Equipment and method for lifting valuable seabed materials

Abstract

To provide a lifting device of submarine valuable substances capable of lifting massive submarine valuable substances with high lifting efficiency, and a lifting method using the same.SOLUTION: A lifting device for lifting submarine valuable substances has a circulatory system duct that includes: a downpipe that reaches the seabed from the sea top, and a riser pipe that reaches the sea top from the seabed. The circulatory system duct is filled with viscous fluid as carrier material, and the riser pipe has multiple flow paths.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present invention relates to an ore-lifting device that transports valuable materials, which are seabed mineral resources, to the sea with high efficiency, and an ore-lifting method using the same. [Background technology]

[0002] Various techniques have been disclosed for ore-lifting methods and ore-lifting devices for transporting and conveying valuable materials such as seabed mineral resources to the sea. Patent 6570000 (JP Patent Publication 2019-120063) describes a ring-shaped pipeline in which a downcomer pipe that reaches the seabed from the sea surface and an upcomer pipe that reaches the sea surface from the sea surface are connected on the seabed side and the sea surface side, a downcomer pipe that reaches the sea surface from the sea surface and an upcomer pipe that reaches the sea surface from the sea surface and a U-shaped pipeline in which a downcomer pipe that reaches the seabed from the sea surface and an upcomer pipe that reaches the sea surface from the sea surface are connected on the seabed side, or a double pipe in which the inner pipe is an upcomer pipe and the outer pipe is a downcomer pipe or vice versa, a carrier material filled in the ring-shaped pipeline, the U-shaped pipeline, or the double pipe pipeline, and a pressure pump that circulates the carrier material. The pipeline has an inlet for carrying in valuable seabed materials, which is provided on the seabed side of the pipeline, and a recovery port for recovering valuable seabed materials, which is provided on the sea surface side of the pipeline. The carrier material has an average particle size of 0.01 mm to 10 mm and a true density of 0.01 to 8 g / cm. 3 The present invention discloses an apparatus for lifting valuable seabed materials, which is a mixture of granular materials and a viscous fluid (Claim 1). According to this, since a viscous fluid containing granular materials is used for lifting valuable seabed materials, it is possible to lift valuable seabed materials, which are granular or lump materials with a diameter of 30 mm or more, with high lifting efficiency.

[0003] Furthermore, Patent Publication No. 6570000 describes that the annular (loop) pipeline may be a double-pipe in which the inner pipe is an ascending pipe and the outer pipe is a descending pipe, or vice versa, the outer pipe is an ascending pipe and the inner pipe is a descending pipe. It also describes that the pipe diameter is preferably at least twice the maximum diameter of the valuable substance granules, since this prevents clogging inside the pipe and increases the efficiency of transportation and conveyance. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent 6570000 Publication DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0005] On the other hand, maximum particle size is 50 mm, 80% particle size is 25 mm, and wet density is 4.1 g / cm 3 It is expected that large chunks of valuable seafloor materials such as these will be lifted (Report on the Comprehensive Assessment of Seafloor Hydrothermal Ore Deposit Development Plan, December 2018, Agency for Natural Resources and Energy, Ministry of Economy, Trade and Industry). Such large, high-density chunks are at risk of sinking during lifting. Even for chunks with smaller grain sizes, such as those with a maximum grain size of 10 to 30 mm, it cannot be said that they will not sink during lifting. If it were possible to lift chunks, including these, with higher lifting efficiency than with conventional technology, productivity would increase, which would be desirable.

[0006] SUMMARY OF THE PRESENT INVETION Therefore, an object of the present invention is to provide a seabed valuable material lifting device capable of lifting lump-shaped seabed valuable materials with high lifting efficiency, and a method of lifting using the same. [Means for solving the problem]

[0007] In light of this situation, the inventors conducted extensive research and discovered that a spherical ore model passing along the pipe wall inhibits the deformation of the viscous fluid around the ore model, thereby suppressing the settling of the ore model, and that therefore, by narrowing the pipe by making the riser pipe into two or more pipes, the ore-lifting efficiency can be improved, which led to the completion of the present invention. That is, the present invention (1) provides an ore-lifting device for valuable materials from the seabed, which has a circulation system pipeline equipped with a downcomer pipe that reaches the seabed from the sea surface and an upcomer pipe that reaches from the seabed to the sea surface, the circulation system pipeline being filled with a viscous fluid that is a carrier material, and the upcomer pipe having two or more flow paths.

[0008] The present invention (2) also provides an apparatus for lifting valuable seabed materials as described in (1) above, characterized in that the two or more flow paths are two or more compartment paths separated by partitions inside the riser pipe.

[0009] The present invention (3) also provides an apparatus for lifting valuable materials from the seabed as described in (1) above, characterized in that the riser pipe is made up of two or more pipes, which pipes form a flow path.

[0010] The present invention (4) also provides an apparatus for lifting valuable seabed materials as described in (3) above, characterized in that the two or more pipes are attached around a central downcomer pipe.

[0011] The present invention (5) also provides an apparatus for lifting valuable sea-bed materials as described in (1) above, further comprising an inlet for transporting valuable sea-bed materials having a maximum dimension X, the inlet being provided on the sea-bed side of the circulating pipeline, and the minimum inner dimension Y1 of the flow passage being 1.5 to 5.0 times X.

[0012] The present invention (6) provides an apparatus for lifting sea-bed valuable materials as described in the above (5), characterized in that the entrance is provided with a screen for separating sea-bed valuable materials having a maximum dimension X from the sea-bed valuable materials.

[0013] The present invention (7) also provides an apparatus for lifting valuable substances from the seabed according to any one of (1) to (6) above, characterized in that the riser pipe or pipes are circular or polygonal pipes with a ratio of the minimum dimension to the maximum dimension of the cross section of 0.5 to 1.

