ES235725A1 - Method of fluid bed roasting - Google Patents

Abstract

Method of separating non-zinc sulfide components, from a finely divided zinc sulphide ore concentrate in a fluidized bed roasting operation, consisting of agglomerating the mineral concentrate into separate particles of a size between 4 and 65 mesh, loading the agglomerates into the upper portion of a columnar fluid bed of the separated particles by maintaining in an essentially fluidized state exclusively by the upward flow of gas, introducing air for the roasting of the sulfides in the lower portion of the fluid bed in an amount by less 5% higher than the amount theoretically required to be combined with the zinc sulfide component of the filler, introduce in the upper portion of the fluid bed but at a substantial distance below the upper surface thereof a sufficient amount of combustible gas to consume said excess air for roasting the sulfides and thus provide a to atmosphere, in the upper portion of the fluid bed, non-oxidant with respect to the sulfides, providing the air for roasting the sulfides and the combustible gas the main source of said fluidizing gas, maintaining the fluid bed at a temperature of at least about 900º c., discharging the roasted zinc particles from the lower end of the fluid bed and removing from the upper end of the fluid bed gases from the roaster containing the volatilized sulphides of the zinc sulphide filler. (Machine-translation by Google Translate, not legally binding)