JPH0319178B2 - - Google Patents

Description

[Detailed Description of the Invention] (Objective of the Invention) (a) Field of Industrial Application The present invention utilizes the incineration ash generated in large quantities after incinerating garbage mainly from ordinary households in an incineration treatment facility. This invention relates to a manufacturing method for creating artificial stone, gravel, etc.

(b) Conventional technology As a general rule, all local governments across the nation incinerate garbage generated from households, but the incineration method is generally to burn it at a constant speed in a rotating incinerator at a temperature of about 700 degrees. The garbage is passed through and incinerated.

Despite the local government's guidance that garbage discharged from ordinary households should be separated into combustible garbage and non-combustible garbage, there are still large items such as so-called oversized garbage, such as empty cans and bottles such as medicine bottles. Incombustible materials such as broken kitchen ceramics, broken metal toys, and used batteries are being disposed of without being classified as combustible garbage.

These non-combustible substances, for example, glass are melted and deformed, metals in empty cans are partially melted and deformed, and ceramics are destroyed and become coarse particles that are mixed with the fine powder ash of combustible substances. In addition, there is a considerable amount of flame-retardant materials such as synthetic resin food packaging, which cannot be completely combusted at around 700 degrees and a considerable amount will melt. It remains in the form of coarse and fine particles.

What is even more important is that a considerable amount of aluminum foil is used for packaging cigarettes and confectionery as well as for cooking, and most of this is deformed into fine particles and remains as is.

For this reason, for example, even if incineration ash is hardened with cement and used for some purpose, a considerable amount of aluminum particles interact with the strong alkaline components of cement and change into aluminum oxide. Some local governments dispose of cement or asphalt in a solid state and dump it into the ocean, but most local governments dump it underground. The current situation is that they are being implanted.

However, in approximation, incineration ash is subjected to high heat treatment to completely burn and completely melt all of its contents, and then rapidly cooled and hardened to form a brittle glass-like solid, which is then crushed to form a sand-like road surface. The technology of using it as a roadbed material during land reclamation was also considered, but its use was limited because it was fragile and had a low specific gravity, so it could be mixed into natural sand in a certain amount. It will not be put into practical use.

(c) Problems to be solved by the invention Although the annual amount of difficult-to-process incineration ash mentioned above is said to be a staggering amount, the actual number cannot be accurately determined. For example, taking Kawaguchi City, Saitama Prefecture, where the present inventor's business office is located, 400,000 people generate 20,000 tons of incinerated ash per year, so it can be estimated that this will occur nationwide. The amount is truly astonishing, and it is steadily increasing every year.

Most of the treatment methods involve renting idle land, burying it deep underground, restoring the topsoil to a certain depth, and returning it in the same manner as the surrounding area, which amounts to 20,000 tons per year. In other words, these days, there is no longer any suitable land available, and we are in dire straits, and the reality is that surrounding cities are also struggling, and the country as a whole is also struggling.

However, the reality of the incinerated ash is that it contains an even more serious problem, and that is that the incinerated ash contains organic mercury from used batteries, as well as considerable amounts of harmful substances such as dioxins and hexavalent chromium. It is.

These harmful substances gradually fall freely deep underground due to the rainwater that permeates into the ground every time it rains, and it is inevitable that they will eventually reach the groundwater, and in a country where all natural resources have been depleted, Even groundwater, the only remaining resource, is in danger of being lost.

We inherited from our distant ancestors a clean and pure land where we could enjoy the changing seasons, and here we built an unprecedented peace and prosperity, but at the cost of that, our descendants were left with an underground contaminated land that could never be repaired. This outrageous behavior is a serious problem that must be stopped as soon as possible.

When considering the means of disposing of incineration ash, the most effective and possible option is to use its constituent molecules to create artificial stone, or to crush it and convert it into gravel. be.

Needless to say in detail, the current domestic demand for gravel is in the hundreds of millions.
Today, the extraction of ash from ordinary rivers is prohibited, and the demand and supply relationship is becoming tighter day by day. If so, this can truly be called good news for the nation.

