Process and Apparatus for Eliminating Ongoing Red-Mud Generation and Valorizing Bauxite Residue Using Multi-Stage Tube-Bundle Centrifugal Separation

Abstract

An inverted high-G multi-tube centrifuge system enables net residue-negative, zero- landfill valorization of Bayer red mud at approximately 40% solids slurry. The modular rotor comprises 104 diamond-coated stainless steel tubes with rounded triangular internal cross-section (9 mm effective ID), vertex-oriented radial discharge slots (single or multiple, with subsequent slots smaller and spaced ~2 cm apart), supported in interchangeable baskets of variable lengths (primarily 1.0 m with one or two slots, and 0.4 m with single slot) by a TIG-welded manifold, inclined spokes, and spoke separators. Operating at 3600 RPM (5500 G), the system achieves sequential processing: a first stage with 1.0 m single-slot tubes produces ultra-clarified pregnant liquor (<5–30 ppm solids) returned to the refinery; a second stage with 1.0 m multi- slot tubes yields high-value Ti / Sc / REE-enriched concentrate from the late slot and Si / Ca-rich reject from the early slot; a dedicated iron recovery stage with 0.4 m tubes produces Fe-enriched concentrate (45–55% Fe as Fe₂O₃) from the slot. Low-value reject (<8–10% original mass) is neutralized and buried subsurface. The process handles fresh, legacy, or blended feeds on one platform, consuming stockpiles and achieving regulatory-compliant zero-landfill closure. 20 26 20 00 21 05 J an 2 02 6 2 0 2 6 2 0 0 0 2 1 0 5 J a n 2 0 2 6

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