a sifter can be used for separating a mixture of different sized solids
centrifugation is separating_mixture. separating_mixture is reversible_process. separating_mixture is not reversible_process. purification_process is separating_mixture. sifter is sieve. separating_mixture is complete_separation. divider is use_to_separate_groups_of_items. panning is separating_mixture. separating_mixture is physical_transformation. divider is not use_to_separate_groups_of_items.