US3438142A

US3438142A - Sea mining method and apparatus

Info

Publication number: US3438142A
Application number: US461785A
Authority: US
Inventors: Manfred G Krutein
Original assignee: Individual
Current assignee: Individual
Priority date: 1965-06-07
Filing date: 1965-06-07
Publication date: 1969-04-15
Anticipated expiration: 1986-04-15

Description

April 5, 1969 M. G. KRUTEIN 3,438,142

SEA MINING METHOD AND APPARATUS Filed June 7, 1965 Sheet of s 'HGJA FIGJB FIG.4 a

Ill/I/Il/ 5 D INVENTOR. 36 MANFRED e. KRUTEIN 5 37 BY 5 ATTORNEYS April 15, 1969 M. G. KRUTEIN 3,438,142

SEA MINING METHOD AND APP AAAA US INVENTOR. MANFRED G. KRUTE IN ATTORNEYS April 15, 1969 M. G. KRUTEIN SEA MINING METHOD AND APPARATUS Sheet Filed June '7,

INVENTOR.

MANFRED G. KRUTEIN ATTORNEYS April 15, 1969 Fil d June 7, 1965 TO PLANTNME FIG.||

M. G. KRUTEIN SEA MINING METHODAND APPARATUS SheetiofS l E m I" INVENTOR.

MANFRED G. KRUTEIN ATTORNEYS April 15, 1969 M. G. KRUTEIN SEA MINING METHOD AND APPARATUS Sheet Filed June 7, 1965 N Kl. E TT U R K G D E R F N A M P24 5 Oj M ATTORNEYS v United States Patent Office 3,438,142 Patented Apr. 15, 1969 3,438,142 SEA MINING METHOD AND APPARATUS Manfred G. Krutein, Palo Alto, Calif. (2550 Willow St, San Diego, Calif. 92106) Filed June 7, 1965, Ser. No. 461,785 Int. Cl. E02f 1/00, 3/88, 7/00 US. Cl. 37195 7 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to dredging or mining from the sea bottom.

Broadly stated, the present invention to be described in greater detail below is directed to a sea mining method and apparatus wherein desired minerals lying at the sea bottom are first conveyed from the sea bottom to the submersed portion of an elongate vessel floating substantially vertically in the sea and are then conveyed vertically from the submersed portion of the vessel to the surface of the sea. The apparatus in accordance with the present invention includes an elongate vessel having an extended tank portion sealed for submersion over a major portion of its length, ballast means for shifting the center of gravity of the vessel between a transport position with the sealed tank lying substantially horizontally in the sea and a mining position with the vessel and tank floating in a vertical position. In mining position the major portion of the sealed tank is submersed in the sea, and minerals are brought to the vessel by dredging or conveying equipment mounted on the furthest submersed portion of the vessel. In accordance with one aspect of the invention, the dredged matter is brought into the submersed portion of the sealed tank. There the matter is dewatered and the desired minerals conveyed upwardly through the tank to the surface of the sea. The minerals are then preferably transported to an underwater stockpile where they can be reclaimed as desired.

Dredging equipment utilized in the past has been mounted on a vessel which floats horizontally on the surface of the sea and which is exposed to continuous wave action at the surface of the sea. This wave action produces a rolling motion to the vessel and deleteriously effects the operative capabilities and maneuverability of dredging equipment mounted on the vessel. The resultant effect of the wave motion on the vessel is to reduce the efficiency of the mining operation and limit the length of the dredging equipment and therefore the sea depth at which the mining or dredging operation can take place effectively. Dredging operations in the past have only been able to extend to depths on the order of between 100 and 200 feet. However, the continental shelves where large mineral reserves lie have an average depth of 423 feet and the most prolific form of mineral deposits in the sea is nodular grains lying on the surface of the sea floor at depths of from 3,000 to 19,000 feet. Ocean mining cannot be successfully performed at these depths with the conventionally used dredge equipment mounted on vessels floating on the surface of the sea.

