Ecuadorian Technicians Learn Mercury-free Gold Recovery Techniques at UBC

Luis Tapia and Diego Barona came to Canada with 120 kilograms of rock in their suitcases. Then they crushed, ground, floated and leached it at the University of British Columbia’s (UBC) metallurgical lab – looking for gold. The two technicians from

Ecuador’s National Research Institute of Geology, Mining and Metallurgy (INIGEMM) learn mercury-free gold extraction techniques at UBC’s mining lab/SANTIAGO SEILER

Ecuador’s National Research Institute of Geology, Mining and Metallurgy (INIGEMM) came to UBC in a CIRDI-sponsored training program to learn best practice techniques for mercury-free gold recovery in artisanal and small-scale mining.

They worked under the guidance of Professor Bern Klein at UBC’s Norman B Keevil Institute of Mining Engineering. Keevil master student, Santiago Seiler Collazo from Uruguay, prepared a work plan in metallurgical research and training for the visiting technicians and provided support and instruction.

About Artisanal and Small-scale Gold Mining in Ecuador

Artisanal and small-scale gold mining (ASGM) is a major economic driver in Ecuador, accounting for approximately 80 per cent of national gold production. ASGM supports over 100,000 miners directly and provides indirect livelihoods for 500,000 Ecuadorians. Although ASGM has the potential to reduce poverty, most ASGM operations in Ecuador are informal and use mercury in gold extraction, which causes significant damage to human health and the environment. Through the CIRDI project, Transformation of Artisanal and Small-scale Mining in Ecuador (TransMAPE), the Institute is working with the government of Ecuador to provide training for regulators and miners that supports cleaner, more efficient ASGM production methods and advances the formalization of the sector.

Before returning to Ecuador, Luis Tapia and Diego Barona talked about their month in UBC’s metallurgical lab:

What are your roles at Ecuador’s National Research Institute of Geology, Mining and Metallurgy (INIGEMM)?

I am Luis Tapia, a chemical engineer and graduate of Escuela Politecnica Nacional (EPN), Ecuador with a specialization in metallurgy. Currently I am in charge of metallurgical processes and activities of the mining, metallurgical and environmental department of INIGEMM. Diego Barona is also a chemical engineer and graduate of EPN with specialization in metallurgy. He is in charge of the analytical laboratory at INIGEMM.

What did you hope to achieve from this learning exchange?

In this visit we hoped to learn more about the operation of UBC’s metallurgical lab. The idea was to replicate all the tests we use in Ecuador to find the best process for the recovery of precious metals and transfer this knowledge to artisan miners to avoid the use of mercury. There were four main objectives for us here. The first one was to learn how to perform the main unit operations of a metallurgical lab. The second one was to develop a methodology and procedure to carry out the same tests that we are doing here, in our lab in Ecuador. The third one was to identify which equipment is needed to perform that methodology at our INIGEMM lab. Finally, the last one was to write a pre-feasibility study for a pilot mercury-free processing plant.

How much rock did you bring with you? Where in Ecuador did it come from? What are you doing with the rock in the lab?

We brought four samples from three zones of southern Ecuador: Camilo Ponce Enriquez, Zaruma and Portovelo. From Ponce Enriquez we had two samples, one from a small-scale miner and the other one a waste pile (Jancheras). In total we were working with 120 kilograms of rocks.

We performed a standard metallurgical test for gold ore extraction. The process was divided into five unit operations: crushing, grinding, gravity concentration, floatation and cyanide leaching.

How will what you are learning at UBC be helpful back in your home lab and in your country?

The experience at UBC has enriched our knowledge of the operation of a metallurgical laboratory, in both theory and practice. We have been learning about the basic operations of a process of concentration of precious metals and interpretation of results. This experience will help us to improve the INIGEMM metallurgical laboratory and transfer this knowledge to artisanal miners processing precious metal ores.

Who will most benefit from what you have learned?

We hope that the Ecuadorian people who work in mining activities especially artisanal and small scale miners will benefit most, because they don’t have enough technical knowledge about their processes for gold recovery. Additionally, everything we learned here is to help us replicate an excellent metallurgical laboratory in Ecuador in order to continue to research environmentally friendly recovery processes of Ecuadorian minerals.

What has surprised or interested you most about being here?

One of the most surprising things is that the technique we used at UBC is the same technique that we learned at our university in Ecuador and that is applied in commercial laboratories. Another thing is that the Coal and Mineral Processing lab at UBC is bigger than a commercial lab. We are interested in improving our knowledge about metallurgical processes by completing this fellowship and if it is possible, in the future to achieve a master’s degree related to mining activities.

Published June 1, 2017

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