TWI660782B - Method and apparatus for desalting bottom ash and converting the desalted ash into cement raw material - Google Patents

Abstract

The object of the present invention is to desalinate bottom ash and use it for cement raw materials while reducing running costs and equipment costs. The solution of the present invention is a method for desalination of bottom ash. The bottom ash is disintegrated by adding more than 0.1 times and less than 1 times the weight of the bottom ash, and the disintegrated bottom ash slurry is processed. Sorting, and washing the fine particle slurry obtained by the sorting. The coarse particles obtained after sorting can be used as cement raw materials. Water can be sprayed into the bottom ash slurry during sorting, and the classification point of the sorting can be set to be greater than 0.5 mm and less than 1 mm, or an acid gas can be added to the particulate slurry during washing. The coarse particles obtained after the sorting can be used as cement raw materials after blowing air, or the fine particle slurry obtained after the sorting can be washed with water or solid-liquid separation can be performed at the same time as the water washing. use.

Description

Method and device for desalination of bottom ash and cement raw material Technical field

The present invention relates to a method and a device for removing chlorine components from waste incineration ash (bottom ash) generated during the incineration of municipal waste and the like, and a method and a device for using the same as a cement raw material after removing the chlorine component from the bottom ash.

Background technique

In the past, most of the bottom ash generated during the incineration of municipal waste was landfilled for disposal at the final disposal site. However, the final disposal site may be depleted. In recent years, it has been used as a raw material for cement. Since the bottom ash is rich in chlorine, it must be removed beforehand when it is used as a cement raw material. The bottom ash has different chlorine concentrations depending on the particle size difference, and the chlorine component is localized on the fine particle side.

Therefore, a device 11 is described in Patent Literature 1 and the like. As shown in FIG. 2, the bottom ash M in the hopper 2 and water W4 having a weight of 1 to 10 times the weight of the bottom ash M are mixed to stir the device 12. After mixing and stirring, the bottom ash slurry S1 is sorted by the sorting device 13 to separate the fine particle slurry S2 and the coarse particles C, and the fine particle slurry S2 is supplied to the tank 14 and washed with water. The acid gas G is introduced into the tank 14 at 15 to promote the decomposition of the slightly soluble salts contained in the fine particle slurry S2, and the slurry S3 discharged from the tank 14 is subjected to solid-liquid separation by the solid-liquid separation device 16 to separate the filtrate L and the fine particles F. The filtrate L is further subjected to water treatment in the drainage treatment device 17, and at the same time, the fine particles F and the coarse particles C are brought together to be used as a cement raw material.

Prior art literature Patent literature

Patent Document 1: Japanese Patent No. 5561326

However, in the desalination of the bottom ash and the cement raw material conversion device 11 described in Patent Document 1 and the like, a large amount of water W4 is used during the slurrying and washing of the bottom ash M. In addition to the problem that the running cost increases, Further, since the sorting device 13, the tank 14, the solid-liquid separation device 16, the drainage treatment device 17, and the like are to be made into a large-scale device, there is a problem that the equipment cost becomes high.

Therefore, the present invention has been made in view of the problems in the conventional technology described above, and its purpose is to reduce the running cost and equipment cost while desalination of bottom ash, and to use it in cement raw materials.

In order to achieve the above object, the present invention is a method for desalination of a bottom ash, which is characterized by adding water to the bottom ash in an amount of 0.1 times or more and less than 1 times the weight of the bottom ash to perform disintegration. The ash slurry is sorted, and the fine particle slurry obtained by the sorting is washed with water. In addition, the disintegration means that the solid particles in a mixed state are separated from the liquid Scattered.

According to the present invention, a small amount of water can be used for disintegration to make the bottom The ash particles are ground to each other, so that the solid particles can be dispersed in a short time, and a small amount of water can be used for subsequent sorting, washing, and solid-liquid separation. Since it will become the drainage object of the water treatment, the amount is also large. Reduced, so can significantly reduce operating costs and equipment costs. In addition, by grinding the particles with each other, a portion having a high chlorine concentration on the surface of the coarse particles can be scraped off, and the desalination efficiency can be improved.

