Abstract: A lance is provided for processing molten metal baths located in metallurgical tanks, and for heating the tanks. A first lance body is displaceable in a second lance body. A mechanism is provided for displacing the first lance body relative to the second lance body such that in a raised burner position of the first lance body, burner nozzles disposed in the second lance body are uncovered by the first lance body and are axially spaced from the lance mouth of the first lance body to receive gas discharge from the lance mouth and to allow burner operation. In a lowered blower position of the first lance body, the burner nozzles are covered thereby. The mechanism for displacing the lance bodies relative to one another permits infinitely variable spacing of the burner nozzles from the lance mouth that is provided for the discharge of gas.