Abstract: A method of carrying out a chemical reaction in a fluidized bed reactor is provided wherein the reactants include at least one finely sub-divided reactant having a particle size substantially smaller than that of the particles constituting the fluidized bed. The reactor includes a downcomer compartment and a riser compartment operated such that the fluidized bed particles circulate by moving down the downcomer compartment and up the riser compartment. The finely divided solid reactant is introduced, either as such, or in an agglomerated form, into the central or upper region of the fluidized bed in the downcomer compartment such that it becomes entrained in the downwardly moving fluidized bed in the downcomer compartment and moves countercurrent to the fluidizing gas towards the lower end of the riser compartment. The reaction products which may be, or include, fine divided solids are carried out of the top of the reactor from the riser compartment.

Abstract: Intermetallic compounds are disclosed in which a platinum/aluminium compound includes copper in proportions chosen to provide desirable color, from yellow through orange to copper/red, to the compound. The compound contains from 50 to 81, preferably 57 to 80% by weight platinum; from 5 to 30, preferably 12.5 to 30% by weight aluminium; and from 1 to 47.5 and preferably 5 to 30% by weight copper.