Copper anode refining system and method

A method for inhibiting the formation of NOx during the refining of metals comprising the steps of:

• providing a charge of scrap metal to a molten metal bath in a furnace equipped with at least one top blown lance assembly and coupled to an oxygen-containing gas source, a fuel source, and a nitrogen gas source;
• melting said scrap metal charge using a melting flame using the fuel and the oxygen containing gas;
• oxidizing or reducing impurities in the melt using the oxygen-containing gas or reducing agents;
• and
• intermittently injecting prescribed volume of nitrogen gas into the furnace headspace using the top blown lance assembly during or after the step of providing a charge of scrap metal to inhibit the formation of NOx during the refining process.

An improvement to the method for continuous refining of copper in an anode furnace, the improvement comprising the steps of:

• charging molten blister copper to the anode furnace and optionally charging copper scrap to the molten blister copper in the anode furnace;
• oxidizing sulfur impurities in the molten blister copper in the anode furnace using a top-blown, coherent oxygen-containing gas stream ejected from a coherent jet lance mounted in a refractory wall of the anode furnace at a location above the top surface of the molten blister copper, said coherent jet lance coupled to an oxygen-containing gas source and a fuel source;
• and
• reducing oxygen in the molten blister copper in the anode furnace using a top-blown, coherent reducing gas stream containing a reducing agent and an inert gas ejected from the coherent jet lance;
• said coherent jet lance coupled to the oxygen-containing gas source, the fuel source;
• a source of the reducing agent;
• and a source of the inert gas.