Abstract: A storage container for solid particulate materials includes a source of `lubrication` gas coupled to a fluidizer. The fluidizer particulate materials are carried from the container by a stream of transport gas. A deflector placed over the container outlet constrains the fluid flow in a substantially horizontal path to prevent the outlet becoming blocked by the solids when the gas flow is cut off. The proportions of particulate material can be varied by selectively varying the pressure in the container, where the container is a pressure vessel.