Using a pilot flash furnace with the capacity of about 1 t/h, suspended copper concentrate particles were water-quenched in the reaction shaft and the settler. These samples as well as dust generated from the furnace were examined by optical microscope. The results are summarized as follows:
(1) Final products in the reaction shaft consisted of molten excessively oxidized particles rich in chalcocite or bornite and solid less oxidized chalcopyrite particles.
(2)The molten excessively oxidized particles were much larger in size than the original and many of them had relatively large amounts of slag.
(3) However neither of solid particles with oxidized rims nor cenospheres showing fragmentation were observed.
(4) The above results have proved the validity of a two-particle model14) for copper flash smelting.