[0014] The present invention (8) also provides a method for lifting valuable materials from the seabed, which comprises filling a circulating pipeline having a downcomer pipe extending from the sea surface to the seabed and an upcomer pipe extending from the seabed to the sea surface with a carrier material, circulating the carrier material with a pump, mixing valuable materials from the seabed into the carrier material, transporting the valuable materials upward together with the carrier material, and recovering the valuable materials from the seabed on the sea surface, wherein the carrier material is a viscous fluid and the upcomer pipe has two or more flow paths. Effect of the Invention

[0015] According to the present invention, the riser pipe has two or more flow paths, and the flow paths can be narrowed, so that the probability that the lumps (valuable seabed materials) in the riser pipe will pass along the pipe wall is increased. The lumps passing along the pipe wall inhibit the deformation of the viscous fluid around the lumps, and the settling of the lumps is suppressed, so that the lumps can be lifted with higher ore lifting efficiency than in the past. In addition, there is no reduction in the overall flow rate. [Brief description of the drawings]

[0016] [Figure 1] FIG. 2 is a cross-sectional view of a riser pipe of an ore lifting apparatus in the first embodiment of the present invention. [Diagram 2] FIG. 4 is another cross-sectional view of the riser pipe of the ore lifting apparatus in the first embodiment of the present invention. [Diagram 3] FIG. 4 is another cross-sectional view of the riser pipe of the ore lifting apparatus in the first embodiment of the present invention. [Figure 4] FIG. 4 is another cross-sectional view of the riser pipe of the ore lifting apparatus in the first embodiment of the present invention. [Diagram 5] FIG. 4 is another cross-sectional view of the riser pipe of the ore lifting apparatus in the first embodiment of the present invention. [Figure 6] FIG. 2 is a cross-sectional view showing an example of an incomplete partition that divides the inside of a circular pipe. [Figure 7] FIG. 11 is a cross-sectional view showing an example of an incomplete partition dividing the inside of a triangular tube. [Figure 8] FIG. 2 is a cross-sectional view showing an example of an incomplete partition dividing the inside of a rectangular tube. [Figure 9] 1A and 1B are model diagrams illustrating the effect of inhibiting the settling of minerals near the pipe wall of the riser pipe of the present invention, where (A) shows the case where the flow passes along the pipe axis and (B) shows the case where the flow passes along the pipe wall. [Figure 10] FIG. 2 is a model diagram illustrating the effect of suppressing the settling of minerals near the wall of the riser pipe of the present invention, showing the case where the minerals pass through a narrow flow path. [Figure 11] FIG. 1 is a schematic diagram of an ore lifting device in a first embodiment of the present invention. [Figure 12]FIG. 2 is a diagram illustrating an ore collecting method of the ore lifting apparatus in the first embodiment of the present invention. [Figure 13] FIG. 4 is a cross-sectional view of a riser pipe of an ore lifting apparatus in a second embodiment of the present invention. [Figure 14] FIG. 11 is another cross-sectional view of the riser pipe of the ore lifting apparatus in the second embodiment of the present invention. [Figure 15] FIG. 11 is another cross-sectional view of the riser pipe of the ore lifting apparatus in the second embodiment of the present invention. [Figure 16] FIG. 2 is a cross-sectional view of a cylindrical container used in a test of a reference example, showing the drop start position. [Figure 17] 1 is a graph showing the results of measuring sedimentation in Reference Example 1, in which the horizontal axis represents time (seconds) and the vertical axis represents sedimentation distance (m). [Figure 18] 1 is a graph showing the results of measuring sedimentation in Reference Example 2. [Figure 19] 1 is a graph showing the results of measuring sedimentation in Reference Example 3. [Figure 20] 1 is a graph showing the results of measuring sedimentation in Reference Example 4. [Figure 21] 13 is a graph showing the results of measuring sedimentation in Reference Example 5. [Figure 22] 1 is a graph showing the results of measuring sedimentation in Reference Example 6. [Figure 23] 13 is a graph showing the results of measuring sedimentation in Reference Example 7. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] The device for lifting valuable seabed materials (hereinafter also referred to as "minerals") of the present invention has a circulation system pipeline with a downcomer pipe that reaches the seabed from the sea surface and an upcomer pipe that reaches from the seabed to the sea surface, the circulation system pipeline is filled with a viscous fluid that is a carrier material, and the upcomer pipe has two or more flow paths. Examples of the circulation system pipeline include a ring-shaped pipeline in which the downcomer pipe and the upcomer pipe are connected on the seabed side and the sea surface side, respectively, a U-shaped pipeline in which the downcomer pipe and the upcomer pipe are connected on the seabed side, and a double pipe in which the inner pipe is the upcomer pipe and the outer pipe is the downcomer pipe, or vice versa, in which the inner pipe is the downcomer pipe and the outer pipe is the upcomer pipe.

[0018] The two or more flow paths of the riser pipe may be two or more partitions divided by partitions inside the riser pipe, or the riser pipe may be composed of two or more pipes, and the pipes are the flow paths. In the case of two or more partitions, the cross-sectional area of ​​each partition may be the same or different. In the case of two or more pipes, the cross-sectional area of ​​each pipe (pipe line) may be the same or different. When using two or more flow paths with different cross-sectional areas, if seabed minerals of appropriate particle sizes are transported to each cross-section, the ore lifting efficiency is improved compared to the case where seabed minerals of the same particle size are transported to a flow path of the same cross-sectional area. In this case, at the seabed entrance, the ore is separated by particle size using a screen, and the ore is allocated to the riser pipe of an appropriate diameter according to the particle size, such as allocating coarse ore to a large diameter pipe and fine ore to a small diameter pipe. In the case of two or more pipes, it is preferable to have two or more pipes for one downcomer pipe. In addition, it is preferable that the pipe walls forming two of the two or more pipes abut or are close to each other. Also, preferably, two or more pipes are affixed around a central downcomer pipe.

[0019] Next, an ore lifting device according to a first embodiment of the present invention will be described. In the ore lifting device according to the first embodiment, the riser pipe has two or more partition passages that are partitioned by partitions inside the riser pipe. The cross-sectional outline shape of the riser pipe is not particularly limited, and examples thereof include a circular pipe, a polygonal pipe, and an irregularly shaped pipe with a ratio of the minimum dimension to the maximum dimension of the cross section of 0.5 to 1.0. Examples of polygonal pipes include a triangle, a square, a pentagon, a hexagon, and an octagon. The maximum dimension of the cross section is the diameter of the smallest circle that includes the cross section, and the minimum dimension of the cross section is the diameter of the largest circle that is included in the cross section.

