BBX Minerals reports strong metals recovery from bioleaching testwork on Ema gold samples
Test results following a bioleaching process at BBX Minerals’ Brazilian gold project have shown a significant increase in precious metals.
BBX Minerals (ASX: BBX) has received initial results from bioleaching tests using a surface bulk sample of mafic intrusive from the Ema gold project in Brazil’s Apuí region.
The tests were conducted at the US facility of EcoBiome Metals LLC to demonstrate how complex mineralisation responds to patent-pending microbial platform technology.
EcoBiome utilised its novel Cultured Gold microbial formula to demonstrate and prove the ability to extract and recover 5E precious metals from an unprocessed sample.
Samples were assayed at an independent laboratory for gold, platinum, palladium, iridium and rhodium using inductively coupled plasma mass spectrometry (ICP-MS).
Increase in 5E metals
Testing of 1-kilogram samples was carried out to determine the appropriate conditions and microbial formulation for the mineralisation.
These demonstrated an overall increase in 5E precious metals assayed following the bioleaching process.
Once ideal conditions were established, a new test using fresh mineralised material was carried out.
Recovery of metals
BBX chief executive officer Andre J Douchane said the EcoBiome technology is capable of significantly increasing the recovery of metals present in the ore.
“We are very pleased to see these initial results but there is a lot of work to be done going forward and, to that effect, we have sent 50kg of material from the Três Estados project to EcoBiome,” he said.
“The material from a known drill hole and will be used to further define and optimise leaching parameters and conditions after which lab pilot plant testing could begin,” Mr Douchane added.
Assaying program
BBX is continuing to advance an assaying program for 20 historic holes drilled at Três Estados.
The work is reported to have produced significant results to date and suggests the potential for a near-surface platinum group metals (PGM) deposit.
Best results have been 20m at 1.45g/t 5E PGM (1.36g/t platinum, 0.07g/t iridium and 0.03g/t rhodium) from surface, including 2m at 3.84g/t 5E PGM (3.72g/t platinum and 0.12g/t rhodium) from 10m and 2m at 1.96g/t 5E PGM (1.84g/t platinum, 0.05g/t iridium and 0.07g/t rhodium) from 18m.
Also returned were assays of 3m at 3.48g/t 5E PGM (2.95g/t platinum, 0.26g/t gold, 0.17g/t iridium and 0.1g/t rhodium) from surface; 2m at 1.81g/t 5E PGM (1.25g/t gold and 0.56g/t iridium) from 16m; 2m at 1.56g/t 5E PGM (0.64g/t platinum, 0.33g/t gold and 0.59g/t iridium) from 20m; and 2m at 1.92g/t 5E PGM (1.82g/t platinum and 0.1g/t iridium) from 24m.