Hydrometallurgical Dewatering & Uranium Ion Exchange Extraction

Clean TeQ Water and Aura Energy incorporated proprietary solid-liquid separation and ion exchange extraction systems into the Bankable Feasibility Study for the Tiris Uranium Project in Mauritania. The industrial cooperation establishes an optimized hydrometallurgical flowsheet utilizing chemical slurry conditioning and continuous ion exchange to process calcrete-type uranium ores ahead of commercial engineering deployment.

Mineral Processing Constraints in Arid Leaching Operations
Uranium extraction from carnotite deposits presents severe operational bottlenecks during post-leach solid-liquid separation due to ultrafine, clay-bearing gangue minerals. These ultrafine particles blind filter cloths, cause erratic filtration rates, and demand extensive fresh water for cake displacement washing.

Traditional pressure filtration plants require complex mechanical maintenance schedules and consume significant energy. Aura Energy required an alternative mineral extraction topology capable of achieving high soluble recovery, operating in water-constrained desert conditions, and producing dry-stackable tailings for direct pit backfilling.

Technical Architecture and Equipment Configuration
Clean TeQ Water supplied two integrated process technologies to replace earlier baseline assumptions of high-pressure filter presses and fixed-bed ion exchange columns.

The ATA dewatering system conditions leached slurry through controlled dual-polymer addition before filtration. The chemical mechanism agglomerates fine clay platelets onto coarse sand grains, establishing a free-draining granular cake structure that maintains porosity under mechanical vacuum. The conditioned material passes over three parallel horizontal vacuum belt filters, executing solid-liquid separation and four-stage counter-current washing without requiring fresh wash water. Washing stages utilize diluted barren liquor sourced directly from downstream ion exchange.

For metal extraction, Clean TeQ Water provided a continuous moving-bed ion exchange (MBIX) system. The fluid design circulates functional resin counter-currently against pregnant leach solution across multi-column stages. The continuous movement handles higher suspended solids without column blinding, optimizes resin site loading capacity, lowers eluent reagent volumes, and delivers an upgraded, high-tenor uranyl solution to final precipitation units.

Flowsheet Validation and Pilot Program Execution
Aura Energy operates the Tiris Optimised Pilot Plant at Bir Moghrein to treat an 80-tonne representative ore bulk sample across primary geological domains. Clean TeQ Water provides the modular ATA and MBIX pilot skid units alongside technical on-site process engineering.

Analytical testing on representative slurry samples validated key processing parameters:
"ATA was the only post-leach dewatering option tested that was shown to be robust across the full range of Tiris ore variability, achieving separation and washing in a single step," according to technical evaluations in the study.

Bench-scale counter-current test runs recovered up to 97.8 percent of soluble uranium. The resulting filtration cake achieved 67 percent solids density, increasing to 79 percent solids via vibration-assisted mechanical consolidation suitable for safe dry disposal within mined-out open pits. The flowsheet simplifies operational equipment counts by substituting three horizontal belt filters for thirteen conventional filter presses.

Edited by Natania Lyngdoh, Induportals editor, with AI assistance.

www.cleanteqwater.com