Iodine crystals can be removed from a mixture by sublimation. Sublimation is a process in which a solid turns directly into a gas without passing through the liquid phase. This can be done by heating the mixture to a temperature above the sublimation point of iodine, which is 184.3 °C. The iodine crystals will vaporize and can be collected on a cool surface.

Here is a step-by-step procedure for removing iodine crystals from a mixture by sublimation:

1. Place the mixture in a heat-resistant container.

2. Heat the container to a temperature above the sublimation point of iodine (184.3 °C).

3. Maintain the temperature for a few minutes to allow the iodine crystals to sublime.

4. Allow the container to cool.

5. Collect the sublimed iodine crystals from the cool surface.

This method is effective for removing iodine crystals from mixtures without affecting other components of the mixture.