The top submerged lance (TSL) technology, developed in the 1970s, is now widely used for the
processing of a range of materials. The key advantage the ISASMELT™ TSL technology provided
was the ability to process feed materials in a highly turbulent bath, reaching close to equilibrium
conditions, uniquely allowing for operation below the liquidus of the molten slag phase. The details
on what happened below the liquidus line in the phase diagram became critical for the successful
operation of the technology. During the development of the ISASMELT™ technology this led to a
collaboration between the Process Technology group of Mount Isa Mines, now part of Glencore
Technology, and the Pyrometallurgy Research Centre (PYROSEARCH) at The University of
Queensland. The fusion of the phase equilibria research into the technology development allowed
for understanding of the behaviour of molten splash, reliable tapping of the furnace, and the ability
to operate the furnace with a refractory lining and achieve a year campaign life in excess of four
years. The outcome has allowed for the highly successful adaption of the ISASMELT™ technology
to recycling of complex feed streams necessary to drive circularity in our modern global economy.