[0020] In the riser pipe, the number of partition passages partitioned by partition walls is 2 or more, preferably 3 or more. Specific examples include the riser pipe 11 (FIG. 1) in which a triangular pipe is partitioned by three partition walls 111 (triangular partition walls) to form four triangular cross-sectional flow passages 11a-11d, the riser pipe 12 (FIG. 2) in which a rectangular pipe is partitioned by a cross-shaped partition wall 121 to form four rectangular cross-sectional flow passages 12a-12d, the riser pipe 13 (FIG. 3) in which a circular pipe is partitioned by a cross-shaped partition wall 131 to form four sector-shaped cross-sectional flow passages 13a-13d, and the circulation pipe that is a double pipe. Examples of such a pipe include an up-pipe 14 (FIG. 4) in which the inner pipe 142 of the circulating pipe is a down-pipe and the outer pipe 141 is an up-pipe, and the inside of the outer pipe 141 is divided by four partition walls 143 to form four semi-fan-shaped cross-sectional flow paths 14a-14d, and an up-pipe 15 (FIG. 5) in which the outer pipe 151 of the circulating pipe, which is a double pipe, is a down-pipe and the inner pipe 152 is an up-pipe, and the inside of the inner pipe 152 is divided by a cross-shaped partition wall 153 to form four fan-shaped cross-sectional flow paths 15a-15d. This narrows the flow path in the up-pipe, shortens the distance between the ascending minerals and the pipe wall, and suppresses the descent of the minerals along the pipe wall. In addition, in FIG. 1 to FIG. 3, one or two of the four flow paths may be down-pipes and the other two or three flow paths may be up-pipes.

[0021] In the first embodiment, the partitions dividing the flow path may be incomplete partitions in which a part of the partitions (complete partitions forming a closed cross section) is missing. Examples of incomplete partitions include those shown in Figs. 6 to 8. Fig. 6(A) shows an incomplete partition in which an end (on the pipe wall side) of a cross-shaped partition dividing the inside of a circular pipe is missing, Fig. 6(B) shows an incomplete partition in which a center (on the pipe axis) of a cross-shaped partition dividing the inside of a circular pipe is missing, and Fig. 6(C) shows an incomplete partition in which a number of holes (punched holes) are formed in a cross-shaped partition dividing the inside of a circular pipe. Also, Fig. 7(A) shows an incomplete partition in which the center of a side of a triangular partition dividing the inside of a triangular pipe is missing, Fig. 7(B) shows an incomplete partition in which a corner of a triangular partition dividing the inside of a triangular pipe is missing, and Fig. 7(C) shows an incomplete partition in which a number of holes (punched holes) are formed in a triangular partition dividing the inside of a triangular pipe. In addition, Figure 8(A) shows an incomplete partition in which the end (on the tube wall side) of the cross-shaped partition that divides the interior of a square tube is missing, Figure 8(B) shows an incomplete partition in which the center (on the tube axis) of the cross-shaped partition that divides the interior of a square tube is missing, and Figure 8(C) shows an incomplete partition in which a number of holes (punched holes) are formed in the cross-shaped partition that divides the interior of a square tube.

[0022] The ratio of the missing portion of the incomplete partition is preferably 10% or less of the side length or circumferential length of the complete partition, since it can clearly divide the flow path and improve the ore lifting efficiency. For example, in Fig. 6(A), the missing portion (l1-l2) of the straight partition 61, which is a part of the cross-shaped partition, is 10% or less of the circular pipe diameter l1, which is the complete partition, in Fig. 7(B), the missing portion (l3-l4) of the straight partition 71, which is a part of the triangular partition, is 10% or less of the length l3 of the complete partition, and in Fig. 8(C), the missing portion (hole) of the straight partition 81, which is a part of the cross-shaped partition, is 10% or less of the straight complete partition.

[0023] In the first embodiment, the minimum inner dimension Y1 of the partition passage of the riser pipe partitioned by the partition wall is 1.5 to 5.0 times, preferably 2.0 to 4.0 times, the maximum dimension X of the mineral. The maximum dimension X of the mineral means the dimension of the largest mineral among the many minerals of various sizes present in the riser pipe, and does not mean the maximum dimension when a minimum dimension and a maximum dimension exist in one mineral. The mineral of the maximum dimension X in the riser pipe can be determined, for example, by providing an entrance for carrying in the seabed valuable material of the maximum dimension X, which is provided on the seabed side of the circulation pipe. An example of such an entrance is the installation of a screen for separating the seabed valuable material of the maximum dimension X from the seabed valuable material. In this way, by setting the minimum inner dimension Y1 of the partition passage of the riser pipe to 1.5 to 5.0 times the maximum dimension X of the mineral, the distance between the rising mineral and the pipe wall becomes close, and the descent of the mineral passing along the pipe wall can be suppressed. An example of the screen is a mesh separation net. When using two or more sections with different cross-sectional areas, a screen corresponding to each cross-section can be installed separately, which will improve the ore-lifting efficiency compared to using a single screen to transport the same grain size of seabed minerals through a passage of the same cross-sectional area.

[0024] Next, the effect of suppressing the settling of minerals near the pipe wall of the riser pipe in the present invention will be described with reference to Figs. 9 and 10. Figs. 9 and 10 are both schematic diagrams showing a state in which a spherical ore model moves relatively downward (settling) in a carrier material. Fig. 9(A) is a schematic diagram of the inside of a single pipe 16 where an ore model Z passes on the pipe axis, and Fig. 9(B) is a schematic diagram of the inside of a single pipe 16 where an ore model Z passes along the pipe wall. Fig. 10 is a schematic diagram of the inside of a pipe where an ore model Z passes through an outer pipe of a double pipe (circular pipe) 16A consisting of an inner pipe 162 and an outer pipe 161 partitioned by a partition wall 163. In both Figs. 9 and 10, the upper diagram shows a longitudinal section, and the lower diagram shows a transverse section. In FIG. 9(A), when the ore model Z sinks downward on the axis of the pipe, the carrier material in the front direction (downward in the figure) along which the ore model Z moves must be pushed away from the side to the back direction (upward in the figure). In order to generate such behavior of the carrier material, the carrier material must undergo large shear deformation around the ore model Z, especially in the area from the lower periphery to the side. In the figure, the arc-shaped dashed line below the arrow is the shear fracture surface. On the other hand, in FIG. 9(B), when the ore model Z sinks downward near the pipe wall, the shear deformation of the carrier material is restricted on one side of the ore, that is, on the pipe wall side. As a result, the relative downward movement (settling) of the ore model Z is suppressed. In FIG. 10, the diameter of the ore model and the inner dimension of the pipe are close, and a large ore model passes through a flow path with a small cross section, and the shear deformation of the carrier material is restricted on both sides. In order to suppress the settling of minerals near the pipe wall, it is preferable that the minimum inner dimension Y1 of the partition passage of the riser pipe is as close as possible to the maximum dimension X of the mineral, that is, 1.5 times, preferably 2.0 times, as long as the size is not large enough to cause pipe clogging. If the minimum inner dimension Y1 of the partition passage of the riser pipe exceeds 5.0 times the maximum dimension X of the mineral, the influence of the pipe wall will not occur, and suppression of mineral settling cannot be expected. In reality, it is necessary to lift many minerals of various sizes less than the maximum dimension X by entraining them with the carrier material, so the minimum inner dimension Y1 of the partition passage of the riser pipe is set to be 1.5 times or more the maximum dimension X of the mineral.

