JPH10230296A - Granulating method of waste sludge and waste soil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To regenerate and reutilize waste sludge and waste soil as a water resistant granulated material by adding a water quantity adjuster into a hydrate waste sludge and waste soil or a defective waste soil to turn the mud like material to a powdery material, granulating the powdery material into a granulated material while adding a binder in a granulator and drying. SOLUTION: The water content adjuster for the free water in the waste sludge and waste soil is added at need into the hydrate waste sludge and waste soil generated at the time of building a tunnel, collecting an aggregate for concrete, manufacturing a Hume pipe or the like or the defective waste soil deteriorated in water permeability in a ground of a school or the like to turn the mud like material to the powdery material. And the powdery material is turned into the granulated material by the granulator after or while adding the binder alone, the binder and a solidifying agent or the binder and a fertilizer component to the powdery material. Further, the granulated material is dried to regenerate and reutilize as the water resistant granulated material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Industrial Application Field] The present invention deteriorates the permeability of ground such as waste mud and waste soil and schools widely in the industrial field related to soil and construction, so that it has to be replaced with new sand. The present invention provides a method for recycling such waste soil, and the processed water-resistant granular material is used not only in the field of civil engineering and construction, but also in the fields of agriculture and horticulture.

[0002]

2. Description of the Related Art Conventionally, a large amount of water-containing waste mud and soil discharged during tunnel excavation, sewage works, collection of concrete aggregate from mountains, production of fume tubes, etc., is generated at a vacuum car or dump truck at a site where it is generated. , Wastes were transported directly to industrial waste disposal sites, or once transported to a treatment site for hydrated waste mud and waste soil, where they were subjected to coagulation and dehydration treatments before being disposed of as industrial wastes. In addition, grounds, such as schools with poor water permeability, where water pools can be formed as soon as it rains, are transported to dumping sites by dump trucks and discarded, and fresh sand is usually transported by dump trucks. It was a target. That is, it can be said that the reuse technology of these water-containing waste mud and waste soil has not been generalized.

[0003]

SUMMARY OF THE INVENTION As described above, it is a main object of the present invention to establish a technology for recycling water-containing waste mud and waste soil, which has not been generalized conventionally. The main issues include the re-use form and the sub-task of establishing a processing system for it. One of the issues was to make the processing system easily transportable by truck to the site where waste mud and waste soil are generated.

[0004]

Means for Solving the Problems As a means for solving the problem of how to recycle waste mud and waste soil, the present inventor has made the waste mud and waste soil into water-resistant granular material. Thought. The granular material, depending on the application, particle size distribution, specific gravity,
Water resistance and strength can be controlled within a certain range, making it usable in fields such as civil engineering, construction, and agricultural and horticultural cultivation. The challenge of establishing a processing system for water-resistant granules is to adjust the amount of free water in water-containing waste mud and waste soil to make the muddy powdery. The problem was solved by means of creating a system that combines the technique of granulating into granules.

[0005]

The operation of the technology for effectively utilizing water-containing waste mud and waste soil established according to the present invention will be described in accordance with various means for solving the above-mentioned problems. First, the amount of free water in water-containing waste mud / waste soil is usually between 0.1 and 10 times the amount of inorganic fine particles mainly composed of clay. This free water is
If necessary, the amount of inorganic fine particles can be reduced to twice or less by adding an inorganic or organic water regulator. In any case, hydrated waste mud and waste soil having a large amount of free water are in a slurry state and a lumpy state usable for clay work, and are difficult to handle. The present inventor firstly, in order to facilitate the handling of this difficult-to-handle hydrated waste mud and waste soil,
A means for regulating the amount of free water in the system was invented. The means and operation will be described in detail. The present inventor has found that various substances are effective in regulating the amount of free water in the system. The following are examples of such substances. Natural polysaccharides, for example, starch, cellulose powder, alginic acid, etc., natural inorganic powders, for example, bentonite, perlite, diatomaceous earth, limes, etc., synthetic polymer compound powders, for example, polyvinyl alcohol, polyacryl Acid soda or its crosslinked product, carboxymethylcellulose and the like are effective in adjusting the free water amount of the hydrated waste mud and waste soil. One or more of these free water water regulators may be used depending on the use of the granulated material, and the free water amount may be 1 to 1
Add to 0% by weight of water-containing waste mud and waste soil system and mix well to adjust the free water amount of the system to 15% by weight or less of inorganic fine particles. , Easy to handle.