In the above-mentioned desalination method of the bottom ash, The bottom ash slurry is sprayed with water, thereby improving the sorting efficiency and simultaneously washing with water.

Furthermore, the classification points of the aforementioned sorting can be set to be greater than 0.5mm and below 1mm. Because the bottom ash is fully disintegrated to disperse the aggregates of particles, and the surface of the coarse particles is scraped off due to the grinding of the particles, the upper limit of the classification point can be set to be small, which can efficiently The bottom ash is desalted.

In the aforementioned water washing, an acid gas or an acid may be added to the aforementioned micro In the particle slurry, the decomposition of sparingly soluble salts such as Friedel's Salt contained in the particle slurry is promoted, so that the desalting rate of the bottom ash can be further improved.

In addition, the present invention relates to a method for desalination of bottom ash and cement raw materials. The method is characterized in that the coarse particles obtained by the aforementioned sorting are used as cement raw materials. According to the present invention, the coarse particles in the desalted bottom ash can be directly used as a cement raw material at a low cost as described above.

The coarse particles obtained by the aforementioned sorting can be used as air spray The use of cement raw materials, and by reducing the water content attached to the coarse particles, the thermal energy loss in the cement firing device can be reduced.

The following fine particles can be used as a cement raw material: The fine particles It is obtained by washing the fine particle slurry obtained by the above-mentioned sorting, followed by solid-liquid separation, or by washing the fine particle slurry while performing solid-liquid separation. According to the present invention, the fine particles in the desalted bottom ash can be used as a cement raw material at a low cost as described above.

Furthermore, the present invention is a desalination device for bottom ash, The feature is that: a disintegrating device is used to dissolve the bottom ash by adding 0.1 times to less than 1 times the weight of the bottom ash to perform disintegration; a sorting device is used to disintegrate the disintegrated bottom ash slurry Sorting; and a water washing device for washing the fine particle slurry obtained by the sorting with water. According to the present invention, it is possible to perform disintegration with a small amount of water to greatly reduce operating costs and equipment costs, and to improve desalination efficiency.

Furthermore, the present invention is a desalination of bottom ash and cement raw material The device further includes a supply device for supplying the coarse particles obtained by the sorting device to the cement manufacturing device. According to the present invention, the coarse particles in the desalted bottom ash can be directly used as a cement raw material at a low cost.

A supply device may be further provided to supply the following fine particles to Cement manufacturing equipment: The microparticles are obtained by washing the microparticle slurry obtained by the aforementioned sorting device with water and then performing solid-liquid separation, or by washing the microparticle slurry with water and performing solid-liquid separation. in accordance with According to the present invention, the fine particles in the desalted bottom ash can be used as a cement raw material at a low cost.

As described above, according to the present invention, the bottom ash can be desalinated while operating costs and equipment costs are reduced, and can be used for cement raw materials.

1‧‧‧ bottom ash desalination, cement raw material device

2‧‧‧ Hopper

3‧‧‧ drum washing machine

4‧‧‧sorting device

5‧‧‧ blowing device

6‧‧‧slot

7‧‧‧Acid gas introduction device

8‧‧‧Solid-liquid separation device

9‧‧‧ drainage treatment device

A‧‧‧air

C‧‧‧ Coarse particles

F‧‧‧ fine particles

G‧‧‧Acid gas

L‧‧‧ filtrate

M‧‧‧ bottom gray

S1‧‧‧ bottom ash slurry

S2‧‧‧fine particle slurry

S3‧‧‧ slurry

W1 ~ W3‧‧‧‧Water

FIG. 1 is an overall structural diagram showing one embodiment of the apparatus for desalination and cement raw material of the bottom ash of the present invention.

Fig. 2 is an overall structure diagram showing an example of a conventional bottom ash desalination and cement raw material converting device.

