JP2012056821A - Method for producing ps ash-based sintered compact, and ps ash-based sintered compact - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recycling method for PS (paper sludge) ash.SOLUTION: Incinerated ash containing PS ash is added with sludge containing a cohesive soil component such as construction sludge and kneaded and shaped, and the resulting shaped article is sintered. Protruding parts of the PS ash having an uneven shape are connected to each other using the sludge as a binder to form a three-dimensionally assembled shape. The useful structural component of the PS ash remains as it is; there is a large void between pieces of the PS ash; and a micropore on the surface of the PS ash is open. Taking advantage of these characteristics, the sintered compact can be used for various applications such as a scavenger of various components and artificial soil.

Description

  The present invention relates to a method for recycling waste, and more particularly to a method for recycling PS (= paper sludge) ash.

Recently, recycling of used paper has been actively carried out, but in that case, a large amount of paper sludge is generated. This paper sludge is reduced in volume by dehydration and incineration to become PS ash.
The particles of PS ash have a complicated uneven shape similar to that of konpeito, and it does not have fluidity just by adding water, and is difficult to compress and solidify. Furthermore, when used paper is recycled, it often contains fluorine, which is a harmful substance derived from printing ink.
Therefore, some are recycled as cement raw materials by utilizing hydraulic free lime contained in PS ash, but most are discarded and landfilled as they are.

JP 2007-230827 A

Thus, because the current landfill site is approaching saturation and it is difficult to secure a new landfill site, the recycling of PS ash is an urgent issue.
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a recycling method utilizing the characteristics of PS ash and a recycling method using the method.

The present invention has been made in order to achieve the above object, and the invention of claim 1 is to add incinerated ash containing PS ash to a sludge containing a viscous earth component and knead and model the sintered product. This is a method for producing a PS ash-based sintered body.
Invention of Claim 2 is a manufacturing method characterized by using construction sludge as sludge in the manufacturing method of PS ash system sintered compact described in Claim 1.
The invention of claim 3 is the method for producing a PS ash-based sintered body according to claim 1 or 2, wherein after adding silt sludge and kneading and modeling, further adding clay sludge or clay and kneading and modeling. Is a manufacturing method characterized by
The invention of claim 4 is the method for producing a PS ash-based sintered body according to any one of claims 1 to 3, wherein slaked lime is added to incinerated ash containing PS ash to insolubilize heavy metals contained in PS ash. Above, it is a manufacturing method characterized by adding the sludge containing a clay component and carrying out kneading modeling.
According to a fifth aspect of the present invention, in the method for producing a PS ash-based sintered body according to any one of the first to fourth aspects, the slag is further kneaded and shaped by adding slag and glass debris, and the sinter is subjected to sintering. And a heavy metal contained therein is integrated with the glass slag and insolubilized.
The invention of claim 6 is a sintered body produced by the method according to any one of claims 1 to 5.

  According to the method of the present invention, it is possible to recycle the material using the morphological characteristics of PS ash.

It is a photograph which shows PS ash. It is a photograph which shows sludge. It is a photograph which shows a basic ball-shaped porous sintered body. It is a photograph which shows the ball-shaped porous sintered compact which added Kibushi clay. It is a photograph which shows the particle structure of the sand-like sintered compact which added slag and glass waste. It is a photograph which shows the growth degree of lawn.

First, raw materials will be described.
<PS ash>
The PS ash is produced by reducing the volume of papermaking sludge generated in the used paper recycling process and papermaking process by dehydration and incineration, and includes any form of soot, flaming dust, and dust. The PS ash has a confetti-like irregular shape when viewed at a microscope observation level, and has many pores inside.
PS ash contains fine-grained components such as silica, alumina, calcium oxide, and iron oxide, and is strongly alkaline.
In the case of derived from used paper, chlorine is often contained due to the use of fluorine, which is a component of printing ink, and chlorine-based bleach in the recycling process.
When used, it may be dry or hydrated.

<Slaked lime>
When PS ash derived from used paper is used, slaked lime (Ca (OH) ₂ ) is used in combination. By using this together, fluorine which is a harmful substance becomes calcium fluoride and insolubilized.
The amount of fluorine present is not measured in advance, and the amount of slaked lime is determined based on the assumed upper limit. Therefore, some slaked lime remains unreacted.

