Penco module

Our Process: Circular Mineral Harvesting

Aclara has developed an environmentally friendly process to extract rare earths from ionic clays, a type of deposit that offers several advantages relative to the more commonly occurring hard rock Rare Earth Element (REE) deposits.

The process has been named Circular Mineral Harvesting, and it is the cleanest way to extract rare earths, causing not only no harm to the environment, but the goal is to leave our project site even better than how we found it.

Aclara has been awarded the 2022 Sustainability Initiative of the Year award, and the 2023 Innovation Award by SEAL Awards. Both awards honor leadership through business sustainability. Learn more here.


The successful completion of the laboratory testing phase (announced on November 09, 2022) gave birth to “Circular Mineral Harvesting”, a unique process that not only results in attractive recoveries of Rare Earths but also minimizes the associated environmental footprint.

Aclara's Rare Earths extraction process - Circular Mineral Harvesting

The extensive testing program carried out during 2021 and 2022 validated the water treatment requirements for the Penco Module flowsheet, thereby satisfying the objective to minimize the freshwater requirements of the process plant through maximizing the recycling of the process liquors within the plant. During this program, an innovative process was conceived which allows the recycling of water in a closed circuit to meet the goal of zero liquid discharge. As a result, the production flowsheet shows that 95% of the water utilized by the process plant is retained within the circuit, that 99% of the main reagent (ammonium sulphate) is recirculated, and that no liquid residues will be produced, thus negating the need for a tailings storage facility.

In addition, the mining activities do not require the use of explosives nor the need to crush and milling the ionic clay feedstock, resulting in an operation with a very low carbon footprint.

The proposed process flowsheet has two patents in place that protect this innovation. The first has already been granted in all the countries that were requested: Chile, Brazil, US, and China, and the second patent has recently been filed and is pending to be granted in China, Brazil, Chile and Australia.

Patent awarded in Chile, Brazil, USA and China