JPH05253319A - Agent for treating incineration ash containing poisonous substance such as heavy metal - Google Patents

Abstract

PURPOSE:To provide an incineration ash treating agent which makes poisonous substances such as heavy metal contained in the incineration ash harmless or prevents elusion by sealing up the substances. CONSTITUTION:This agent for treating incineration ash containing poisonous substances such as heavy metal comprises 4.0-6.0wt.% of sodium chloride, 0.3-2.0wt.% of ammonium chloride, 4.0-6.5wt.% of potassium carbonate, 0.1-0.4wt.% of cobalt chloride, 4.0-7.0wt.% of sodium carbonate and 0.6-3.0wt.% of boric acid. The rest are water and inevitable impurities.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an incineration ash treatment agent containing harmful substances such as heavy metals for detoxifying incineration ash of various wastes such as heavy metals and other hazardous substances such as industrial waste, municipal waste and sludge. is there.

[0002]

BACKGROUND OF THE INVENTION In most cases, various kinds of waste are finally discharged as incinerated ash. The incineration ash of these various wastes is generally mercury, hexavalent chromium, lead, cadmium, cyan, organic phosphorus, arsenic, PC.
Since it contains harmful substances such as B, trichlorethylene, tetrachloroethylene, organic chlorine, heavy metals such as copper, zinc, and fluoride, it must be treated at a given final disposal site in a strictly regulated manner.

On the other hand, direct landfilling or dumping of incineration ash containing such harmful substances as heavy metals is a dangerous treatment method, and harmful substances such as heavy metals contained therein are eluted and pollute the environment again. It is extremely difficult to handle in terms of collection and transportation because it causes secondary pollution and the shape of incineration ash is amorphous or fine powder, and the landfill site where these are finally disposed is The soil is also unstable and dangerous.

However, installation of the final disposal site is difficult due to land use,
It is becoming difficult due to problems such as improper processing and other problems in the area. In particular, the tightness of final disposal sites in metropolitan areas is severe, and the incineration ash is currently moving over a wide area beyond the prefecture.

[0005] In order to overcome this situation, a method of detoxifying harmful substances such as heavy metals, recycling and reducing the amount of incinerated ash, and recycling it is being sought.

The treatment agent of the present invention renders harmful substances such as heavy metals contained in incinerated ash harmless or contains them.
The purpose is to prevent elution. In addition, this will enable the secondary use of incinerated ash and recycling.

[0007]

The present invention is intended to solve the above problems, and the gist thereof is as set forth in the claims of the present application.

That is, the incineration ash treating agent of the present invention comprises sodium chloride, ammonium chloride, potassium carbonate, cobalt chloride, sodium carbonate, boric acid or borate,
Is included in a specific amount.

The content of each component is sodium chloride 4.0.
-6.0 wt%, ammonium chloride 0.3-2.0 wt%, potassium carbonate 4.0-6.5 wt%, cobalt chloride 0.1-0.4 wt%, sodium carbonate 4.0-7 .0
% By weight, boric acid (in the case of borate, converted to boric acid) 0.
6 to 3.0% by weight, balance water and unavoidable impurities.

The reason for limiting the blending amount of each component is that if it is less than the lower limit, it becomes difficult to render harmful substances such as heavy metals harmless and contain it, while if it exceeds the upper limit, the effect does not change, and the solubility is also increased. This is because there is a limit, and when a large amount is added, adverse effects such as not being completely dissolved and remaining as turbidity occur. Of course, it is uneconomical.

The addition amount of boric acid or borate salt (in the case of borate salt, the addition amount in terms of boric acid) may be 0.6 wt% or more and 3 wt% or less in the total liquid, preferably 0. 6 to 2
% By weight. Even if added in a large amount, the solubility is limited, and in a small amount, it becomes difficult to contain harmful substances such as heavy metals.

The boric acid used in the present invention is orthoboric acid, metaboric acid, tetraboric acid, oxidized boric acid, etc., and any of them can be used. The borate used in the present invention includes metaborate, orthoborate, diborate, tetraborate, pentaborate, hexaborate and octaborate among seven types. One or two or more.

The preferred borate is sodium or potassium borate, or a mixture of sodium borate and potassium borate, but sodium tetraborate (Na ₂ B ₄
O ₇ ) is particularly preferred.

[0014]

EXAMPLES Examples of the present invention will be shown below together with comparative examples. The treatment agents of the examples of the present invention and comparative examples were produced according to the formulations shown in Table 1 below. The treatment liquid formulations of Examples and Comparative Examples are as shown in Table 1.

[0015]

[Table 1]

Next, the treating agents of the above Examples and Comparative Examples were added little by little to the incineration ash containing harmful substances in the following proportions, and were mixed and stirred at room temperature for 10 to 15 minutes to uniformly mix them. Then, it was naturally dried for 1 to 2 weeks. The incinerated ash thus obtained was in the form of dry powder.

(Treatment) 100% by weight of incinerated ash Treatment liquid 1.8% by weight Elution analysis of harmful substances such as heavy metals in the incinerated ash powder products treated with the treating agents of the above Examples and Comparative Examples and untreated incinerated ash did. The results are shown in Table 2. As is clear from Table 2,
In the untreated incineration ash and the incineration ash treated with the comparative treatment agent, elution of harmful substances such as heavy metals is observed, whereas the incinerated ash treated with the treatment agent of the present invention contains harmful substances such as heavy metals. Almost no elution was observed, indicating that it was contained and rendered harmless. In the rightmost column of Table 2, the judgment criteria based on the provisions of the law on waste treatment and cleaning (abbreviated as Waste Treatment Law in Table 2) are also shown.

[0018]

[Table 2]

[0019]

Industrial Applicability As described above, according to the present invention, harmful substances such as heavy metals contained in incinerated ash of industrial waste, municipal waste, etc. can be contained and made harmless. Disposal can be facilitated and its industrial effect is extremely large. In addition, since the incinerated ash is made harmless, it can be used as a paving material or can be used for a secondary purpose such as in blocks, which is a useful invention from the viewpoint of resource saving and recycling.

Claims (3)

[Claims] 1. Sodium chloride 4.0 to 6.0% by weight, ammonium chloride 0.3 to 2.0% by weight, potassium carbonate 4.0 to 6.5% by weight, cobalt chloride 0.1 to 0.
4% by weight, sodium carbonate 4.0 to 7.0% by weight, boric acid 0.6 to 3.0% by weight, balance water and unavoidable impurities,
Incinerator ash treatment agent containing hazardous substances such as heavy metals. 2. Sodium chloride 4.0 to 6.0% by weight, ammonium chloride 0.3 to 2.0% by weight, potassium carbonate 4.0 to 6.5% by weight, cobalt chloride 0.1 to 0.
4% by weight, sodium carbonate 4.0-7.0% by weight, borate 0.6-3.0% by weight in terms of boric acid, balance water and unavoidable impurities Agent. 3. The borate is sodium borate and / or
Alternatively, it is potassium borate, and the incineration ash treatment agent containing harmful substances such as heavy metals according to claim 2.