[0025] Examples of valuable seabed materials include manganese crusts, manganese nodules, cobalt-rich crusts, sulfide deposits (hydrothermal deposits), rare earth mud, and granular, powdery, or lump-shaped ores extracted from methane hydrates that exist on the seabed at depths of several hundred to several thousand meters. The ores may be coarse particles of 0.75 mm or more, with a maximum particle size of 50 mm or more and a particle density of 4.1 g / cm. 3 The above-mentioned high density agglomerates may also be used.

[0026] The carrier material of the first embodiment is used for lifting valuable seabed materials, and is a viscous fluid. As the viscous fluid, the viscous fluid described in Patent Publication No. 657000 can be used. That is, the viscous fluid has a viscosity at 5°C (JIS Z8803; method for measuring viscosity of liquid) of 1000 mPa·s or more, preferably 1,300 mPa·s or more, particularly preferably 2,000 mPa·s or more, and further preferably 3000 mPa·s or more. In addition, the plastic viscosity at 5°C is 100 Pa·s or less, and the yield stress at 5°C is 5 Pa or more. The yield stress and the plastic viscosity can be measured by a method conforming to JIS Z8803 using a rotational and vibration type viscometer. The viscosity of 5°C is set because the seawater temperature is generally stable at 5°C at a depth of several tens of meters or more from the seawater surface, and most of the downcomer and upcomer pipes are exposed to an environment of 5°C. The upper limit of the viscosity of a viscous fluid at 5°C is 100,000 mPa s. If the viscosity increases beyond this, the fluid becomes closer to a solid, and it becomes practically difficult to pump.

[0027] The viscous fluid may be water-based, oil-based, or emulsion-based, but water-based and emulsion-based fluids are preferred, and water-based fluids such as polymer solutions are particularly preferred because they are inexpensive and easy to handle. Polymer solutions include suspensions. The polymer in the polymer solution may be either natural or synthetic, but synthetic fluids are preferred because a fluidized material can be obtained with a small amount of blend. An example of an emulsion system is mayonnaise, which is a mixture of oil or water and an emulsifier.

[0028] As the polymer in the polymer solution, those generally called thickeners, thickening materials, and water absorbents can be used, for example, bentonite, methylcellulose (MC), sodium carboxymethylcellulose (CMC), polyethylene oxide (PEO), sodium hydroxyethylcellulose (HEC), polyvinyl alcohol (PVA), polyacrylamide (PAAM), sodium polyacrylate, starch, gums, pectin, metal alginates, alginic acid esters, etc. Examples of gums include guar gum, xanthan gum, gellan gum, diutan gum, etc. Examples of metal alginates include sodium alginate, calcium alginate, potassium alginate, etc. These compounds can be used alone or in combination of two or more.

[0029] In the first embodiment, the viscous fluid may contain granular material. The granular material described in Japanese Patent No. 657000 can be used. The granular material is other than the valuable seabed material, and is contained in the viscous fluid in advance before use. The granular material has an average particle size of 0.01 mm to 10 mm, preferably 0.1 to 8 mm, and a true density of 0.01 to 8 g / cm. 3 The average particle size is calculated using a known calculation method based on particle size distribution. Such granular materials may be of rock origin, plant or organism origin, resin material, or fiber material, or may be a mixture thereof. Specific examples include foamed beads, glass beads, sand such as silica sand, silt or gravel, wood, and metal powder such as iron powder. The amount of the granular materials to be blended is 0.1 to 80 parts by weight, preferably 0.3 to 60 parts by weight, and more preferably 0.5 to 50 parts by weight, based on 100 parts by weight of the viscous fluid.

[0030] According to the first embodiment, the inside of the riser pipe is divided by partitions to form partition passages, or the minimum inner dimension Y1 of the riser pipe partition passage is set to 1.5 to 5.0 times the maximum dimension X of the mineral, so that the mineral is affected by the pipe wall during lifting. Therefore, sedimentation is suppressed, and valuable materials in granular and agglomerated form, which are mineral resources, can be transported and conveyed from the seabed several thousand meters deep to the sea surface with high lifting efficiency, specifically 60% or more, preferably 80% or more. The lifting efficiency is the value obtained by dividing the lifting speed by the carrier material flow rate.

[0031] In the first embodiment, the forces that suppress the settling of the minerals include viscous resistance, buoyancy, and effective bearing capacity. The viscous resistance and buoyancy are borne by the viscous fluid, and the effective bearing capacity is borne by the granular material. When the seafloor minerals are located close to the pipe wall, the viscous resistance and effective bearing capacity are influenced by the pipe wall.

[0032] Next, the ore lifting device of the first embodiment and the ore lifting method using the same will be described with reference to FIG. 11. The pipeline in the ore lifting device of the first embodiment is a ring (loop). The ore lifting device 10 has a ring-shaped pipeline 7 that connects a descending pipe 1 that reaches the seabed from the sea surface and an ascending pipe 2 that reaches the sea surface from the seabed on the seabed and on the sea surface, a carrier material 3 filled in the ring-shaped pipeline 7, a pressure pump 4 that circulates the carrier material 3, a delivery inlet 5 for delivering the seabed valuable material provided on the seabed side of the pipeline 7, and a recovery port 6 for recovering the seabed valuable material Z provided on the sea surface side of the pipeline 7. The facility on the sea surface is usually installed on a platform such as an ore lifting ship or an ore lifting float. The ascending pipe 2 has four compartments divided by cross-shaped partitions inside the circular pipe shown in FIG. 3.

