Abstract: A bulk granular solids gravity flow curing vessel comprises an upper curing unit having a top opening for receiving particulate solids, a lower curing unit coupled to receive particulate solids from the upper curing unit, and at least one of the upper and lower curing units including a first intermediate section having substantially vertical sidewalls, a first hopper positioned to receive the particulate solids from the intermediate section, and a first velocity adjustment means positioned in the intermediate section and/or the first hopper. A bulk granular solids gravity flow curing vessel comprising a first section having substantially vertical sidewalls, a first hopper positioned to receive particulate solids from the first section, and a first velocity adjustment means positioned in the first section is also described.