Tellurium from Copper Anode Slime and Refinery Effluent by Ambient-Temperature Vacuum Phase Separation: Closing the CdTe Supply Gap

Tellurium is the rare case of a critical material that is nowhere mined on purpose. World output is 500-750 t/year - less than gold - and more than 90% of it is recovered from copper anode slime, a by-product of electrolytic copper refining. Supply is therefore governed by copper production, while demand is governed by photovoltaics: cadmium telluride thin-film modules consume approximately 40% of annual tellurium output, CdTe manufacturing capacity has grown from 2.8 GW in 2022 to 14 GW/year by 2026-2027, and the industry projects 100 GW by 2030. At the modern absorber intensity of 15.2 t/GW, the 100 GW target alone requires approximately 1,520 t of tellurium per year - two to three times present world production - and the gap cannot be closed by exploration because tellurium orebodies of economic grade do not exist. China accounted for approximately 75% of refined output in 2024, up from 67% in 2023. This paper describes the application of ambient-temperature deep-vacuum phase separation, the Arbok Critical-Materials Recovery platform, to tellurium in copper anode slime and in copper-refinery effluent, and presents a feedstock-level techno-economic model. At 2% Te in slime a tonne yields approximately 20 kg of tellurium, approximately USD 3,600 at prevailing prices; at 4% approximately USD 7,200, before selenium, copper, gold and silver recovered from the same tonne. The distinguishing feature relative to prior art is that separation is driven by phase change rather than by roasting, leaching chemistry or sorption, eliminating SO2 and CO2 from the recovery step and extending recovery to the effluent fraction that is presently not recovered at all.