Tapping of PGM-Ni mattes: an industry survey

and its environment encounter some of the highest heat fluxes in an operating furnace, which make the operations around the taphole critically important for safe and reliable tapping. This is particularly the case for platinum group metal (PGM) mattes, which are tapped at higher temperatures and typically superheated by 300–650°C (Shaw et al., 2012), making them aggressive to the tap-hole refractories. Nickel mattes are tapped are lower temperatures and are less aggressive than PGM mattes (Table I). Matte tap-holes require frequent maintenance involving repairs either with furnace power off or at reduced power, which impacts the overall smelter availability and utilization. The objective of all producers is to tap matte out of the furnace safely and reliably while minimizing downtime associated with tap-hole maintenance. This is done at various levels of sophistication in the industry, depending on factors such as the smelter matte production (i.e. furnace size), the dependency on downstream converting (on-site or offsite), smelter personnel experience, etc. Very little information is published within the industry on matte tapping practices and tap-hole maintenance. A questionnaire was distributed to PGM and nickel matte producers regarding three key aspects of matte tapping: tap-hole design, tap-hole operation/tapping practices, and tap-hole maintenance. The responses received from these producers are summarized and presented in this paper. A questionnaire was composed with key questions on each key aspect of matte tapping: tap-hole design, tap-hole operation/tapping practices, and tap-hole maintenance. The questionnaire was sent via e-mail to a large number of producers and responses were returned by e-mail. When required, clarifications were obtained to ensure the data was interpreted correctly. The responses received were compiled and summarized in tabular format, as presented in this paper.