JPS5895575A - Forming and caking method for incineration residue of manicipal refuse - Google Patents

Abstract

PURPOSE:To obtain a burnt caked body wherein harmful heavy metal is fixed in a stable state by rethrowing inorganic materials such as glass separated from an incineration residue of municipal refuse together with municipal refuse. CONSTITUTION:Metal and incombustibles are removed from an incineration residue produced at a manicipal refuse incinerating plant to obtain inorganic mateials consisting essentially of waste glass and soil and stones. The inorganic materials are crushed or formed. This, formed body is rethrown in an incinerator together with municipal refuse to be burnt. After the burning, a burnt body and other residues are separated from the mixture of the burnt body and residue to obtain a burnt caked body. In this caked body, harmful heavy metal is fixed in a stable state.

Description

Detailed Description of the Invention Municipal waste incineration residue (hereinafter referred to only as incineration residue) amounts to 10 to 15% of the municipal waste weight, and 400% of municipal waste is produced annually nationwide.
The amount of residue is large, ranging from 1,000 to 6,000,000 tons, especially in urban areas where it is difficult to secure land for residue disposal, making residue disposal an extremely serious social problem.

The present invention addresses the situation where it is difficult to secure landfill sites for residues by turning municipal waste incineration residue into molded products and effectively using them for roadbed materials, concrete aggregates, etc. The purpose is to fix harmful metals, etc. within the molded product and prevent environmental pollution caused by residue treatment.

Conventionally, most of the incineration residue is disposed of in landfills, but problems such as heavy metal contamination of leachate in landfills, stability of the landfill ground, and dust generation in the wind at landfills have been pointed out, There are major problems not only in securing land but also in the treatment method itself. In addition, there is also a method of dividing the incineration residue and using it for roadbed materials, etc.
Due to the presence of " is required for large violets, making economics a problem.It has also been pointed out that there is a problem in economics when using artificial lightweight aggregates.The present invention solves such problems. This was done to solve the problem.After recovering metals from the residue and removing incombustibles, the remaining inorganic materials are crushed.They are molded or simply molded, and the molded products are put back into the municipal waste incinerator along with municipal waste. This method is characterized by the fact that after firing with the heat of combustion of municipal waste, the fired product is separated from other inorganic substances to obtain a fired solidified product, and the harmful heavy metals in the residue are fixed in the molded product during the firing process. There is no risk of environmental pollution such as elution or dust generation, and there is no danger in construction because the glass is molten.Furthermore, the heat and equipment required for firing are By using heat and incineration equipment and simultaneously feeding molded materials into the waste, the ventilation resistance of the waste layer can be improved and the incineration efficiency can be improved. This is unnecessary and therefore allows for significant reductions in equipment and operating costs compared to conventional solidification processes that utilize the heat of oil combustion.

Example A specific example of the invention will be described along with the drawings.

Municipal waste is supplied from a hopper 1 to a supply port 3 by a packet crane 2. At the same time, molded products made from the municipal waste incineration residue are transported from the molded product storage hopper 16 to the crane 2 to collect the inorganic content of municipal waste (100% by weight of municipal waste).
0~15%)'! il" is supplied to the supply port 3. The city tomi and the molded material put into the supply port are dried in the drying zone 4, and the city tomi is combusted in the combustion zone 5 (at a temperature of 800 to 1200 degrees Celsius).
) The molded product is fired and solidified by the heat, and is cooled together with the incineration residue in a cooling zone 6. (Temperature: 150 to 400°C) Iron scraps 17 are removed in a porcelain sorter 7, and incombustible materials are removed in a separate female sieve in 8. After that (noncombustible materials are returned to the furnace), a shape separator 8 separates the fired molded product 9 from other residue 10, and the fired molded product is made into a product. The residue is further crushed at the same time that mixed metals are removed by a crushing surface 11 and classifiers 12 and 13, and then sent to a molding machine 1.
In step 4, mold while adding water or a suitable binder 15 (shape: bispherical, pellet-like, columnar, etc., size = 10~
50yyimxlO~50mml molded product storage hopper-1
It is stored in 6.

The properties of the fired product obtained in this way have an apparent specific gravity of 1.4.
~2.0 degree, crushing strength 300~7000kg/cm2
The water absorption rate is 10% or less, and it can be fully used as concrete aggregate or roadbed material.

[Brief explanation of drawings]

The drawing is an explanatory diagram of an apparatus system for carrying out the present invention. 1. ．． ．． n city garbage hottuno《1, 1 6. ．． ．． ．． Molding storage hopper, 2. ．． ．． ．． Noket Crane, 3
．． ．． ．． ．． Supply port, 5... combustion zone, 7... magnetic separator, 8... sieve separator, 8.・．． ．． Shape separator, 1
1. −． ．． Pulverizer, 12.13... Classifier, 1
4... Molding machine.

Claims (1)

[Claims] (1) Metals and incombustible materials are removed from the residue discharged from municipal waste incineration plants, and the resulting inorganic materials, mainly composed of glass chips and soil and stones, are formed or crushed and shaped, and then re-injected into the incinerator along with the municipal waste. After firing, the fired molded product and other residues are separated from the fired product residue mixture to obtain a fired molded solidified product.