Abstract: Apparatus for the continuous sulphur drossing of lead to reduce its copper content including a plurality of reaction vessels arranged in series, each reaction vessel having a curved bottom and a stirrer for creating a vortex of the contents. Bullion and sulphur are fed into the series through a vortex at controlled rates and through the series at controlled temperatures and a controlled total reaction time, optimally between 8 and 15 minutes. The bullion, dross and unreacted sulphur, if any, are overflowed from vessel to vessel and into an unagitated vessel for separation of the dross and bullion. The bullion feed device splits the undrossed bullion into a metered stream and an unmetered stream, the unmetered stream being utilized to carry away the separated dross for further processing.