Stirring of molten metals

A method of stirring molten metal within a container, the method including:

• applying a current to a first electrically conducting coil coupled to a first tooth of an electromagnetic stirrer at a first time to generate a first magnetic field configuration;
• and
• applying a current to a second electrically conducting coil coupled to a second tooth of the electromagnetic stirrer at a second time to generate a second magnetic field configuration, such that the changes in magnetic field configuration cause movement of the molten metal within the container;
• wherein the first and second teeth extend from a base and each have a proximal end and a distal end that is further from the base than the proximal end, each distal end defining a tooth end face that is curved;
• and wherein a length of the first tooth is greater than a length of the second tooth.

Apparatus for stirring a molten metal, the apparatus comprising:

• an electromagnetic stirrer including a core having a base, a plurality of teeth, and a plurality of electrically conducting coils;
• and
• connections for applying a current to the electrically conducting coils;
• wherein the plurality of teeth each have a proximal end and a distal end that is further from the base than the proximal end, each distal end defining a tooth end face;
• wherein:
• the plurality of teeth includes a first tooth and a second tooth;
• the tooth end face for the first tooth is not parallel to the second tooth;
• the tooth end faces of the plurality of teeth are curved;
• and
• a radius of curvature of the tooth end faces is substantially equal to a radius of curvature of a container surface configured to hold molten metal.

Apparatus for stirring a molten metal, the apparatus comprising:

• an electromagnetic stirrer including a core having a base, a plurality of teeth, and a plurality of electrically conducting coils;
• and
• connections for applying a current to the electrically conducting coils;
• wherein the plurality of teeth each have a proximal end and a distal end that is further from the base than the proximal end, each distal end defining a tooth end face;
• and
• wherein:
• the plurality of teeth includes a first tooth and a second tooth;
• the tooth end face for the first tooth is not parallel to the second tooth;
• a length of the second tooth is greater than a length of the first tooth;
• and
• the tooth end faces are provided such that an air gap between one or more tooth end faces and an outer wall of a container for the molten metal is less than 10 cm.