BacTech - Results from Bioleach Testing
BacTech Moves Program Forward on Strong Gold Recovery
Results from Commercial Bioleach Testing
TORONTO, ON., July 19, 2021 – BacTech Environmental Corporation (OTC:BCCEF, CSE:BAC)
(“BacTech” or the “Company”), a commercially proven environmental technology company
delivering effective and eco-friendly biomining and remediation solutions, is pleased to
announce very positive gold recovery results from its commercial bioleach testing completed
by third-party metallurgical leader ALS Laboratories in Perth, Australia.
In a program designed with added rigor to test the entire commercial process, final results
show a range of 95.5% to 96.4% gold recovery on three arsenopyrite/pyrite concentrates
collected from mines in Ponce Enriquez, Ecuador. Testing of the total flowsheet comprised the
following unit operations: material preparation; the bio-oxidation process; separation of the
oxidized residue; and finally, carbon in leach cyanidation (CIL) of the residue for gold extraction.
Samples were either tested individually or as a blend, in order to confirm the process flexibility
for managing various treatment scenarios in which a range of feedstocks with different
compositions would be delivered to the plant. The table below shows the gold recoveries
obtained from the tests conducted using a variety of feedstock combinations. The arsenic
content of all the feedstock combinations tested was very high.
Feedstock
Supplied to the
Test
Feedstock
Gold Head
Grade (g/t)
Feedstock
Arsenic
Content
(%)
Bio-oxidized
Gold Grade
for CIL
processing
(g/t)
Tail Gold
Grade After
CIL Gold
Extraction
(g/t)
Gold
Recovery
(%)
Conc. 1 + Conc.3 54.6 16 55.0 2.15 96.1
Conc. 5 21.7 12.9 28.1 1.27 95.5
Conc. 1+ Conc. 3
+Conc. 5
39.6 14.6 52.8 1.92 95.4
“With successful gold recovery testing behind us, we’re excited to take the next step forward
into the feasibility study with confidence. We’re proceeding with the understanding that we
can expect quality and consistent gold recoveries using a range of feedstocks with favourable
solubility of arsenic and iron from the bioleaching process,” said Ross Orr, President and CEO of
BacTech. “These high recoveries are especially pleasing considering that one of the tested
feedstocks was a cyanide tails residue which can be difficult to bioleach due to its high toxicity.
Clearly our upfront washing process of the tails residue sample safely and successfully
mitigated the effects of residual cyanide during the oxidation process, and ultimately convert
tailings into stable, eco-friendly products. This is an important result, considering the large
number of cyanide residues available in the region which could provide additional feedstocks to
our plant.”
As announced in an April 21 press release, diagnostic leaching had been used as a rapid and
early determinant to define the mineralogical deportment of the gold in the test work samples
and the absolute release of gold from the refractory matrix by oxidation. This diagnostic tool
proved valuable in the current work by indicating that virtually all of the refractory gold would
be amenable to recovery by bioleach processing with no evidence of gold encapsulated in silica.
The 95.5% to 96.4% strong range of gold recovery obtained from the latest comprehensive test
work remains exceptional when compared to existing bioleach projects that have been in
successful production for many years. These latest results show the excellent amenability of
materials to the bioleach process and support earlier diagnostic test results. With further
advances in process development, including optimization of the bioleach residence time and
the upfront washing process, it is likely that additional gold recovery gains will be realized
throughout the entire process.
The neutralization process, where limestone is added and calibrated to raise the pH of the
bioleach liquor to facilitate the precipitation of the ferric arsenate, is now also being reviewed.
This will demonstrate that the precipitate passes the TCLP (Toxicity Characteristic Leaching
Procedure) requirements for stability set out by the U.S. Environmental Protection Agency
(“EPA”) when depositing such wastes and will provide input to project permitting.
The Company expects to announce the engineering firm that will undertake the Feasibility
Study shortly. BacTech continues to evaluate potential sites for the proposed plant, considering
items such as having access to a reasonable quality of fresh water, the proximity to power and
the sourcing of reagents for neutralization requirements. The Company will update the market
in due course.
This press release has been reviewed by Dr. Paul C. Miller Ph.D Chem. Eng. C.Eng. MIMM.,
considered a qualified expert for reporting purposes.
Ponce Enriquez Bioleaching Project
BacTech is planning to build its new owner-operated bioleaching facility in Ponce Enriquez,
Ecuador, in a region where arsenic is well-known to exist in the gold ore. The Company’s plan is
to build a 50 tpd bioleach plant capable of treating high gold/arsenic material. A 50 tpd plant,
processing 1.5 ounces of gold per tonne of feed, similar to feeds available to the Company,
would produce approximately 26,000 ounces per year. Plant designs are modular and can be
expanded without affecting ongoing production.
BacTech continues to investigate the prospects of establishing additional modern mining
operations across other areas of Ecuador, Peru, Colombia, and Central America. Where
possible, the Company will partner with national and local governments, non-governmental
organizations (NGOs), and others to assist with the funding of these projects.
About BacTech Environmental Corporation
BacTech is a proven environmental technology company, delivering effective and eco-friendly
biomining and remediation solutions to commercial operations to smartly process and recover
preferred metals (gold, silver, cobalt, and copper) and safely remove and transform harmful
contaminants like arsenic into benign EPA-approved products for landfill. Tapping into
numerous environmental and economic advantages of its proprietary method of bioleaching,
BacTech uses naturally occurring bacteria, harmless to both humans and the environment, to
neutralize toxic mining sites with high-pay potential. BacTech is publicly traded on the CSE
under the symbol “BAC” and on the OTC as “BCCEF”. There are presently 138,112,204 common
shares of BacTech issued and outstanding.
For further information contact:
Ross Orr
President & CEO, BacTech Environmental Corporation
416-813-0303 ext. 222,
Email: [email protected]
Website: https://bactechgreen.com/
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Special Note Regarding Forward-Looking Statements
This news release contains “forward-looking information”, which may include, but is not limited to, statements
with respect to future tailings sites, sampling or other investigations of tailing sites, the Company’s ability to m ake
use of infrastructure around tailings sites or operating performance of the Company and its projects. Often, but
not always, forward-looking statements can be identified using words such as “plans”, “expects”, “is expected”,
“budget”, “scheduled”, “estimates”, “forecasts”, “intends”, “anticipates”, or believes” or variations (including
negative variations) of such words and phrases, or state that certain actions, events or results “may”, “could”,
“would”, “might” or “will” be taken, occur or be achieved. Forward-looking statements involve known and
unknown risks, uncertainties and other factors which may cause the actual results, performance, or achievements
of the Company to be materially different from any future results, performance or achievements ex pressed or
implied by the forward-looking statements. Forward-looking statements contained herein are made as of the date
of this news release and the Company disclaims, other than as required by law, any obligation to update any
forward-looking statements whether because of new information, results, future events, circumstances, or if
management’s estimates or opinions should change, or otherwise. There can be no assurance that forward -looking
statements will prove to be accurate, as actual results and future events could differ materially from those
anticipated in such statements. Accordingly, the reader is cautioned not to place undue reliance on forward-
looking statements.
The Canadian Securities Exchange (CSE) has not reviewed and does not accept re sponsibility for the adequacy or
the accuracy of the contents of this release.
This press release does not constitute an offer to sell or a solicitation of an offer to buy any of the shares, nor is it a
solicitation of interest from a prospective investor.