JPH07313950A - Granular material made from waste and waste treatment method - Google Patents

Abstract

PURPOSE:To recycle city waste and water treatment sludge as concrete aggregate, roadbed material, or reclaiming material by treating the waste easily and efficiently. CONSTITUTION:A crushed mixture of city waste and/or water treatment sludge with limestone or a mixture of crushed waste and crushed limestone is burned at 1000-1500 deg.C in a rotary furnace into compact particles 40 mm or less in diameter. Since the city waste and the water treatment sludge are a clay-type material, the particles have a property of cement clinker. The particles have enough strength and are free from the elution of harmful substances so that they can be utilized effectively as concrete aggregate, roadbed material, reclaiming material, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a granular material produced from waste and a method for treating the waste, and more particularly, as a concrete aggregate, a roadbed material, a backfill material, etc. by treating municipal waste and water treatment sludge. The present invention relates to a granular material produced from waste and a waste treatment method for effective utilization.

[0002]

2. Description of the Related Art Municipal refuse is either incinerated or landfilled without being incinerated. In recent years, the amount of municipal waste generated has been increasing, and soaring incineration costs and shortage of landfills have become a problem.

On the other hand, a large amount of water treatment sludge such as sewage treatment sludge and tap water treatment sludge is discharged from each water treatment plant. These water-treated sludges are dehydrated and then incinerated, or they are disposed of in landfill without being incinerated, and the amount of the generated sludge is enormous. Therefore, the shortage of landfill is a problem.

Therefore, recently, research and development have been carried out for the effective reuse of municipal waste and water-treated sludge. Particularly, for sewage sludge incineration ash, this is molded,
A method of producing a lightweight aggregate by firing has been proposed (Japanese Patent Publication Nos. 61-14099 and 61-14100).
issue).

[0005]

SUMMARY OF THE INVENTION In the above conventional method,
Sewage sludge needs to be dehydrated and fired to form incinerated ash, and sewage sludge cannot be used as it is.

[0006] On the other hand, with respect to municipal waste, some proposals such as fertilization have been proposed, but at present, no practical method has been proposed for effectively reusing a large amount of municipal waste.

[0007] The present invention has been made in view of the above-mentioned conventional circumstances, and is effective as a concrete aggregate, a roadbed material, a backfill material, etc. by easily and efficiently treating municipal waste and water treatment sludge. It is an object of the present invention to provide a granular material produced from waste and a method of treating the waste, which can be utilized.

[0008]

The particulate matter produced from the waste according to claim 1 is a mixture of municipal waste and / or water treatment sludge and limestone, which is then crushed in a rotary calcination furnace to 1000-1.
It is characterized in that it is composed of a hardened granular material having a particle diameter of 40 mm or less obtained by firing at 500 ° C.

The particulate matter produced from the waste of claim 2 is
Municipal refuse and / or water treatment sludge and limestone are crushed and mixed together, and then 1000 to 15 in a rotary firing furnace.
It is characterized in that it is composed of a hardened granular material having a particle diameter of 40 mm or less obtained by firing at 00 ° C.

According to a third aspect of the waste treatment method of the present invention, municipal waste and / or water treatment sludge and limestone are mixed and pulverized and then calcinated in a rotary calcination furnace at 1000 to 1500 ° C. to obtain a particle size of 40.
It is characterized in that it is made into a granular body of which the size is not more than mm.

In the waste treatment method of claim 4, municipal waste and / or water treatment sludge and limestone are crushed and mixed, and then calcinated in a rotary calcination furnace at 1000 to 1500 ° C. to obtain a particle size. It is characterized in that it is a compacted grain of 40 mm or less.

The present invention will be described in detail below.

In the present invention, first, municipal waste and / or water treatment sludge and limestone are put into a mill or the like and mixed and ground. Alternatively, the municipal waste and / or water treatment sludge and the limestone are separately crushed and then mixed (hereinafter, for the mixed pulverization of the municipal waste and / or water treatment sludge and the limestone, the municipal waste and / or the water treatment is performed. The case where sludge and limestone are mixed separately may be referred to as "individual crushing".). In this mixed pulverization or pulverization, it is preferable to dry the municipal waste and / or the water-treated sludge in advance.

