KR101039657B1 - Method for mixing and disposing of coal ash for early stabilizing dredged constructing fill ground - Google Patents

Abstract

PURPOSE: A coal ash mix-disposal method for the early stabilization of dredged and reclaimed soil is provided to improve the sedimentation and self-weight consolidation speed of the dredged and reclaimed soil. CONSTITUTION: A coal ash mix-disposal method for the early stabilization of dredged and reclaimed soil comprises the following steps: mixing 90~10wt% of dredged soil and 10~90wt% of coal ash to obtain coal ash mixed process soil(S110); adding seawater to the coal ash mixed process soil(S120); inserting the coal ash mixed process soil into a disposal facility for precipitating(S130); removing surface water from the facility using a wasteway(S140); and improving the ground property of the obtained dredged and reclaimed soil using a drainage method of pore water(S150).

Description

METHODS FOR MIXING AND DISPOSING OF COAL ASH FOR EARLY STABILIZING DREDGED CONSTRUCTING FILL GROUND}

The present invention relates to a method for dumping coal ash for early stabilization of dredged landfill, and more specifically, in the construction of dredged landfill to dump coal ash treated soil mixed with dredged soil, which is a by-product of coal-fired power plant, when constructing dredged landfill. The present invention relates to a coal ash mixing dumping method for early stabilization.

Coal ash, a byproduct of coal-fired power plants, consists of fly ash, bottom ash and cinder ash. In recent years, attempts have been made to directly sort and recycle waste incinerators, except that fly ash is about 60% recycled, and most of it is landfilled and disposed of, especially in the past 20-30 years. The amount of coal ash that is buried in the coal mine is not only significant, but the cost of securing and dumping the ash processing plant is very high. Moreover, the general coal ash plant is located on the coast near the coal-fired power plant, and is treated by the strong wind compared to the inland part. Due to the blowing of fine dust from the surface layer, it is a serious problem for the living environment of nearby residents. Landfill coal is a mixture of fly ash and bottom ash.

Previously, fly ash and bottom ash are separated and recycled through separate screening process for landfill coal, but not only for direct use of coal ash generated from incinerator but also for sorting process for landfill coal that is dumped in thermal power plant ash processing plant. If it is recycled to the ground composition without the need for it, it will be an economical way to reduce the time and cost required for the primary processing.

To date, fly ash has been recycled more than 60% as a cement substitute, and bottom ash has recently been proposed to improve the compaction characteristics and apply it as road fill material. The proposal has not been proposed yet.

In the meantime, the dredged sediment from the inland sea or the open sea is dumped and settled inside the dumping site when the dredging landfill is being built, and the method of increasing the strength of the dredging dumping ground is applied by applying the consolidation promotion method. In the process of pumping up the dredged soil, disturbed stabilized dredged soils, the pollution of nearby marine and coastal environment caused by floating matters is becoming a serious problem.In particular, as the dredging transport distance increases, not only for dredging facilities but also pollution becomes more serious. It is happening. In addition, recently, due to the depletion of high quality dredged soil, there is a limit to the application of dredging landfilling method for large-scale construction of land.

In addition, coal ash is classified as general waste among industrial wastes, so it can be directly used for the construction of landfills, but its specific gravity and unit weight are smaller than those of general dredged soils, so the sedimentation and self-consolidation characteristics are generally used. Problems apply directly to pump dredging and dredging techniques.

The present invention has been made to solve the above problems, by mixing and dumping coal ash during dredging landfill composition, compared to the landfills composed of pure dredged soil, the coal ashing effect of fly ash (fly ash) and cohesive soil and coal ash assembly Interference sedimentation is suppressed by minute (bottom ash series) and sedimentation speed is increased. After sedimentation is completed, self-consolidation speed is increased by increasing permeability coefficient. The aim is to provide a coal ash dumping method for the early stabilization of dredged landfills, which can shorten the time and cost for improvement.