<Sludge>
Since most of PS ash is already ceramicized and does not melt, sludge is used as a sintered binder. Therefore, sludge contains a viscous soil component. There are various types of sludge, such as purified water sludge, sewage sludge, and construction sludge, but construction sludge is preferred. This is because construction sludge is originally soil, and clay and silt, which are clayey soils, account for the majority. In addition, the thing with cement is alkaline.
When used, it may be dry or hydrated.

<Other viscous soil component sources>
What was produced from the cohesive soil layer may be used in combination with sludge as a cohesive soil component supply source. For example, if PS ash is kneaded and granulated with silt sludge, and a clay ball with high clay quality, such as Kibushi clay, is made to make a core ball, PS ash is added to easily enlarge the ball. be able to. When used in combination, the sintered body has high strength. When Kibushi clay is added, the sintered body is colored orange to brown.

<Mineral, glass scrap>
Slag is a by-product that comes out when smelting metal from ore, and is currently disposed of by landfill just like PS ash, but it contains heavy metals such as mercury and arsenic, which are harmful substances. Sometimes it is difficult to handle.
Thus, elution of heavy metals contained in the slag can be prevented by integrating with the solidified product of glass, ie, molten slag, which has been cooled after melting glass waste.
In the present invention, a sintered body is produced from the above-described PS ash and sludge. Depending on the application, mineral slag and glass scraps are also mixed, and heat is used in the sintering process to fix heavy metals to glass. In order to recycle the slag.

<Carbon, titanium, etc.>
In addition, the use can be expanded by adding carbon or titanium.

Next, a manufacturing method will be described.
First, slaked lime is added to PS ash to insolubilize fluorine contained in PS ash.
Subsequently, PS ash, sludge and water are put into a granulator (mixer), mixed and granulated to form balls. Rather than throwing in the whole amount from the beginning, it becomes easy to make a ball by putting it in stages while considering the amount of water contained in PS ash etc. from the beginning. The size of the balls is assumed to be No. 4 to pachinko balls. After that, depending on the application, a plurality of balls may be rounded up by hand, or formed into various shapes using a mold.
Hereinafter, a specific kneading modeling method will be described for each blending example.

Formulation Example 1 (basic)
(1) PS ash (moisture content of about 20-30%, 900 g) + sludge (washed silt sludge, moisture content of about 20-30%, 900 g) is put into a granulator and kneaded for about 3 minutes.
(2) Water (100 cc, 40 cc) is divided into two stages and charged into a granulator, and kneaded and granulated for about 10 minutes in total to produce a core ball.
In order to further enlarge the ball, the following steps (3) and (4) are subsequently performed.
(3) Water (20 cc) + PS ash (water content of about 20-30%, 100 g) is put into a granulator to increase the size of the balls.
(4) Further, water is added as appropriate while checking the state of the ball to obtain a finished ball.
In order to make the balls larger or uneven, the small balls and large balls made in the above steps (2) and (4) are combined and rounded by hand.

Formulation example 2 (kibushi clay added)
(1) PS ash (moisture content of about 20-30%, 900 g) + sludge (washed silt sludge, moisture content of about 20-30%, 900 g) is put into a granulator and kneaded for about 3 minutes.
(2) Water (100 cc) + Kibushi clay (50 g) is put into a granulator, and further kneaded and granulated for about 5 minutes to make a core ball.
(3) Water (100 cc) + PS ash (water content of about 20-30%, 150 g) is put into a granulator, and the balls are enlarged over about 5 minutes.
(4) Water (50 cc) + PS ash (water content of about 20 to 30%, 100 g) is put into a granulator to further enlarge the balls.
(5) Further, water is appropriately added while checking the state of the ball to obtain a finished ball.

Formulation example 3 (carbon addition)
This is a partial modification of Formulation Example 1 and Formulation Example 2, which is sintered in an oxygen-deficient atmosphere so as to produce an smoldered brick and burnt incompletely to produce black to black silver (= black) carbide. Alternatively, carbon (powder) is added to the final stage of sintering to coat the surface of the sintered body with carbon, or the sintered body is immersed in carbon water after sintering to coat the surface of the sintered body with carbon. Two or more of the above three types of blackening methods may be selected and used in combination. However, this method is preferably employed because the most efficient blackening method is an incomplete combustion method.

Formulation Example 4 (with titanium oxide added)
This is a partial modification of Formulation Example 1 and Formulation Example 2, in which titanium oxide is spray-coated after sintering, and the surface of the sintered body is coated with titanium oxide.

