JPH10120459A - Production of sintered compact of sludge-burned ash - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a sintered compact capable of providing a product having a small bulk specific gravity and capable of being readily treated by mixing burned ash of sewage sludge with washing clay, forming the mixture by extruding, and drying and burning the extruded mixture. SOLUTION: A washing clay obtained by dehydrating a dirty mud of a dirty water formed when washing a pit sand, a quartz sand, etc., by water, and water sprayed when extinguishing fire of burned ash of sewage sludge, can be efficiently utilized. Further, a trouble on an operation surrounding such as generation of powder dust is hardly caused when treating the burned ash. The washing clay, which is only utilized for reclamation as the dirty mud, can be effectively utilized. For example, the sintered compact is obtained by blending 40% burned ash of the sewage sludge, 30% clay and 30% washing clay in terms of dried powder, further kneading the mixture regulated to be 30% based on the body, forming the kneaded body into a brick having a desired shape by an extrusion molding machine and burning the brick. When the washing clay having a high alkali content is used, the burning can be performed at a lower temperature such as 1,000 deg.C and further the sintered compact having a small bulk specific gravity can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a sintered body using incinerated ash of sewage sludge, and more particularly to a method for producing a sintered body which has a low bulk specific gravity and is easy to handle. .

[0002]

2. Description of the Related Art Sewage sludge discharged from sewage treatment plants is incinerated in waste treatment plants and the like, and incineration ash is generated as a residue. This incineration ash is recycled as conventional landfill or ocean dumping. It is intended to be used effectively.

At present, as a method of recycling incinerated ash, as disclosed in Japanese Patent Application Laid-Open No. 62-176951, plastic ceramic raw materials are added to incinerated ash, and molded and fired with a press or the like to produce ceramic products such as bricks and tiles. That is being done.

[0004]

However, the incinerated ash of sludge is sprinkled at the time of fire extinguishing, and is usually handled in a state containing about 40% of water. Therefore, the incinerated ash containing water is dried, mixed with plastic clay and pressed, and a drying step is required. For example, JP
Even in 2-176951, the incinerated ash is dried, and the heat is not effectively used. Also, the dried sludge incineration ash is fine,
In addition, the density was low, dust was generated, and it was difficult to handle. Furthermore, the molded article of JP-A-62-176951 is mixed with a plastic clay and requires firing at a high temperature of 1100 ° C. or higher.

[0005]

In view of such problems, the inventors of the present invention have conducted various tests to solve these disadvantages, and have accomplished the present invention.

[0006] In other words, mixed with incineration ash of sewage sludge,
This is a method for producing a sludge incineration ash sintered body obtained by extrusion, drying, and firing. In the present invention, washed clay refers to clay-like soil obtained by dewatering sewage sludge generated when washing mountain sand, silica sand, or the like.

[0007]

According to the present invention, at least about 30% of water content is required for extrusion molding, but water sprayed at the time of extinguishing incinerated ash can be used effectively, and dust is generated when handling incinerated ash. There is no trouble in the working environment such as doing. Further, the present invention utilizes washed clay, and can effectively utilize what was used only for landfill as sludge. In addition, when a clay with a high alkali content is used as the washed clay, a sintering temperature as low as about 1000 ° C. and a sintered body having a small bulk specific gravity are obtained. In the case of a bulky product such as a brick, the sintered body is easily handled. And so on.

[0008]

[Example] Sludge incineration ash, clay, and rinsing clay are blended so that sludge incineration ash 40% clay 30% rinsing clay 30% on a dry powder basis, and water is further reduced to 30% with respect to the clay. Prepare and knead. At this time, the sludge incineration ash contains 4
It has a moisture content of about 0%, does not scatter sludge incineration ash, and does not cause any operational problems such as dust. Moreover, other clays (all 2
When about 5% water content is mixed, this water is effectively used as it is as the water of the clay. The kneaded clay thus formed is formed into a brick having a desired shape by an extruder. The formed brick is dried at 80 ° C. for 24 hours, and then heated at a rate of 990, 1020, 1 at a rate of 100 ° C./hour.
050, 1080, 1100 ° C.
It is kept for a while and then fired so as to be naturally cooled.

[0009] As a result, sintering is completed at a relatively low temperature of 990 to 1050 ° C., and thereafter oversintering occurs. Further, the bulk specific gravity of the fired body is as small as 1.6 or less, so that the fired product can be easily handled.

Claims (1)

[Claims] A method for producing a sludge incineration ash sintered body obtained by mixing incineration ash of sewage sludge and washing clay, extruding, drying and firing.