Critica Limited has achieved a roughly 30% reduction in sulphuric acid consumption in the hydrometallurgical circuit of its Jupiter Rare Earth Project, confirmed by independent labs. This milestone complements earlier gains in concentrate grade and rare earth recovery, underpinning a lower-cost processing route ahead of the Q3 2026 scoping study.
- Sulphuric acid use cut from ~1.4-1.6 to ~1.0 tonne per tonne feed
- Independent validation by ANSTO, GAVAQ, and AMML
- Builds on prior improvements in magnet rare earth recovery and concentrate grade
- Ongoing testwork to refine acid bake conditions and reagent use
- Scoping study targeted for release in Q3 2026
Significant Reduction in Acid Consumption Validated
Critica Limited (ASX:CRI) has announced a substantial 30% cut in sulphuric acid consumption in the hydrometallurgical flowsheet for its Jupiter Rare Earth Project. Independent testwork conducted by ANSTO, GAVAQ, and AMML confirms that approximately 1.0 tonne of acid per tonne of feed can now be achieved, down from a previous range of 1.4 to 1.6 tonnes. This reduction is a crucial step in lowering reagent costs, a major component of hydrometallurgical processing expenses.
Optimisation Builds on Earlier Metallurgical Gains
This latest advance extends Critica’s ongoing optimisation trajectory. Earlier pilot plant results reported in April and May 2026 demonstrated an 81% recovery of magnet rare earth oxides (MagREO) and a 14× upgrade to a ~3% total rare earth oxide (TREO) concentrate, while rejecting 95% of the feed mass. These beneficiation improvements have materially reduced the volume of material requiring downstream processing, setting the stage for cutting acid consumption in the acid bake process.
CEO Jacob Deysel emphasised the integrated approach: "Our objective has never been to optimise individual parts of the process in isolation. Success comes from maintaining strong rare earth recoveries while systematically improving every stage of the processing flowsheet." The recent acid consumption results underpin this philosophy by balancing reagent reduction with sustained extraction performance.
Technical Details of Hydrometallurgical Testwork
The acid bake optimisation involved parallel programs at three independent laboratories: the Australian Nuclear Science and Technology Organisation (ANSTO), the Centre for Science and Technology of Mineral and Environment (GAVAQ), and Australian Minmet Metallurgical Laboratories (AMML). These studies tested acid addition rates and operating parameters to reduce sulphuric acid use without compromising rare earth extraction efficiency, which remained above 84% across test conditions.
Test results showed acid consumption consistently around 1.0 tonne per tonne feed at bake temperatures of 260°C for 3-4 hours, with rare earth extraction rates ranging from 84% to 92%. The convergence of outcomes across multiple labs strengthens confidence in the acid bake process optimisation.
Pathway to Scoping Study and Further Work
Critica is continuing hydrometallurgical optimisation and validation testwork to refine acid bake parameters across feed materials with varying TREO grades. The company plans to integrate these metallurgical improvements into its upcoming engineering and project development efforts. The Jupiter Scoping Study remains on track for release in Q3 2026, expected to incorporate these cost-saving advances.
Alongside the Jupiter Project, Critica’s portfolio includes the Mt Lindsay Project in Tasmania, providing exposure to tin and tungsten. The rare earths and critical minerals from these projects are positioned to serve sectors such as defence, semiconductors, and electrification.
Technical Foundations Strengthened Ahead of Resource Upgrade
The company’s optimisation journey aligns with recent drilling that confirmed broad, near-surface high-grade zones at Jupiter, supporting an imminent resource upgrade and reinforcing the project's development potential. These metallurgical gains complement resource growth prospects, collectively enhancing Jupiter’s economic outlook.
Bottom Line?
Critica’s acid consumption cut materially improves Jupiter’s processing economics, but the full impact awaits the Q3 scoping study and ongoing validation.
Questions in the middle?
- How will reduced acid consumption influence overall project operating costs in the upcoming scoping study?
- Can Critica sustain or improve rare earth recovery rates while further lowering reagent use?
- What are the implications of these metallurgical advances for downstream product qualification and market positioning?