Heating, mixing and hydrating apparatus and process

A system for mixing a material with a gas/vapour, the system comprising:

• a reservoir for a process liquid comprising the material and a carrier liquid;
• an apparatus comprising a passage defined by a wall and having an inlet for the process liquid comprising the material and the carrier liquid and an outlet such that the process liquid can flow from the inlet towards the outlet and a rotatable member provided with a vapor/gas nozzle for introducing a gas/vapour at supersonic velocity into the passage at a mixing zone, wherein a cross sectional area of the mixing zone is smaller than a cross sectional area of the passage upstream of the mixing zone and a cross sectional profile of the mixing zone can be varied, said apparatus being in fluid connection with the reservoir;
• a collection vessel for mixed material in fluid connection with the apparatus;
• a heating element for raising the temperature of the process liquid upstream of the mixing zone;
• a pump for pumping the process liquid from the reservoir, through the apparatus and into the collection vessel;
• a source of gas/vapour in fluid connection with the nozzle of the apparatus;
• a control system for controlling:
• i. positions of at least one of a movable flap and a projection in the apparatus for varying the cross sectional profile of the mixing zone;
• and
• ii. at least one of a pressure and temperature of the gas/vapour;
• and at least one of:
• iii. the heating element for raising the temperature of the process liquid upstream of the mixing zone;
• iv. the pump for pumping the process liquid through the apparatus;
• and
• v. the rotatable member of the apparatus in order to vary an angle between the direction of the flow of gas/vapour and the direction of flow of the process liquid.