JPH046310A - Production of garbage incineration - Google Patents

Abstract

PURPOSE:To obtain garbage incineration ash not containing substantially any heavy metals by a method wherein some adsorbing materials mainly having animal bone powders are disposed at an upper part and a lower part of a combustion part, mercury vapor is adsorbed at an upper adsorbing material and other heavy metals are adsorbed by the lower adsorbing material and then the garbage is incinerated. CONSTITUTION:Animal raw bones are cut into such sizes as those facilitating combustion, the bones are fed into a pressure cooker and boiled. Then, the bones are fed into an incinerator, burned, naturally cooled and their temperatures are returned to a room temperature or its approximate temperature. After burning and cooling operations, the bones are crushed, fed into a powdering machine to make powder-like bone powder. Raw material substances such as animal bone powders or clay substances are weighted to obtain a predetermined composition, agitated, water is added and mixed, thereafter they are formed. The formed product is dried, baked, cooled and then formed into an adsorbing material. The adsorbing materials having animal bone powder are disposed at the upper part and the lower part of the combustion part. Mercury vapor generated when the combustion is carried out is adsorbed by the upper adsorbing material and other heavy metals settled during the combustion and separated from the main body of the incineration ash.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing garbage incineration ash that does not contain harmful heavy metals.

(Conventional technologies and issues) A new culture is being created by modern industry and industry developed by humans, but on the other hand, it has a great impact on the natural environment, going beyond the purifying effect of nature and causing destruction of nature. Pollution is occurring.

In order for humankind to always maintain a healthy and cultured life, it is necessary to eliminate the negative effects of industrial development and create a new environment suitable for the development of life. The problem of disposal of garbage incineration ash, which is the most familiar daily pollution, is a problem not only in Japan but also in countries around the world.

Regarding this issue of garbage incineration ash treatment, various researches have been conducted by related organizations in various countries, and reusable products have been developed.
Cadmium 13ppm, lead 980ppm, chromium 230ppm
ppm), which is an obstacle to the development of reusable products.

These toxic heavy metals are also responsible for the fact that garbage incinerators are attracting attention as a new source of pollution. That is, in addition to conventional sulfur oxides SOx and soot and dust in flue gas, hydrogen chloride and harmful heavy metals in incineration ash have been picked up.

Therefore, as a result of various studies on the removal of heavy metals from garbage incineration ash, the present inventor found that by adopting a specific incineration method, garbage incineration ash that does not contain heavy metals can be obtained.
We have arrived at the present invention.

(Means for Solving the Problems) The present invention provides a method for producing food waste incineration ash in which food waste is burned in an incinerator to produce food waste incineration ash. Place the adsorbent as a material,
The mercury vapor generated during combustion is adsorbed to the upper adsorbent,
A method for producing garbage incineration ash substantially free of harmful heavy metals is characterized in that garbage is incinerated while other heavy metals that precipitate during combustion are adsorbed to the lower adsorbent.

Garbage is garbage generated from daily life, and when incinerated in the usual way, it contains organic matter, ignition loss components, humic acid, residual silicon dioxide), metals, toxic heavy metals, etc.

The present invention includes continuous furnaces, batch furnaces, fixed furnaces, fluidized bed furnaces,
It can be carried out in any incinerator such as

In the present invention, adsorbents mainly made of animal bone powder are placed in the upper and lower parts of the combustion section.

Here, the adsorbent based on animal bone powder is made of animal bone powder, clay, reinforcing material (e.g., alumina), alkaline material (e.g., garbage burned ash), and fine pores are formed in the adsorbent during firing. Materials (e.g. organic powders such as wood flour, rice bran, wheat dregs, rice husks, waste wood powder, starch dregs, shochu dregs, etc.)
It is made by suitably blending additives such as , molding, and firing.

The animal bone meal used here uses bones that have conventionally been mostly discarded at livestock farms, especially bones of animals such as cows, horses, sheep, etc., which are mainly composed of hard bones.

