Mixed flotation is a commonly used process in the flotation of polymetallic sulfide ores. It involves first mixing and floating all the valuable minerals, and then separating them sequentially. This process is suitable for polymetallic ores with relatively low levels of valuable minerals (high gangue content) and where the valuable minerals are aggregated. This process has many economic advantages. Under coarse grinding conditions, a large amount of gangue can be discarded after mixed flotation, significantly reducing the amount of ore entering subsequent operations, especially lowering the cost of subsequent grinding operations. This reduces equipment investment, lowers electricity consumption, and saves on reagent usage and infrastructure investment. The disadvantage of this process is that because the surface of the mixed concentrate is coated with collectors, and there is excess collector in the pulp, it can make subsequent separation difficult.
For polymetallic ores with high levels of valuable minerals and coarse-grained dispersibility, mixed flotation is not suitable; priority flotation is preferable.