JP6740772B2 - Dewatering floor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a dehydration bed, and more particularly to a dehydration bed for removing water from a substance such as ore containing water.

Conventionally, as a method of removing water from ores containing water, a method of dehydrating by applying heat from a heat source using electricity or a heat source using steam and evaporating water adhering to the ore is widely used. It was However, it is necessary to provide utility auxiliary equipment for preparing electric power and steam, and the cost for operating these equipments becomes a problem.

In order to deal with such a problem, for example, Patent Document 1 discloses a technique of dehydrating dredged soil by natural drying. However, it does not show matters concerning the type of water permeable material or a separation method for separating the water permeable material and the dehydrated soil when the sludge after dehydration is collected by a heavy machine or the like.

JP, 2002-316200, A

The present invention has been proposed in view of such circumstances, until the water content of a substance containing water (substance to be dehydrated) reaches a desired value without using heat energy such as electric power. It is an object to provide a method capable of efficiently dehydrating.

The present inventor has conducted extensive studies in order to solve the above problems. As a result, by using a dehydration floor formed by laminating a plurality of specific layers, and by depositing the dehydration target substance on the dehydration floor, water can be efficiently removed from the dehydration target substance by a simple method. They have found that they can be removed, and have completed the present invention.

(1) A first aspect of the present invention is a dehydration bed for dehydrating a substance containing water by depositing the substance, which is composed of sand having a predetermined particle size in order from the lower layer. A first layer and a second layer made of gravel having a particle size larger than that of the sand of the first layer are laminated, and a pipe provided with a plurality of holes is embedded in the first layer. It is a dewatering floor.

(2) The second invention of the present invention is the same as the first invention, wherein a third layer made of the same substance as the substance containing water is further laminated on the second layer for dehydration. On the floor.

(3) A third invention of the present invention is the dehydration floor according to the first or second invention, wherein a wire mesh is provided on the uppermost surface of the second layer.

(4) A fourth invention of the present invention is the dehydration floor according to any one of the first to third inventions, wherein the dehydration floor is laid and used on concrete inclined at a predetermined angle. ..

(5) The fifth invention of the present invention is the invention of any one of the first to fourth inventions, wherein the particle diameter of the sand forming the first layer is 2 mm or more and 19 mm or less, and the second layer is formed. The floor for dehydration, wherein the particle size of the gravel to be used is more than 19 mm and 200 mm or less.

(6) The sixth invention of the present invention is the dehydration method according to any one of the first to fifth inventions, wherein the substance containing water is an ore containing chromite obtained by a hydrometallurgical process of nickel oxide ore. It is a floor.

(7) A seventh invention of the present invention is a dehydration treatment method of removing the water from a substance containing water and collecting the substance, which is composed of sand having a predetermined particle size in order from the lower layer and is provided with a plurality of holes. A pipe for burying the pipe, and a second layer composed of a gravel having a particle diameter larger than that of the sand of the first layer, are laminated at a predetermined angle. A method for dehydration treatment comprising laying on inclined concrete and depositing the substance containing water on the uppermost surface of the floor for dehydration.

By using the dehydration floor according to the present invention, the moisture contained in the substance to be dehydrated is effectively removed by the consolidation by gravity and the permeation in the direction of gravity by the permeable floor without using thermal energy such as electric power. It is possible to efficiently dehydrate until the desired water content is reached.

It is sectional drawing for demonstrating the structure of the floor for dehydration. 3 is a graph showing the results of dehydration test in Example 1. FIG. 7 is a graph showing the results of the dehydration test in Comparative Example 1. FIG.

Hereinafter, specific embodiments of the present invention (hereinafter, referred to as “this embodiment”) will be described in detail. The present invention is not limited to the following embodiments, and various modifications can be made without departing from the spirit of the present invention. Further, in the present specification, the notation “X to Y” (X and Y are arbitrary numerical values) means “X or more and Y or less”.

<<1. Dehydration floor ≫
The dewatering floor according to the present embodiment is for removing water from a substance containing moisture (hereinafter, also referred to as “substance to be dehydrated”) so as to have a desired moisture content. It is used so that the substance to be dehydrated is deposited on top of the.

