The content of oxygen in molten metallic copper is reduced during the copper refining process by adding pure carbon monoxide, produced by electrolysis of carbon dioxide in a solid oxide electrolysis cell (SOEC), thereby removing oxygen through the reduction of CuO to Cu. This way, the purity of the metallic copper is increased.

Provided herein is a process of fire refining blister copper, comprising the steps of (a) providing molten blister copper into an anode furnace; (b) when sulfur concentration of the molten blister copper provided in step (a) is above a first prescribed target value, oxidizing sulfur in the molten blister copper by blowing oxygen containing gas into the molten blister copper until the first prescribed target value has been reached; (c) subsequently lowering the sulfur and oxygen content in blister copper by blowing inert gas into the molten blister copper until a second prescribed target value has been reached, wherein the inert phase (c) is continued until the second prescribed target value of the oxygen concentration is below 4000 ppm, and the second prescribed target value of the sulfur concentration is below 500 ppm; (d) when certain condition(s) occur, subsequently reducing oxygen in the blister copper; and (e) optionally casting.

Provided is a method for melting copper scrap and/or refining blister copper, comprising the steps of: (a) charging of copper scrap into an empty anode furnace and melting the copper scrap; (b) charging molten blister copper into the anode furnace; (c) optionally charging more copper scrap into the anode furnace and melting the copper scrap; (d) optionally repeating steps (b) and/or (c) one or more times until the anode furnace is full and a desired amount of copper scrap has been charged and melted until a final copper batch is obtained; and (e) refining the final copper batch to obtain anode copper.

Ultrasonic probes containing a plurality of gas delivery channels are disclosed, as well as ultrasonic probes containing recessed areas near the tip of the probe. Ultrasonic devices containing these probes, and methods for molten metal degassing using these ultrasonic devices, also are disclosed.

Ultrasonic probes containing a plurality of gas delivery channels are disclosed, as well as ultrasonic probes containing recessed areas near the tip of the probe. Ultrasonic devices containing these probes, and methods for molten metal degassing using these ultrasonic devices, also are disclosed.

Methods for removing sludge and/or impurities from a molten metal are disclosed herein, as well as sludge removal devices and systems for use in the methods. Sludge removal devices that can reduce the downstream deposition of sludge in certain process components through upstream deposition and subsequent removal from the molten metal are also disclosed.

A method of operating a concentrator may comprise producing a final copper concentrate and periodically or continuously analyzing the produced final copper concentrate to obtain a grade value of the produced final copper concentrate. The produced final copper concentrate may be sent to a downstream smelting operation if/when the grade value of the produced final copper concentrate is at or above a minimum acceptable grade threshold and may be sent to a downstream hydrometallurgical operation capable of producing copper cathode, if/when the grade value of the produced final copper concentrate is below or falls below the minimum acceptable grade threshold.

A copper alloy such as brass and bronze centered on rod products in which machinability is mainly required contains a certain amount of lead. The scrap of these products has been recycled at a high rate. A lead-removing step is indispensable for recycling the scrap of these products for low-lead products, and development of lead-removal techniques is urgently necessary. It is known that a material containing metal element calcium exhibits an effect in removing lead in a copper alloy, and since there are differences in the specific gravity and the melting point between a de-leading agent and a copper alloy, a de-leading method at a practical mass production level is required. In order to solve this problem, for the purpose of de-leading treatment of a copper alloy molten metal, there is provided a cored wire for lead removal characterized in that a metal band which does not affect the components of a copper alloy molten metal is used as a sheath material; a single de-leading agent and/or a de-leading coagent such as an aggregation/floatation agent for a PbCa compound required for a step is used as contents; and physical properties that endure mechanical and continuous feed by a cored wire feeding device are provided.

Provided herein is a process of fire refining blister copper, comprising the steps of (a) providing molten blister copper into an anode furnace; (b) when sulfur concentration of the molten blister copper provided in step (a) is above a first prescribed target value, oxidizing sulfur in the molten blister copper by blowing oxygen containing gas into the molten blister copper until the first prescribed target value has been reached; (c) subsequently lowering the sulfur and oxygen content in blister copper by blowing inert gas into the molten blister copper until a second prescribed target value has been reached, wherein the inert phase (c) is continued until the second prescribed target value of the oxygen concentration is below 4000 ppm, and the second prescribed target value of the sulfur concentration is below 500 ppm; (d) when certain condition(s) occur, subsequently reducing oxygen in the blister copper; and (e) optionally casting.

Provided is a method for melting copper scrap and/or refining blister copper, comprising the steps of: (a) charging of copper scrap into an empty anode furnace and melting the copper scrap; (b) charging molten blister copper into the anode furnace; (c) optionally charging more copper scrap into the anode furnace and melting the copper scrap; (d) optionally repeating steps (b) and/or (c) one or more times until the anode furnace is full and a desired amount of copper scrap has been charged and melted until a final copper batch is obtained; and (e) refining the final copper batch to obtain anode copper.