The present disclosure relates to a method for the pyrometallurgical smelting of metal-containing raw materials, waste materials and/or secondary waste materials (M), wherein these are fed in shredded form to a smelting unit (1) which includes a smelting zone (6), a main reaction zone (7) and a secondary reaction zone (8) and are smelted in the presence of an oxidizing, reducing and/or inert gas and/or gas mixture (G), such that a liquid melt phase (9), a liquid slag phase (10) and a gas phase are formed. The oxidizing, reducing and/or inert gas and/or gas mixture (G) is supplied in compressed form via at least one injector (11) and is expanded adiabatically within the smelting unit (1) and is then injected as adiabatically expanded gas and/or gas mixture into the liquid slag phase (10).