In addition, the present invention solves the environmental problems caused by dust generated in the coal ash dumping ground by recycling a large amount of coal ash generated in the coal-fired power plant or currently dumped in the ash treatment plant, and due to excessive dredged soil collection by reducing the amount of dredged soil It is possible to minimize the problems of marine and coastal environmental pollution, and to reduce the environmental problems caused by chemical fiber-based drain boards and cement-based treatment methods, which are widely used as general ultra soft ground methods. Another object is to provide a coal ash mixing dumping method for stabilization.

Features of the present invention for achieving the above object,

A process for producing a mixed ash soil by mixing dredged soil and coal ash dredged by a pump according to a mixing ratio while supplying coal ash pre-stored in a tank through a dredging conveying pipe to a dump site to produce a coal ash mixed treated soil; A seawater addition step of adding seawater using a seawater supply apparatus to adjust the water content of the coal ash mixed treatment soil; A laying / settling process of laying the coal ash mixed treated soil having a controlled water content in the dumping site and settling it; A supernatant removal process for removing the upper supernatant through the waterway when the sedimentation is completed; And it is characterized by consisting of an improved process for improving the ground properties by performing a compaction or drainage method of pore water on the pour ground.

Here, the coal ash mixes the fly ash-based coal ash fine powder and bottom ash-based coal ash granulated powder generated directly from the thermal power plant incinerator.

Here, the coal ash is mixed with 10 to 90% by weight of coal ash fine powder and 90 to 10% by weight of coal ash powder.

Here, the coal ash directly uses the landfill coal, which is dumped in the coal-fired power plant ash processing plant, without undergoing a separate separation process.

Here, the coal ash mixes fly ash-based coal ash fine powder directly generated in the thermal power plant incinerator, and bottom ash-based coal ash powder and dumped coal ash dumped at the thermal power plant ash processing plant.

Here, the coal ash is a fly ash-based coal ash generated directly from the coal-fired power plant incinerator in the same amount as the ash content of fly ash-based coal ashes and bottom ash-based coal ashes dumped in the coal-fired power plant ash processing plant. The fine powder and coarse ash powder of bottom ash series are mixed.

Here, the mixing ratio of the coal ash mixed treatment soil is mixed with 10 to 90% by weight of the coal ash, and 90 to 10% by weight of dredged soil.

Here, the dredged soil includes viscous soil and silt.

Here, the water content is 400% or more.

According to the landfill ground composition method using the mixed treatment soil of the present invention configured as described above, coal ash fines (fly ash-based) and viscous soils are compared to landfills composed of pure dredged soil by mixing and dumping coal ash during dredging landfill composition. Interference sedimentation is suppressed by coagulation effect and coal ash (bottom ash series), and sedimentation speed is increased. After sedimentation is completed, self-weight consolidation speed is increased due to increase of permeability coefficient. There is an advantage that can shorten the time and cost for the improvement of dredged landfill.

In addition, according to the present invention to solve the environmental problems caused by the dust generated in the coal ash dumping ground by recycling a large amount of coal ash generated in the coal-fired power plant or currently dumped in the ash treatment plant, by reducing the amount of dredged soil to extract excessive dredged soil Due to this, it is possible to minimize marine and coastal environmental pollution problems, and to reduce environmental problems resulting from chemical fiber-based drain boards or cement-based treatment methods, which are widely used as general ultra soft ground methods.

1 is a view schematically showing the configuration of a landfill composition using coal ash and dredged soil according to the present invention.
Figure 2 is a process chart for explaining the coal ash mixing dumping method for early stabilization of dredged landfill according to the present invention.
3 to 5 is a graph showing the sedimentation-weight-consolidation rate according to the coal ash mixing dumping method for early stabilization of the dredged landfill according to the present invention.

Hereinafter, with reference to the accompanying drawings, the landfill composition using the coal ash and dredged soil according to the present invention will be described in detail.

