Abstract: Apparatus for circulating molten metal in a furnace comprises an electromagnet the coil of which is adapted for energisation from an alternating current source and the core of which is elongate and projects from both ends of the coil. The core is disposed so that 25% to 50%, preferably 37%, of its length is at one axial side of the mid-point of the coil, and the part of the core projecting at the said one axial side of the coil has a coating or casing of a refractory material. The apparatus may be mounted with its core horizontal in a side wall of the furnace but it is preferred to dispose the core vertically with the heat shield close to the surface of the molten metal. A duct member may surround said part of the core and may be shaped to direct the molten metal laterally. A partition or other form of baffle may be disposed externally of the duct between the inlet and outlet of the duct to prevent the molten metal leaving the outlet of the duct from passing straight back to the inlet of the duct.