Process Factors Affecting Flotation–Water Quality
The flotation process is carried out in medium water, but the water used for flotation varies from time to time. The composition of water has a great influence on flotation, and attention must be paid to the quality of water used for flotation.
According to different situations, flotation water can be divided into the following categories:
1. Soft water: The water in most rivers and lakes is soft water, and it is also the most used water in the flotation process. It is characterized by relatively low salt content, generally less than 0.1% salt, and less polyvalent metal ions.
2. Hard water: water with a hardness greater than 4 is collectively referred to as hard water. Hard water is detrimental to the flotation of fatty acid agents because the Ca2+, and Mg2+ ions consume the collector and often destroy the selectivity of the process.
3. Saltwater: Sea water and part of lake water are salt water. They are characterized by high salt content, generally 0.1% to 5%. Brackish water is used for flotation, which is important for coastal mines, or in salty lake areas. Minerals that are naturally hydrophobic, such as coal, can be floated in salt water even without dosing.
4. Backwater: The characteristic of flotation backwater is that it contains more organic and inorganic agents, and its composition is also more complex.
How does water affect the flotation of the flotation machine?
Depending on the properties of the water, the main effects of water on flotation are:
The ions dissolved in water are surrounded by a dipole of water, which is the hydration of the ions. Minerals become less buoyant if they are hydrated. For some hydrophobic ore particles, such as sulfur, coal, molybdenite, etc., the hydration effect is weak; while for some hydrophilic minerals, such as oxide ore and quartz, the hydration effect is stronger. But it should be noted that the main function of water in flotation is to form ore pulp, which is convenient for minerals to float up through air bubbles under the action of chemicals. In addition to oxygen, nitrogen and inert gases, there are carbon dioxide gas and water vapor in the air.
Dissolution of various substances in water. Since water has a large dipole moment, the ore particles in the water interact with the water. Due to the dissolution of substances in water, the water used in flotation can mainly dissolve substances, and the reason is that various organic and inorganic compounds are dissolved in the water itself. Therefore, during the flotation process, water quality control (such as softening, removal of unavoidable ions, aeration, and oxidation, etc.) should be carried out.