The dredging vessel in accordance with the present invention is designed-to float in a vertical position during dredging or mining operations so that with the major portion of the vessel submerged the vessel is affected to a minimum extent by wave action adjacent the surface of the sea. This mining vessel is highly stable in vertical position thereby providing great stability and thus maneuverability to the actual equipment that picks up and moves the mined minerals. The stability of the mining vessel permits ocean mining at virtually any depth desired since mining equipment extending to any depth can be attached to this vertically floating vessel. In one embodiment of the present invention, the cross sectional area of the mining or dredging vessel is reduced or suitably shaped over the region of heavy wave action to maintain the effects of wave motion on the dredging vessel at a minimum.

With a dredge constructed in accordance with the present invention and having the mining or dredging equipment which conveys the minerals from the sea bottom to the vessel located on the submerged end of the vessel, the required length of the dredging or conveying equipment is effectively reduced from that presently used by the submerged length of the vessel. This construction provides better maneuverability for the conveying equipment due to the shorter length of mining equipment in mining operations where the distance between the lower submersed end of the vessel and the sea bottom is small,

In accordance with another aspect of the present invention, the dredging vessel is powered to move through the sea at selectible low rates of speed whereby the dredging operation can take place during patterned slow traverses across a mineral deposit lying on the sea bottom for maximum recovery of the desired minerals.

In accordance with still another aspect of the present invention, hydraulic conveying equipment is used to convey the minerals from the sea bottom into a portion of the dredge vessel which is located far beneath the surface of the sea but maintained at atmospheric pressure due to communication with atmosphere upwardly through the vessel. This construction permits the utilization of the difference in pressure at the bottom of the sea and at the location within the dredging vessel to convey the minerals into the vessel. After the minerals have been passed into the vessel and separated from the conveying hydraulic fluid or water, the water can then be conveniently pumped out of the vessel. This arrangement eliminates the amount of work required to move the minerals from the sea bottom to the level of the lower submersed portion of the vessel.

In accordance with still another aspect of the present invention, the matter recovered from the sea bottom and conveyed into the dredge or vessel is separated as to desired and undesired minerals. Then the desired minerals can be conveyed vertically within the vessel to the surface of the sea and the undesired minerals exhausted from the vessel back into the sea. This arrangement reduces the amount of work that would otherwise be required in past methods for the recovery of desired minerals since it is unnecessary to convey undesired minerals the submersed length of the vessel.

In accordance with still another aspect of the present invention, minerals recovered from the sea or even minerals transported across the sea to a processing plant are stockpiled and blended underneath the surface of the sea.

Until the present time stockpiling and blending of raw materials has been a very expensive operation. Typical methods and apparatus for stockpiling and blending raw materials are illustrated and described in US. Patent No. 3,069,027 to Dischinger wherein raw materials are stacked in large stockpiles on large land areas and reclaimed by a mechanism cutting through the stockpile. This method consumes a large land area that is very often quite expensive especially if the land area is located at or immediately adjacent to a navigable harbor.

Where raw materials being stockpiled have been dredged from the ocean floor and deposited on barges or otherwise carried to a processing plant in barges, the transportation and mining operations are influenced to a great extent by the weather, and it becomes very important to accomplish as much of the mining and transporting operation during fair weather as possible so as to convey the maximum amount of material to the processing plant where it can be stockpiled and used over an extended period of time. In this manner the processing plant can operate continuously while the mining and transporting operation operates intermittently or seasonably.

In order best to accomplish transportation of raw materials over water for stockpiling at a remote location during available time, a minimum amount of time should be spent in the docking and unloading of raw materials at the destination. With past methods and apparatus for stockpiling on land a great deal of time has been consumed and costly equipment required for docking and unloading the transportation vessels. Furthermore, this type of operation requires expensive docking facilities, and considerable damage can be caused both to the transportation vessel and the docking facilities during docking of the vessel.

In accordance with the present invention, a number of loads of minerals are transported over the surface of the sea and each dumped in shallow water in a predetermined position of a pattern on the sea surface with the various loads evenly distributed over the pattern and a plurality of loads at substantially every position so that an underwater stockpile with a pattern of adjacent and superimposed mineral load layers is produced on the sea bottom. The minerals in a number of different loads are simultaneously reclaimed and blended as desired from the underwater stockpile by cutting across and through load layers with dredging equipment.

