BBX Minerals achieves successful bioleaching of gold and PGEs from Brazil project

BBX Minerals (ASX: BBX) reports that its environmentally and sustainable beneficiation process has been successful in bioleaching gold and platinum group elements (PGEs) from samples mined at its Ema project in Brazil.

The pilot plant operated by EcoBiome Metals of The Woodlands, Texas, achieved an operational availability rate of 100%.

Bioleach test results produced a significant increase in gold, palladium and rhodium values compared with previously reported assays from the same holes as now subjected to the US pilot plant.

Fire assays returned 3.32 grams per tonne palladium and 0.04g/t gold.

The tests were conducted on a 50kg sample taken from a homogenised drill sample from the Ema project, which is located south of the Amazon regional town of Apui.

Extraction of metals by natural process

BBX Minerals holds a mining licence for Ema first issued in 2019 by the Amazonas state government.

BBX’s key assets are the Três Estados and the Ema gold projects in the Apuí region of Brazil, 60km south of the town of Apui (population 22,000).

The company describes itself as a “unique” exploration and mineral processing technology operation.

The bioleach process being used extracts precious metals naturally and has been developed initially for the primary purpose of extracting PGE at its flagship Tres Estados project.

It is expected that this technology will be transferable and relevant to many other PGE projects, the company says.

Testing requires patient juggling of factors

BBX has signed a product supply and IP licence agreement with microbiology specialist EcoBiome.

Chief executive officer Andre J. Douchane said these results hold significant importance, as they indicate a “notable” increase in recovery.

“Pilot plant testing is an iterative (requiring repeated testing) learning process that requires time and optimisation of variables such as grind size, reagent addition, pH (acidity levels testing), temperature, agitation rates and oxygen addition,” he added.

Plans to build own plant in Brazil

“The ultimate goal is to have a fully operational pilot plant along with equipment for bio-assaying the resource drill holes within a time frame of 30 to 46 days,” Mr Douchane said.

The company intends to construct its own pilot plant near its existing laboratory located in Catalao, Brazil.

BBX has previously stated that the Apui region has good infrastructure — it has direct access to the Trans-Amazonian Highway and a port on the Amazon River along with an airport — but remains “vastly under-explored”.

The area has been the subject of shallow artisanal mining.