Abstract: The invention relates to a process for removing tin, arsenic and antimony from molten lead by means of oxygen or oxygen-containing gas mixtures, which is or are blown into the molten lead by means of at least one gas nozzle (2). To avoid damage to the gas nozzle, at least the oxygen outlet region (13) thereof, located in the molten lead (6), is enveloped by an inert gas.

Abstract: The invention relates to the treatment of a liquid with a gas. A gas injector, for example oxygen, is surrounded with a sheath to carry a flow of a liquid under treatment (for example lead) which is taken up and circulated by the pump. The end of the injector is thereby protected by moving away the bubbles of oxygen. Application for example in the refining of metals, for example non ferrous metals, food liquids, paper pulps and the production of sulfur.

Abstract: A process and device for the removal of arsenic, tin and antimony from crude lead by industrial oxygen is disclosed in which the oxygen is introduced into a turbulent fluid stream of lead restricted in a limited volume. The oxygen containing fluid stream passes into a larger volume in which the compounds which are to be separated float on the surface in the form of oxides and run off from the surface. The device includes two cylinders of different volume and one within the other. The cylinders are immersed at different depths in molten lead in the smelting crucible, a steam of fluid lead is introduced in the smaller cylinder by a lead pump and oxygen is introduced into this fluid lead stream.