Abstract: Device to deliver comburent and combustible gases, such as oxygen, methane or similar, and/or solid combustible materials inside a melting container, the device comprising a first unit (18) functioning as a burner and/or supersonic lance, and a second unit (19) functioning as a burner and/or carbon lance, the units (18, 19) being reciprocally oriented so that the respective streams delivered (21, 22) meet around a point (20) located above or around the upper level of the layer of slag (17), giving rise, during the normal melting cycle, to a substantially stoichiometrically balanced reaction between oxygen and carbon. Melting method using at least one of the devices as above.