Pumping system

A pumping system for pumping a medium comprising a liquid with ore particles from an underground or subsea location to a surface at a raised level, the system comprising:

• at least one pressure exchange chamber, located at a lower altitude than the raised level, and comprising an elongate pipe which extends in a transverse orientation, and having a driving fluid valve arrangement at one end, and a pumped medium valve arrangement at an opposite end;
• a pressurised discharge at a delivery end of the system on the pumped medium valve arrangement side of the pressure exchange chamber;
• a riser extending upwardly from the delivery end to the raised level and for delivering the medium thereto;
• a fluid source at approximately the same level as the pressure exchange chamber to provide water to mix with ore to create the medium;
• a filling mechanism operable to fill the pressure exchange chamber with the medium;
• and
• a positive displacement pump connected to the pressure exchange chamber and operable to pump a driving fluid in direct contact with the medium so that the medium is displaced from the pressure exchange chamber to the pressurised discharge by the driving fluid,
• wherein the driving fluid valve arrangement is located at the end of the pressure exchange chamber connected to the positive displacement pump and comprises a driving fluid entry valve, and a driving fluid exit valve and the pumped medium valve arrangement comprises a pumped fluid entry valve whereby the medium can be fed into the pressure exchange chamber and a pumped fluid exit valve whereby the medium can be discharged from the pressure exchange chamber, and an actuator associated with each valve and being configured to displace the valve between an open position and a closed position, the valves being configured such that the flow of the medium and the driving fluid assists in closing the driving fluid entry and driving fluid exit valves and assists in opening the pumped fluid entry and exit valves.