FIG. 1 is a cross-sectional view for explaining the structure of the dewatering floor according to the present embodiment. In FIG. 1, the dehydration floor 1 is placed on a paved concrete 50, and the dehydration target substance X is deposited on the dehydration floor 1.

Specifically, as shown in FIG. 1, the dewatering floor 1 includes a first layer 10 composed of sand 11 having a predetermined particle diameter and a sand 11 constituting the first layer 10 in order from the lower layer. The second layer 20 composed of the gravel 21 having a large particle diameter is laminated. Further, in the dewatering floor 1, a pipe 12 having a plurality of holes is embedded in the first layer 10. Further, preferably, the third layer 30 made of the same substance as the substance X to be dehydrated may be further laminated on the second layer 20.

The dewatering floor 1 having such a structure is a water-permeable floor (water-permeable floor) having voids. The dewatering floor 1 is used, for example, placed on the paved concrete 50, and by depositing the dewatering target substance X, water is squeezed out from the deposited dewatering target substance X by a consolidation action. Then, water permeates in the direction of gravity on the dewatering floor 1, and moisture is gradually removed from the substance X to be dehydrated. Then, the water that has permeated through the dewatering floor 1 and moved in the direction of gravity is taken into the pipe 12 buried inside the first layer 10, and passes through the pipe 12 to be recovered at a predetermined location. As described above, according to the dehydration floor 1, moisture can be efficiently removed by a simple operation of depositing a dehydration target substance without using energy such as electric power.

In addition, preferably, the third layer 30 made of the same substance as the substance X to be dehydrated is further laminated on the second layer 20, so that the gravel 21 and the first layer 30 constituting the second layer 20 are formed. It is possible to prevent the sand 11 forming the layer 10 from being dug up and mixed with the substance to be dehydrated. That is, when recovering the substance X to be dehydrated that has been dehydrated to a desired moisture content, it is performed by excavating using a heavy machine such as a wheel loader or a shovel car. By providing the third layer 30 made of the same substance as the substance X, it is possible that the third layer 30 acts as a buffer layer, and the dewatering target substance to be collected mixes with the gravel forming the second layer 20. Can be prevented. It is desirable that the third layer 30 covers the entire upper surface of the second layer 20.

Here, the substance containing water to be dehydrated (substance to be dehydrated) is not particularly limited, and an ore containing water in a predetermined ratio can be applied. Specifically, for example, an ore containing chromite (Cr ₂ O ₃ ) obtained by a hydrometallurgical process of nickel oxide ore can be used. The ore containing chromite as a main component has a particle size in the range of about 100 μm to 1 mm, can be obtained by physical separation from a hydrometallurgical process, and has a weight moisture content of about 12% to 15% immediately after separation. is there. Incidentally, in the ore containing chromite as a main component, it is generally necessary to reduce the water content to about 7% to 8%.

In particular, chromite obtained by the hydrometallurgical process of nickel oxide ore not only contains water, but also contains heavy metal ions. Therefore, in order to prevent such water containing heavy metal ions from directly flowing out to the soil, river, or sea area, it is desired to effectively remove the water by a simple method and recover it. In this respect, according to the dewatering floor 1 of the present embodiment, it is possible to efficiently dewater without using energy such as electric power, and it is possible to effectively collect dewatered water.

(1) 1st layer The 1st layer 10 is a layer which comprises the bottom layer of the said dewatering floor 1, and is comprised from the sand 11 which has a predetermined particle diameter. The sand 11 is not particularly limited as long as it has voids and water permeability, and for example, natural sand or the like can be used. Further, as the sand 11, even if a heavy machine such as a wheel loader is placed on the third layer 30 which is the uppermost layer of the dewatering floor 1, crushing or crushing does not occur, and the strength is such that the layer can be maintained. Is preferred.

The sand 11 that constitutes the first layer 10 has a smaller particle size than the gravel 21 that constitutes the second layer 20 described later. Specifically, the particle size of the sand is preferably 2 mm or more and 19 mm or less, and more preferably 5 mm or more and 15 mm or less.

The thickness of the first layer 10 is not particularly limited, and can be appropriately set according to the amount (treatment amount) of the substance X to be dehydrated and the like. Specifically, for example, the layer thickness can be about 50 mm to 1000 mm.