By stockpiling raw materials under water as provided in accordance with the present invention, docking time for the barge is completely avoided so maximum advantage can be taken of good weather conditions for effectuating the mining and transporting operations over the sea. Additionally, the likelihood of damege to the barge and berth as is often caused during docking operations is avoided. Furthermore, the cost of the off-shore area on which underwater stockpiles are established is far less than that for conventional stockpiles positioned on dry land, and the cost of unloading the mineral stacking equipment is avoided.

In accordance with the present invention, one method and apparatus for reclaiming minerals from underwater stockpiles is a dredging vessel provided with fore and aft anchor assemblies for locating anchors at two opposing sides of the underwater stockpile and port and starbord anchor assemblies for locating anchors at the two other sides of the underwater stockpile. Means are provided for moving the dredge vessel between the fore and aft anchor assemblies and the port and starboard anchor assemblies to cause the dredging apparatus on the dredging vessel to sweep arcs across the underwater stockpile for picking up or reclaiming minerals in a plurality of loads thereby effectively to blend the material as it is reclaimed.

In accordance with another aspect of the present in vention, another method and apparatus for reclaiming minuerals from the underwater stockpile is the provision of a dredging apparatus at one end of a pontoon arm and means for rotating the pontoon arm about the opposite end to direct the dredging apparatus in arcs across the underwater stockpile. In one embodiment of this aspect of the present invention, the end of the pontoon arm that is caused to rotate about a rotating member is rotatably held against a barge which can be located between a pair of dolphins in a string of dolphins along one side of the underwater stockpile. The dredged material is conveyed from the dredging apparatus along the pontoon arm to the barge and thence to an adjacent land mass for conveyance to the processing plant. This assembly requires only the location of a plurality of dolphins along the side of the stockpile and the mooring of the barge to only two of the dolphins at any one time. With this apparatus the reclaimed minerals picked up by the dredging apparatus can be passed through a separation stage either at the dredge end of the pontoon arm or at any position along the length of the pontoon arm so that by the time the minerals reach land they are separated and dewatered for use as desired.

Other objects and advantages of this invention will become apparent when reading the following description and referring to the accompanying drawings in which similar characters of reference represent corresponding parts in each of the several views.

In the drawings:

FIG. 1A is a schematic elevational view of a mining or dredge vessel constructed in accordance with the present invention and floating in its horizontal position;

FIG. 1B is a schematic elevational view of the vessel of FIG. 1A illustrated in its vertical dredging position and partially broken away;

FIG. 2 is a cross sectional view of a portion of the vessel illustrated in FIG. 1A taken along line 22 in the direction of the arrows;

FIG. 3 is a cross sectional view of a portion of the structure shown in FIG. 1A taken along line 3-3 in the direction of the arrows;

FIG. 4 is an enlarged elevational sectional view of the lower portion of the dredge illustrated in vertical position in FIG. 1B and showing an alternative embodiment of the present invention;

FIG. 5 is an enlarged elevational sectional view of a portion of the structure in FIG. 4 delineated by line 5-5 schematically illustrating operation of a portion of the structure illustrated in FIG. 4;

FIG. 6 is a schematic elevational view of the underwater stockpiling method and apparatus in accordance with the present invention;

FIG. 7 is a plan view schematically illustrating the barge load configuration in the underwater stockpiling method in accordance with the present invention;

FIG. 8 is an elevational view schematically illustrating the reclaiming blending method and apparatus in accordance with the present invention;

FIG. 9 is a plan view schematically illustrating one method and apparatus of reclaiming stockpiled material in accordance with the present invention;

FIG. 10 is en elevational view of the structure illustrated in FIG. 9 taken along line 1010 and schematically illustrating operation of the apparatus illustrated in FIG. 9;

FIGS. 11 and 13 are plan views similar to FIG. 9 but illustrating alternative apparatus to that illustrated in FIG. 9; and

FIGS. 12 and 14 are views similar to FIG. 10 but illustrating respectively the structures shown in FIGS. 11 and 13.

