Abstract: Metal in the molten state is transferred from one treating stage or zone to a succeeding stage or zone by gravity flow, the flow from one zone to the next being controlled by gas pressure, thus eliminating the need for valves, gates or similar moving parts. The process is particularly adapted to the treating of ferrous metal, more particularly to the making of steel. By providing sufficient zones in the series a continuous process can be run, starting with feed from a blast furnace, and conducting the material through alloying stages and a degassing stage and into a continuous casting zone.