[0033] The annular (loop) pipeline may be a flexible pipe, for example, a general piping. In the annular pipeline, the lower end of the riser pipe and the lower end of the downcomer pipe may be connected to form a continuous pipe. The riser pipe has four compartments, but the downcomer pipe does not need to have a partition. This is because the downcomer pipe is a return pipe for the carrier material, and does not cause the problem of the sedimentation of seabed minerals of the present invention. Therefore, the cross-sectional area of ​​the compartments of the riser pipe and the flow path cross-sectional area of ​​the downcomer pipe may be the same or different.

[0034] The annular pipeline 7 has a pump 4 for circulating the carrier material 3. The pump 4 is a pressure pump, and there is no particular restriction on where it can be installed as long as it is within the pipeline system. In addition, since the pump 4 is installed within the annular pipeline system, even if there is a large difference in elevation between the delivery port 5 on the seabed and the recovery port 6 on the sea surface, the pump 4 does not experience any load other than the friction loss of the inner wall of the pipeline, so that the carrier material 3 or the carrier material 3 containing seabed valuables can be efficiently pressure-fed over long distances.

[0035] The annular pipeline 7 has an entrance 5 for carrying seabed valuable materials, which is provided on the seabed side of the pipeline 7. The entrance 5 is a place where granular ore collected from a known ore collector is carried in. It is preferable to provide a double door or a revolving door as the entrance 5, since it can prevent leakage of the carrier material 3 filled in the pipeline. FIG. 12 shows a revolving door 5a installed at the entrance 5. The revolving door 5a has a door panel 52 that is cross-shaped in side view with a rotation axis 51 at its center, and is installed in the vicinity of the entrance 5 so as to be freely rotatable. Around the entrance 5, there are an upper casing 55 of a partial arc shape and a lower casing 53 of a partial arc shape, in which the door panel of the I-shaped part of the cross shape is in close contact. In addition, the symbol 54 is a plate-like body that extends obliquely upward from the upper end of the lower casing 53, which widens the entrance and makes it easier to carry in the ore Z. According to the revolving door 5a, the pipeline 7 is always isolated from the outside while the door panel 52 is rotating, and the ore Z can be carried into the pipeline 7 while maintaining the pressure inside the pipeline 7.

[0036] Further, at the entrance 5, there is installed a screen 57, which is an optional component, for separating sea-bed minerals having a maximum dimension X from the sea-bed minerals. That is, the screen 57 can be, for example, a separation net with openings (sieve mesh) of dimension X, and allows the introduction of sea-bed minerals having a size smaller than the maximum dimension X from sea-bed minerals having various sizes, and prevents the introduction of minerals having a size larger than the maximum dimension X. As a result, the minimum inner dimension Y2 of the largest partition passage Y1 among the partition passages divided by partitions in the riser pipe 2 can be determined to be 1.5 to 5.0 times X.

[0037] The annular pipeline 7 has a recovery port 6 provided on the sea side of the pipeline 7 for recovering the seabed valuable material X. The recovery port 6 may also be provided with equipment on the sea side. That is, for example, the equipment on the sea side has a pressure pump, a separation tank, a crushing device, a mineral dressing device, and an adjustment tank. The separation tank employs a gravity settling separation method, and recovers carrier material 3 containing seabed minerals from the bottom end of the separation tank, and circulates carrier material 3 not containing seabed minerals from the top end of the separation tank. The crushing device may be a known stone crushing device. The mineral dressing device separates the crushed seabed minerals into unnecessary minerals and useful minerals, and may be a known mineral dressing device.

[0038] Next, a method for lifting valuable materials from the seabed using the ore lifting device 10 of FIG. 11 will be described. First, in the ore lifting device 10 of FIG. 11, the pressure pump 4 is operated. This causes the carrier material 3 to circulate in the annular pipeline 7. Next, an ore collector (not shown) is operated to collect ore Z from, for example, an ore deposit Y on the seabed at a depth of 1,000 m, and the ore Z is carried into the pipeline 7 from the inlet 5 of the pipeline 7. The ore Z carried in from the inlet 5 is carried up in the riser pipe 2 together with the circulating carrier material 3. The collected ore Z flows in the pipe 7 while maintaining the relative position of the granular ore Z as much as possible, even if it is a coarse grain or a lump, or a high-density particle, because the carrier material 3 is a viscous fluid and the riser pipe 2 is partitioned by a cross-shaped partition wall 131 as shown in FIG. 3, forming a narrow flow path (partition path), and the collected ore Z is transported and conveyed with high ore lifting efficiency without significantly settling from the carrier material 3. In particular, although large ores close to the maximum dimension X cannot avoid settling while rising, when they settle downward along the pipe wall, the shear deformation of the carrier material is restricted on the pipe wall side. As a result, it is possible to suppress the relative downward movement (settling) of the ore.

[0039] The ore Z transported to the sea is introduced into a separation tank together with a carrier material 3 from an unloading port 6, where it is separated into a carrier material 3 containing ore Z and a carrier material 3 not containing ore Z. The carrier material 3 containing ore Z is introduced into a crushing device and crushed, and the crushed ore Z is further introduced into a dressing device and separated into unwanted ore and useful ore.

[0040] According to the first embodiment of the ore lifting equipment and ore lifting method, a viscous fluid carrier material circulates inside a circular pipeline, and the inside of the ascent pipe is narrowly divided by a partition, so that valuable materials such as lumps and high-density granular materials can be lifted with high ore lifting efficiency, long-distance transportation of about 1,000 m is possible, and no waste is produced.

[0041] Next, an ore lifting device and an ore lifting method according to a second embodiment will be described. In the second embodiment, the description of the same components as those in the first embodiment will be omitted, and the differences will be mainly described. The second embodiment differs from the first embodiment in the riser pipe. That is, in the second embodiment, the riser pipe is a plurality of pipes. In the second embodiment, the circulation system pipeline may be a ring-shaped pipeline in which a downcomer pipe and a riser pipe are connected on the seabed side and the above sea side, respectively, a U-shaped pipeline in which a downcomer pipe and a riser pipe are connected on the seabed side, and an inner pipe is a riser pipe.

