Treatment of granular materials which require to be heated to drive off volatile constituents and which require to be cooled, for example foundry sand containing an organic binder, comprising the step of maintaining a mass of the material at a treatment temperature lying in the range of 250 DEG C-400 DEG C for between four and thirty hours. The mass may be initially heated by virtue of a manufacturing process in which the mass has been previously used. Alternatively, the mass may be initially heated by a pre-heating step such as heating in a fluidised bed. Alternatively, the mass may be heated by being placed in the heat transfer relationship with a second mass of the material which has been previously heated, for example, in a fluidised bed. An apparatus for performing the method is also disclosed.
展开▼
