A method and apparatus for removing metallic material from a circulating well fluid stream provides a treatment vessel that is divided into first and second sections. Each of the sections includes a magnetic field that can be in the form of one or more magnets. In one embodiment, multiple magnets are provided in each of the sections. Manifolds attach to an influent and to an effluent of the treatment vessel. Each manifold enables selective transfer of fluid to either of the selected sections. Similarly, discharge of circulating fluid can be from either of the sections via a discharge manifold. The treatment vessel enables continuous treatment by valving fluid flow so that only one section need be used at a time in order that the other section could be serviced for removing collected metallic material from the magnetic field or from the magnets.