Leach Testing Begins on Santa Anna's High-Grade Rare Earth Deposits: A Game-Changer for Power Minerals Ltd
Power Minerals Limited (ASX: PNN) has commenced a significant leach testing program on high-grade rare earth elements (REE) samples from the weathered zone of its Santa Anna Project in Brazil. This critical step aims to assess recovery rates and establish processing pathways for the company's exceptionally high-grade REE finds.
Exceptional REE Grades Signal Major Opportunity
The testing program focuses on 23 individual samples collected from six intervals across five separate drillholes from Power's recent reverse circulation (RC) drilling campaign. These samples average an impressive 0.75% TREO (7,523 ppm), with multiple intervals exceeding 1.0% TREO, highlighting the consistent high-grade mineralization in the sampled area.
Most notably, Power's drilling at Santa Anna has delivered remarkable results, including intersections of up to 4.34% TREO (43,385 ppm) containing 26.0% MREO (Magnetic Rare Earth Oxides). These include critical elements neodymium (Nd) and praseodymium (Pr), which are essential components for permanent magnets used in electric vehicles, wind turbines, and defense technologies.
"The leach testing program is an important next step in our exploration pathway at the Santa Anna Project," said Power Minerals Managing Director Mena Habib. "The independent leach testing of high-grade REE samples from our recent drilling will provide us with a clearer picture of what may be recovered in terms of the key light rare earth elements, neodymium and praseodymium, as well as niobium from the Santa Anna Complex."
Understanding Ionic Clay Leach Testing
The leach testing program is being conducted by independent laboratory SGS Geosol in Brazil, utilising an industry-standard AMSUL (Ammonium Sulfate) leach test analysis. This method involves cold leaching of pulverised samples with ammonium sulfate solution for 30 minutes, followed by filtration and analysis using Inductively Coupled Plasma Mass Spectrometry (ICP-MS).
This testing is particularly significant as it will determine the proportion of REEs that are adsorbed onto clay minerals (ionic REEs) compared to those trapped within acid-resistant REE-bearing minerals in the weathered zone. Ionic clay deposits are highly prized in the REE industry due to their typically lower processing costs and environmental impact compared to hard-rock REE mining.
The results of this testing program are expected within the current month and will inform Power's targeting for planned ongoing drilling at the Project, which aims to deliver a maiden Mineral Resource Estimate.
Santa Anna Project: Impressive Drilling Results
The Santa Anna Project continues to deliver exceptional results across multiple drilling campaigns. Highlight results from Power's maiden RC drilling program include:
- 114m at 3,012ppm TREO from surface, including 16m at 5,300ppm TREO
- 60m at 9,202ppm TREO from surface, including 14m at 18,768ppm TREO
- 34m at 4,544ppm TREO from surface containing 21.3% MREO
Recent auger drilling has yielded even more impressive results:
- 15m at 13,212ppm TREO from surface, containing 24.2% MREO, including 4m at 28,827ppm TREO and 1m at a remarkable 43,385ppm TREO
- 13m at 7,882ppm TREO from surface, including 3m at 12,295ppm TREO
- 25m at 8,809ppm TREO from surface, including 5m at 15,975ppm TREO
These results place the Santa Anna Project among the highest-grade REE discoveries globally, particularly notable for its near-surface mineralisation and high proportion of magnetic rare earth oxides.
What Are Ionic Clay REE Deposits?
Ionic clay REE deposits represent a specialised and highly valuable type of rare earth resource. Unlike traditional hard-rock REE deposits that require intensive processing, ionic clay deposits contain rare earth elements that have been naturally leached from their source rocks and adsorbed onto clay minerals during weathering processes.
These deposits are particularly valuable because:
- They typically allow for simple, low-cost extraction using salt solutions rather than aggressive chemicals
- They often contain higher proportions of the most valuable heavy rare earth elements
- They generally have lower levels of radioactive elements compared to hard-rock deposits
- Mining and processing have substantially lower environmental impacts
The Santa Anna Project's potential as an ionic clay REE deposit could position it as one of the most economically attractive REE projects outside of China, which currently dominates global ionic clay REE production.
The Science Behind Ionic Clay REE Deposits
Ionic clay deposits form through natural weathering processes over millions of years. When REE-bearing source rocks (often carbonatites or alkaline igneous rocks) are exposed to tropical or subtropical weathering conditions, the rare earth elements can be leached out and then adsorbed onto clay minerals through ion exchange.
In these deposits, the rare earth elements are not chemically bound within mineral structures but rather held by weak electrostatic forces on the surfaces of clay particles. This makes them readily extractable using simple leaching solutions like ammonium sulfate, which can displace the REEs from the clay surfaces without requiring energy-intensive crushing, grinding, or aggressive chemical processing.
The leach testing at Power Minerals Ltd will specifically quantify what proportion of the REEs at Santa Anna are in this valuable "ionic" form versus being locked in mineral structures that would require more intensive processing.
Future Plans and Investment Potential
Power Minerals holds the entire Santa Anna Carbonatite Alkaline Complex under two permits covering 17.05km², representing a significant scale exploration and development opportunity. To date, only a small portion of the Santa Anna alkaline complex has been thoroughly drilled, leaving substantial areas untested.
The company's goal is to systematically map and sample the niobium and REE mineralisation both laterally and at depth. With high-grade REE and niobium mineralisation established from multiple drilling campaigns, and with leach testing now underway, Power is positioned to rapidly progress further drilling with the aim of confirming a maiden Mineral Resource Estimate.
Why Investors Should Track Power Minerals
Power Minerals presents a compelling investment opportunity in the critical minerals space for several key reasons:
- World-class REE grades – The Santa Anna Project has delivered some of the highest-grade REE results globally, with values up to 4.34% TREO
- High-value REE mix – The project shows high proportions of magnetic rare earth oxides (MREO), which command premium prices in the market
- Potential low-cost extraction – If confirmed as ionic clay deposits, processing costs could be significantly lower than traditional hard-rock REE projects
- Large exploration upside – With only a small portion of the 17.05km² project area tested to date, substantial expansion potential exists
- Critical minerals exposure – The project provides exposure to both rare earth elements and niobium, both considered critical minerals for clean energy and defense applications
The coming leach test results represent a significant near-term catalyst that could substantially de-risk the project and provide clear direction for future development pathways. With the global push toward electrification and clean energy technologies driving unprecedented demand for rare earth elements, Power Minerals is positioning itself at the forefront of this critical sector.
As the company advances toward a maiden Mineral Resource Estimate, investors should keep a close watch on developments at this promising critical minerals project.
Want to Capitalise on This Rare Earth Opportunity?
To learn more about Power Minerals' high-grade Santa Anna REE Project and its potential as a world-class ionic clay deposit, visit www.powerminerals.com.au today. With exceptional grades up to 4.34% TREO and ongoing leach testing, this ASX-listed company offers investors exposure to critical minerals essential for the clean energy revolution.