In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. The following terms are defined in consideration of the functions of the present invention, and may be changed according to the intentions or customs of the user, the operator, and the like. Therefore, the definition should be based on the contents throughout this specification.

1 is a view schematically showing the configuration of a landfill composition using coal ash and dredged soil according to the present invention.

Referring to FIG. 1, the landfill construction apparatus using coal ash and dredged soil according to the present invention includes a tank 110, a pump 120, a mixed feed pipe 130, and a seawater supply device 140. .

First, the tank 110 is pre-stored coal ash.

Here, coal ash is a mixture of fly ash-based coal ash powder and bottom ash-based coal ash powder generated directly from the coal-fired power plant incinerator. The coal ash powder is 10 to 90% by weight and coal ash powder is 90 to 10% by weight. Mix. In this case, when the coal ash fines are less than 10% by weight, the coal ash fines are more than 90% by weight, and the coal ash fines are more than 90% by weight, and the coal ash fines are less than 10% by weight, and the general mixing conditions of the landfill coal embedded in the ash processing plant Differently, in order to use the landfill coal directly in an unrefined state, there is a disadvantage in that it is necessary to select and separate to re-control the blending ratio.

Here, coal ash may also directly use the landfill coal dumped at the coal-fired power plant ash processing plant without undergoing a separate separation process.

Here, coal ash is mixed with fly ash coal ash powder generated directly from the thermal power plant incinerator and bottom ash coal ash powder according to the ratio of fly ash and bottom ash dumped at the coal power plant ash processing plant. The same ratio of fly ash and bottom ash in the landfill coal ash dumped at the coal-fired power plant ash processing plant is based on the fly ash-based coal ashes directly generated from the coal-fired power plant incinerator, and the bottom ash type directly generated from the thermal power plant incinerator. Mix the coal ash powder. At this time, in the case of the landfill coal ash, it is preferable that the fly ash-based coal ash fine powder and bottom ash-based coal ash content investigation are preceded.

In addition, the pump 120 dredges and supplies dredged soil. At this time, the dredged soil includes viscous soil and silt.

On the other hand, the mixed conveying pipe 130 receives the dredged soil fed by the dredging by the coal 120 and the pump 120 discharged from the tank 110, respectively, and is fed to the dumping, the coal ash and dredged soil is mixed according to the mixing ratio. Here, the mixing ratio of coal ash and dredged soil is preferably 10 to 90% by weight of coal ash, and 90 to 10% by weight of dredged soil, but when the coal ash is less than 10% by weight and the dredged soil is more than 90% by weight of the landfill composition In the improvement of the later ground, the improvement cost and shortening effect of the coal ash are reduced, and when the coal ash is more than 90% by weight and the dredged soil is less than 10% by weight, most of the landfill composition is precipitated as coal ash. It is difficult to expect a great cohesive effect or difficult to perform a function as soil soil after completion of landfill.

Then, the seawater supply device 140 adds seawater to adjust the sedimentation state, that is, the water content of the coal ash mixed treated soil mixed with coal ash and dredged soil. At this time, the water content is more than 400%, but when the water content is less than 400%, the lateral earth pressure of the ground created at the completion of the dumping is large, which affects the stability of the shores to be constructed in the construction of the landfill, which increases the size of the shores. The disadvantage is that pipe transfer is not good.

Hereinafter, with reference to the accompanying drawings, the landfill composition method using coal ash and dredged soil according to the present invention will be described in detail.

Figure 2 is a process chart for explaining the method of landfill construction using coal ash and dredged soil according to the present invention, Figures 3 to 5 is the sediment-weight according to the coal ash mixing dumping method for the early stabilization of the dredged landfill according to the present invention It is a graph showing the consolidation speed.

First, after examining the physical properties of the dredged soil, the indoor mixing test is carried out to determine the mixing ratio of coal ash and dredged soil according to the physical properties of the dredged soil (S100).

