A method and apparatus for heat treating a particulate product including fluidizable as well as non-fluidizable particles. The particles are fed to a first perforated bed plate of a fluidized bed apparatus comprising at least one further stage formed by a second perforated bed plate. Heat treating gas...http://www.google.ca/patents/US5133137?utm_source=gb-gplus-sharePatent US5133137 - Method and apparatus for heat treating a particulate product
