JPH0826740B2 - Deep sea mineral resource heavy liquid lifting method and ore feeding device used to carry out said method - Google Patents

Description

[Detailed Description of the Invention] Technical Field This invention relates to a deep-sea mineral resource heavy liquid ore lifting method, which uses the buoyancy generated by a heavy liquid having a specific gravity greater than the bulk specific gravity of the deep-sea mineral resource ore to lift deep-sea mineral resource ore, mainly manganese nodules and cobalt-rich crust ore, mined from the deep seabed, together with the heavy liquid through a lifting pipe from the seabed to the surface of the sea, and to an ore supply device used to carry out this method.

Background Art The main conventional background technology for lifting deep-sea mineral resources from the seabed to the surface is the continuous bucket (CL)
B) method and hydraulic ore-lifting method.

The CLB method involves using a number of buckets attached to long looped ropes at regular intervals to lift the cobalt-rich crust found on the seabed at depths of 800 to 2,400 meters, and then lifting the extracted ore. However, this method has drawbacks, such as difficulty in lifting ore when the water depth is deeper than the aforementioned 2,400 meters, and a limited lifting capacity.

The hydraulic ore lifting method uses hydraulic power to lift manganese nodule ore, which is widely concentrated in the Clarion-Clipperton belt of the North Pacific Ocean at depths of 4,000 to 6,000 meters, up to the sea surface through a lifting pipe. This method can be further classified into the following three methods.

The first air lift ore lifting method involves injecting high-pressure air from an air compressor on a marine vessel into an ore lifting pipe via an air lift injection device located at a depth of approximately 2,000 m, to lift manganese nodule ore to the sea surface. In this method, the air compressor is located on a marine vessel, so:
This has the advantage that the maintenance of the air compressor is easy, but has the disadvantage that the power required for the air compressor is very large.

The second centrifugal pump ore-lifting method involves operating a high-head, multi-stage, centrifugal submersible motor pump located inside a lifting pipe to lift manganese nodule ore to the sea. Because the centrifugal pump is located at a depth of at least 1,000 m, maintenance of the centrifugal pump is difficult, and the power required is less than that of the air lift ore-lifting method, but it still has the disadvantage of requiring a large amount of power.

The third high-concentration slurry ore lifting method involves finely pulverizing manganese nodule ore using a crusher located on the deep seabed, turning it into a high-concentration slurry, feeding it into a piston pump also located on the deep seabed, and then lifting it to the surface via a lifting pipe. This method has the advantage of requiring a smaller diameter ore lifting pipe for the same amount of ore lifted compared to the airlift ore lifting method and centrifugal pump ore lifting method.
It requires high-level technological development of reliable subsea equipment (crushers, piston pumps) and has the drawback of requiring very large power.

Disclosure of the Invention The object of this invention is to provide a deep-sea mineral resource heavy liquid ore-lifting method, which uses the buoyancy generated by the heavy liquid, which has a specific gravity greater than the bulk gravity of the deep-sea mineral resource ore, to continuously lift deep-sea mineral resource ore containing useful heavy metals mined from the deep seabed, mainly manganese nodules and cobalt-rich crust raw ore, together with the heavy liquid, from the seabed to the surface via an ore-lifting pipe using far less power than any of the ore-lifting methods described in the background art section above, and an ore-feeding device to be used for carrying out this method.

Fig. 1 shows the concept of the deep-sea mineral resource heavy liquid ore-lifting method that is the object of this invention. Heavy liquid (including heavy suspension) adjusted to a specific gravity that allows deep-sea mineral resource (hereinafter referred to as nodule) raw ore to be lifted by the buoyancy generated by the heavy liquid is pumped by operating piston pump 2 installed on marine vessel 1 to submarine U-shaped pipe 4 connected to downcomer pipe 3 laid to the deep seabed, and then discharged onto marine vessel 1 via lifting pipe 5.

Meanwhile, ore nodules extracted from the deep seabed by a mining machine (or ore collector) 6 are fed into a submarine U-shaped pipe 4 through a feeder 7, and then the ore nodules are lifted together with the heavy liquid through the lift pipe 5 by the buoyancy generated by the heavy liquid and discharged onto the marine vessel 1. In this case, the power of the piston pump 2 is only consumed to overcome the total heavy liquid head loss in the pipes 3, 4, and 5 and in the feeder 7, and the difference in heavy liquid pressure head between the outlet of the lift pipe 5 and the inlet of the downcomer 3; no power is required to lift the ore nodules from the seabed to the surface, as this is achieved by the buoyancy generated by the heavy liquid.

