Sunday Creek Project Achieves Up to 95.6% Gold Recovery with Low-Arsenic Antimony Concentrate

Metallurgical Breakthrough at Sunday Creek

Southern Cross Gold Consolidated Ltd (ASX, SX2, TSX, SXGC) has reported a significant metallurgical development at its Sunday Creek Gold-Antimony Project in Victoria, Australia. The company’s Stage 2 test work demonstrated a successful selective flotation process that produces a high-grade antimony-gold concentrate with notably low arsenic content, alongside excellent native gold recovery. This advancement marks a critical step in unlocking the project’s full economic potential.

The selective flotation technology effectively separates antimony minerals from arsenic-bearing sulphides, a challenge that has historically complicated processing in similar deposits worldwide. The resulting antimony concentrate grades between 48.2% and 53.1% Sb, with arsenic levels maintained between 0.1% and 0.2%, comfortably below the 0.6% threshold typically required by smelters. Gold grades in the concentrate reach up to 93.2 grams per tonne, underscoring the dual-metal value proposition.

Triple Product Stream and High Gold Recovery

The project’s processing strategy now encompasses three distinct product streams, a gravity concentrate capturing 37.3% to 51.4% of gold as high-grade native gold; an antimony-gold flotation concentrate recovering 28.8% to 36.5% of gold; and a sulphide concentrate accounting for the remaining 15.5% to 18.0% of gold recovery. Overall gold recovery across these streams ranges impressively from 92.3% to 95.6%, a testament to the robustness of the metallurgical approach.

Michael Hudson, Southern Cross Gold’s President and CEO, highlighted the strategic significance of these results, noting that the ability to produce multiple high-value products simultaneously enhances the project’s market appeal and economic resilience. He also pointed to the favorable timing given antimony’s exemption from the recent US Executive Order on Reciprocal Tariffs and ongoing Chinese export restrictions, which have tightened global supply chains for this critical metal.

De-Risking and Pathway to Commercialisation

The metallurgical development program has incorporated extensive sampling from the Apollo and Rising Sun prospects, covering geometallurgical variability across the deposit. The company has established processing and plant design parameters aimed at scaling up through locked-cycle testing and pilot plant evaluation targeted for completion by 2027.

Craig Brown, a metallurgical consultant and Fellow of the Australasian Institute of Mining and Metallurgy, described the selective flotation achievement as a significant advancement. The process reduces reliance on blending strategies to manage arsenic content, potentially simplifying downstream processing and improving concentrate payability.

Strategic Implications Amid Global Supply Constraints

Antimony is a critical metal used in flame retardants, semiconductors, defense munitions, and energy transition technologies. China currently dominates global antimony supply, and recent export restrictions have heightened supply risks. Southern Cross Gold’s Sunday Creek project, with its high-grade, low-arsenic antimony concentrate, positions itself as a strategically important Western source of this metal.

The project’s inclusion in the US Defense Industrial Base Consortium and alignment with Australia’s AUKUS-related legislative changes further underscore its potential role in securing critical mineral supply chains for allied nations.

Looking Ahead

Southern Cross Gold plans to continue metallurgical optimization, including multi-stage cleaning and locked-cycle testing, alongside ongoing drilling programs. The company’s strong landholding, robust geological framework, and advancing metallurgical understanding place Sunday Creek on a promising trajectory toward commercial viability.