Alkalinity is defined as the capacity of a water to neutralize strong acids. In natural waters, this capacity is generally attributable to bases such as HCO3-, CO32 and OH- as well as to species often present in small concentrations such as silicates, borates, ammonia, phosphates and organic bases. Carbonate alkalinity of process waters in mineral processing may change as a result of the seasonal climatic changes, the fresh water source and the amount of recycled process water. Any mineral processing plants in general and flotation plants in particular will have process waters with different alkalinities. Therefore, carbonate alkalinity should be of concern in flotation.