The present inventor has invented a method of processing waste mud and waste soil into water-resistant granules in order to reuse the waste mud and waste soil which have been powdered and which have been easily handled. The operation will be described below. First, a predetermined amount of a binder aqueous solution alone or a binder aqueous solution and a solidifying agent are added to powdery waste mud and waste soil, and a binder aqueous solution and a fertilizer component are added in the case of soil cultivation, and granulation is performed. Becomes water-resistant granules. The function of this binder is to combine clay and soil particles in waste mud and waste soil into water-resistant granules. The function of the solidifying agent is to take in clay or soil particles into the system when the solidifying agent crystallizes and solidifies to form water-resistant granules. Granules made using the solidifying agent are used in civil engineering and construction fields. In so-called soil cultivation specifications used in the fields of agriculture and horticulture, granulation is performed using only a binder without using a solidifying agent. At that time, a fertilizer component can be added to the system. In the case of a school or other ground, free water may be included as a result of water sprinkling to collect dust when collecting waste soil. In this case, the pH of the free water is 5.0 to 5.5.
In many cases, a lime-based water control agent is used to neutralize the acidic water and control the amount of free water. The amount of the binder to be added is suitably in the range of 0.1 to 15% of the waste mud / waste soil by dry matter calculation, and the amount of addition can be determined depending on the water resistance, strength, and intended use of the granular material.

In the above description, a waste mud and waste soil recycling system is highlighted, and an example of the system will be described here. 1 to 2 hoppers to receive waste mud and waste soil
the good things of the size of the m ^3. The waste mud and waste soil supplied from the popper into the fixed amount enter a mixer where a predetermined amount of a solidifying agent is added as required. In the mixing machine, waste mud and waste soil are changed from muddy or lump to powdery. This powdery material is supplied to the granulator as it is, but it is also possible to provide an appropriate screen before it and supply it except large stones. The drum type is convenient for the granulator. A predetermined amount of a binder aqueous solution is supplied to the powder by a sprayer, and the powder is granulated by rotation of a drum. A hot air dryer can be installed at the outlet of the granulator to dry the granules and make them water resistant.

[0008]

The present invention will be described below in detail with reference to examples. 1. Clay waste discharged from a concrete aggregate manufacturing plant in Ryotsu City, Niigata Prefecture, had a moisture content of 38%, and was a lump that could be used for clay work. 100 g of perlite powder was added to 1 kg of the waste soil, and the mixture was mixed well to form a smooth powder. This system has an average degree of polymerization of 1700,
100 ml of a 10% aqueous solution of PVA having a saponification degree of 98 mol% was added, and the mixture was granulated and dried in the sun. The granules were water resistant and did not disintegrate when placed in water for 72 hours. The average weight diameter of the granulated product was 3.8 mm, and the amount of particles having a particle size of 2 mm or more accounted for 63%. In addition, as a result of a CBR test according to the J1S A 1211 method, the CBR value after blending with water was 6.8%, indicating that it could be used for backfilling.

[0009] 2. Embodiment 1 FIG. 50 g of powdered cellulose was added to 1 kg of the same waste soil as used in 1 above, and mixed well to obtain a powder. To this system, 100 g of cement was added and mixed. 1 of the same PVA used in
150 ml of a percent aqueous solution was added to the system and granulated, followed by hot-air drying. This granulated product had an average weight diameter of 10.5 mm and had water resistance, and had a CBR value of 15.5 bar cents after water mixing according to JIS A 1211. It was found that this granulated material could be used as a lower roadbed material for simple asphalt pavement.

