Method and system for carrying out treatment of granular substances with pollutants adhered

Abstract

Object of the invention is to finely granulate the granular substances with pollutants, such as the contaminated soils and incinerated ashes, adhered and to separate the pollutants from the granular substances efficiently and further to enable the unnoxious granular substances, from which pollutants as above have been separated, to be recycled. After carrying out fine granulation of the granular substances by carrying out a coarse disintegrating treatment on the granular substances with pollutants adhered through the first fine granulation machine 21, the granular substances, which have been finely granulated by the first fine granulation machine, are subjected to, by the second fine granulation machine 22, mutual polishing among the granular substances themselves being acted by mutual rubbing forces of the substance themselves and thus the pollutants, such as heavy metals and dioxin class substances adhering strongly to the surfaces of the granular substances are separated and also the granular substances without containing the pollutants are classified from the granular substances which have already been finely granulated by the first and second fine granulation machines by the vibrational screen 30 and the classification means 50.

Description

[0001] 1. Field of the Invention[0002] The present invention relates to a method for finely granulating granular substances with pollutants such as incinerated ashes adhered.[0003] The present invention relates to a method for carrying out fine granulation of granulating granular substances with pollutants such as soils contaminated by heavy metals, oily constituents and the like adhered and incinerated ashes conveyed from through flying incinerator and also carrying out separation of granular substances without containing pollutants or granular substances, from which most of the pollutants are removed, from the granular substances which are subjected to fine granulation treatment mentioned as above.[0004] 2. Description of the Prior Art[0005] Hitherto, unrecycable inflammable substances such as unrecycable raw garbages have been burnt up through a stoker type or fluidized bed type incinerator and the burnt up ashes have been transferred as incinerated ashes to a disposal plant.[000...

AI Technical Summary

Problems solved by technology

Since in the method 2 of solidification by cement, cement is mixed in the incinerated ashes, there exists a fatal disadvantage that the volume of the incinerated substances increases.

Further, alkaline of the incinerated ashes, which are subjected to mixing cement in them, is intensified and hence risk of elution of lead and the like is rather built up.

In the method 3 of treatment by agent, a pH adjustment is important and still, due to the reason that kinds of substances contained in the incinerated ashes are varied and not to be fixed, pH adjustment is not easy and addition of agent is supposed not to be effective when the pH adjustment is not carried out adequately.

In the method 4 of stabilization by acid or other solvent, because the stabilization is carried out in a condition with heavy metals remained, it is hard to prevent heavy metals from elution in long term.

In the method 5 of treatment by carbonation, maintenance control of the plant is hard and further equipments are complicated and hence this method is not practical.

Consequently, in this method sufficient effect can not be anticipated for the heavy metals and dioxin class substances adhered to granular substances in a massed granular state.

However, in view of considerations over a long period of time, in the solidification through fusion too, the possibility of elution of heavy metals trapped within the fused substances buried in the disposal plant can not be denied.

Further, there gives rise problems such that construction cost of the facilities and treatment cost are high because large facilities such as incinerating furnace and a large quantity of fuel are required for the solidification through fusion due to high temperature for fusing incinerated ashes.

On the other hand, in recent years, there gives rise to a problem such that soils in the vicinity of chemical factories and metal refineries are contaminated by heavy metals, organic chlorine or oily constituents.

Also beach shore soils contaminated by crude oil being effluent to ocean because of disasters at sea and also crude oil adheres to the drug out soils which are conveyed through a tunnel digging of a land subsidence at the area of crude oil deposited and consequently the treatment of such soils becomes hard frequently.

Further, the soils with pollutants in questions adhered (contaminated soils) include the soils which are Contaminated by mixing aforementioned incinerated ashes into them.

Also since the incinerated ashes are formed of a soft texture, it is not only hard to detach dioxin class substances adhered to them by means of an usual crushing machine but it is not possible to do so because, if the incinerated ashes are crushed by crushing machine, for example a ball mill, the granular substances of the incinerated ashes are also granulated and thus the granular substances with dioxin class substances adhered can not be separated and, on the contrary, reduction of their volume becomes hard.

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