A Dated Hypothesis on Scandium Recovery from Existing HPAL Ni-Co Operations Without Increasing Ore Throughput

This preprint formulates and dates a bounded scientific hypothesis: in at least some existing High Pressure Acid Leach (HPAL) nickel–cobalt operations treating scandium-bearing laterites, a measurable fraction of scandium may remain present in upstream acidic process liquors before iron and aluminium neutralization and could therefore be recoverable as a by-product without increasing ore throughput. The document proposes a transparent order-of-magnitude framework expressed in mg Sc per tonne of ore and illustrates how small recoveries may translate into annual Sc₂O₃ production at unchanged mining rates. This work is theoretical and archival in nature. It does not provide operational parameters, plant design, feasibility conclusions, investment advice, process recipes or proprietary industrial information. The objective is to date the hypothesis, define the mass-balance logic and support future analytical validation.