A system for collecting mercury from feed material that can be tailings comprises: a water inlet for forming a slurry containing the tailings; at least one screen for separating tailings from the slurry to form a screened slurry; a rotatable collection chamber containing at least one plate, a drive for rotating the collection chamber for collecting mercury on the plate to provide a discharge material comprising water and treated tailings, the treated tailings containing less mercury than in the feed material.