Referring now to the drawings with particular reference to FIGS. 1A and 1B, the present invention is directed to a sea mining method and apparatus wherein matter generally designated at A is dredged or conveyed from the bottom of the sea B by a conveying or dredging apparatus C to the lower submerged portion of an elongate vessel D floating substantially vertically in the sea. The material from the lower portion of the vessel D is conveyed to the surface E of the sea and onto the transportation means such as, for example, the barge schematically illustrated as F. While the invention is particularly adaptable for ocean mining and will be described with reference thereto, the term sea. is used herein to mean any body of water whether it be a land locked lake area, a river region or the ocean either above a continental shelf adjacent a large land mass or over the deep sea bottom at a region far from a land mass.

The vessel D is provided with an elongate hull 11 which is constructed for floating in a substantially horizontal position for transportation to and from the mining or dredging area as shown in FIG. 1A and which includes ballast associated therewith for changing the center of gravity of the vessel to cause the hull to float in a vertical mining position as shown in FIG. 1B with the major portion of the hull 11 submerged beneath the sea surface E. Naturally, by proper adjustment of the ballast the vessel D can be caused to float in positions in between the horizontal and vertical positions illustrated to account for irregularities in the sea floor being mined.

In the embodiment of the present invention illustrated in FIGS. 1 and 2, the hull 11 includes a central substantially cylindrical, preferably framed, chamber or tank 12 sealed along its length from the stern 13 of the vessel which in mining position is located far below the surface of the sea to the bow 14 of the vessel which in mining position projects a short distance above the surface of the sea to the how 14 of the vessel which forms with the tank 12 ballast tanks 16 which can be flooded for causing the hull 11 to float in vertical mining position as illustrated in FIG. 1B or which can be filled with pressurized air for bringing the hull 11 back into horizontal position.

The shape ofthe shell is selected to provide desired stability and form minimum resistance for motion through the sea in the various operable positions of the vessel. While the tank 12 is illustrated and described as cylindrical in shape for withstanding high pressure when the vessel is in mining position, the tank can be of any suitable cross section or can be in the form of several cylindrical tanks.

In accordance with one aspect of this invention, the cross sectional area of the hull structure 11 is reduced or suitably shaped over the length of the structure that would normally be subjected to the greatest wave action when the vessel is arranged in vertical mining position. This construction is illustrated in FIG. 3 which shows the reduced cross sectional area structure G adjacent the surface of the sea when the vessel is in vertical position.

The vessel D can either be provided with its own propulsion system for driving in horizontal transportable position or can be towed in this position. It is also provided with a suitable propulsion system for moving the vessel when it is located in vertical mining position. This propulsion system can include regular propellers or thrusters or Voith-Schneider propellers located at certain positions along the length of the vessel.

The fuel tanks for the vessel propulsion system are conveniently located between the shell 15 and the tank 12 at suitable locations along the length of the hull 11, and a control room 18 provided with separate sections for operation in horizontal and vertical positions is located at the bow 14 of the vessel which is positioned above the surface of the sea when the vessel is in vertical mining position.

The conveying or dredging apparatus C can be any one of a wide variety of conventional or especially adapted dredging assemblies such as, for example bucket ladder, grab bucket, clam shell, drag line, hydraulic, suction, or air lift dredging equipment.

As illustrated in FIG. 1, a hydraulic dredge assembly uniquely cooperating with the mining vessel D to permit mining with a minimum of work includes an exterior conveying pipe 21 provided with a head 22 such as a cutter head on the end thereof and connected via a swivel coupling 23 and a connection pipe 24 to the interior of the tank 12. The position of the conveying pipe 21 is controlled by a winch operated cable 25 operable from the control room 18 for lowering the conveying pipe 21 to the sea floor when the vessel is in vertical mining position and where the pipe end can be supported by suitable rollers 22 or a car-like member. A stanchion 26 is provided on the deck of the vessel for transportation of the conveying assembly in horizontal transporting position. 4

The connection pipe 24 provides communication between the conveying pipe 21 and an interior conveying pipe 27 adapted for conveying the dredged material interiorly of the tank 12 in the vessel D to a separating location H therein below the surface of the sea. With the interior of the tank 12 communicating upwardly through the vessel with atmosphere, the ditferential in pressure between the bottom of the sea and the separating location H with in the dredging vessel forces the dredged matter A bydraulically by means of sea water upwardly through the exterior pipe 21 and interior conveying pipe 27. At the location H within the vessel, the conveying water is sep arated in a dewatering chamber 28 from the mined matter and exhausted to the sea from a sump 29 via an exhaust pump 30. The dewatered mined matter can then be lifted from the chamber 28 by a conventional bucket elevator arrangement 31 to the bow of the vessel for discharge through a chute 20 into the transport barge F. The water exhausted via pump 30 can be utilized to aid in the forward propulsion of the vessel D in its vertical position.

