Abstract: The invention relates to a method for heat treatment of fine calcium carbonate bearing material comprising preheating fine material containing a coarse and a fine fraction. The preheated material is delivered into a fluidized bed calcining means wherein the coarse fraction is calcined and the fine fraction is delivered by process air to an adjacent vertically arranged gas flash calciner furnace in which it is calcined.

Abstract: The present invention relates to a process for roasting gold containing ore in which a flash furnace means is provided, in particular a gas suspension furnace for roasting the ore. Hot gas and the gold containing ore to be roasted are supplied to the furnace means, wherein the hot gas roasts the ore within the furnace means at temperatures between about 500.degree. C. and 700.degree. C. while the ore is suspended in the hot gas, after which the roasted ore is discharged from the furnace means along with the hot gas. In the apparatus of the present the ore to be calcined may optionally be preheated, prior to the ore entering the furnace means, by suspending the fresh ore in hot gas.

Abstract: A process for the continuous production of a calcined product containing a high level of reactive oxide valves, from a preheated raw material containing calcium carbonate values, said process comprising,(a) introducing the preheated raw material to the bottom of a generally vertically oriented gas suspension calcining furnace, whereby said preheated raw material is thereafter suspended in an ascending stream of heated gas to thereby pass vertically upwardly through the gas suspension calcining furnace;(b) passing the ascending gas stream through a plurality of burners, into which fuel and air are injected, that are vertically spaced from each other, in the gas suspension furnace, at a number of levels in the flow direction of the heated gas, and(c) collecting the calcined product.

Abstract: A method to operate a flash calcination unit with both atmosphere and temperature control is described for mineral processing requirements and other atmosphere controlled processes. The method can be used to process phosphate, gold ore or activated carbon. The critical steps of the method involve an initial mixing of fine material combined with stoichiometric burning using at least one staged combustion furnace in a vertically oriented suspension calcination furnace. This effects control of oxygen or atmosphere in the combustion furnace with attendant control of temperature in that furnace.