Abstract: A metallurgical lance incorporates an indirect cooling system, separate from and independent of the reactants which are fed through a center passageway (12) to a melt, bath or the like. An outer passageway (10) extends around the center passageway (12) and its outer wall (14) is exposed to heat flux. A coolant flows through the outer passageway (10). Auxiliary means (22) are positioned within the outer passageway (10) to enhance the take-up of heat from the outer wall (14). The coolant is a two-phase mixture, preferably gas and water. The auxiliary means may be a helical fin (22) or a wire packing within the coolant flow path. Enhanced cooling is achieved by (a) the extended metal surface area provided by the auxiliary means, and/or (b) surface evaporation of a film of liquid deposited on the auxiliary means and/or on the inside of the outer wall (14).