Here, in the first layer 10, a pipe 12 having a plurality of holes is embedded therein. The pipe 12 is, for example, a hollow pipe having a diameter of about several mm to several hundred mm and at least one end of which is open, and the surface of the hollow pipe (the surface of the pipe 12) is provided with a plurality of holes. ing. By embedding such a pipe 12 inside the first layer 10, the moisture derived from the substance X to be dehydrated that has permeated from the uppermost layer by gravity passes through a plurality of holes provided on the surface of the pipe 12. It is taken inside and drained.

The size of the pipe 12 can be appropriately adjusted according to the size of the dewatering floor 1 and the thickness of the first layer 10, but for example, the diameter is about several mm to several hundred mm as described above, A length of several meters to several tens of meters can be used. Further, the diameters of the plurality of holes provided in the pipe 12 can be appropriately set according to the diameter of the pipe 12 itself, and can be, for example, about 0.5 mm to 3 mm. When the pipe 12 is embedded in the first layer 10, the surface located at the bottom of the pipe 12 is not provided with holes, and the pipe 12 can be drained through the pipe 12.

For example, the pipes 12 can be provided at the same height level and at predetermined intervals when the dehydration floor 1 is viewed in cross section as shown in FIG. 1. Alternatively, the pipes 12 may be randomly provided inside the first layer 10. Further, the installation interval of the pipes 12 is not particularly limited, and the pipes 12 may be installed without any interval, but they are preferably installed at intervals of 1 m to 20 m, and more preferably at intervals of 5 m to 12 m. ..

(2) Second Layer The second layer 20 is a layer provided on the first layer 10, and is composed of gravel 21 having a particle diameter larger than that of the sand forming the first layer 10. The gravel 21 is not particularly limited as long as it has a particle size larger than that of the sand of the first layer 10 and has water permeability. For example, crushed stone obtained by crushing rock or the like with a crusher and classifying it into a predetermined size can be used. Further, as the gravel 21, even if a heavy machine such as a wheel loader is placed on the third layer 30, which is the uppermost layer of the dewatering floor 1, crushing or crushing does not occur, and the strength is such that the layer can be maintained. Is preferred.

Specifically, it is preferable to appropriately adjust the particle size of the gravel 21 in consideration of the particle size of the sand 11 of the first layer 10, for example, when the particle size of the sand 11 is 2 mm or more and 19 mm or less. The particle size of the gravel 21 is more than 19 mm and 200 mm or less. Further, more preferably, the gravel 21 having a particle diameter of 25 mm or more and 150 mm or less is used.

Thus, when the second layer 20 is constituted by the gravel 21 having a particle diameter larger than that of the sand 11 constituting the first layer 10, when the substance X to be dehydrated is deposited on the dewatering floor 1 and dehydrated. It is possible to prevent the upper layer portion from being clogged due to the component contained in the water and preventing the water from permeating into the first layer 10 which is the lowermost layer. That is, it is possible to prevent poor dehydration. In addition, it is possible to prevent the cake layer from being formed in the upper layer portion due to the components contained in the water. In this way, in the dehydration floor 1, it is possible to efficiently dehydrate the substance X to be dehydrated while maintaining the water permeation rate.

In particular, chromite minerals contain very fine particles. Even when dehydration is carried out using such a chromite mineral as a dehydration target substance, according to the dehydration bed 1, only the fine particles thereof are allowed to permeate, so that clogging and formation of a cake layer are effectively performed. Can be prevented.

The thickness of the second layer 20 is not particularly limited, and can be appropriately set according to the amount (treatment amount) of the dehydration target substance X, the layer thickness of the first layer 10, and the like. Specifically, for example, the layer thickness can be about 100 mm to 1000 mm.

Here, it is preferable that the wire mesh 40 is provided on the uppermost surface of the second layer 20. The wire mesh 40 is used to protect the second layer 20 composed of the gravel 21, and for example, when depositing the dehydration target substance X or when digging after dehydration, the second layer 20 and the subsequent layers of the second layer 20 are removed by a heavy machine or the like. It is possible to prevent the lower layer from being disturbed. When the third layer 30 is provided on the second layer 20, the wire mesh 40 can prevent the substance X to be dehydrated that constitutes the third layer 30 from mixing with the gravel 21.

