Floatation is a method used to separate:

Floatation is a process commonly used in mineral processing to separate different minerals based on their surface properties. It works by exploiting the differences in hydrophobicity (water-repelling properties) of the minerals. In the floatation process, air bubbles are introduced into a slurry of ground ore mixed with water and chemicals. The hydrophobic particles attach to the air bubbles and rise to the surface, forming a froth that can be collected. In contrast, hydrophilic particles remain in the slurry and do not float.

Given this process, the correct answer points to the separation of two or more ores contained in a mixture. This is applicable because floatation is designed to differentiate between various minerals that may be present together in one sample, allowing for the recovery of valuable resources while discarding unwanted materials.

The other options focus on scenarios that do not align with the typical applications of floatation processes. For instance, separating a single ore from surrounding material pertains more to direct mining techniques rather than specifically utilizing floatation. Similarly, distinguishing between ores and non-metallic minerals or separating waste materials from pure metals indicates processes that may employ other methods like screening, gravity separation, or chemical extraction, rather than the floatation technique, which is specifically aimed at multiple mixed ores