METHOD OF EXPLOITING POTASSIUM SALTS FROM AN UNDERGROUND DEPOSIT

摘要

The present invention pertains to a mineral exploitation method and, more specifically, to a method for extracting potassium salts from underground deposits. In the method according to the present invention, an intermediary stage is carried out between the primary mining and secondary mining stages, and in this intermediary stage sinks (8) are created that receive the water-immiscible fluid (9) used in the primary mining stage, exposing an amount of potassium chloride remaining on the cavern ceiling, at the end of the primary mining stage, which will be dissolved by a second solvent during the secondary mining stage.

主权项

1. A method for exploiting potassium salts from an underground deposit, comprising:
injecting into a cavity generated in the underground deposit, aqueous solvent of potassium salt and a water-immiscible fluid through a first pipe into a well in communication with the cavity; removing a brine comprising dissolved potassium salt through a second pipe in a well in communication with the cavity, wherein the solvent allows for side expansion of the cavity to form a cavern and wherein the water-immiscible fluid forms an insulating interface between the aqueous solvent and ceiling of the cavern; and gradually elevating an injection point of the aqueous solvent and of the water-immiscible fluid to allow for vertical expansion of the cavern in a controlled manner, the side expansion being repeated periodically with vertical elevation of the cavern; wherein, after a final elevation of the injection point and side expansion of the cavern: water is injected through orifices perforated in the first pipe and the second pipe to form a sink on the cavern ceiling to receive the water-immiscible fluid that flows from the ceiling of the cavern; and a solvent is injected to dissolve exposed potassium salt after the sink has received the water-immiscible fluid.