The material, shape, and the like of the wire mesh 40 are not particularly limited, and for example, a wire mesh having a diameter of 1 mm to 5 mm formed in a mesh shape can be used. Further, the mesh opening size and the like are not particularly limited, and for example, a mesh having a wire interval of 10 mm to 1000 mm can be used. The mesh size can be appropriately adjusted according to the particle size of the gravel 21 forming the second layer 20, the size of the dehydration target substance X forming the third layer 30, and the like.

The wire mesh 40 is preferably provided on the entire uppermost surface of the second layer 20, but may be provided at regular intervals. Further, the wire mesh 40 also acts as a mark for the operator of a heavy machine such as a wheel loader to grasp the minable depth when the substance X to be dehydrated is mined after dehydration, and therefore, a position that can be the mark ( For example, it is preferable to provide it at a position visible from the side).

In addition, although the aspect which comprises the gravel 21 whose particle diameter is larger than the sand 11 which comprises the 1st layer 10 was demonstrated as above-mentioned, it is not limited to this. For example, the second layer may be formed by laminating a plurality of water-permeable nonwoven fabrics.

(3) Third Layer In the dewatering floor 1, preferably, a third layer 30 made of the same substance as the substance X to be dehydrated may be laminated on the second layer 20. When the wire mesh 40 is provided on the uppermost surface of the second layer 20, the third layer 30 is provided on the wire mesh 40.

Here, in the dehydration floor 1, when the third layer 30 is provided as the uppermost layer, the dehydration target substance X is deposited on the third layer 30 to perform dehydration. As described above, the third layer 30 is composed of the same substance as the substance X to be dehydrated, and thus acts as a so-called buffer layer. Therefore, by providing the third layer 30 in this manner, for example, when the substance X to be dehydrated deposited on the third layer 30 is mined after dehydration, the lower layers after the second layer 20 are disturbed. Can be prevented.

The installation mode of the third layer 30 is not particularly limited, but it is desirable to provide it so as to cover the entire upper surface of the second layer 20.

<<2. Usage of dehydration floor (dehydration treatment method) ≫
As shown in the example of the state of use of the dewatering floor 1 shown in FIG. 1, the dewatering floor 1 is used by being laid on, for example, paved concrete 50. Specifically, it is preferable that the concrete 50 serving as a base on which the dewatering floor 1 is laid has a structure that is slightly inclined in a predetermined direction by a predetermined angle.

In this way, by laying the dewatering floor 1 on the concrete 50 that is inclined at a predetermined angle, the dewatering floor 1 itself is inclined. Then, the water dehydrated from the dehydration target substance X deposited on the dehydration floor 1 moves to the lower layer inside the dehydration floor 1 by gravity, and then the pipe 12 embedded in the first layer 10 is removed. When the water is drained through, the moisture will flow smoothly in the direction of inclination. As a result, the water removed from the substance X to be dehydrated can be efficiently drained, and by providing a recovery pit or the like at the tip of the inclined dewatering floor 1, efficient recovery can be achieved. ..

As described above, for example, the water adhering to the ore containing chromite as a main component contains heavy metal ions, and after dehydration, the water is recovered and then detoxified with a detoxification facility or the like. Is required. Even in such a case, since the water can be efficiently collected in the collection pit or the like, it can be easily subjected to the detoxification process through the collection pit.

The inclination angle of the concrete 50 on which the dewatering floor 1 is laid is not particularly limited, and when water removed from the substance X to be dehydrated is removed and recovered via the pipe 12 embedded in the first layer 10, The angle may be such that the water content smoothly flows through the pipe 12 in the collecting direction. For example, the one tilted at an angle of about 1 degree to 10 degrees can be used.

In the first layer 10 of the dewatering floor 1, the pipes 12 are buried at intervals of, for example, 1 m to 20 m. Therefore, the water that has permeated from the upper layer to the lower layer of the dewatering floor 1 may not necessarily be taken into the pipe 12 while the water level is low. However, even if the water is not taken into the pipe 12 in the first layer 10, when it permeates to the bottom surface of the first layer 10 of the dewatering floor 1, it flows on the inclined concrete 50 in the inclination direction. Therefore, by providing a recovery pit ahead of that, it is possible to effectively recover.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples.

[Example 1]
As shown in FIG. 1 showing the use condition, a dehydration bed having voids and water permeability is used, and an ore containing chromite having a water content of 14% (chromite ore) is placed on the dehydration bed. It was deposited in a conical shape and a dehydration test was conducted.

