Recovery of zinc from zinc calcine by the iron-reduction distillation process - fundamental studies of zinc extraction by the iron-reduction distillation process (2nd report)

The iron reduction distillation process consists of two successive reduction stages for a mixture of iron oxide and zinc oxide with a Fe/Zn mole ratio of 2 as the starting material. Experiments were carried out to investigate the reduction stages by using zinc calcine as a zinc oxide source. Thermodynamic estimations on the behavior of minor elements were also made. Some minor elements which are more noble than iron were reduced to metals on the first reduction stage. Cadmium was volatilized above 70% during the first reduction, and lead was vaporized during the second reduction. Since most of the coexisting minor metal values such as gold, silver and copper are concentrated in the metallic iron, their recovery with high efficiency can be expected by magnetic separation of the residue.