Then, the coal ash stored in the tank 110 is mixed with the dredged soil dredged by the pump 120 in accordance with the mixing ratio while transferring to the dump through the mixed transport pipe 130 to produce a coal ash mixed treatment soil (S110). At this time, the mixing ratio of the coal ash mixed treatment soil is preferably blended with 10 to 90% by weight of coal ash, and 90 to 10% by weight of dredged soil.

In this state, seawater is added to the coal ash mixed treatment soil using the seawater supply device 140 to control the sedimentation state of the coal ash mixed treatment soil, that is, the water content (S120).

Then, the coal ash mixed treated soil having a water content controlled by sea water is laid in the dumping site and settled (S130).

Then, when the sedimentation is completed to remove the upper supernatant through the runway (S140).

When the removal of the upper supernatant is completed, the ground characteristics are improved by performing a compaction method or a drainage method of pore water on the placed ground (S150).

On the other hand, as a result of experiments with the landfill composition method using coal ash and dredged soil according to the present invention was able to obtain the results shown in Figures 3 to 5.

FIG. 3 adds seawater to a coal ash mixed treatment soil in which coal ash is mixed with 20, 40, 60, and 80% by weight using a seawater supply device 140 to give a water content of 400%, and settles according to coal ash content during dumping. -It shows the self-consolidation rate, Figure 4 gives a water content of 600%, shows the sedimentation-self-consolidation rate according to the coal ash content during dumping, Figure 5 gives a water content of 800%, to the coal ash content at dumping It shows the sedimentation-self-weight consolidation rate according to.

3 to 5, the sedimentation and self-consolidation rate can be confirmed to be faster when the coal ash is mixed with the dredged soil at 20, 40, 60, 80% by weight than when only the pure dredged soil is dumped. The higher the mixing amount of coal ash, the faster the sedimentation and self-weight consolidation rate.

In addition, when the water content is high, and the mixing amount of coal ash is increased, it can be seen that the sedimentation and self-weight consolidation rate is faster.

On the other hand, the present invention has been described a method of dumping by mixing the coal ash and dredged soil, but dumping the coal ash first in the bottom of the landfill, and then dump the dredged soil in the upper, or dumping the dredged soil in the bottom of the landfill first, and then dumped the coal ash on the top You may.

As those skilled in the art would realize, the described embodiments may be modified in various ways, all without departing from the spirit or scope of the present invention. It is to be understood, however, that the present invention is not limited to the specific forms referred to in the description, but rather includes all modifications, equivalents, and substitutions within the spirit and scope of the invention as defined by the appended claims. Should be.

110 tank 120 pump
130: mixed conveying pipe 140: sea water supply device

Claims (9)

90 ~ 10% by weight of dredged soil containing viscous soil and silt, dredged by a pump according to the mixing ratio while supplying the coal ash already stored in the tank through the dredging conveying pipe to the dump site;
10 to 90% by weight of fly ash type coal ash fine powder and 90 to 10% by weight coal ash granulated powder, but directly from the ash ash fine ash of fly ash type ash dumped in the coal-fired power plant 10 to 90 weights of coal ashes from fly ash-based coal ash generated, bottom ash-based coal ash from landfill coal ash dumped in thermal power plant ash processing plant, and bottom ash-based coal ash powder generated directly from thermal power plant incinerator A mixed soil manufacturing process for producing coal ash mixed treated soil by mixing%;
A seawater addition step of adding seawater using a seawater supply device to adjust the water content of the coal ash mixed treatment soil to 400% or more;
A laying / settling process of laying the coal ash mixed treated soil having a controlled water content in the dumping site and settling it;
A supernatant removal process for removing the upper supernatant through the waterway when the sedimentation is completed; And
A coal ash mixing dumping method for early stabilization of a dredged landfill ground, comprising: an improvement process for improving ground characteristics by performing a compaction method or a drainage method of pore water on a poured ground. delete delete delete delete delete delete delete delete

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