Alvo Minerals Limited is a minerals exploration company, with a focus on the under-explored Palmeiropolis region of central Brazil. Alvo identified this region in 2018 when the Brazilian Federal Geological Survey department announced a public auction for their Palmeiropolis Volcanogenic Hosted Massive Sulphide (VMS) Project.
Alvo participated in this auction and eventually acquired an option to undertake exploration on the Palmeiropolis Tenements and acquire 100% ownership in those tenements, subject to various conditions. Following the success of the auction, Alvo set about consolidating the acquisition of interests in various surrounding exploration permits into the control of Alvo and its subsidiaries. The Consolidated exploration tenure is called the Palma Project.
In 2023, Alvo entered into a binding agreement for the purchase of the Bluebush Rare Earth Element Project, adjacent to its existing Palmeiropolis exploration base and The Palma Cu-Zn Project. The opportunity for this purchase only became available to Alvo through its local presence and proven exploration execution capabilities in Brazil.
The Palma Cu-Zn Project
The Palma Project comprises approximately >850km2 of granted exploration licences and applications, including 70km of strike of the prospective VMS geological lithologies. The Palma Project’s key tenements were the subject of extensive historical work completed in the 1970s and 80s and resulted in the identification of advanced targets of VMS mineralisation. Considering that VMS mineralisation often occurs in clusters, Palma represents an outstanding opportunity for Alvo to explore a district scale VMS Project.
The two main prospects within the Palmeiropolis Tenements (the ‘C1’ and ‘C3’ deposits) are the subject of an estimated inferred mineral resource compliant with JORC Code 2012. Alvo’s inferred mineral resource estimate (MRE) totals 4.6M tonnes, primarily comprised of 179,000 tonnes of zinc, 44,000 tonnes of copper and 3Moz of silver, (determined at an NSR cut-off rate of US$60/t). This MRE is based on historical drilling only and is due to be updated in 2023.
The Company has an aggressive program underway, exploring the Palma Project for VMS style mineralisation. This program started immediately after listing on the ASX in October 2021, with the Company using local connections and knowledge to progress its efforts. This includes the acquisition of advanced in-house exploration equipment – including Electromagnetic (EM) and Induced Polarisation (IP) equipment, as well as an Auger rig for cheap, flexible and fast in-house exploration.
Alvo has combined >32,000m of historic drilling results, with >21,500m of its own drilling results (2021-2023) with results continuing to exceed expectations on grade and thickness compared to the existing MRE.
The Bluebush Ionic Clay REE Project
The Bluebush Ionic Clay REE Project neighbours Alvo’s Palma VMS Project and Cana Brava Ni/Cu/PGE Project. Bluebush is considered highly prospective for Rare Earth Elements (“REEs”) hosted in surficial saprolites, confirmed as the highly-valued ionic clay classification.
Bluebush is along strike from, and on the same biotite-rich granitic intrusion -Serra Dourada, that hosts the Serra Verde ionic clay REE Project, which is the only ionic clay REE project currently in construction anywhere in the world outside of China. Serra Verde is in the final stages of construction with production scheduled to begin in late CY2023.
Serra Verde has an estimated Mineral Resource of 911Mt @ 1,200ppm Total Rare Earth Oxide (TREO) and a Mineral reserve of 350Mt @ 1,500ppm TREO. With a high percentage of the higher value heavy and magnet REEs, Serra Verde is projecting a mine life of over 20 years initiating in late CY2023. Ionic clay hosted REE deposits are highly favoured due to the relatively simple processing required to create a REE concentrate and the high levels of Heavy (HREO) or Magnet (MREO) rare earth element oxides as compared to the Light (LREO)^.
The Serra Verde deposit is hosted in the weathered saprolite profile of the Serra Dourada biotite granite, the same granite which is mapped on the Bluebush areas. Alvo released metallurgical testwork on auger drill samples, which confirmed the status of Bluebush as an ionic clay (adsorption) REE Project. The results showed excellent extractions of REEs using industry standard ammonium sulphate solution (AMSUL).
High-value magnet rare earths (MREO) recovery rates using weakly acidic (pH 4) AMSUL at ambient temperatures achieved the following extractions (after 30 minutes):The early-stage exploration completed by the vendors included multiple mineralised clay intercepts from the various prospects across Bluebush, included highlights such as:
- Neodymium (Nd): up to 89%, averaging 60%
- Praseodymium (Pr): up to 86%, averaging 57%
- Dysprosium (Dy): up to 53%, averaging 37%
- Terbium (Tb): up to 69%, averaging 48%
- Total MRE (Nd, Pr, Dy + Tb): up to 83%, averaging 56%
^ REE Definitions:
HREO Heavy rare earth oxides are defined by their higher atomic weights relative to light rare earth oxides. HREOs include oxides of gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu) and often include scandium (Sc) and yttrium (Y). Uses include computer and phone displays, and fibre optic cables.
MREO Magnet rare earth oxides can handle greater saturation magnetization than more common elements such as iron and allow for fabrication of stronger and smaller magnets. These can be used for climate economy products such as electric vehicles and wind turbines. MREOs include oxides of Nd, Pr, Dy, Tb, Eu and Y and are some of the highest value REEs.
LREO Light rare earth oxides are defined by lower atomic weights compared to heavy rare earth oxides. LREOs include lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu). Used as stabilisers in catalytic compounds and elements in hybrid batteries.
 For more information, please refer to Serra Verde company website: https://serraverde.com/en/home/
 Refer to Serra Verde presentation: https://www.cetem.gov.br/antigo/images/palestras/2015/iiisbtr/05-denilson-fonseca.pdf