[0042] In the first embodiment, the cross-sectional contour shape of each of the tubes constituting the multiple tubes of the riser tube is not particularly limited, and may be a circular tube or a polygonal tube with a ratio of the minimum dimension to the maximum dimension of the cross section of 0.5 to 1.0. Examples of polygonal tubes include a triangle, a square, a pentagon, a hexagon, and an octagon. The definitions of the maximum dimension and the minimum dimension of the cross section are the same as those in the first embodiment. The multiple tubes may all have the same shape or different shapes. In addition, the multiple tubes may be attached around a central downcomer tube or multiple tubes adjacent to a downcomer tube, and among these, those attached around a central downcomer tube are preferred.

[0043] Specific examples of the riser pipe consisting of a plurality of pipes include the riser pipe 21 (FIG. 13) consisting of three circular pipes 21a-21c, each of which has an equilateral triangular line connecting its axis, the riser pipe 22 (FIG. 14) consisting of eight circular pipes 221 arranged around a central downcomer pipe 222 (circular pipe), and the riser pipe 23 (FIG. 15) consisting of seven hexagonal pipes, each of which has six hexagonal pipes 231 arranged around a central hexagonal pipe 232. Of the three circular pipes in FIG. 13, one may be a downcomer pipe and the other two may be riser pipes. Also, of the seven hexagonal pipes in FIG. 15, one or more pipes other than the central one may be a downcomer pipe, and the other two or more may be riser pipes. This narrows the flow path in the riser pipe, shortens the distance between the ascending minerals and the pipe wall, and suppresses the descent of the minerals along the pipe wall.

[0044] In the second embodiment, the minimum inner dimension Y2 of the largest pipe among the two or more pipes that are the rising pipes is 1.5 to 5.0 times, preferably 2.0 to 4.0 times, the maximum dimension X of the mineral. The definition of the maximum dimension X of the mineral is the same as the definition of the maximum dimension of the mineral in the first embodiment. In the second embodiment, as in the first embodiment, the minimum inner dimension Y2 of the pipe can be determined, for example, by providing an inlet for carrying in the seabed valuable material of the maximum dimension X, which is provided on the seabed side of the circulation system pipe. Examples of such an inlet include the installation of a screen for separating the seabed valuable material of the maximum dimension X from the seabed valuable material. In this way, by setting the minimum inner dimension Y2 of the largest pipe among the two or more pipes that are the rising pipes to 1.5 to 5.0 times the maximum dimension X of the mineral, the distance between the rising mineral and the pipe wall becomes close, and the descent of the mineral passing along the pipe wall can be suppressed. In addition, when two or more pipes with different cross-sectional areas are used, appropriate screens corresponding to the respective cross sections may be installed. This improves the ore-lifting efficiency compared to transporting seabed minerals of the same particle size sorted by a single screen into two or more channels of the same cross-sectional area.

[0045] In the second embodiment, the effect of inhibiting the settling of minerals near the wall of the riser pipe is similar to the effect of inhibiting the settling of minerals passing along the wall of the riser pipe in the first embodiment, and therefore a description thereof will be omitted.

[0046] In the second embodiment, the sea-bed valuable material and the carrier material are similar to those in the first embodiment, and therefore will not be described further.

[0047] According to the second embodiment, the riser pipe is made of a plurality of pipes, or the minimum inner dimension Y1 of the pipe with the largest inner dimension among the plurality of pipes of the riser pipe is set to 1.5 to 5.0 times the maximum dimension X of the mineral, so that the mineral is affected by the pipe wall during lifting. Therefore, settling is suppressed, and valuable materials in granular and agglomerated form, which are mineral resources, can be transported and conveyed from the seabed several thousand meters deep to the sea surface with high lifting efficiency, specifically 60% or more, preferably 80% or more. In the second embodiment, the force suppressing the settling of the mineral is the same as in the first embodiment, and the description thereof will be omitted.

[0048] Next, a second embodiment of the ore lifting equipment and an ore lifting method using the same will be described (not shown). The ore lifting equipment of the second embodiment is the same as the ore lifting equipment of the first embodiment shown in Fig. 11, except that the riser pipe is three circular pipes as shown in Fig. 13. Therefore, only the differences from the ore lifting equipment of the first embodiment and the ore lifting method using the same will be described below.

[0049] In the annular (loop) pipeline, the lower end of the riser pipe 2 and the lower end of the downcomer pipe 3 are connected to form a continuous pipe. The downcomer pipe 3 is circular in shape and its cross-sectional area is approximately equal to the total cross-sectional area of ​​the three riser pipes 2. An inlet 5 for carrying seabed minerals is provided at the connection between the downcomer pipe 3 and the riser pipe 2. The connection between the downcomer pipe 3 and the inlet 5 and between the inlet 5 and the riser pipe 2 may be liquid-tight to prevent the carrier material from leaking into the surrounding sea area or seawater from mixing into the pipe. The cross-sectional area of ​​the downcomer pipe 3 in this example may be larger or smaller than the total cross-sectional area of ​​the three riser pipes 2.

[0050] Next, a method for lifting valuable materials from the seabed using the ore lifting device of the second embodiment will be described. First, the pressure pump is operated in the ore lifting device. This causes the carrier material to circulate in the annular pipeline. Next, the ore collector is operated to collect granular ore Z from, for example, an ore deposit Y on the seabed at a depth of 1,000 m, and the ore is carried into the riser pipe from the inlet of the pipeline. The granular ore Z carried in from the inlet is carried upward in the three pipes that are the riser pipes together with the circulating carrier material. Although large ores close to the maximum dimension X cannot avoid settling while rising, the three pipes each have a narrow flow path, so that when the ores settle downward along the pipe walls, the shear deformation of the carrier material is restrained on the pipe wall side. As a result, it is possible to suppress the relative downward movement (settling) of the ores.