The construction illustrated in FIG. 1 permits the material being mined to be hydraulically conveyed into the vessel by the difference in hydraulic pressure from the bottom of the sea to a location within the vessel thereby reducing the work required to lift the material.

The mining Vessel positioned in mining position vertically in the sea is affected to a minimum degree by the wave action of the sea since the wave action is primarily concentrated at the surface of the sea, and the required length of the dredging equipment exteriorly of the vessel is reduced over that required in conventional dredging operations by the submerged length of the vessel.

FIG. 4 illustrates an alternative embodiment of the present invention wherein the mined matter is separated within the vessel into desired and undesired minerals, and only the desired minerals are conveyed to the surface of the sea while the undesired minerals are exhausted from the lower submersed portion of the vessel. As illustrated in FIG. 4, the dewatered matter 32 is conveyed via a conventional conveyor 33 to a series of separating

stages

34, 35 and 36 located within the tank 13 below the separating location -H'. The construction of the separating

equipment

34, 35 and 36 can include screen members or riiiles or magnetic separators for separating the desired from the undesired minerals and depends upon the types of minerals being mined. The desired minerals are drawn off from

separators

34, 35 and 36 via conduits 34', 35' and 36', respectively, to the elevator 31' for conveyance to the bow of the vessel above the surface of the sea. The undesired or waste minerals are dropped through one of a plurality of drop chambers 37 back to the sea bottom.

A typical chamber 37 as illustrated schematically in FIG. 5 includes an inlet opening 38 for receiving the waste minerals from the lowest separator chamber 36 and a lower outlet opening 39 for returning the waste mineral to the sea. A pair of

valves

41 and 42 provide communication from the top of the drop chamber 37 to the sea and are operable from the interior of tank 12 via

handles

41 and 42. Additionally, a spill valve 43 when opened near the top of chamber 37 permits water spillage into a spill tank 44.

In typical operation of the illustrated drop chamber 37 with the outlet opening 39 and the

valves

41 and 42 closed and the spill valve 43 open the inlet 38 is opened and Waste materials dropped into chamber 37 until the chamber is substantially full. Then inlet opening 38 and spill valve 43 are closed and valves 41 and 4.2 opened so that water fills up the chamber 37 forcing air out of the upper of the two valves thereby to equalize the water pressure interiorly of the drop chamber 37 with the water pressure at the exterior of the submerged portion of the vessel. Then outlet opening 39 can be opened to permit the waste minerals to drop by gravity to the ocean floor. By then closing outlet opening 39 and

valves

41 and 42, spill valve 43 can be opened and same water spilled into tank 44 to equalize the pressure in the drop chamber 37 with that in the interior of the vessel. Then inlet opening 38 can again be opened and waste minerals again dropped into the chamber 37 while permitting the water displaced by the waste to flow out through the spill valve 43 into tank 4-4. By utilizing a plurality of drop chambers 37 at the lower submerged end of the vessel, certain of the chambers 37 can be in the process of exhausting waste materials back to the sea while waste materials are being dropped from the last separating chamber 36 into another drop chamber 37.

As will be appreciated from the above, the various sizes and shapes of the mining vessel and associated equipment depend to a large extent on the particular conditions of the mining site in which the vessel is used. If the vessel is maintained at sea at the mining site for an extended period of time, such as years at a time, the design of the vessel is primarily governed by the desired characteristics for floating the vessel in vertical mining position. On the other hand, if the mining vessel is to be operated at an area reasonably accessible to a harbor for repairs or for return after a short length of time, greater emphasis is placed on the design of the vessel for transportation in horizontal transporting position. Naturally, the length of the vessel and its associated mining equipment depend upon the particular mining operation to which it is to be applied and the mining area which it is designed to handle.

The minerals recovered from the ocean bottom in accordance with the present invention can be stockpiled and blended for use by the underwater stockpiling and blending method and apparatus as illustrated in FIG. 6-14.