(d) Means to solve the problem When incineration ash is subjected to high heat treatment to remove all metals and harden it, it becomes a glass-like dark brown solid.The contents can be roughly divided into: (1) Ceramics. Silicon compounds from debris, glass, etc. (2) Since the main component is carbon compounds from combustible and flame-retardant substances, if a calcium-based substance is added and fused to this, it will turn into a stone-like substance. However, it is foreseeable that many bubbles will form inside the stone due to the addition of calcium-based substances, the melting temperature that changes greatly due to this, and the fuming gas that is violently generated as the heated melting temperature rises. If the incineration ash contains complex substances, the hardness of the stone-like bodies disappears, or the methods for removing the various metals contained in a considerable amount and the optimum heating temperature that should be set while processing these are required. Since it is an aggregate, it is extremely complex, and after a large amount of experimental results, I have come to believe that solving the various problems mentioned above is the absolute means to achieve the invention of the present application.

(Structure of the Invention) (E) Examples and Effects As a result of various experiments, the melting temperature for melting incineration ash and turning it into artificial stone with crystals and hardness comparable to natural stone was determined to be around 1200 degrees Celsius (inside the furnace). All temperatures described below are furnace temperatures).

Therefore, what should be considered is a calcium-based additive that melts and mixes with the incinerated ash at around 1200 degrees, but since the purpose of the present invention is artificial stone and gravel, it should be supplied at the lowest possible price and in a stable supply amount. is an essential requirement, and there is a limit to the types of cement that can be used.The results of various experiments under such conditions have shown that cement that has already been subjected to high heat treatment at about 1400 degrees during the production process is the most effective. With this, it was confirmed that incineration ash fuses into a magma with the desired viscosity at around 1200 degrees Celsius, and when this is slowly cooled and hardened, it becomes a stone-like body with the desired dense crystals and hardness. It is.

However, the problem here is that when the incineration ash is heated to around 1200 degrees, the flame-retardant residual substances burn violently and continue to spew out smoking gas, and even if they are slowly cooled and hardened, they become dense crystals. However, countless large and small air bubbles are created inside the stone bodies, which makes them brittle.Additionally, what is considered a further problem is that they are mixed into the incineration ash at a ratio of 30% to 40%. various non-ferrous metals including ferrous metals,
At temperatures around 1,200 degrees, it becomes coarse particles and is scattered throughout the stone body, and as time passes, it becomes exposed as rust on the surface of the stone body.

The above-mentioned scattered state of generated gas and metals must be removed at all costs. First, various chemical treatment methods were tried as a gas treatment measure, but none were successful as the content of the incineration ash residue was unspecified. It was hardly effective.

The measures we had to take here were to first raise the temperature of the incinerated ash to a temperature much higher than around 1200 degrees.
In other words, the residue that continues to burn at around 1200 degrees is heated to a higher temperature until it is completely combusted, and then a brittle hardened material is created using only the naturally cooled incineration ash, which is then mixed with an appropriate amount of cement. It is a means of melting at around 1200 degrees.

As a result of the above, an unexpected situation was discovered during various experiments to determine how high the excessive temperature rise above 1200 degrees should be set.

When the temperature rises to around 1,500 degrees, the various metals in the incinerated ash almost completely melt and coalesce, and due to the difference in specific gravity, an alloy mass forms at the bottom of the molten incinerated ash and separates from the brittle hardened body of incinerated ash alone. Because it precipitates, it can be easily separated and recovered, and it has also been found that at about 1200 degrees, most of the remaining ceramic particles, which remain in considerable amounts, are melted. If you mix the hardened material and an appropriate amount of cement and melt it again at around 1200 degrees, there is no longer any risk of gas generation, and it will melt into the desired magma shape over a certain period of time. It becomes a grayish-brown, dense crystalline substance with an unconfined compressive strength of approximately 800 kg/cm, which is comparable to natural rock of late Cretaceous granite.

Here, to describe the action of cement mixed with the brittle hardened body made only of incinerated ash mentioned above, the brittle hardened body made only of incinerated ash is finally It has the meaning of mixing cement into a stone-like body and how to strengthen its hardness.The requirements for this are to first melt the brittle hardened body of incinerated ash, and then slowly cool it and then turn it into a hardened stone. It is necessary to provide the conditions for additives to form stone-like bodies. However, in order to obtain an additive that met these requirements, various types of lime were initially used as samples, but a good molten state could not be obtained.Afterwards, various experimental results led to the use of only incinerated ash to make commercially available Portland cement. By mixing it with a brittle hardened material and heating it at around 1200 degrees for about 1 hour, a suitable molten state is obtained, and by slow cooling, a stone-like material with high hardness is obtained. In view of the convenience of available Portland cement, Portland cement was adopted as the optimal hardening agent for the brittle hardened material made only of incineration ash.