The raw bones of these animals are cut into sizes that are easy to burn, then put into a pressure cooker and heated at around 200 to 400 degrees Celsius for about 90 minutes.
Boil for about 0 minutes. Next, this bone was placed in a kiln and heated to 90
It is fired at about 0 to 1100°C for about 60 to 180 minutes, and then allowed to naturally cool in the furnace for about 60 minutes to return to room temperature or a state close to this temperature.

If organic substances other than the blue component, such as gelatin, fat, protein, and glue, remain in the bones, they will cause oxidative decay, so it is important to ensure that they are removed. By the above boiling process, organic matter adhering not only to the outside but also to the inside of the pores can be separated and removed from the bone in all directions.

By then passing through the above baking process, remaining organic matter can be completely removed, and at the same time the humidity in the bone can be reduced.
The water content can be reduced to several percent or less, preferably to almost 0%. According to the above-mentioned firing conditions, the bone turns into a skeleton and maintains its original tissue state having countless pores.

After the above-mentioned baking and cooling, the bone is crushed and powdered to produce approximately 20 to 200 meshes, particularly preferably 50 to 1 mesh.
00 mesh powdered bone meal.

In the case of bovine bones, the above-mentioned bone powder has a yield of 40% by weight compared to raw raw bones. The particles contain calcium (approximately 33
The main components are phosphorus (about 16.7%), barium (about 1.03%), sodium (about 0.76%), sulfur (about 0.064%), and magnesium, potassium, chlorine, It is made of amine, iron, etc., and has countless microscopic pores that communicate between the inside and outside of the particle. This bone meal is alkaline because it contains calcium.

The clay may be anything that acts as a binder, such as bentonite, acid clay, activated clay, kaolin clay,
Examples include sericite, pyrophyllite, fireclay, montmorillonite, chloride, and the like.

The proportion of animal bone powder and clay in the adsorbent may be within a range that functions as an adsorbent when incinerating heavy metals, but clay is usually in the proportion of 100 parts by weight of animal bone powder.
The amount is 25 to 400 parts by weight, preferably 45 to 230 parts by weight.

The adsorbent is made by weighing these raw ingredients to have a predetermined composition, stirring, adding water and mixing, then molding, drying the resulting molded body, baking, and cooling to make the adsorbent. . The molded body is usually granular (e.g. powder) and has a size of 1 to 15 m.
It is about m. The drying temperature and firing temperature are usually 2
It is around 00°C, and around 800 to 1200°C.

The obtained adsorbent material mainly composed of animal bone powder is placed in the upper and lower parts of the combustion section in the incinerator. Mercury vapor generated during combustion is adsorbed by the upper adsorbent, and other heavy metals that precipitate during combustion are adsorbed by the lower adsorbent, and each is separated from the main body of the incineration ash, so heavy metals (mercury, cadmium, lead,
Substantially does not contain chromium, etc. (Usually, garbage incineration ash 1
per kg, alkyl mercury Q: 0.05 mg or less, cadmium: 1 mg or less, lead: 10 mg or less, hexavalent chromium: 5 mg or less, preferably these heavy metals are not detected)
Garbage incineration ash is obtained.

Note that the adsorbent may be placed not only in the upper and lower parts of the combustion part in the incinerator but also in the combustion part. In this case, the adsorption performance of heavy metals is further improved,
The proportion of heavy metals contained in garbage incineration ash can be further reduced.

(Effects) According to the present invention, garbage incineration ash substantially free of heavy metals can be obtained.

Therefore, since the incineration ash obtained according to the present invention can be used for many purposes, the present invention can be an effective means for solving the problem of garbage incineration ash disposal.

Furthermore, garbage incinerators can be prevented from becoming a source of pollution in the sense of being a source of heavy metals.

Claims (1)

[Claims] In a method for producing garbage incineration ash, in which garbage is burned in an incinerator to produce garbage incineration ash, adsorbents mainly made of animal bone meal are placed in the upper and lower parts of the combustion section to reduce waste generated during combustion. Garbage incineration ash that is substantially free of harmful heavy metals and is characterized by incinerating garbage while adsorbing mercury vapor to the upper adsorbent and adsorbing other heavy metals that settle during combustion to the lower adsorbent. manufacturing method.