Characterisation and classification of non solid wastes coming from a reductive acid leaching process of manganiferous ore

The present work was focused on the characterization and classification of the solid wastes coming from the leaching process for manganese extraction in reductive acid environment. The aim of this study was to find process conditions that reduced treatment costs of waste or, even better, to valorize solids as raw materials for other industries. The effect of particles size on the manganese extraction in reductive acid leaching process was investigated, with lactose like reducing agent. Particle size didn’t show a large influence on extraction yields, in the investigated process conditions. This aspect suggests the use of the leaching waste for civil works; in fact, the treatment of biggest particles would allow the use of leaching solid wastes like fills material to be applied, as example for street construction. The classification of solid wastes demonstrated that only the solid waste produced by leaching and neutralization processes (performed in order to remove iron from liquor leach) can be classifiable as no-dangerous; an improvement of solid washing let to classify this waste as inert, with a consequent obvious significant reduction of solid disposal costs. Possible application of ore and waste as raw materials in the ceramic industry unfortunately was demonstrated to be not feasible.