[0010] 3. The ground at the nursery school in Tatsuno City, Nagano Prefecture, had poor drainage, and water could form immediately after rain. The following test was performed using a sample obtained by homogenizing soil up to 10 cm from the surface of the ground. 3.5 g of lime was added to 1 kg of soil having a moisture content of 28%, mixed well, and 100 ml of a 5% aqueous solution of silanol-modified PVA was added, followed by granulation and hot-air drying. Also,
To 1 kg of soil having a moisture content of 11%, 50 ml of a 10% aqueous solution of silanol-modified PVA was added without adding lime, and granulation was performed followed by hot-air drying. The average weight diameter of the lime-added system was 3.0 mm, and the average weight diameter of the lime-free system was 2.8 mm. According to the JISA1211 method, the CBR value after water mixing was 3.2% in the lime-added system and 3.0% in the lime-free system. As a result of measuring the water permeability of the soil before and after treatment by the constant water level method,
The permeability of the ground soil before treatment is 0.006 cm /
The water permeability of the granulated product was 0.1 in the lime addition system.
172 cm / s, 0.165 cm /
s. The water permeability of the granules was measured half a year after returning the granules to the ground, and both showed a decrease of 5% or less.

4. The water-containing waste mud from the concrete aggregate collection factory in Ichihara, Chiba Prefecture, was added with a flocculant and dewatered.
It is a soft, clay-like mass containing a percentage of moisture. To 1 kg of this waste mud, 70 g of pearlite fine powder and diatomaceous earth 30
When g is added and mixed well, the system changes from a soft lump state to a smooth powder state. N: P ₂ O
₅ : K ₂ O = 12: 18: 12, 1% fertilizer component. Granulation was carried out using 100 ml of an aqueous solution in which 2% of the same PVA was used as in Example 1 above.
At this time, the particle diameter portion of 2 to 4 mm occupies 60% or more. The pH of the soil water was adjusted to 4.5. This was used as a nursery for rice, but there was no difference between commercially available soil and the growth of seedlings.

[0012]

The effect of the present invention is, as shown in the embodiment,
Until now, there was no general method of reuse, such as when excavating tunnels, collecting aggregate for concrete, manufacturing waste fumes and waste soil when manufacturing fume tubes, and schools that have deteriorated due to aging and poor permeability. The purpose of the present invention is to provide a method of reusing waste ground of the ground for civil engineering, agricultural use, horticultural use and the like. One of the most significant effects is that the method of the present invention eliminates the need to transport a large amount of waste mud and waste soil from a work site in the city to a suburban waste disposal site far away by a vacuum car or dump truck. But also. Of course, the effect on cost is also great.

Claims (2)

[Claims] Claims: 1. Excavation of tunnels, collection of concrete aggregates, production of fume stubs, and the like, including waste mud and waste soil and poor waste soil with poor water permeability of grounds such as schools.
If necessary, add a water flow regulator for waste mud and waste soil and mix to convert the mud to a powder, and then add the binder alone or the binder and the solidifying agent or the binder and the fertilizer component to the powder. A method for granulating waste mud and waste soil, wherein the granulated material is processed into granules using a granulator after or while being added, dried, and then recycled as water-resistant granules. 2. A natural product polysaccharide as a free water water regulator,
For example, starch, powdered cellulose, powdered alginic acid, etc., natural inorganic powders, for example, bentonite, perlite, diatomaceous earth, limes, etc., synthetic polymer compound powders, for example, polyvinyl alcohol, sodium polyacrylate or a mixture thereof One or more of a crosslinked product, carboxymethylcellulose and the like are used, and as a binder, for example, one or two selected from polyvinyl alcohol, a modified silanol of polyvinyl alcohol, and an emulsion copolymer of ethylene / vinyl acetate The method for granulating waste mud and waste soil according to claim 1, wherein one or two of cement and gypsum are used as the solidifying agent.