Method and apparatus for mining nodules from beneath the sea
AssigneeCommissariat a l'Energie Atomique
InventorsPierre Balligand, Yves Corfa, Pierre Lemercier, Paul Marchal, Jean Vertut
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Abstract
Polymetallic nodules are collected by means of a plurality of self-propelled vehicles which move upwards and downwards between the sea floor and a surface platform under the action of excess ballast which is partially and progressively released as the vehicle approaches the bottom. The vehicles are propelled along the sea floor by means of at least two supporting units each having at least one helical propulsion fin, the remainder of the ballast being released in order to return the vehicles upwards for docking, unloading and energy-recharging in the surface platform.
Claims10
A method of exploitation of a deposit of polymetallic nodules on a sea floor from a platform located at the surface of the sea, said polymetallic nodules comprising metallic material and sterile material, said nodules being adapted to be treated for separating the sterile material from the metallic material, said method including the steps of,
- (a) charging with energy a plurality of self-propelled vehicles, said vehicles being provided with means for dredging and stocking said nodules, and loading said vehicles with releasable ballast,
- (b) downwardly displacing said vehicles into the sea from the platform under the action of excess ballast,
- (c) releasing a portion of said excess ballast at the vehicles' approach to the sea floor to make softer the landing of the vehicle on the sea floor,
- (d) propelling said vehicles on the sea floor by self-propelling means carried by the vehicles, the self-propelling means consisting of at least two supporting units of revolutions, each said unit being provided with at least one helical propulsion fin, in order to dredge and stock said nodules, and simultaneously and progressively releasing said ballast so that said released ballast permanently compensates for the added weight of the stocked nodules,
- (e) upwardly displacing said vehicles back to the platform by releasing the remaining portion of ballast,
- (f) discharging the stocked nodules on said platform.
Dependencies are inferred from the claim text.