Copper smelting process

A process for the recovery of copper from secondary raw materials comprising the step of, in at least one feed batch, smelting a feedstock comprising the raw materials in a furnace for the recovery from the furnace of a concentrated copper intermediate,

• whereby the feedstock of raw materials is introduced gradually into the furnace, the feedstock comprising copper, and optionally at least one metal that under the furnace operating conditions is more noble than tin, at least partly as an oxide,
• whereby the feedstock further comprises iron, and optionally at least one metal or compound that under the furnace conditions is at most as noble as iron or zinc, the iron and metal at most as noble as iron or zinc at least partly being present in their elemental form,
• whereby heat is generated inside the furnace by the redox reactions converting elemental iron and metals or compounds at most as noble as iron or zinc to oxides and converting oxides of copper and of metals more noble than tin to elemental metal,
• whereby the elemental metals at least partly collect in a molten liquid metal phase and the oxides at least partly collect in a supernatant liquid slag phase,
• whereby the liquid phases are able to separate out and at the end of the smelting step at least one of the liquid phases is at least partially removed from the furnace, whereby the slag phase is removed as a smelting slag and the metal phase is removed as the concentrated copper intermediate,
• wherein,
• during the smelting step an excess of the elemental form of iron and of metals or compounds that are under the furnace conditions at most as noble as iron or zinc is maintained in the furnace relative to the amount required for completing the redox reactions, and
• further heat input into the furnace is provided during the smelting step by the injection of an oxygen containing gas for the oxidation of the excess of iron and of metals or compounds at most as noble as iron or zinc present in the furnace and optionally for the combustion of a combustible source of carbon and/or hydrogen that may in addition be introduced into the furnace.