The oxidation rate of minerals is a key indicator for evaluating ore properties, as the degree of oxidation significantly impacts flotation in several ways:
Increased ore sliming
The oxidation of many metallic and gangue minerals alters the ore's original, robust structure, generating earthy or clay-like minerals and increasing the volume of mineral slimes.
Increased compositional complexity, affecting floatability
For instance, when chalcopyrite oxidizes, it leaves behind various residual metal sulfides while simultaneously forming new secondary minerals such as malachite, azurite, and chrysocolla. The presence of these minerals significantly influences the overall beneficiation process.
Altered physicochemical properties of mineral surfaces, reducing the floatability of valuable minerals
For example, surface oxidation of chalcopyrite can form a thin film of malachite; since this film is hydrophilic, it reduces the chalcopyrite's floatability and adversely affects flotation performance.