A recovery process that separates diamonds from lighter materials using a dense medium is called what?

• A. Grease Belt
• B. Microdiamond Testing
• C. Dense Media Separation
• D. Ore Grade

Answer: (C)

Dense Media Separation uses a dense medium to separate diamonds from lighter materials by buoyancy. In this method, a slurry made from a dense material (like ferrosilicon or magnetite) in water creates a medium with a specific gravity chosen between the densities of diamonds and the surrounding rock. Diamonds have a higher density than most waste rock, so when the ore is introduced, the diamonds tend to sink into the dense medium while lighter materials float or report to the lighter stream. This allows for separation and concentration of the diamonds from the rest of the material.

The other options represent different concepts: a grease-based recovery method relies on the sticky grease to trap diamonds, not a density-based separation; microdiamond testing is a laboratory identification method, not a separation process; and ore grade refers to how much diamond content is present in ore, not how the diamonds are separated from the material.

Thus, the process described is Dense Media Separation.