Forms used to implement the invention

Hereinafter, the embodiments for implementing the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of the desalination and cement raw material device of the bottom ash of the present invention. The device 1 is provided with a hopper 2 for receiving garbage incineration ash (hereinafter referred to as “bottom ash”) M, and a drum washing machine 3 for Crushing the bottom ash M supplied by the hopper 2; a sorting device 4 for sorting the bottom ash slurry S1 discharged from the drum washing machine 3; an air blowing device 5; for coarse particles C in the sorting device 4 Blow air A; tank 6 for washing particles of particle slurry S2 discharged from sorting device 4; acid gas introduction device 7 for introducing acid gas G into tank 6; solid-liquid separation device 8 for use A filter press or the like for solid-liquid separation of the slurry S3 discharged from the tank 6; and a drainage treatment device 9 for performing water treatment on the filtrate L discharged from the solid-liquid separation device 8.

As the drum washing machine 3 of the disintegrating device, such as a stock KDW type manufactured by KIKOSHA CO., LTD. The drum washing machine 3 is a disintegrating device, which is provided with a rotary drum in which a plurality of lifters are arranged upright, and can efficiently grind the particles of the bottom ash M with each other with a small amount of water, and let solid particles The aggregates dispersed in a short time.

The sorting device 4 can use a water sieve (vibrating sieve), etc., and is equipped with a sprinkler A water spraying device for spraying water on the bottom ash slurry S1 which is a sorting object.

The blowing device 5 is provided to sort the bottom ash in the sorting device 4 In the slurry S1, the coarse particles C in the sorting device 4 are sprayed with air A to remove the water adhering to the coarse particles C. The coarse particles C discharged from the sorting device 4 may also be blown with air A.

The acid gas introduction device 7 is provided to introduce the acid gas G into the tank 6. As for the acid gas G to be introduced, the exhaust gas of a CO ₂ rich cement kiln or the exhaust gas of a chlorine diverting device rich in SO ₂ can be used. . Instead of the acid gas G, an acid such as sulfuric acid, nitric acid, acetic acid, or formic acid may be added to the fine particle slurry S2 in the tank 6.

Next, an operation of the apparatus 1 having the above-described configuration will be described with reference to FIG. 1.

Put the bottom ash M received in the hopper 2 into the rotating drum of the drum washing machine 3, and at the same time, add water W1 that weighs about 0.5 times that of the bottom ash M to the bottom ash M in the drum, and let the bottom ash M The particles are ground to each other to disperse the solid particles. The weight of the water W1 that can be supplied to the drum washing machine 3 The amount is adjusted within a range of 0.1 to 1 times the weight of the bottom ash M.

Then, the bottom ash slurry S1 discharged from the drum washing machine 3 is supplied. It is given to the sorting device 4 and sorting is performed. At this time, the sorting device 4 is sprayed with water W2 having a weight of about 0.8 times that of the bottom ash M, and the blowing device 5 blows air A to the coarse particles C having a particle size of about 0.7 mm or more obtained by the sorting to remove Moisture attached to coarse particles C. By adjusting the weight of the water W2 sprayed from the sorting device 4 in the range of 0.1 to 2 times the weight of the bottom ash M, not only the sorting efficiency can be improved, but also the moisture content of the fine particle slurry S2 can be adjusted. The classification point of the sorting device 4 is adjusted within a range of more than 0.5 mm and less than 1 mm.

The fine particle slurry S2 containing fine particles is supplied from the sorting device 4 Go to the tank 6 to wash the fine particles with water. Furthermore, the acid gas G is added to the tank 6 from the acid gas introduction device 7 to promote decomposition of sparingly soluble salts such as Friedel's Salt contained in the fine particle slurry S2. At this time, the pH of the fine particle slurry S2 in the tank 6 is adjusted to 2 to 12, preferably 4 to 9, and more preferably 6 to 8.

The slurry S3 is supplied from the tank 6 to the solid-liquid separation device 8 and water W3 is supplied. The solid-liquid separation device 8 is supplied as washing water, and the water-washing slurry S3 performs solid-liquid separation at the same time, and the fine particles F and the filtrate L are separated. The filtrate L is discharged into the water through the drainage treatment device 9 and the fine particles F are combined with the coarse particles C discharged from the sorting device 4 and supplied to a cement manufacturing device through a supply device (not shown) for use as a cement raw material .