Formulation example 5 (mineralization + glass waste added)
(1) PS ash (water content of about 20 to 30%, 800 g) + sludge (washed silt sludge, water content of about 20 to 30%, 800 g) is put into a granulator and kneaded for about 3 minutes.
(2) Slag (200 g) + glass scrap powder (150 g) is put into a granulator and further kneaded for about 5 minutes.
(3) Water (150 cc) is put into a granulator and kneaded and granulated for about 5 minutes to make a core ball.
(4) Water (50 cc) + PS ash (water content of about 20 to 30%, 100 g) is put into a granulator to further enlarge the balls.
(5) Further, water is appropriately added while confirming the kneading state to obtain a finished ball.

Next, the balls taken out from the granulator are dried as they are or after they are packed into a mold and compression-molded.
Usually, it is dried for about half a day in a dryer set at about 100 to 150 ° C., and after taking out, it is cooled for about half a day. By sufficiently drying, there are no inconveniences such as cracks or lack of strength when sintering described later.
Next, the dried product is put in a firing furnace, baked at a high temperature of 1000 ° C. or more for about half a day to about a day, and cooled to room temperature. Even if Kibushi clay is not included, if it is desired to color orange to brown, it may be taken out and cooled rapidly. If not colored, slowly cool in the furnace. The cooled object is a ceramic sintered body. In addition, since sintering temperature is 1000 degreeC or more, even if chlorine remains in PS ash, a dioxin will not generate | occur | produce.

(Properties of sintered body, application)
The sintered body of Formulation Example 1 is made of PS ash shown in FIG. 1 and sludge shown in FIG. 2, and has a ball shape as shown in FIG. According to the microscopic inspection, the convex portions of the concavo-convex PS ash are connected to each other using sludge as a binder and assembled into a three-dimensional shape. Therefore, there is a large gap between the PS ash, and the pores on the surface of the PS ash are open.
This sufficiently large pore volume can be used as an adsorption site for various components or an impregnation site for repellents, and can be used as a deodorant, a water treatment filter, a pest control agent, a livestock flooring, and the like. It can also be used as a microbial site.

In addition, it has a component composition similar to that of soil, is lightweight, has excellent water retention and water permeability, and can be used as artificial soil. For example, when it is used for hydroponics, the roots are not easily collapsed between the sintered bodies, and the supply amount of water or liquid fertilizer is small. In addition, it can also be used as soil for green floor soil, sand, rooftop greening, rooftop gardens, and planters. Furthermore, it can be applied to the roots of foliage plants as a moisture regulator.
Furthermore, since it is strong in alkali and rich in minerals, it can be used for disinfection of fields, promotion of composting, and soil improvement.
The irregular balls are easy to mesh with the PS ash constituting the balls, and can be used as a non-slip agent instead of salt, so there is no need to worry about the occurrence of salt damage.
In addition, if an object shaped in an appropriate shape is buried in the desert ground and water is supplied to the plant, the plant can absorb water from it and promote desert greening.
Furthermore, it can be used for indoor and outdoor flooring and wall materials by utilizing the negative ion generation effect of ceramics.

  Kibushi clay is added to the balls of the sintered body of the blending example 2 and is enlarged as shown in FIG. This ball can be used for the same application as the sintered body of Formulation Example 1, but has increased strength, and is particularly useful for schoolyards, parking lots, and green slip-adjusting sand for golf courses that are loaded. Further, since it is colored orange to brown, it can be used for identification display.

The sintered body of Formulation Example 3 is colored black. This is different from those of Formulation Example 1 and Formulation Example 2.
Because it is colored black, it uses the far-infrared effect of black body radiation and sprays it on the road surface to use it as a snow melting agent and road surface anti-freezing agent. Can be used to promote or prevent frost.
In particular, when the irregular balls are colored in Formulation Example 1, it has both anti-slip and snow melting / road surface freezing prevention functions, which is useful.

  Since the sintered body of Formulation Example 4 is coated with titanium oxide, a sterilizing and deodorizing effect can be expected by photocatalytic action.

The sintered body of the blending example 5 is melted into slag, and is not porous like the blending examples 1 to 4 described above.
This sintered body can be spread in places where strength is required, such as schoolyards and parking lots, using high strength.
Further, since the glass can be colored freely, it is possible to make a cosmetic sand as shown in FIG. 5 by adding a colorant such as a vegetable colorant or a resin together with glass waste.