Figure 2 shows the concept of a centrifugal pump ore lifting method, which is a representative hydraulic ore lifting method described in the previous background art section, for comparison with the heavy liquid ore lifting method of the present invention. Nodule ore mined by a mining machine 6 on the deep seabed is hydraulically transported by a centrifugal pump 8 and discharged together with seawater through a lifting pipe onto a surface ship 1. In this case, the power of the centrifugal pump 8 required to lift the nodule ore from the deep seabed onto the surface ship 1 is consumed to overcome the head loss in the ore lifting pipe 5 and the head caused by the water depth, and to lift the nodule ore from the deep seabed to the surface. This centrifugal pump ore lifting method has the disadvantage of requiring much greater power than the heavy liquid ore lifting method of the present invention shown in Figure 1.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a conceptual diagram of a deep-sea mineral resource heavy liquid ore-lifting method embodying this invention. Figure 2 shows a conceptual diagram of a centrifugal pump ore-lifting method, one of the prior arts, for comparison with the heavy liquid ore-lifting method. Figure 3 is a detailed diagram of Figure 1, including the equipment in the ore-dressing plant 9 on the marine vessel 1 and the ore-feeding devices 7 and 16 on the deep seabed. Figure 4 is a side view of Figure 3 and an enlarged view of the ore-feeding devices 7 and 16.

BEST MODE FOR CARRYING OUT THE INVENTION In order to explain the present invention in more detail, the present invention will be described with reference to the accompanying drawings. In FIG. 3, a bulk specific gravity of 1.04 to 3.00 is shown.
Selected heavy liquids (including heavy suspensions) having a specific gravity greater than the bulk density of the nodule ore estimated in the range of 87.
The heavy liquid is produced by mixing heavy liquid materials such as ferrosilicon and barite, which are widely used in heavy liquid dressing, with seawater and additives in a heavy liquid preparation tank 10 inside the marine vessel 1. The heavy liquid is discharged through a downcomer 3, a subsea U-tube 4, and a lifting pipe 5 by operating a piston pump 2 installed inside the marine vessel 1. Next, the ore is mined on the deep seabed by a mining machine (or ore collector) 6, and the nodule raw ore is crushed to a particle size that can float up inside the lifting pipe 5 together with the heavy liquid. The ore is then fed into the ore feeder 7 via a transport pipe 11 together with seawater.

In Fig. 4, after the ore feed valve 12 of the ore feeder 7 is opened, nodule ore is fed tangentially into the upper cylindrical part of the ore feeder 7, and fine seabed sediments and overflowing seawater contained in the nodule ore are discharged through the discharge valve 13. When the ore feeder 7 is filled with nodule ore,
The feed valve 12 and discharge valve 13 are then closed.
After the throttle valve 17 installed inside is throttled, the seawater valve 15 and the lower valve 14 are opened, and heavy liquid is fed into the ore feeder 7 through the lower valve 14.
When seawater is supplied from the bottom of the ore supply device 7, it moves from the bottom to the top and is discharged from the seawater valve 15. After that, the seawater valve 15 is closed, and then the upper valve 21 is opened, so that the pressure of the heavy liquid in the ore supply device 7 and the submarine U-shaped pipe 4 is balanced. After the nodule raw ore that has risen to the top of the ore supply device 7 is supplied into the submarine U-shaped pipe 4 by operating the upper screw conveyor 18, the operation of the upper screw conveyor 18 is stopped, and then the upper valve 21 is closed, and the throttle valve 17 in the submarine U-shaped pipe 4 is fully opened. Next, the ore supply device 7
After the seawater pump 19 installed on the upper outside of the
The seawater inlet valve 20 is opened, seawater is fed in from the top of the ore supply device 7, the heavy liquid in the ore supply device 7 moves downward, and the heavy liquid is sent into the submarine U-shaped pipe 4 through the lower valve 14. Then, the lower valve 14 and the seawater inlet valve 20 are closed, and the seawater pump 19 is then started.
The operation of the ore supplying device 7 is stopped, and the ore supplying device 7 is filled with seawater.

In FIG. 4, another ore feeding device 16 of the same type as the ore feeding device 7 is operated in parallel with the ore feeding device 7, so that nodule raw ore can be continuously fed into the submarine U-shaped pipe 4.

As a result of the above, the ore feeding devices 7 and 16 alternately repeat the same operations described above,
The nodule ore fed from 16 into the submarine U-tube 4 rises together with the heavy liquid through the submarine U-tube 4 and into the lifting pipe 5 due to the buoyancy generated by the heavy liquid, and is continuously lifted up, and is discharged together with the heavy liquid from the lifting pipe outlet 22 on the marine vessel 1.

The nodule ore discharged together with the heavy liquid is separated from the heavy liquid in a separator 23 in the ore dressing plant 9. The heavy liquid separated from the nodule ore is recovered by a heavy liquid recovery device 24, and after the specific gravity etc. is adjusted for reuse, it is discharged into a heavy liquid preparation tank 10.
The nodule ore separated from the heavy liquid in the separator 23 is recovered as nodule concentrate by operation of a concentrator 25 provided in the ore dressing plant 9, as required.