In the present invention, the municipal waste refers to kitchen waste, paper waste, wood chips, cloth, and other combustible waste, but even if a small amount of non-combustible waste such as plastic, styrofoam, and metal is contained, no problem occurs. Absent.

On the other hand, the water treatment sludge is a water treatment sludge such as a sewage treatment sludge or a water treatment sludge discharged from a water treatment plant such as a sewage treatment plant or a water treatment plant.

The mixing ratio of limestone to be mixed with these municipal solid waste and / or water treatment sludge or its crushed product is equal to or more than the dry weight of the municipal waste and / or water treated sludge or its crushed product, preferably urban. It is 1 to 20 times the dry weight of waste and / or water-treated sludge or its crushed product. If the proportion of limestone is less than the dry weight of municipal waste and / or water-treated sludge or its crushed product, the amount of clinker mineral produced by firing in the subsequent step will be small and the resulting granules will become brittle. , Concrete aggregate, roadbed material,
It becomes unsuitable for applications such as backfill materials. Even if the mixing ratio of limestone is too large, the effect of the addition is not so different, the amount of limestone used per amount of treated municipal waste or water treatment sludge increases, and the treatment cost becomes high, which is not preferable.

The degree of the mixed pulverization or the individual pulverization is not particularly limited, but in the usual case, only the dried product of the municipal waste and / or the water-treated sludge or the dried product and limestone is charged into a mill to obtain 10 ~ 20 minutes treatment, particle size 20 ~ 1
It is preferable to use a pulverized product of about 00 μ.

A mixed pulverized product obtained by mixing and pulverizing municipal waste and / or water-treated sludge and limestone, or obtained by individually pulverizing and mixing urban trash and / or water-treated sludge and limestone. The pulverized mixture is then charged into a rotary kiln (rotary kiln) such as a rotary granulation kiln to obtain 10
Bake at 00 to 1500 ° C.

If the firing temperature is less than 1000 ° C., it is not possible to obtain a sufficiently hardened granular material, which makes it unsuitable for use as a concrete aggregate, a roadbed material, a backfill material and the like. Further, even if the firing temperature exceeds 1500 ° C., there is no great difference in the tightly closed state, and the firing cost is high, so the firing temperature is set to 1000 to 1500 ° C.

The firing temperature is preferably 1200 ° C. or higher in order to obtain a particularly well-pressed granular material. At the time of this firing, by mixing glass cullet containing an alkali component in the firing raw material, it is possible to improve the tightness of the fire and thus to lower the firing temperature. For example, by mixing the glass cullet in the firing raw material in an amount of 5% by weight or less, the firing temperature is 1000 ° C.
Granules that have been sufficiently baked can be obtained to some extent.

The resulting granules usually have a particle size of 0.
In the range of 5 to 40 mm, the average particle diameter is 25 mm, which can be used as it is as a concrete aggregate, a roadbed material, a backfill material, or the like.

The granular material obtained according to the present invention is a cement-like substance in terms of composition, since it is a burned product of municipal waste and / or water-treated sludge, which is a clay-based substance, and limestone.
Therefore, it has a property of solidifying when wet, and can be extremely effectively used as a concrete aggregate, a roadbed material, a backfill material and the like. That is, for example, when this granular body is laid on a road surface or the like, and then water is sprinkled, the granular bodies are bonded and solidified to form a road surface or a base surface having sufficient strength for walking or running.

By the way, municipal waste and / or water treatment sludge generally contains volatile metal compounds such as Pb, Zn and Cd.

In the present invention, in firing, a rotary kiln with a preheater is used, and these volatile metal compounds are extracted by the preheater and then cooled under temperature control to concentrate and recover each volatile metal compound. You can also

[0025]

Since municipal waste and water-treated sludge are clay-based substances, clinker minerals are produced in the same manner as cement and clinker-like particles are obtained by mixing limestone with this and firing.

The obtained granules have sufficient strength, and there is no problem of elution of harmful substances.
It can be effectively used as a roadbed material and backfill material.

In particular, this granular material has the property of solidifying when wet, and is extremely useful for road surface construction and the like.