[0051] According to the second embodiment of the ore lifting equipment and ore lifting method, a viscous fluid carrier material circulates within a circular pipeline, and the ascent pipe consists of multiple pipes, so that valuable materials such as lumps and high-density granular materials can be lifted with high ore lifting efficiency, long-distance transportation of about 1,000 m is possible, and no waste is produced.

[0052] In the first and second embodiments, the ore lifting device and the ore lifting method are not limited to the above-mentioned embodiment, and the pipeline may be U-shaped, with the downcomer pipe and the upcomer pipe connected on the seabed side and not connected on the sea surface side. In this case, a return pipe is installed on the sea surface side between the upcomer pipe and the downcomer pipe to return the carrier material to the downcomer pipe.

[0053] The ore lifting device and ore lifting method of the present invention are not limited to the above embodiment, and various modifications can be made. For example, in the riser pipe of Figs. 1 to 3, the number of partition passages can be two, three, or five or more by changing the shape and number of partition walls. In this case, the cross-sectional areas of the partition passages may be the same or different. In the double pipe of Fig. 4, both the inner pipe and the outer pipe may be riser pipes. In this case, the inner pipe may be partitioned by a partition wall. In the double pipe of Fig. 5, both the inner pipe and the outer pipe may be riser pipes. In this case, the outer pipe may be partitioned by a partition wall. In addition, Figs. 4 and 5 are not limited to double pipes, and may be triple pipes or more. When triple pipes or more are used as the riser pipe, the inner pipe becomes the partition wall, so the partition wall with a straight cross section can be omitted. In addition, a known sorting method other than a screen can be used as a method for sorting the seabed valuable material of the maximum dimension X from the seabed ore. For example, a mineral sorting machine separate from the ore lifting device may be operated on the seabed, and the seabed minerals with the maximum dimension X may be selected by the mineral sorting machine, which may then be dumped into the loading port by a shovel. Alternatively, a search machine capable of measuring the size of minerals may be operated on the seabed to determine the maximum dimension X of the seabed minerals in advance. In this case as well, the installation of a screen may be omitted.

[0054] (Sedimentation test) Next, in order to verify the settling behavior of the ore occurring near the wall of the riser pipe in the ore lifting apparatus and ore lifting method of the present invention, the following settling test was carried out as a reference example.

[0055] Reference Example 1 (Sedimentation Test No. 1) A cylindrical acrylic container 31 having a height of 4 m and an inner diameter of 100 mm, as shown in Figure 16, was filled with carrier material, and a spherical ore model simulating valuable seabed material was dropped from the top of the cylindrical container to determine the relationship between the time required for the ore model to sink and the sinking distance.

[0056] <Ore model A (sedimentary material)> Diameter 50.8mm, density 6.00g / cm 3 A perfect sphere made of zirconia was used. This ore model A has a size and specific gravity equal to or greater than that of ore Z, which is a valuable seabed material. A perfect sphere is a sphere whose cross section is nearly a perfect circle.

[0057] <Carrier substance A> 77.9% by mass of tap water, 7.1% by mass of bentonite, and 15.0% by mass of silica sand (No. 6) were mixed in a container to prepare carrier substance A. The plastic viscosity of carrier substance A at 25°C was 56 Pa s, the yield stress was 38.9 Pa, and the density was 1.38 g / cm. 3 The yield stress and plastic viscosity were measured using a rotational viscometer in accordance with JIS Z 8803: Method for measuring viscosity of liquids.

[0058] <Test Method> The temperature of the carrier material was 5°C, which corresponds to the seabed temperature. However, because the viscosity of carrier material A at 5°C and 25°C is almost the same, it was determined that the temperature had little effect, and the experiment was performed at room temperature (25°C). In addition, silica sand (No. 6) was used in a uniformly dispersed state in the carrier material. First, the ore model was buried under the liquid surface, and the center of the ore model A was kept 100 mm below the liquid surface. After waiting about 20 seconds until the liquid surface was stationary, the ore model was gently released. Next, the elapsed time and the sinking distance were measured. The falling start position was on the pipe axis (position Z2) and along the pipe wall (position Z1) (see Figure 16). The results are shown in Figure 17. In Figure 17, the symbol △ indicates on the pipe axis, the symbol ▲ indicates along the pipe wall, and the thick straight solid line indicates the predicted value. (Prediction of settling along the tube axis)

[0059]

number

[0060]

number

[0061] In Reference Example 1, the (pipe diameter) / diameter of the ore model is 2.0, and the ore model and the pipe wall are close to each other even on the pipe axis. From FIG. 17 and the results of the settling prediction on the pipe axis, the time it takes for the ore model to sink 3 m is the same on the pipe axis and the pipe wall, or is shorter along the pipe wall. In the measurement results for all of the drop start positions, the time it takes for the ore model to sink 3 m was several tens of times the predicted value. Thus, in Reference Example 1, the settling speed of the ore model was suppressed regardless of the starting position of the ore model's introduction.

[0062] Reference Example 2 (Sedimentation Test No. 2) <Test Method> Ore model B, diameter 15.9 mm, density 3.82 g / cm 3 The same test method as in Example 1 was used, except that a mixture of 93.2 mass% tap water and 6.8 mass% bentonite was used as carrier substance B. The plastic viscosity of carrier substance B at 25°C was 3.6 Pa s, the yield stress was 12.6 Pa, and the density was 1.12 g / cm. 3 The results are shown in Figure 18. In Figure 18, the symbol ◯ indicates the tube axis, the symbol ● indicates the tube wall, and the thick straight solid line indicates the predicted value.

[0063] In Reference Example 2, the (pipe diameter / ore model diameter) is 6.3, and the ore model on the pipe axis is away from the pipe wall. From the results in Figure 18, the time it takes for the ore model charged along the pipe wall to sink 3 m is one-tenth of that on the pipe axis. In addition, the predicted value when charged on the pipe axis was close to the measured value when charged on the pipe axis. This shows that the ore model passing along the pipe wall is suppressed from sinking by the pipe wall. This is thought to be because the pipe wall restrains the shear deformation of the carrier material for the sinking ore model.

[0064] Reference Example 3 (Sedimentation Test No. 3) <Test Method> Diameter 25.4mm, density 5.97g / cm 3A complete zirconia sphere (ore model C) was used, and the same test method as in Reference Example 1 was used, except that the carrier material A in Reference Example 1 was used. The results are shown in Figure 19. Note that in Reference Example 3, no calculation was performed to predict sedimentation along the tube axis. In Figure 19, the symbol △ indicates the tube axis, and the symbol ▲ indicates along the tube wall.