Referring now to FIG. 6, there is illustrated the manner in which mined minerals transported from an ocean mining operation as described above or from another source for stockpiling at a processing plant are dumped from the bottom unloading barge F into a stockpile J below the surface of the sea in shallow water. A matrix or pattern of rows and columns is provided on the sea surface such as, for example, by means of sets of alignment guide members located along two mutually perpendicular axes for properly designating a particular region of the pattern at which each barge load of minerals is to be dumped. As illustrated in FIGS. 6 and 7, the pattern can consist of regions located along the length of shoreline via location posts 51 and 52 provided in pairs which when vertically aligned from the tugboat guiding the loaded barge F designate general positions noted as 1, 2, 3 Similarly, pair of buoys designated 53 and 54 spaced at equal intervals outwardly from the shore and spaced apart generally by the width of the load can be used to designate regions located at successively greater distances from the shoreline.

A plurality of mineral loads are dumped from the barges on the sea surface in a shallow water evenly distributed over the matrix or pattern with a plurality of loads dumped at each position of the matrix to produce a stockpile I of adjacent and superimposed mineral loads.

The mineral loads can be deposited by a bottom unloading barge navigated by a tug without the necessity for docking the barge and utilizing expensive unloading equipment and extended docking time. When the mineral loads have been deposited in adjacent and superimposed load layers, a stockpile is formed. Then by reclaiming the minerals in a pattern cutting across and through load layers, the minerals of a number of different loads are effectively blended as the minerals are reclaimed for utilization at a nearby processing plant. FIG. 8 illustrates a suction dredge barge 60 cutting through the stockpile in sweeping arcs indicated by curved lines K in FIG. for

effectively traversing the width of the loads while at the same time cutting down through the loads to elfectively blend the material being reclaimed. FIGS. 9l4 illustrate various methods and apparatus for reclaiming the stockpiled material.

As illustrated in FIGS. 9 and 10, a suction dredge indicated as 60 and provided with a cutter head 61 is swung in arcs centered at the main anchor 62 by winches which move the dredge back and forth between auxilliary anchors 63 and 64 spaced on the sides of the stockpile. The dredge 60 is moved in short length steps from one end of the stockpile at which is located one main anchor 62 to the other end of the stockpile at which is located another main anchor 62 so that the arcs X permit the entire stockpile to be claimed while simultaneously blended. The reclaimed material from the stockpile is pumped through a floating pipeline to shore from whence it can fiow through a stationary line to the feed point of the processing plant. If desired, dewatering equipment can be arranged along the stationary pipeline and the conveyance of the minerals converted from a pipeline conveyance to a belt conveyor. The conveying apparatus naturally depends upon the properties and sizes of the particles in the stockpile.

Referring now to FIGS. 11 and 12, there is shown a suction pipe without cutter head mounted on a simple pontoon 71. The pontoon 71 is located at the end of a pontoon arm 72 which is swingably rotated about a pivot point on a support barge 73 which is moored against two dolphins of a series of dolphins 74 spaced along the shoreline alongside the stockpile J. The pontoon 71 is moved in arcs-L by the action of winches and swing lines 75 and 7 6 to blend the minerals in the stockpile while reclaiming the minerals for use in a processing plant. The reclaimed minerals are pumped through a pipeline 77 along the pontoon arm 72 and via a short section of floating pipeline 78 to stationary pipelines 79 located at periodic points along the shoreline and thence to the processing plant.

FIGS. 13 and 14 illustrate a reclaiming apparatus similar to that shown in FIGS. 11 and 12 but wherein the reclaiming apparatus on the end of the pontoon arm includes a bucket dredge 80 for reclaiming the minerals from the stockpile J and depositing them on a dredge mounted trommel 81 in which coarse materials can easily be dewatered and dropped onto a belt conveyor 82 for transportation along the pontoon arm 73 to the processing plant. In this arrangement the fines and water flow back directly to the water from the dewatering trommel.

Naturally the selection of the most desirable reclaiming method and apparatus of the types illustrated depends upon the nature and properties of the particular raw material in the underwater stockpile.

