Froth flotation is the ore dressing process that requires the finest size of ore.

- Froth flotation:
Froth flotation is a process used for selectively separating hydrophobic materials from hydrophilic. It is one of the most widely used methods for ore beneficiation. In this process, the finely ground ore is mixed with water and a collector chemical such as xanthate. The collector selectively adsorbs onto the surface of the desired mineral, making it hydrophobic. Air bubbles are then introduced into the mixture, and the hydrophobic mineral particles attach to the bubbles and rise to the surface as a froth. The froth, containing the valuable mineral, is then skimmed off while the gangue particles sink to the bottom.

- Finest size of ore:
The size of the ore particles is an important factor in the froth flotation process. The ore particles need to be finely ground to increase the surface area available for interaction with the collector chemical. The finer the particles, the greater the surface area and the better the attachment of the collector to the mineral particles. This allows for better separation of the valuable minerals from the gangue.

- Advantages of froth flotation:
Froth flotation has several advantages over other ore dressing processes:
1. Selective separation: It allows for the selective separation of valuable minerals from gangue based on their hydrophobicity.
2. Wide applicability: It can be used for a wide range of ores and minerals, including sulfide ores, oxide ores, and industrial minerals.
3. High recovery rates: It has high recovery rates for valuable minerals, often exceeding 90%.
4. Versatility: It can be easily modified and optimized for different ore types and conditions.
5. Environmentally friendly: It is a relatively low-energy process and does not require the use of toxic chemicals in large quantities.

In conclusion, froth flotation is the ore dressing process that requires the finest size of ore. The finer the ore particles, the better the attachment of the collector chemical and the more effective the separation of valuable minerals from gangue.