A system and method for the calcination of minerals. The system comprises a vertically disposed reactor segment configured to impart horizontal forces on particles passing through the reactor segment in a vertical direction; an injector unit for receiving granular feedstock, the injector unit being disposed at a top portion of the reactor segment, whereby granules of the feedstock move through the reactor segment in a granular flow under at least one of a group consisting of a force of steam, gravitational force and a centrifugal force; a reactor heat exchange unit thermally coupled to a wall of the reactor segment for providing heat to the flowing granules inside the reactor segment through heat transfer through the wall of the reactor segment; one or more inlets formed in the reactor segment for introducing a superheated gas into the reactor segment to create conditions of a gas-solid multiphase system; and one or more exhaust openings formed in the retort segment such that gas products are at least partially flushed from the reactor segment under the flow of the superheated gas from the inlets to the exhaust openings.