As described above, in the embodiment, a roller is used. The washing machine 3 etc. disintegrate the bottom ash M with a small amount of water, thereby letting the particles of the bottom ash M Grinding each other, so that solid particles can be dispersed in a short time. Therefore, a small amount of water can be used in each step of the sorting device 4, the tank 6, the solid-liquid separation device 8 for sorting the broken bottom ash slurry S1, and the sorting device 4 is not required. , Tank 6, solid-liquid separation device 8 is made into a large-scale device. In addition, the amount of waste water to be treated by the waste water treatment device 9 can be significantly reduced, and the entire device 1 can significantly reduce the running cost and the equipment cost. In addition, in the drum washing machine 3, the surface of the coarse particles of the bottom ash M having a high chlorine concentration is scraped off by grinding the particles with each other and washed with water to improve the desalination efficiency.

In the embodiment, the drum washing machine 3 is used. As the disintegrating device, other types of devices capable of dissolving the bottom ash M by using a small amount of water can also be used.

Moreover, although the tank 6 is lined up by a solid-liquid separation device 8 such as a filter press The slurry S3 is washed with water and subjected to solid-liquid separation, but the slurry S3 may be subjected to solid-liquid separation using a dehydrator or the like.

In addition, a part of the filtrate L can also be returned to the drum washing machine 3 and / or the sorting device 4 and / or the solid-liquid separation device 8 for reuse. At this time, the conductivity of the filtrate used for recycling should be measured to determine the amount of filtrate to be recycled.

What's more, the uses of the desalted coarse particles C and fine particles F are not limited to cement raw materials, but can also be used for roadbed materials.

Claims (10)

A method for desalination of bottom ash, which is characterized by adding water to the bottom ash which is more than 0.1 times and less than 1 times the weight of the bottom ash for disintegration: sorting the disintegrated bottom ash slurry; The sorted fine particle slurry is washed with water; the aforementioned disintegration refers to dispersing aggregates of solid particles in a mixed state with the liquid. The method for desalination of bottom ash according to claim 1, wherein during the aforementioned sorting, water is sprayed on the bottom ash slurry. For example, the desalination method of bottom ash of claim 1 or 2, wherein the classification point of the aforementioned sorting is set to be greater than 0.5 mm and less than 1 mm. The method for desalination of bottom ash according to claim 1 or 2, wherein an acid gas or an acid is added to the aforementioned fine particle slurry during the aforementioned water washing. A method for desalination and cement raw material conversion of bottom ash, characterized in that the coarse particles obtained by the aforementioned sorting in the method for desalination of bottom ash according to any one of claims 1 to 4 are used as cement raw materials. For example, the method for desalination of bottom ash and the conversion of cement raw materials according to claim 5 uses air as a raw material for the cement by blowing air on the coarse particles obtained through the aforementioned sorting. A method for desalination and cement raw material of bottom ash, characterized in that the following fine particles are used as cement raw materials: the particles are obtained by the aforementioned sorting in the method of desalination of bottom ash according to any one of claims 1 to 4 Those obtained by washing the fine particle slurry with water and then performing solid-liquid separation, or those obtained by washing the fine particle slurry with water and performing solid-liquid separation at the same time. A bottom ash desalination device, comprising: a disintegrating device for adding to the bottom ash more than 0.1 times and less than 1 times the weight of the bottom ash to perform disintegration; a sorting device for dissolving the The disintegrated bottom ash slurry is sorted; and a water washing device is used to wash the fine particle slurry obtained by the sorting; wherein the disintegration refers to dispersing the solid particles in a mixed state with the liquid. A device for desalination and cement raw material of bottom ash, further comprising a supply device for supplying coarse particles obtained by the sorting device in the desalination device of the bottom ash of claim 8 to the cement manufacturing device. . A device for desalination and cement raw material of bottom ash is further provided with a supply device for supplying the following fine particles to a cement manufacturing device: the fine particles are passed through the aforementioned components in the desalination device of the bottom ash according to claim 8. The microparticle slurry obtained by the sorting device for separation is washed with water and solid-liquid separation is performed, or the microparticle slurry is washed with water and solid-liquid separation is performed at the same time.