Abstract:

The global depletion of easily accessible primary copper reserves (from mined oxide/sulfide concentrates) has led to secondary copper processing assuming an ever-increasing importance within the worldwide copper industry. The contribution from recycled copper scrap is a significant fraction of the global copper production and is currently estimated at 29%.

The main impurities found in copper scrap are lead, tin, zinc, iron, and nickel. These elements can only be removed by using both highly oxidizing conditions and the addition of fluxes with multiple refining steps. The most recently designed secondary copper reverberatory units generate significant quantities of high-temperature fluid oxidic slags which have been been found to be very corrosive to the typical magnesia-chrome refractories commonly used in primary copper processing vessels.

Alumina-chrome refractories, however, have been found to be highly resistant to these refining slags and have contributed significantly to increasing the lining life in the slag line zones of these secondary refining furnaces. Furthermore, these brick exhibit minimal penetration of slag and metal into the working surface and can be economically recovered from the used lining, crushed and reintroduced into the feedstock used for manufacturing new brick for relining the secondary copper furnaces.

This paper discusses the potential scope for the future of scrap copper recycling in North America and the alumina-chrome refractory furnace linings required for optimal production processes. It also predicts the likelihood of recovering a high percentage of the used alumina-chrome furnace brick for reintroduction into the feedstock for new brick production.

Keywords: copper recycling, sustainability, alumina-chrome refractory, furnace lining design

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Mr. Jonathon McBride