Mount Ridley’s Selectro pushes gallium recovery into the critical-minerals spotlight

Mount Ridley Mines has reported 94.9% gallium recovery from a third-party bauxite sample using its Selectro process, adding a strategically important metal to the aluminium and iron recoveries announced earlier this month. The result strengthens the company’s case that its leach technology could extract several critical materials from a single feedstock, while also highlighting the technical work still required before any commercial pathway is established.

The gallium result follows Mount Ridley’s 15 October 2026 announcement that the same test delivered 91.9% aluminium recovery and 96.7% iron recovery. All three metals were recovered together in a single leach conducted below 100°C, according to the company.

The test used a composite prepared from 16 vacuum drill samples taken from four drill holes across the Athena and Ceres prospects within Australian Silica Quartz Group’s Darling Range bauxite project in Western Australia. Gallium was measured using inductively coupled plasma mass spectrometry, or ICP-MS, a method suited to the low concentrations typically found in bauxite.

The composite contained a reported gallium head grade of 80 parts per million. Mount Ridley calculated recoveries of 94.9% for gallium, 91.9% for aluminium expressed as aluminium oxide, and 96.7% for iron expressed as iron oxide.

The company’s comparison with the conventional Bayer process is central to the announcement. Mount Ridley says roughly 70% of the gallium in bauxite is extracted into liquor during Bayer digestion, with the remainder reporting to bauxite residue, commonly known as red mud. Selectro recovered 95% of the gallium into solution in one leach, while leaving a silica-rich residue with more than 90% of the silica retained in that residue.

That comparison is technically notable, but it should not be read as a completed process flowsheet. The reported recoveries describe metal extraction into solution, not the production of separated, purified gallium, aluminium or iron products. The next stage will determine whether the high extraction rates can translate into usable products and commercially credible operating economics.

Gallium is produced mainly as a by-product of bauxite refining and zinc processing. The United States Geological Survey’s 2026 commodity summary estimates that China accounted for about 900,000 kilograms of low-purity primary gallium production in 2025, while the United States reported no primary production. The same USGS data show that China also held the overwhelming majority of global production capacity.

The metal is used in compound semiconductor materials including gallium arsenide and gallium nitride. These materials support applications such as high-frequency communications, radar, optoelectronics and power electronics, where their performance can exceed that of conventional silicon in specific operating conditions.

Supply concentration has turned gallium into a strategic issue rather than a niche materials story. Mount Ridley’s announcement says China introduced export licensing for gallium in August 2023 and later restricted exports to the United States, with a subsequent suspension of the broader ban scheduled to run until 27 November 2026 while licensing controls and restrictions affecting United States military users remain relevant.

The policy backdrop is also driving investment in alternative supply. Alcoa, together with government and industry partners from Australia, Japan and the United States, reached a final investment decision in July 2026 for a gallium production plant at the Wagerup alumina refinery in Western Australia. That project illustrates the advantage of recovering gallium from an existing bauxite and alumina stream; Mount Ridley is pursuing a different proposition based on its proprietary leach chemistry.

Selectro is Mount Ridley’s wholly owned and patent-pending leach technology. The company describes it as a closed-loop process designed to recover multiple critical minerals from one leach circuit, with reagent recycling and a lower reagent-cost profile than conventional hydrochloric acid leaching. Earlier work on Mount Ridley’s Grass Patch feed demonstrated recoveries of scandium, heavy rare earth elements and gallium, while the new test extends the technology to a third-party bauxite feed.

The broader corporate context is important. Mount Ridley remains an Australian critical-minerals explorer focused on heavy rare earth elements, gallium and scandium across its Western Australian projects. Its Grass Patch project, located about 25 kilometres north of Esperance, has defined heavy rare earth, scandium and gallium resources identified through 70,000 metres of historical drilling. The company is now pairing upstream exploration with downstream processing and separation research.

The immediate work programme is consequently focused on separation and purification of gallium, aluminium and iron from the Selectro leach solution. Mount Ridley also plans to assess a second bauxite test, conduct further third-party testing on different feedstocks and continue the accelerated design and construction of a Selectro demonstration plant.

For investors and industry participants, the significance of the announcement lies in the combination of recovery and feedstock flexibility. A single test that extracts three target metals above 90% is a useful technical signal, especially in a market seeking new gallium supply outside China. However, the result remains an early-stage process milestone. Product purity, separation performance, reagent consumption, residue management, scale-up behaviour, capital requirements and permitting will determine whether the concept can move beyond laboratory and pilot work.

Mount Ridley’s announcement therefore expands the strategic narrative around the company without resolving the commercial question. Selectro has now shown strong extraction performance on bauxite supplied by an external party, but the next test is whether those recoveries can be converted into separated products at a cost and scale acceptable to potential partners. Until that work is completed, the technology’s value remains prospective rather than demonstrated through operating revenue or commercial production.