Copper anode refining system and method

A copper anode refining system comprising:

• a copper metallurgical furnace having a refractory wall, the furnace adapted to contain a bath of molten copper having a top surface and said furnace defining a headspace above the top surface of the copper bath;
• at least one multi-functional, coherent jet lance connected to sources of oxygen-containing gas, inert gas, reducing agent and fuel, said coherent jet lance mounted in said furnace refractory wall at a location above the top surface of the copper bath;
• and
• a controller operatively controlling the flow of oxygen-containing gas, inert gas, reducing agent and fuel to the at least one coherent jet lance;
• wherein a melting flame comprising the fuel and the oxygen-containing gas is produced from the at least one coherent jet lance to heat the molten copper or melt any scrap copper charges provided to the furnace;
• and
• wherein a coherent oxygen-containing gas stream is produced from the coherent jet lance to oxidize sulfur in the copper bath;
• and
• wherein a coherent reducing gas stream containing the reducing agent and the inert gas is produced from the coherent jet lance to reduce oxygen in the copper bath.

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 the oxygen-containing gas source and the 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.