Abstract: The invention provides an apparatus for removing ferrous particles from metal contaminated oil and gas process liquids or slurries and method of use. The magnetic separator apparatus comprises a vessel with an inlet and an outlet configured to allow the flow through of a liquid or slurry, or to hold a liquid or slurry inside. A plurality of magnetic rod devices is mounted upon at least one frame member secured to the vessel such that they extend into the interior of the vessel. Each magnetic rod device has a first condition in which it is operable to attract ferrous particles, and a second condition in which it is operable to dispose of ferrous particles. Embodiments of the invention provide a magnetic separator apparatus for removing ferrous particles from contaminated liquids and slurries which are stored in a storage facility.