Water used in flotation, or the ore itself, may contain soluble salts that affect the interaction between reagents and minerals, and can cause mineral activation or inhibition. These include compounds such as carbonates, sulfates, phosphates, calcium, magnesium, sodium, chlorides, and silicon.
Water with a high calcium salt content is hard water. In hard water, flotation using hydrocarbon acids and soaps consumes a large amount of reagents.
When water comes into contact with metallic minerals, it contains metal ions such as iron, copper, and zinc. If the minerals are sulfide minerals, these metals will become sulfates in the water, making them difficult to dissolve.
The dissolved oxygen content in water has a significant impact on the flotation process. Oxygen adsorption on mineral surfaces enhances the hydrophobicity of the minerals, promoting the interaction between certain collectors (xanthates, dioxins) and the mineral surface, thereby accelerating the flotation process and improving flotation parameters. When the flotation water contains a large amount of organic matter (such as humus and microorganisms), it consumes the dissolved oxygen in the water, thus reducing the flotation rate of sulfide minerals and, in severe cases, disrupting the entire flotation process.