[0065] Reference Example 4 (Sedimentation Test No. 4) <Test Method> The test was carried out in the same manner as in Reference Example 3, except that a mixture of 91.6 mass% tap water and 8.4 mass% bentonite (carrier material C) was used instead of carrier material A. The results are shown in Figure 20. That is, Reference Example 4 is Reference Example 3 in which the blending of silica sand (No. 6) in the carrier material is omitted.

[0066] From the results of Reference Examples 3 and 4, where the (pipe diameter / ore model diameter) is 3.9, the time it took for the ore model introduced along the pipe wall to sink 3 m was a fraction of that required on the pipe axis. This shows that the pipe wall suppresses the sinking of the ore model passing along the pipe wall. This is thought to be because the pipe wall restricts the shear deformation of the carrier material for the sinking ore model. It is also found that when silica sand (No. 6) is included in the carrier material, the sinking of the ore model is significantly suppressed both on the pipe axis and along the pipe wall.

[0067] Reference Example 5 (Sedimentation Test No. 5) <Test Method> Diameter 12.7mm, density 5.70g / cm 3 The test was carried out in the same manner as in Reference Example 1, except that a perfect zirconia sphere (ore model D) was used and a mixture (carrier material D) of 65.2 mass% tap water, 4.8 mass% bentonite, and 30.0 mass% silica sand (No. 6) was used. The results are shown in Figure 21. Note that in Reference Example 5, no calculation was performed to predict settling along the tube axis. In Figure 21, the symbol △ indicates the tube axis, and the symbol ▲ indicates along the tube wall.

[0068] Reference Example 6 (Sedimentation Test No. 6) <Test Method> The test was carried out in the same manner as in Reference Example 5, except that a mixture of 93.2 mass% tap water and 6.8 mass% bentonite (carrier material B) was used instead of carrier material D. The results are shown in Figure 22. That is, Reference Example 5 is Reference Example 4 except that the blending of silica sand (No. 6) in the carrier material is omitted. In Figure 22, the symbol △ indicates the pipe axis and the symbol ▲ indicates along the pipe wall.

[0069] From the results of Reference Examples 5 and 6, it was found that the time it took for the ore model introduced along the pipe wall to sink 3 m was one tenth of that on the pipe axis. This shows that the pipe wall suppresses the sinking of the ore model passing along the pipe wall. In addition, it was found that when silica sand (No. 6) was included in the carrier material, the sinking of the ore model was significantly suppressed both on the pipe axis and along the pipe wall.

[0070] Reference Example 7 (Sedimentation Test No. 7) <Test Method> Diameter 19.1mm, density 3.83g / cm 3 The test was conducted in the same manner as in Reference Example 1, except that a perfect alumina sphere (ore model E) was used and a mixture (carrier material E) of 79.1 mass% tap water, 5.9 mass% bentonite, and 15.0 mass% silica sand (No. 6) was used. The results are shown in FIG. 23. In Reference Example 7, calculations were not performed to predict settling along the pipe axis. In FIG. 23, the symbol ◯ indicates the pipe axis, and the symbol ● indicates along the pipe wall. From the results of Reference Example 7, the time it took for the ore model inserted along the pipe wall to settle 3 m was several tenths of that on the pipe axis. This shows that the pipe wall suppresses settling of the ore model passing along the pipe wall. [Industrial Applicability]

[0071] According to the present invention, granular and lump seabed ore can be lifted with high ore lifting efficiency. [Explanation of symbols]

[0072] 1 downcomer 2. Ascending pipe 3. Carrier Substances 4. Pressure pump 5 Loading entrance 6 Collection port 7 Conduit 10. Ore lifting equipment 11~15 Rising pipe with compartment 21-23 Ascending pipe consisting of multiple pipes Z Ore

Claims

1. An ore lifting device having a circulation system pipeline including a downpipe that reaches the seabed from the sea surface and an uppipe that reaches the sea surface from the seabed, The circulatory system is filled with a viscous fluid that is a carrier material, The riser has two or more flow paths; The minimum inner dimension Y1 of the flow passage is 1.5 to 5.0 times the maximum dimension X of the seabed resource material to be lifted.

2. 2. The apparatus for lifting valuable substances from the seabed according to claim 1, wherein said two or more flow paths are two or more compartment paths defined by partitions within the riser pipe.

3. 2. The apparatus for lifting valuable materials from the seabed according to claim 1, wherein said riser pipe comprises two or more pipes, said two or more pipes being two or more flow passages.

4. 4. The apparatus for lifting seabed valuable materials according to claim 3, wherein said two or more pipes are attached around a central downcomer pipe.

5. 2. The apparatus for lifting valuable materials from the seabed according to claim 1, further comprising an entrance for carrying in valuable materials from the seabed having a maximum dimension X, the entrance being provided on the seabed side of said circulating pipeline.

6. 6. The apparatus for lifting sea-bed valuable materials according to claim 5, further comprising a screen at said entrance for separating sea-bed valuable materials having a maximum dimension X from said sea-bed valuable materials.

7. An apparatus for lifting valuable materials from the seabed as described in claim 1, characterized in that the riser pipe is a circular or polygonal pipe with a ratio of the minimum dimension to the maximum dimension of the cross section of 0.5 to 1.

8. An apparatus for lifting valuable materials from the seabed as described in claim 3 or 4, characterized in that the two or more pipes are circular or polygonal pipes with a ratio of the minimum dimension to the maximum dimension of the cross section of 0.5 to 1.

9. A method for lifting valuable materials from the seabed, comprising filling a circulation pipeline having a downcomer pipe extending from the sea surface to the seabed and an upcomer pipe extending from the seabed to the sea surface with a carrier material, circulating the carrier material with a pump, mixing the valuable materials from the seabed into the carrier material, transporting them upward together with the carrier material, and recovering the valuable materials from the seabed on the sea surface, wherein the carrier material is a viscous fluid, the upcomer pipe has two or more flow paths, and the minimum inner dimension Y1 of the flow paths is 1.5 to 5.0 times the maximum dimension X of the valuable materials from the seabed to be lifted.

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