which shows the relationship between the eluate pH and the conversion ratio of elution chromium to hexavalent chromium (hexavalent chromium in the test solution / total chromium in the test solution) related to the laboratory experiment conducted to embody the present invention. is there. It is a figure which concerns on the laboratory experiment implemented in order to embody this invention, and shows the relationship between basicity and eluate pH. It is a figure which concerns on the laboratory experiment implemented in order to embody this invention, and shows the relationship between the elution rate of Ca and eluate pH. It is a figure which shows the relationship between the elution rate of Si and the elution rate of all chromium which comprise the laboratory experiment implemented in order to embody this invention, and which comprises the frame | skeleton of slag. It is a figure which shows the relationship between the elution rate of Ca and the elution rate of total chromium which comprise the laboratory experiment implemented in order to embody this invention, and which comprises the frame | skeleton of slag. It is a figure which shows the relationship between a basicity and the elution rate of Si and Ca in connection with the laboratory experiment implemented in order to embody this invention. It is a figure which shows the relationship between the melting temperature of sample slag, and the elution amount of hexavalent chromium in the laboratory experiment implemented in order to embody this invention. It is a figure which shows the relationship between the melting temperature of sample slag, and the density | concentration of hexavalent chromium in connection with the laboratory experiment implemented in order to embody this invention. It is a figure which shows the relationship between the melting temperature of a sample slag, and Si and Ca in connection with the laboratory experiment implemented in order to embody this invention.

Explanation of symbols

F _{m1 to} F _m5 ... melting device, K _m ... waste (sludge dewatered cake)
DESCRIPTION OF SYMBOLS 1 ... Waste supply apparatus, 2 ... Conditioner supply apparatus, 3 ... Incinerator, 3a ... Duct, 4 ... Cyclone, 4a ... Incineration ash supply apparatus, 5 ... Melting furnace, 5a ... Slag discharge port, 5b ... Duct, 6 DESCRIPTION OF SYMBOLS ... Water cooling device, 7 ... Secondary combustion device, 8 ... Temperature reduction tower, 9 ... Bag filter, 9a ... Fly ash air transfer device, 10 ... Chimney 21 ... Waste supply device, 22 ... Conditioning agent supply device, 23 ... Incineration Furnace, 24 ... Incinerated ash supply device, 25 ... Melting furnace, 25a ... Slag discharge port, 25b ... Duct, 26 ... Water cooling device, 27 ... Boiler, 28 ... Decrease tower, 29 ... Bag filter, 29a ... Fly ash air transfer Equipment: 30 ... Chimney 31 ... Hopper, 32 ... Conditioner supply device, 33 ... Hopper, 34 ... Melting furnace, 34a ... Slag discharge port, 35 ... Water cooling device, 36 ... Temperature reducing tower, 37 ... Bag filter, 38 ... Chimney 41 ... Waste supply device, 42 ... Conditioning agent supply device , 43 ... gasifier, 43a ... ducts 44 ... melting furnace, 44a ... slag discharge port, 45 ... water cooler, 46 ... boiler, 47 ... reduced cooling tower, 48 ... bag filter, 49 ... chimney

Claims (3)

  Waste supply device, incinerator for incinerating waste supplied from this waste supply device, cyclone for collecting incineration ash in exhaust gas discharged from this incinerator, and incineration ash supply device from this cyclone A melting furnace for melting the incinerated ash supplied via the water, a water cooling device provided at a lower position of the melting furnace for rapidly cooling the molten slag discharged from the slag discharge port, and measuring the basicity of the incinerated ash The basicity of the incineration ash is 0.6 to any one of the basicity measurement device, the chromium concentration measurement device that measures the chromium concentration of the incineration ash, the waste supply device, or the incinerator. Chromium concentration adjustment for supplying a chromium concentration adjusting agent to any one of a basicity adjusting agent supplying device for supplying a basicity adjusting agent to 1.0 and the waste supply device or the incinerator Agent supply device, front Melting of incinerated ash, which consists of a dust collector that further collects fly ash in the exhaust gas discharged from the cyclone, and a chimney that releases the exhaust gas discharged from this dust collector and from which fly ash has been removed to the atmosphere apparatus.   The incinerator ash melting device according to claim 1, further comprising a conveying device that supplies fly ash collected by the dust collector to the incineration ash supply device from the dust collector to the melting furnace. Waste supply device, incinerator for incinerating waste supplied from the waste supply device, incineration ash supply device for supplying incineration ash discharged from the incinerator to a melting furnace, and base of the incineration ash and basicity measuring device for measuring the degree, and chromium concentration measuring device for measuring the chromium concentration of the ash, the waste feed instrumentation 置Ma other in any one of the incinerator, from the incinerator One of the basicity adjusting agent supply device that supplies the basicity adjusting agent so that the basicity of the incinerated ash discharged is 0.6 to 1.0, and the waste supply device or the incinerator. First, a chromium concentration adjusting agent supplying device for supplying a chromium concentration adjusting agent, a melting furnace for melting the incinerated ash supplied from the incineration ash supplying device, and a lower position of the melting furnace, and discharged from a slag discharge port Water cooling equipment for rapidly cooling molten slag Melter ash characterized by comprising.

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