Growth for the future

Northam’s metallurgical operations, located at Zondereinde treat PGM and base metal concentrates from our three mines, as well as from third parties. This is in addition to high value feeds from our US recycling business.

Northam’s processing and refining capability presents a significant strategic advantage for the group. As an integrated metals producer, Northam’s smelting capability dates back to 1993, when the metallurgical complex was first commissioned. At the time the smelter contained a 15MW furnace, which was used to treat Zondereinde’s output. Spare capacity was used to treat third party material, and then later arisings from Booysendal. More recently the smelter was expanded with an additional furnace, which has grown capacity to 35MW, and is now able to process in excess of 1 million ounces.

With growing output from the Booysendal complex, and the prospect of Eland being recommissioned, the new furnace is able to accommodate the higher volumes emanating from the mining growth. The new furnace incorporates a number of advances in the area of PGM smelting. These include extended refractory lining life expectancy, metal containment and cooling, along with best practice in terms of monitoring, tapping and furnace control functions.

Within the smelter, the PGM-containing matte is tapped from the furnace and sent to the converter for the removal of iron. The matte is then quenched with water and bagged, before being transported to the BMR, or base metals removal plant where nickel (Ni) and copper metals (Cu) are removed through chemical processes in the form of crystalline nickel sulphate and copper cathode.

The remaining PGM solutions are filtered and dried to produce a final concentrate ready for shipment to the Heraeus refineries located in Hanau (Germany) and Port Elizabeth (South Africa), and to Johnson Matthey in the United Kingdom, where individual precious metals are toll-refined to final metal purity of 99.95%. Northam sells refined metal to contractual metal customers at various global destinations.

A new, upgraded furnace slag concentrator was commissioned during F2024. This is sized for our new medium-term steady-state production target of 1.5 Moz and is currently working through slag inventory.

The new production target requires further upgrades to the metallurgical facilities, and the necessary planning and procurement has commenced. Upgrades at the smelter facility include a planned expansion of furnace 1 from installed capacity of 20 MW to 30 MW, to be undertaken during the scheduled rebuild of the furnace in F2028, together with the construction of an additional iron-reduction convertor. At the BMR, the high-pressure leach circuit will be twin-streamed, and the copper electrowinning circuit will be further expanded. All upgrades are scheduled to be completed before F2031.

Metallurgical facility overview

Metallurgical facility overview
(Select image to view large Metallurgical facility overview chart)