Furnace used mainly for the production of copper and lead.
Process consisting of submerging a steel lance called ISASMELT that injects oxygen and gas producing a turbulence in the furnace tub in which temperatures of between 1,000ºC and 1,200ºC are achieved.
It needs a refractory of great resistance to abrasion, produced by the high agitation of the broth, as well as the chemical attack produced by the slag.