Ann: HMW Phase 1 Funding & Offtake Secured with US Based Partner, page-156

Here’s an assessment of extraction routes for Hombre Muerto West (HMW), weighing conventional pond‐evaporation against a hybrid pond + nanofiltration (NF) scheme. The summary below outlines key pros and cons, followed by a deeper dive into each approach and its fit for HMW.

Solar‐ponds + NF offers a compelling balance: you leverage HMW’s already under‐construction evaporation‐pond train to pre‐concentrate its high‐grade, low‐impurity brine (859–880 mg/L Li), then switch to membrane separation to rapidly polish and further enrich Li. This hybrid can reduce land‐take and water loss, accelerate recovery from 18–24 months down to under 6 months, and push Li yields toward 90%—well above the ~50% typical of ponds alone Panorama Minero: Latest NewsNS Energy Business.

Current Planned Process at HMW

Galan’s Phase 1 design pumps brine from seven production wells into a cascade of shallow solar ponds, concentrating the feed to lithium chloride via sequential evaporation, with first output targeted in H1 2025 Panorama Minero: Latest News NS Energy Business.

Nanofiltration and Direct‐Li Extraction (DLE) Technologies

Membrane‐based DLE methods—especially NF and electrodialysis—can selectively separate Li⁺ from divalent cations in brine, achieving concentration factors up to 12× in days versus months for solar ponds ScienceDirect ScienceDirect. NF membranes exhibit fluxes up to 22.5 L·m⁻²·h⁻¹, compared to <0.6 L·m⁻²·h⁻¹ under typical solar‐pond conditions (30–50 °C) ScienceDirect.
Evove’s commercial DLE flow sheet, for example, uses NF as a first stage to strip out Mg²⁺ and Ca²⁺, creating a refined feed for downstream ion‐exchange and polishing steps to battery‐grade Li₂CO₃ The Chemical Engineer.
Membrane/ED DLE processes routinely demonstrate >90% Li recovery and lower CO₂ emissions per ton of Li produced, versus ~50% recovery and higher lifecycle emissions from pond‐only routes SpringerLink.

Hybrid Evaporation + Nanofiltration Approach

A two-stage system uses solar ponds to concentrate HMW brine from ~860 mg/L to ~2 000 mg/L Li, shrinking brine volume and reducing Mg load before NF treatment ScienceDirect.
Subsequent NF then polishes the stream—removing remaining divalent impurities and boosting Li concentration above 4 000 mg/L in days—cutting overall processing time by >70% and halving pond footprint ScienceDirect.
This hybrid can reduce required evaporation area by over 50%, greatly lowering land use and brine loss to evaporation ScienceDirect.

Suitability for Hombre Muerto West

HMW’s lithium grade (859–880 mg/L) and low Mg/Li (~1.8) yield an ideal feedstock for NF modules, which perform best on moderately concentrated, low‐impurity brines Panorama Minero: Latest News NS Energy Business.
Integrating NF leverages HMW’s nearly built pond infrastructure, adding modular DLE skids rather than a full standalone plant, optimizing capex and deployment speed Saltworks Technologies.
Moreover, modular NF allows spent brine reinjection—critical for preserving high‐altitude aquifers—and slashes freshwater use compared to additional evaporation stages SpringerLink.

Conclusion and Recommendation

Pond evaporation + nanofiltration offers a technically sound, economically attractive route for HMW, potentially boosting Li recovery to ~90%, cutting project timeline, and reducing environmental footprint compared to solar ponds alone The Chemical EngineerSpringerLink.
We recommend piloting a hybrid NF skid on a side‐stream of HMW’s Phase 1 ponds to validate membrane performance, optimize operating conditions, and refine capex/opex estimates before full‐scale roll-out Saltworks Technologies.