However, the manner in which this Portland cement acts on brittle hardened bodies made only of incinerated ash is a completely new method in which it acts not as a hydration coagulant in concrete construction, but as a hardening agent for brittle hardened bodies made only of incinerated ash. Calcium, which is the main component of cement, fuses well with the silicon compounds and carbon compounds, which are the main components of incineration ash, at high temperatures of around 1200 degrees.
In addition, by acting as a hardness strengthening agent for the brittle cured product, a dense crystalline product with high hardness can be obtained by slow cooling.

Moreover, its shape can be freely created depending on the container used during slow cooling and hardening, and when it is crushed to make gravel as necessary, it can be used as concrete aggregate as high-quality gravel with most of the metals removed. It's something you get.

In addition, the experimental results show that when the above melting temperature is increased from around 1200 degrees, the crystal density gradually becomes coarser and the strength decreases in proportion to the rate of increase, and when the melting temperature is lower than around 1200 degrees, it is not sufficiently melted and the temperature eventually reaches 1200 degrees. Before and after is said to be the most effective.

(f) Effects of the Invention As described above, by using the method of the present invention, the entire country is now completely contaminated deep underground, and the huge amount of garbage incineration ash, for which it is difficult to find a way to dispose of it, can be completely eliminated. This is then turned into artificial stone, which is then crushed and converted into high-quality gravel from which most of the metals have been removed.Currently, natural river gravel is completely prohibited from being mined, and mountain gravel has almost all been mined. As a result, the metals exposed on the surface of each stone grain are used as concrete aggregate without treatment, and this causes expansion and cracking of concrete due to oxidizing gas. The fear of an accident will be completely dispelled.

However, while the market price of artificial stone and gravel is not high, the manufacturing cost according to the present invention is comparatively low due to direct costs such as melting energy costs, cement as an auxiliary material, labor costs, and depreciation costs. When indirect costs are taken into account, it seems like the project is just a flop in terms of profitability, but this is an extremely short-sighted view.

This is because the current means of disposing of incinerated ash in each local government is to lease idle private land as mentioned above, dig it deeply and bury it, and then cover it with a certain amount of topsoil so that it is in the same condition as the surrounding soil. The total cost of land lease, excavation, restoration, transportation, etc. is not a small amount, and if the material is solidified with concrete or asphalt and then dumped into the ocean, the cost becomes even more expensive. Therefore, it is about 40% to 50% of the manufacturing cost of the present invention.

Furthermore, in the present invention, the amount of alloy lumps recovered from the incinerated ash is about 30% to 40% of the incinerated ash, which makes it difficult to use as a general casting raw material due to its complex components. However, if it can be supplied at a price about 50% lower than that of raw material pig iron for general casting, it can be used for heavy weights such as forklift vehicles and crane vehicles, which are used only based on hardness and specific gravity, regardless of the material. Other uses, such as fixed anchors for fishing nets for aquaculture and fish farming, require a large amount of energy, and if you add this up, and the melting processing energy is recovered and reused using a condensate turbine system, the energy processing cost can be reduced at least. Approximately 30% of the cost will be reduced, and with this, it will be possible to maintain a break-even point.

However, since the main purpose of the claimed invention is not to pursue corporate profits but to preserve the precious national land, even if there is a shortfall in terms of profitability, it will be minimal. Therefore, this should be considered an important technology that should be fully utilized even if it is covered by national funds.

Claims (1)

[Claims] 1 The incineration ash generated by incinerating the garbage is heated and melted to a furnace temperature of around 1500 degrees, and all the fumes from the incineration up to that point are released, and then it is cooled and hardened to form a brittle hardened body. None, the metal lump synthesized by various metals that are separated and precipitated with a difference in specific gravity at the bottom of the brittle hardened body is removed and used as a composition casting raw material, and the brittle hardened body is reused with an appropriate amount of cement. The cement is mixed and used as a hardening agent for the brittle hardened body, heated and melted at a furnace temperature of around 1200 degrees for a certain period of time, and then slowly cooled and hardened to produce artificial stone or crushed. A method for producing artificial stones, gravel, etc. using garbage incineration ash, which is characterized by the following characteristics: