JP2018003421A - Water bottom resource collection method and system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water bottom resource collection method and system enabling a specific resource included in a deposit of a water bottom to be efficiently collected.SOLUTION: The water bottom resource collection method is provided in which a specific resource 20c included in a deposit 20 of a water bottom B is fed in a lifted manner onto the water and is collected. In the water bottom resource collection method, the deposit 20 is continuously classified into the coarse-grained deposit content 20a including a coarse-grained fraction relatively large in a grain diameter much more and a fine-grained fraction 20b including relatively small in the grain diameter much more by using a cyclone type centrifugal separation device 3 arranged in the water. Thus, the resources 20c are unevenly distributed in one of the coarse-grained deposit content 20a and the fine-grained deposit content 20b. One of deposit content 20a and 20b with unevenly distributed resources 20c is fed in a lifted manner onto the water, and the other of deposit content 20a and 20b is made to remain on the water bottom B.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method and system for collecting bottom resources, and more particularly to a method and system for collecting bottom resources that can efficiently collect specific resources contained in sediment on the bottom.

  In the development of marine resources, deposits containing marine resources such as rare earths are picked up on a pick-up vessel using a pump lift, an air lift or the like. Then, the collected deposits are transported to a beneficiation facility using a shuttle ship or the like, and the beneficiation facility performs the beneficiation. The proportion of marine resources contained in sediment is very small. For this reason, in order to extract a small amount of marine resources, a huge amount of sediment is collected from the seabed. Along with this, a large amount of cost is required for picking up and transporting deposits. Furthermore, after depositing and depositing deposits, a large amount of unnecessary materials such as tailings and residues remain, so that disposal of these unnecessary materials also requires a large amount of cost.

  Thus, a deposit transport method has been proposed that can reduce the energy required to transport the deposit deposited on the water bottom onto the water surface (see Patent Document 1). In this sediment transport method, the transport cost of deposits is reduced by using the hydrogen gas and oxygen gas generated by electrolysis of water near the bottom of the water, thereby reducing the cost required for lifting the deposits. Can do. However, in this method, since the yield of the deposit is not different from the conventional one, it is not possible to reduce the cost required for transporting the deposit and disposing of the unnecessary material.

Japanese Patent Laying-Open No. 2015-74925

  An object of the present invention is to provide a method and a system for collecting a bottom resource that can efficiently collect a specific resource contained in a bottom sediment.

  In order to achieve the above object, a method for collecting a bottom resource according to the present invention is arranged in water in a bottom resource collection method in which a specific resource contained in a bottom sediment is lifted and collected. Using a cyclone-type centrifugal separator, the deposit is a coarse-grained deposit containing a larger amount of coarser particles having a relatively larger particle size and a fine-grained deposit containing more fine particles having a relatively smaller particle size. The resources are unevenly distributed to one of the coarse-grained deposit and the fine-grained deposit, and the one of the deposits having the unevenly-distributed resource is placed on the water. It is pumped and the other said deposit is left on the bottom of the water.

  The underwater resource collection system of the present invention is a cyclone type centrifugal separation system that is disposed in water in a underwater resource collection system that includes a lifting means for transporting a specific resource contained in sediment in the bottom of the water. An apparatus, an inflow means for allowing the deposit to flow into the centrifuge, and a connecting portion for connecting the centrifuge and the lifting means, and the deposit is relatively moved by the centrifuge. The resource is continuously classified into a coarse-grained deposit containing more coarse particles having a larger particle size and a fine-grained deposit containing more fine particles having a relatively small particle size. The deposit is unevenly distributed in any one of the deposit and the fine-grained deposit, and either the deposit in which the resource is unevenly distributed is sent to the lifting means through the connecting portion, and the other deposit is Structure released from the centrifugal separator into water. Characterized in that the.

  According to the method and system for collecting bottom resources according to the present invention, sediments on the bottom containing specific resources are separated from coarse deposits and fine deposits using a cyclone centrifuge arranged in water. By classifying them into minutes, resources are unevenly distributed in either one of the deposits. Then, only one of the deposits in which a specific resource is unevenly distributed is extracted and transported to the water, and the other deposit is left on the bottom of the water. Thereby, while reducing the total amount of sediments to be pumped onto the water, the resources can be pumped onto the water in a concentrated state, so that resources existing on the bottom of the water can be efficiently collected. In connection with this, it becomes advantageous to reduce the work and cost which dispose of an unnecessary thing. Moreover, it becomes possible to set a classification boundary particle size to a very small particle size by classifying using a cyclone type centrifugal separator.

  When the classification boundary particle size by the centrifugal separator is in the range of 10 μm or more and 30 μm or less and the resource is unevenly distributed in the coarse deposit, the resource having the characteristic of being unevenly distributed in the coarse deposit is efficiently used. Can be collected. The resource is, for example, a rare earth concentrated in a biological phosphate.

  The inflow speed of the deposit to the centrifugal separator by the inflow means is variable, and the classification boundary particle diameter by the centrifugal separator can be changed by changing the inflow speed. With this configuration, the classification boundary particle size can be appropriately changed according to the resource to be collected, which is more advantageous for efficiently collecting the resource. Moreover, since it can be used for collecting various bottom resources, the versatility becomes very high.

It is explanatory drawing which illustrates embodiment of the collection system of the underwater resource of this invention. It is explanatory drawing which expanded the centrifuge of FIG. 1 and its vicinity. It is explanatory drawing which illustrates the condition inside the centrifuge of FIG. 2 by a longitudinal cross-sectional view. It is explanatory drawing which illustrates the centrifuge of FIG. 3 by AA sectional view. It is explanatory drawing which illustrates another embodiment of the extraction system of the underwater resource of this invention. It is explanatory drawing which expanded the centrifuge of FIG. 5 and its vicinity. It is a graph which shows the particle size distribution of the deposit (classified mud) before classifying with the centrifuge, and the deposit after classifying.

  Hereinafter, a method and system for collecting water resources according to the present invention will be described based on the embodiments shown in the drawings.

  The present invention is a method and system for lifting and collecting a specific resource 20c contained in the sediment 20 at the bottom B. In the embodiment illustrated in FIGS. 1-4, the case where the rare earth contained in the muddy deposit 20 as the resource 20c is collected is shown.

  As shown in FIG. 1, a bottom resource collection system 1 (hereinafter referred to as a collection system 1) according to the present invention includes a lifting means 2 for lifting sediment 20 on the bottom B and a cyclone disposed in the water. A centrifuge 3, an inflow means 4 for allowing the sediment 20 to flow into the centrifuge 3, and a connecting portion 5 for connecting the centrifuge 3 and the lifting means 2.

  Furthermore, in this embodiment, it has a mining means 6 for mining the sediment 20 on the bottom B, a storage tank 7a for storing the mined deposit 20, and a discharge pipe 8 connected to the centrifugal separator 3. Yes. A collecting ship 9 is connected to the lifting means 2, and a support ship 10 is connected to the mining means 6 via a cable 10c.

  The lifting means 2 includes a lifting device 2 a and a lifting pipe 2 b that connects the lifting device 2 a and the lifting ship 9. The lifting device 2a is composed of, for example, an air lift pump, a slurry pump, a sand pump, or the like.

  The centrifugal separator 3 uses the centrifugal force to further increase the coarse deposit 20a containing a larger amount of coarse particles having a relatively large particle size and fine particles having a relatively small particle size. Classification is made into a fine-grained deposit 20b containing a large amount. As shown in FIGS. 2 to 4, the inside of the centrifugal separator 3 has a truncated cone shape in which the lower inner diameter is smaller than the upper inner diameter. An inlet 3a is provided in the upper part of the centrifugal separator 3, and a descending vortex that flows downward along the inner wall of the centrifugal separator 3 by flowing the sediment 20 from the inlet 3a at a high speed, In the center of the centrifugal separator 3, a rising vortex that flows upward is generated.

  When the sediment 20 is introduced from the inflow port 3a, the coarse sediment 20a having a relatively large specific gravity is greatly affected by the centrifugal force caused by the descending vortex, and therefore descends while swirling along the inner wall along the descending vortex. Then, it is discharged from an underflow outlet 3b provided below the centrifugal separator 3. On the other hand, the fine particle deposit 20b having a relatively small specific gravity is less affected by the centrifugal force caused by the descending vortex, and therefore rises along the central ascending vortex and overflows above the centrifugal separator 3. It is discharged from the outlet 3c.

  The size of the particle size that serves as a boundary for classification by the centrifugal separator 3 (hereinafter referred to as a classification boundary particle size) can be appropriately determined according to the type of the resource 20c to be collected. The classification boundary particle size can be changed by changing the size of the centrifuge 3 itself or the inflow speed of the deposit 20 that flows into the centrifuge 3. A plurality of centrifugal separators 3 may be connected to classify the deposit 20 into several stages.

  The inflow means 4 has an inflow device 4a and an inflow pipe 4b. The inflow device 4a is configured by, for example, a slurry pump or a sand pump. Inflow device 4a of this embodiment is arranged inside storage tank 7a. The inflow device 4a is connected to the inflow port 3a through the inflow pipe 4b. This inflow device 4a has a variable specification that can change the inflow speed of the deposit 20 into the centrifugal separator 3 arbitrarily or in several stages. If it does in this way, it can use for extraction of various resources 20c, without exchanging centrifuge 3, and versatility is very high.

  The connecting portion 5 is a tubular body that connects either the underflow outlet 3b or the overflow outlet 3c of the centrifugal separator 3 and the lifting means 2, and in this embodiment, the underflow outlet 3b and the lifting means 2 are connected. And connected. A discharge pipe 8 is connected to either the underflow outlet 3b or the overflow outlet 3c to which the connecting portion 5 is not connected.

  Rare earths have the property of being concentrated in biological phosphates. And the phosphate which a rare earth concentrates distributes abundantly in the coarse particle part with a comparatively big particle diameter of about 20 micrometers-125 micrometers, and the content rate of the rare earth distributed in the fine particle part below 20 micrometers is small. Therefore, in this embodiment, the underflow outlet 3b and the lifting device 2a are connected by the connecting portion 5, and the discharge pipe 8 is connected to the overflow outlet 3c.

  The mining means 6 includes a mining device 6a for mining the deposit 20 and a connecting pipe 6b. The mining device 6a and the storage tank 7a are connected via a connection pipe 6b, and the deposit 20 mined by the mining apparatus 6a is sequentially sent to the storage tank 7a through the connection pipe 6b. As the mining device 6a, various types of construction machines and underwater robots can be adopted depending on the state of the deposit 20 to be mined and the work environment. The mining device 6a can be configured such that an operator gets on board and operates, or can be configured to be remotely operated from the water.

  The mining device 6a of this embodiment includes a rotary blade that excavates the deposit 20, and a suction facility that sucks the excavated deposit 20 and sends it to the connecting pipe 6b. Power is supplied from the support vessel 10 to the mining device 6a through the cable 11a.

  Next, a method for collecting a specific resource 20c using the collection system 1 will be described below.

  First, the mining apparatus 6a is operated to mine the muddy deposit 20 on the bottom B containing the resource 20c (for example, rare earth). In this embodiment, the deposit 20 excavated by the suction facility is sucked together with the surrounding water while excavating the deposit 20 with the rotary blades of the mining device 6a. The deposit 20 mined by the mining device 6a is sequentially sent to the storage tank 7 through the connection pipe 6b.

  The deposit 20 stored in the storage tank 7 is caused to flow into the inlet 3a of the centrifugal separator 3 through the inlet pipe 4b by the inlet device 4a. The inflow speed of the deposit 20 to the centrifugal separator 3 by the inflow device 4a is appropriately set according to the classification boundary particle size.

  The classification boundary particle size suitable for uneven distribution of the resource 20c in one of the coarse deposit 20a and the fine deposit 20b varies depending on the type of the resource 20c, the state of the deposit 20 containing the resource 20c, and the like. . Therefore, it is preferable to know beforehand the classifying boundary particle diameter capable of efficiently distributing the resources 20c to be collected by conducting experiments or the like.

  As described above, the rare earth has a characteristic that it is unevenly distributed in the coarse deposit 20a having a particle diameter of 20 μm or more. Therefore, when the resource 20c is a rare earth, the classification boundary particle size may be set in the range of 10 μm to 30 μm.

  In addition, the rare earth is contained in the deposited portion having a particle size of 20 μm or less, although the content ratio is small. Therefore, when the amount of deposit 20 that can be mined is small, it may be preferable to set the classification boundary particle size to 20 μm or less. However, if the classification boundary particle size is made smaller than 10 μm, the content of rare earth contained in the coarse-grained deposit to be collected is lowered, so that the efficiency is reduced.

  When the classification boundary particle size is set to be larger than 20 μm, it is possible to further increase the rare earth content in the coarse deposit 20a to be collected. Therefore, when the amount of deposit 20 that can be mined is large and efficiency is important, the classification boundary particle size may be set to 20 μm or more. However, if the classification boundary particle size is larger than 30 μm, the amount of rare earth discharged from the overflow outlet 3c increases. Therefore, the classification boundary particle size is set to 20 μm, for example.

  In the centrifugal separator 3, the deposit 20 flowing in from the inlet 3a has a larger amount of coarse particles 20a including a larger amount of coarse particles having a relatively larger particle size and a larger amount of fine particles having a relatively smaller particle size. The finely divided deposit 20b is continuously classified. The coarse grain deposit 20a classified by the centrifugal separator 3 is discharged to the underflow outlet 3b, and the fine grain deposit 20b is discharged to the overflow outlet 3c. The resource 20c is unevenly distributed in one of the coarse grain deposit 20a and the fine grain deposit 20b.

  Then, one of the deposits in which the resources 20c are unevenly distributed is sent to the lifting device 2a through the connecting portion 5, and is transported to the water collecting boat 9 through the lifting pipe 2b. The other sediment with a relatively low content of the resource 20c is discharged into the water or the bottom B through the discharge pipe 8, and remains in the bottom B.

  In this embodiment, the resource 20c to be collected is a rare earth, and the classification boundary particle size by the centrifugal separator 3 is set to 20 μm. Therefore, the deposit 20 includes coarse particles having a larger particle size of 20 μm or more. It is classified into a deposited portion 20a and a fine-grained deposited portion 20b containing more fine particles having a particle size smaller than 20 μm. Most of the rare earth contained in the deposit 20 is unevenly distributed in the coarse-grained deposit 20a together with the biogenic phosphate.

  Then, the rare earth is discharged to the underflow outlet 3b together with the coarse particle deposit 20a, passes through the connecting portion 5, and is pumped onto the water by the pumping means 2. The fine-grained deposit 20b containing almost no rare earth is discharged to the underflow outlet 3b, passes through the discharge pipe 8, is discharged into the water from the discharge port of the discharge pipe 8, and remains on the bottom B.

  As described above, in the present invention, by using the centrifugal separation device 3 disposed in water, the coarse particles 20a and the fine particles 20b are classified, so that one of the deposits is collected in the submerged stage. The specific resource 20c is unevenly distributed. Then, only the deposits in which the resources 20c are unevenly distributed are extracted and transported to the water, and the other remains on the bottom B. Therefore, since the total amount of the sediment to be transported to the water can be reduced and the resources 20c can be transported to the water in a concentrated state, the resources 20c existing on the bottom B can be efficiently collected. Along with this, it is possible to significantly reduce the cost required for transporting the collected deposits and disposing of unnecessary items.

  Further, in the conventional method, when the resource 20c contained in the deposit 20 has a low content rate, it is difficult to collect and use because the cost effectiveness in the collection business is low. However, by adopting the present invention, even if the resource 20c has a low content rate, efficient collection is possible, and it is easy to promote the collection business.

  In the present invention, since the centrifugal separator 3 is used as a means for classifying the deposit 20, the classification boundary particle size can be set to a very small particle size. Therefore, even when the classification boundary particle size suitable for uneven distribution of the resources 20c is small as in the case of collecting rare earth, it becomes possible to classify with high accuracy. Moreover, a large amount of sediment 20 can be classified rapidly and continuously by the centrifugal separator 3. Since the deposits that are continuously classified and the resources 20c are unevenly distributed are continuously pumped onto the water by the pumping means 2, it is extremely advantageous to improve the sampling efficiency.

  5 and 6 show another embodiment of the collection system 1 of the present invention. In the previous embodiment, the case where the resource 20c having the characteristic of being concentrated in the coarse-grained deposit 20a has been described, but in this embodiment, the characteristic of being concentrated in the fine-grained deposit 20b having a certain particle size or less. The case where the resource 20c which has is collected is illustrated.

  In the sampling system 1 of this embodiment, the mining device 6a includes the storage tank 7a, the inflow means 4, the centrifugal separator 3, and the discharge pipe 8, and is configured to be able to move integrally. The deposit 20 mined by the mining device 6a is structured to be stored in the storage tank 7a disposed inside the mining device 6a via the connecting pipe 6b. An inflow device 4a is installed inside the storage tank 7a, and the inflow device 4a is connected to the inlet 3a of the centrifugal separator 3 through the inflow pipe 4b.

  A discharge pipe 8 is connected to the underflow outlet 3 b of the centrifugal separator 3. The overflow outlet 3 c of the centrifugal separator 3 is connected to a storage tank 7 b installed outside the mining device 6 a through the connecting portion 5. Inside the storage tank 7b, a lifting device 2a is installed, and the lifting device 2a is connected to the unloading ship 9 via a lifting pipe 2b.

  Next, a method for collecting the resource 20c using the collection system 1 will be described below.

  First, the mining device 6a is operated to mine the bottom 20 sediment 20 containing the resources 20c. The deposit 20 mined by the mining device 6a is sequentially sent to the storage tank 7a through the connecting pipe 6b. The deposit 20 stored in the storage tank 7a is sequentially introduced into the inlet 3a of the centrifugal separator 3 through the inlet pipe 4b by the inlet apparatus 4a. In the centrifugal separator 3, the deposit 20 flowing in from the inlet 3a is continuously classified into a coarse deposit 20a and a fine deposit 20b. Most of the resources 20c contained in the deposit 20 are unevenly distributed in the fine-grained deposit 20b.

  The fine-grained deposit 20b in which the resources 20c are unevenly distributed is discharged from the overflow outlet 3c and sent to the storage tank 7b through the connecting portion 5. The fine grain deposit 20b and the resource 20c stored in the storage tank 7b are sent to the collection vessel 9 through the lifting pipe 2b by the lifting device 2a. The coarse particle deposit 20a is discharged to the underflow outlet 3b, passes through the discharge pipe 8, is discharged into the water from the discharge port of the discharge pipe 8, and remains on the bottom B.

  For example, copper, lead, zinc, average, silver, and other polymetals and methane hydrate, etc. present in submarine hydrothermal deposits have the property of concentrating in fine sediment 20b having a certain particle size or less in water. ing. Therefore, in order to efficiently collect these resources 20c, as in this embodiment, the resources 20c are unevenly distributed in the fine-grained deposits 20b by the centrifugal separator 3, and the fine-grained deposits 20b are collected on the water. Then, it is preferable to leave the coarse grain deposit 20a on the bottom B.

  A rare earth mud (raw mud MW) set to a density assumed when flowing a mud-like bottom sediment containing rare earth into a cyclone centrifuge arranged in water was prepared. And classification was performed by the centrifugal separator which has arrange | positioned this raw mud MW in water. The underflow deposit UF discharged from the underflow outlet of the centrifugal separator and the overflow deposit OF discharged from the overflow outlet were collected. About this UF, OF, and the raw mud MW before classification, each particle size distribution and rare earth concentration were analyzed. The classification boundary particle diameter by the centrifugal separator was set to 20 μm. The result of the particle size distribution is as shown in the graph of FIG.

  As shown in FIG. 7, in the raw mud MW, the coarse particle deposit of 20 μm or more is about 20%, but by classifying with a centrifugal separator, the coarse particle deposit of 20 μm or more became 50% or more. More than 80% of the coarse particle deposit of 20 μm or more contained in the raw mud MW is classified into the underflow deposit UF. The volume ratio of the underflow deposit UF discharged from the underflow outlet after classification to the raw mud MW was 16.9%, and the weight ratio was 39.3%. Therefore, it can be understood that the rare earth mud can be classified by the centrifugal separator even in water, and the volume of the sediment to be transported to the water can be greatly reduced by performing the classification. Along with this, it is possible to reduce the work and cost of disposing of unnecessary items.

  The rare earth concentration of the raw mud MW was 3733 ppm, and the rare earth concentration of the underflow deposit UF was 8070 ppm. Therefore, it can be understood that the rare earth contained in the deposit can be concentrated in the underflow deposit UF by performing classification using a centrifugal separator.

DESCRIPTION OF SYMBOLS 1 Submarine resource collection system 2 Lifting means 2a Lifting apparatus 2b Lifting pipe 3 Cyclone centrifugal separator 3a Inlet 3b Underflow outlet 3c Overflow outlet 4 Inflow means 4a Inflow apparatus 4b Inlet pipe 5 Connecting part 6 Mining means 6a Mining device 6b Connection pipes 7a, 7b Reservoir 8 Release pipe 9 Pick-up ship 10 Support ship 10a Cable 20 Deposit 20a Coarse-grained deposit 20b Fine-grained deposit 20c Specific resource B Water bottom

Claims (5)

In the method for collecting bottom resources, the specific resources contained in the bottom sediments are lifted and collected on the water.
Using a cyclone centrifuge disposed in water, the deposit is further divided into a coarse sediment containing a larger amount of coarse particles having a relatively large particle size and a fine particle having a relatively small particle size. By continuously classifying into the fine-grained deposit containing a large amount, the resource is unevenly distributed in one of the coarse-grained deposit and the fine-grained deposit, and either of the resources in which the resource is unevenly distributed A method for collecting water resources, wherein the sediment is pumped to the water, and the other sediment is left on the bottom.   The method for collecting bottom resources according to claim 1, wherein a classification boundary particle diameter by the centrifugal separator is in a range of 10 µm to 30 µm, and the resources are unevenly distributed in the coarse sediment.   The method according to claim 2, wherein the resource is a rare earth concentrated in a phosphate of biological origin. In a bottom resource collection system comprising a lifting means for transporting specific resources contained in bottom sediment to the water,
A cyclone centrifuge arranged in water, an inflow means for allowing the deposit to flow into the centrifuge, and a connecting portion for connecting the centrifuge and the lifting means,
By the centrifugal separator, the deposit is continuous to a coarse-grained deposit containing a larger amount of coarser particles having a relatively large particle size and a fine-grained deposit containing more fine particles having a relatively smaller particle size. And the resources are unevenly distributed in one of the coarse-grained deposit and the fine-grained deposit, and any one of the deposits in which the resources are unevenly distributed is transferred to the lifting means through the connecting portion. A bottom resource collection system, wherein the other sediment is sent to the water from the centrifugal separator.   The inflow speed of the deposit into the centrifuge device by the inflow means is variable, and the classification boundary particle diameter by the centrifuge device is changed by changing the inflow speed. Underwater resource collection system.

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