Specifically, the dewatering bed is made of natural sand having a particle size of 2 mm to 19 mm, and a pipe having a diameter of 50 mm, a length of 10 m, and a large number of holes on the surface is embedded therein. The first layer and the second layer composed of gravel having a particle diameter in the range of 19 mm to 100 mm were sequentially laminated from the lower layer. Further, on the uppermost surface of the second layer, a wire mesh made of wire having a diameter of 2 mm was stretched over the entire surface. Further, upon dehydration, a layer made of the same chromite ore as the substance to be dehydrated was further laminated on the second layer as the third layer.

Using such a dehydration bed, chromite ore, which is a substance to be dehydrated, was deposited in a conical shape on the third layer, and a dehydration test was performed over 1,000 hours. The evaluation was performed by measuring the water content at specific five points in the deposit of the chromite ore deposited in a conical shape.

Table 1 below shows the average water content (%) in a predetermined dehydration time (time from the start of the dehydration test). The average water content (%) refers to the average of the water content at five locations in the chromite ore deposit. In addition, FIG. 2 is a graph showing the results of the dehydration test of Example 1, showing changes in the weight content of water at each of five points in the deposit with the elapse of dehydration time. It should be noted that FIG. 2 shows the positions of the five specific locations sampled in the conical chromite ore deposit (front view).

[Comparative Example 1]
In Comparative Example 1, a flat floor assuming paved concrete was used, and the same chromite ore (weight water content 14%) as in Example 1 was deposited as a substance to be dehydrated to perform a dehydration test.

Table 2 below shows the average water content (%) in a predetermined dehydration time (time from the start of the dehydration test). FIG. 3 is a graph showing the results of the dehydration test of Comparative Example 1, showing changes in the weight content of water at each of five points in the deposit with the elapse of dehydration time.

As shown in the results of FIG. 2 and FIG. 3, in Example 1 using the dewatering floor having a specific configuration, as compared with Comparative Example 1 using only a flat floor, any portion of the deposit of chromite ore It can be seen that even in the above, dehydration is carried out uniformly, and the dehydration rate is high, and effective and efficient dehydration is possible.

Specifically, as shown in Tables 1 and 2, for example, the average water content was 8.2% in the flat floor assuming the concrete pavement of Comparative Example 1 when the dehydration time was 405 hours. Thus, the dewatering floor of Example 1 has 6.4%, and the dewatering floor used in Example 1 can effectively and quickly remove water contained in the substance to be dehydrated. I understand.

1 Floor for Dehydration 10 First Layer 11 Sand 20 Second Layer 21 Gravel 30 Third Layer 40 Wire Mesh 50 Concrete X Dehydration Target Substance

Claims (7)

A dewatering bed for dewatering a substance containing water by depositing the substance,
From the bottom layer,
A first layer composed of sand of a predetermined particle size,
A second layer composed of gravel having a particle size larger than the sand of the first layer;
Is laminated, and a pipe having a plurality of holes is buried in the first layer. The dewatering floor according to claim 1, wherein a third layer made of the same substance as the substance containing water is further laminated on the second layer. The dewatering floor according to claim 1 or 2, wherein a wire mesh is provided on the uppermost surface of the second layer. The dehydration floor is
The dewatering floor according to any one of claims 1 to 3, which is used by being laid on concrete inclined at a predetermined angle. The particle diameter of the sand forming the first layer is 2 mm or more and 19 mm or less,
The dewatering floor according to any one of claims 1 to 4, wherein the gravel forming the second layer has a particle size of more than 19 mm and 200 mm or less. The dehydration floor according to any one of claims 1 to 5, wherein the substance containing water is an ore containing chromite obtained in a hydrometallurgical process of nickel oxide ore. A method of dehydration treatment for removing water from a substance containing water to recover the substance,
In order from the lower layer, a first layer made of sand having a predetermined particle size, in which a pipe having a plurality of holes is embedded, and a gravel having a particle size larger than that of the sand of the first layer A dewatering floor, in which the second layer and the second layer are laminated, is laid on concrete inclined at a predetermined angle,
A dehydration treatment method of depositing the substance containing water on the uppermost surface of the dehydration floor.

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