  The components of the sintered body of Formulation Example 1 were analyzed and the results were as follows.

In the table, “Escalyu” (registered trademark) is a fermentation aid for compost of other companies, and is composed of powder particles mainly composed of calcium silicate crystals having a large amount of voids. It is included for comparison.
It was confirmed that PS ceramic products A and B were products of the present invention, and the elution of harmful substances was below the standard.

(Capture)
The following results were obtained when the effect of capturing various components was confirmed using the large ball of the sintered body of Formulation Example 1.

(Pest control effect)
When a large impregnated pore of the sintered body of Formulation Example 1 was impregnated with a chemical as a pest repellent and brought close to the insect, the effect was confirmed for spiders, millipedes, ants, worms, strawberries and slugs. did it.

(Bio-modular effect)
The large ball of the sintered body of Formulation Example 1 was used as a biomodule, and was immersed for a predetermined time in a solvent in which Bacillus subtilis was melted to nest it. And when this was installed in a pond, which is a closed water system, and the changes in chemical oxygen demand (COD) and biochemical oxygen demand (BOD) were observed, as shown below, the clear water purification action was demonstrated. Expression was confirmed.

(Fertilizer effect)
The small balls of the sintered body of Formulation Example 1 were mixed with lawn sand and sprayed on the growing lawn. After 42 days, the difference was confirmed as shown in FIG. did it.

  A comparison of composts obtained by mixing small particles of the sintered body of Formulation Example 1 with organic substances and compost commodities commercially available was as follows.

From this result, it was confirmed that the possibility of gas damage, nitrogen starvation, and excessive nitrogen generation due to secondary fermentation was significantly reduced.

Moreover, the following test was performed by mixing the small balls of the sintered body of Formulation Example 1 into the cow dung and cow manure sawdust mixture.
Test 1. A small amount of small balls were mixed in the cow dung and cow manure sawdust mixture, and the mixture was statically cultured in a thermostatic bath at 4 to 60 ° C., and the number of Escherichia coli and the number of aerobic mesophilic bacteria were measured.
As a result, Escherichia coli quickly became below the detection limit at a culture temperature of 20 ° C. or less when about 1% of small balls were added, but remained at 30 ° C. and 37 ° C. during the test period. In 37 ° C. culture, E. coli was killed by addition of about 2% or more. Aerobic mesophilic bacteria were reduced by about 1 to 20 orders with the addition of 1-2% PS ash.
Test 2. 0 to 3% of Kodama was mixed with the manure-sawdust mixture discharged from the beef cattle barn and deposited and fermented. The product temperature, moisture, PH, total nitrogen content, organic matter content, E. coli and aerobic mesophilic bacteria count were measured.
As a result, compost mixed with 1-3% of Kodama at the time of deposition was delayed in the start of the rise in product temperature, particularly in cold regions. Moreover, the tendency for the organic matter decomposition | disassembly rate during a composting period to be suppressed was seen compared with the additive-free zone. Escherichia coli in the composting process was below the detection limit more quickly in the Kodama addition group than in the No additive group.

  Since the sintered compact produced by the method of the present invention can be used for various applications, PS ash can be used as a raw material without waste.

Claims (6)

  A method for producing a PS ash-based sintered body, characterized by adding sludge containing a viscous earth component to incinerated ash containing PS ash, kneading and shaping, and sintering the shaped article. In the manufacturing method of PS ash system sintered compact according to claim 1,
A manufacturing method characterized by using construction sludge as sludge. In the manufacturing method of PS ash system sintered compact according to claim 1 or 2,
A production method comprising adding a silt sludge and kneading and shaping, and further adding clay sludge or clay and kneading and shaping. In the method for producing a PS ash-based sintered body according to any one of claims 1 to 3,
A manufacturing method characterized by adding slaked lime to incinerated ash containing PS ash to insolubilize heavy metals contained in PS ash, and then kneading and shaping sludge containing a clay component. In the method for producing a PS ash-based sintered body according to any one of claims 1 to 4,
Furthermore, the manufacturing method characterized by adding a mineral waste and glass waste, kneading and shaping, and melting the mineral waste and integrating the heavy metal contained therein with the glass slag to insolubilize.   The sintered compact manufactured by the method in any one of Claim 1 to 5.