Industrial Applicability As described above, the deep-sea mineral heavy liquid ore-lifting method of this invention is capable of continuously lifting large quantities of deep-sea mineral resource raw ore, mainly manganese nodules and cobalt-rich crusts containing useful heavy metals such as manganese, cobalt, and nickel, which are widely concentrated on the deep seabed around the world, from the seabed to the surface.Since the ore is lifted by the buoyancy generated by the heavy liquid, which has a specific gravity greater than the bulk gravity of the deep-sea mineral resource raw ore, this method has the advantage of requiring far less power than any of the ore-lifting methods of conventional technology.

Claims (2)

[Claims] [Claim 1] A method for lifting deep-sea mineral resource ore mined from the deep seabed, together with heavy liquid, from the seabed to the surface via a lifting pipe by using the buoyancy generated by the heavy liquid, which has a specific gravity greater than the bulk gravity of the deep-sea mineral resource ore, characterized by comprising the following steps: (a) A step of producing a selected heavy liquid (including a heavy suspension) having a specific gravity greater than the bulk gravity of the deep-sea mineral resource (hereinafter referred to as nodule) raw ore by mixing a heavy liquid material, seawater, and additives in a heavy liquid preparation tank (10); (b) A step of feeding the heavy liquid into a downcomer pipe (3) by operating a piston pump (2), and discharging it from the lifting pipe outlet (22) via a submarine U-shaped pipe (4) and a lifting pipe (5); and (c) A step of feeding the nodule raw ore into the submarine U-shaped pipe (4) by operating a feeder (7), comprising the following steps a to d. a. After the ore feed valve (12) is opened, the nodule ore is fed tangentially through the upper cylindrical part of the ore feeder (7) via the transport pipe (11). The nodule ore is mined by the mining machine (6) and crushed to a particle size that can float with the heavy liquid inside the lift pipe (5).
A process of discharging the fine seabed sediments and overflowing seawater contained in the nodule ore through the discharge valve (13). b. After the ore feeder (7) is filled with the nodule ore, the ore feeder valve (12) and the discharge valve (13) are closed, and then the throttle valve (17) is opened.
a step of throttling the seawater in the ore feeder (7) and then opening the seawater valve (15) and the lower valve (14), and supplying heavy liquid from the bottom of the ore feeder (7) through the lower valve (14), thereby moving the seawater in the ore feeder (7) from the bottom to the top and discharging it through the seawater valve (15), and then closing the seawater valve (15), and then opening the upper valve (21), and balancing the pressure of the heavy liquid in the ore feeder (7) and the subsea U-shaped pipe (4).c. a step of operating the upper screw conveyor (18) to feed the nodule raw ore that has risen to the top of the ore feeder (7) into the subsea U-shaped pipe (4), and then stopping the operation of the upper screw conveyor (18), and then closing the upper valve (21), and fully opening the throttle valve (17) in the subsea U-shaped pipe (4). d. After operating the seawater pump (19), the seawater inlet valve (20) is opened to send seawater into the ore supply device (7) from the top, thereby moving the heavy liquid in the ore supply device (7) to the bottom;
After being sent through the lower valve (14) into the submarine U-tube (4),
A step of closing the lower valve (14) and the seawater inlet valve (20), then stopping the operation of the seawater pump (19), and filling the ore supply device (7) with seawater. D. A step of operating another ore supply device (16) of the same type as the ore supply device (7) installed in parallel with the ore supply device (7), and continuously supplying nodule raw ore into the submarine U-shaped pipe (4). E. A step of alternately repeating the same operation on the ore supply devices (7 and 16), thereby supplying seawater from the ore supply devices (7 and 16) to the submarine U-shaped pipe (4).
The manganese nodule ore fed into the axial pipe (4) is
The buoyancy generated by the heavy liquid causes the ore to rise through the ore lifting pipe (5) via the undersea U-shaped pipe (4) together with the heavy liquid, thereby continuously lifting the ore, and then discharging it together with the heavy liquid from the ore lifting pipe outlet (22) on the marine vessel (1). [Claim 2] A feed valve (12) for feeding nodule ore, which has been mined by a mining machine (or ore collector) (6) and crushed to a particle size that can float with heavy liquid in a lift pipe (5), into an ore feeder (7 and 16); and a discharge valve (13) for discharging fine seabed sediments and overflow seawater contained in the nodule ore from the ore feeder (7 and 16).
a seawater valve (15) for discharging seawater from the ore feeders (7 and 16); a lower valve (14) for supplying heavy liquid from the submarine U-shaped pipe (4) into the ore feeders (7 and 16); an upper valve (21) for balancing the pressure of the heavy liquid between the ore feeders (7 and 16) and the submarine U-shaped pipe (4); a screw conveyor (18) for feeding nodule raw ore that has floated to the top of the ore feeders (7 and 16) into the submarine U-shaped pipe (4); and a seawater inlet valve (20) for inletting seawater into the ore feeders (7 and 16) after stopping operation of the screw conveyor (18).