[0028]

EXAMPLES The present invention will be described more specifically with reference to Examples and Experimental Examples.

The municipal waste used in the examples is
It is general combustible municipal waste, which has been previously dried at 100 ° C for 30 minutes. The water-treated sludge (sewage-treated sludge) was dried at 100 ° C. for 30 minutes.
The weight of municipal waste and water treatment sludge in is shown as dry weight.

Example 1 Municipal waste and / or water-treated sludge (dry product) and limestone were mixed and pulverized in a mill at a ratio shown in Table 1 for 15 minutes to obtain a pulverized product having an average particle size of 50μ. This pulverized product was put into a rotary kiln (in the case of No. 3, glass cullet was mixed in an amount of 3% by weight with respect to all the firing materials), and the mixture was fired at the temperature shown in Table 1 for the time shown in Table 1. A granular material having an average particle size shown in was obtained. Among the obtained granules, the crushing strength was measured by the following method and the elution test was performed on the concrete specimens having the following composition, in which the particle diameter of 5 mm or less was fine aggregate and the particle diameter of 5 mm or more was coarse aggregate, and the elution test was performed. The results are shown in Table 1.

For comparison, when crushing and firing were carried out in the same manner except that limestone was not used, it was not possible to obtain particulate matter from either municipal waste or water-treated sludge.

Mixing of concrete (parts by weight) Cement: 300 kg Fine aggregate (granular particles with a particle size of 5 mm or less): 700 kg Coarse aggregate (granular particles with a particle size of 5 mm or more): 1050 kg Water: 165 kg Crush strength measuring method JIS A 1108 It was carried out by the method specified in 1.

Dissolution test method A test solution was prepared according to JIS K No. 13 of 1973, a test method for metals contained in industrial waste, and JIS K 0
The amount of trace components eluted was determined by the test method of 102 factory wastewater.

[0034]

[Table 1]

Experimental Example 1 The uniaxial compressive strength and the modified CBR of each of the granules obtained in Example 1 were measured by the method specified in the paving outline.

As a result, as shown in Table 2, it was confirmed that a road surface having sufficient performance in any case and having excellent durability can be formed when used as a road surface material or the like.

[0037]

[Table 2]

N in Example 1 except that municipal waste and / or water-treated sludge (dry product) was previously crushed by a mill to an average particle size of 50 μ and then mixed with limestone having an average particle size of 50 μ.
o. Granules were produced under the same composition and firing conditions as those of Nos. 1 to 6, respectively, and characteristic tests were conducted in the same manner. In each case, an average particle diameter almost equal to that of the granules obtained in Example 1,
Granules were obtained that exhibited crush strength, non-dissolution, uniaxial compression strength, and modified CBR.

[0039]

As described above in detail, according to the granular material and the waste treatment method produced from the waste of the present invention, it can be used as concrete aggregate, roadbed material, backfill material, etc. from municipal waste and water treatment sludge. Useful granules can be obtained easily, efficiently and inexpensively.

The particulate matter produced from waste and the method for treating waste according to the present invention are effective in reducing the amount of waste and effectively reusing it, and its industrial and social utility is extremely useful as a resource-saving technique. Is large.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication C04B 18/10 Z B09B 3/00 303

Claims (4)

[Claims] 1. Municipal waste and / or water treatment sludge and limestone are mixed and pulverized, and then 1000 to 15 in a rotary firing furnace.
Granules produced from waste consisting of compacted granules with a particle size of 40 mm or less, obtained by firing at 00 ° C. 2. Municipal waste and / or water-treated sludge and limestone are crushed and mixed, respectively, and then calcinated in a rotary calcination furnace at 1000 to 1500 ° C. to obtain a particle size of 40 m.
Granules produced from waste consisting of compacted granules of m or less. 3. Municipal waste and / or water treatment sludge and limestone are mixed and pulverized, and then 1000 to 15 in a rotary firing furnace.
A method for treating waste, which comprises firing at 00 ° C. to obtain a compacted particle having a particle size of 40 mm or less. 4. Municipal waste and / or water-treated sludge and limestone are crushed and mixed together, and then calcinated in a rotary calcination furnace at 1000 to 1500 ° C. A waste treatment method characterized by the following.