It will be apparent that with the underwater stockpile and blending system in accordance with the present invention, the stockpiling is accomplished on submerged land which is far less expensive than surface land adjacent the water area without the necessity for expensive docking, unloading, and stockpile blending apparatus. It is far easier to reclaim the stockpiled minerals than to dredge the same sort of materials that have been sedirnented and hardened through thousands of years. While conventional reclaiming methods and apparatus on land stored stockpiles require the complete oollection of the entire stockpile, the underwater stockpiling method and apparatus in accordance with the present invention can be utilized to reclaim only the top layer or layers of stockpiled minerals while leaving the bottom mineral layers for emergency periods. Furthermore, with the present invention a minimum amount of site preparation for the storage area is required.

In the preparation of the site, if the existing area is not of the desired depth, dredging can be done. The dredged depth can be on the order of the maximum reclaiming depth to allow a certain amount of settling of the bottom with time. If the bottom settles beyond the expected amount, the material at the bottom of the stockpile can be left in place or, if necessary, mined with a vertically floating vessel.

If after some years of operation it is desired to increase the capacity, this can be easily done without encountering the complications as would be involved in a stockpile on land.

Although the foregoing invention has been described in some detail by Way of illustration and example for purposes of clarity of understanding, it is understood that certain changes and modifications may be practiced within the spirit of the invention.

What is claimed is:

1. The method of mining minerals from the sea bottom comprising the steps of: conveying minerals from the sea bottom to a chamber maintained at substantially atmospheric pressure below the surface of the sea; conveying said minerals under atmospheric pressure conditions from said chamber to the surface of the sea; transporting said separated minerals across the surface of the sea in a plurality of loads in surface vessels; dumping said loads in a uniform pattern on the water surface above a shallow stock pile area with each load deposited in a predetermined position of the pattern so that an underwater pattern of adjacent and superimposed mineral layers is produced; reclaiming said minerals from said storage area to the surface of the sea in a pattern cutting across and through said layers effectively to blend the materials of a number of different loads in the reclaimed mineral supply; and transporting the desired minerals across the surface of the sea onto land as desired.

2 The method of claim 1 characterized further in that said reclaiming and transporting steps include the steps of swinging a conveyor assembly across the underwater stockpile and discharging the reclaimed material from the conveyor assembly to shore.

3. The method of claim 2 including the step of dewatering the minerals at the surface of the sea and then conveying the dewatered minerals to land.

4. A mineral stockpiling and blending method comprising the steps of: transporting a plurality of loads of minerals over the surface of the sea in vessels; dumping each of said loads in a predetermined position of a pattern on the sea surface in shallow water and with the plurality of loads substantially evenly distributed over such pattern a plurality of loads deep so that an underwater stockpile with a pattern of adjacent and superimposed mineral load layers is produced; reclaiming said minerals from the underwater stockpile in a pattern cutting .across and through said load layers effectively to blend the minerals of a number of different loads in the reclaimed mineral supply; and transporting said reclaimed mineral supply to land as desired.

5. The mineral stockpiling and blending method of claim 4 characterized further in that said reclaiming step includes the step of reclaiming minerals from the stockpile in a plurality of arcs each centered along one side of the stockpile and with the center of each arc spaced from the center of adjacent arcs.

6. The mineral stockpiling and blending method of claim 4 characterized further in that said reclaiming step includes reclaiming minerals from the stockpile in a plurality of arcs cutting across the stockpile and with all arcs having a common center.

7. The mineral stockpiling and blending method of claim 4 including the step of dewatering the minerals at the surface of the sea and conveying the dewatered minerals to land.

References Cited UNITED STATES PATENTS 227,988 5/1880 Meech 2 99 318,860 5/1885 Bowers 37195 570,876 11/1896 LeGrand 214-10 X 665,835 l/190l Miller 3769 X 868,774 10/1907 Goth 37-67 X 3,069,027 12/1962 Dischinger 21410 OTHER REFERENCES Power publication, vol. 61, No. 25. pps. 976979, June 23, 1925, Submerged Storage and Coal Handling Equipment at Philo.

ABRAHAM G. STONE, Primary Examiner.

ALAN E. KOPECKI, Assistant Examiner.

US. Cl. X.R. 3758; 2998