Sibanye-Stillwater’s Furnace 1 crucible design has been upgraded to improve sidewall campaign lifeCampaign life and reliability. Tenova Pyromet was awarded the contract for the engineering, supplySupply and construction for the Furnace 1 crucible upgradeUpgrade. The crucible upgradeUpgrade included a larger furnace diameter, new hearth and sidewall liningLining-cooling system designs, and new matteMatte and slagSlag tap-hole designs. A new composite copperCopper-graphiteGraphite cooler design is used to prevent sulphidation corrosionCorrosion that commonly occurs in PGMPlatinum Group Metals (PGM) smelters. The novel lower sidewall design employs a graphiteGraphite back liningLining combined with forced air cooling to remove excess heat from the working liningLining adjacent to the critical matteMatte-slagSlag tidal zone. As part of the upgradeUpgrade, the matteMatte tap-hole installation was elevated above the hearth skewback level. The paper describes the design changes and its role in improving the furnace operationFurnace operation and reliability. The upgraded furnace has been in operation since August 2022. Observations during the first matteMatte tap-hole lintel repair are presented. The furnace performance since start-up is discussed and evaluated against the objectives specified for the upgradeUpgrade project.