Canadian Mining Journal

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R & D: BacTech Environmental Engages Laurentian University for Ecuador Bioleach Study



TORONTO: BacTech Environmental Corporation today announced that it has engaged the services of Laurentian University specifically, the Vale Living with Lakes Centre located in Sudbury, Ontario, to provide bioleach test work for concentrates collected in Ecuador.

BacTech is investigating the use of bioleaching to process high arsenic/high gold concentrates produced at flotation plants in the Ponce Enrique area of southern Ecuador. The use of flotation eliminates the need for artisanal miners to use mercury to recover precious metals. The area is known for its abundance of arsenopyrite ore.

Under the current study, BacTech will obtain from concentrate producers in the area, 150 kg of what would be considered a representative sample of the current production. In addition, BacTech will also seek to obtain 3 separate samples of 20 kg each consisting of low, medium, and high levels of arsenic.

The study at Laurentian will be conducted under the guidance of Dr. Paul Miller (Ph.D. Chem. Eng. C.Eng. MIMM), the Company’s Vice President of Metallurgy and a leading expert in bioleaching. Dr. Nadia Mykytczuk of Laurentian will work in concert with BacTech, as well as oversee the work on behalf of the University.

Dr. Mykytczuk’s research group and collaborators recently received several grants totaling over CAD$1 million from both federal and provincial funding agencies to assist with research being done at the school with respect to biomining as a means of reclaiming historic tailings. The end result of the test work will be to prove that bioleaching can not only liberate the gold from the refractory ore, but also stabilize the high levels of arsenic as ferric arsenate (U.S. EPA approved for landfill).

Work will also be contracted out to a well-recognized, external metallurgical laboratory to independently verify the improvement in gold recovery obtained from the bioleach study.

It is anticipated the study will take between 4 – 6 months, with the results providing valuable information and input for the design of a bioleach plant in Ponce Enrique. Given the fact that the area has a number of concentrators, BacTech will only be obliged to build a bioleach circuit.

To put this in perspective, if the plant to be built is to treat 40 tpd of concentrate, the need for a nominal 200 tpd ore treatment plant incorporating crush grind and flotation would be eliminated, saving considerable capital. A 40 tpd bioleach plant is estimated to cost approximately USD$10 million.

Dr. Mykytczuk is a Northern Ontario Heritage Fund Corporation Industrial Research Chair in Biomining, Bioremediation and Science Communication. She is an Assistant Professor in the School of the Environment at Laurentian University. Her research focuses on using molecular tools for developing and optimizing bioleaching technologies for improved metal recovery and remediation of mine wastes.

“This is a very exciting new area for the Company. Using bioleaching, we hope to carve out a new niche in the gold processing market that has the potential to offer very real environmental advantages compared to current practices. We will be processing material in Ecuador instead of exporting jobs to other countries, creating employment and a new tax base for the government. The test work to be completed at Laurentian is critical to the development of this project,” said Ross Orr, President and CEO of BacTech.