By: Joseph Bishop, Ph.D.  ACEER Foundation (Chair, Science and Education Advisory Committee)

Soon after boarding the boat for the 4-5 hour boat trip to the Los Amigos Biological Station every researcher and student comes face-to-face with one of the most important livelihoods in the Madre de Dios region – Gold Mining.  Regional maps reveal that the Peruvian Government has designated a continuum of mining concessions along the Madre de Dios River.  Due to gold mining’s economic and social importance, as well as its environmental and public health impacts, ACA and the ACEER started to offer visits to mining dredges among their educational activities.

Promoting new gold mining technologies the ACEER Foundation and the Amazon Conservation Association (ACA) with several partners hosted two CleanGold demonstrations in March 2008.  The partnership included Kristina Shafer of Artminers.org: Institute for Sustainable Mining, David Plath of CleanGold ® LLC, Nigel Pitman of ACA, Manuel Reinoso, Asociación de Mineros Artesanales del Sur medio y Centro del Perú, Miguel Herrera, Asociación de Pequeños Mineros Auríferos de Madre de Dios, Hugo Miranda, Asociación de Pequeños Mineros Auríferos de Boca Amigos, Rocío Martinez, biologist and community education specialist, and Joe Bishop ACEER Foundation.

The CleanGold ® process involves two parts.  The first is to insert an array of panels into the sluice of each mining dredge.  The panels are a material patented by David Plath that attracts and collects mineral concentrates containing gold as they pass over the panels.  The second part relies on a modified version of panning techniques used by gold miners for more than 100 years.  One benefit of this technology is that it requires very few changes to how miners already mine gold.

David Plath led two CleanGold ® demonstrations.  One near Puerto Maldonado at the community of Tres Islas and the second was near the Los Amigos Biological Station at the community of Boca Amigos.  Each demonstration included 3-4 days at each location installing the CleanGold panels, training the owner and workers, and testing the installation and mineral concentrates.  This was followed by a one day public demonstration at each location where local miners and public officials were invited to learn about the new technology.  There were 40 participants among the two demonstrations.  These were followed by a public presentation at the regional government in Puerto Maldonado that was attended by 45 people.

The goal was to introduce technologies that eliminate the need for mercury (Hg) during the mining process.  Gold in the Madre de Dios is no bigger than very fine sand.  During gold extraction mercury is added to the mineral concentrate and, acting like a magnet, it binds with the gold forming an amalgam.  Finally, before the gold goes to market, the amalgam is heated to burn off the mercury concentrating the gold.  When heated mercury volatilizes, forming a toxic gas just as it is released into the air and water around the mining sites.

Mercury’s toxicity has been shown to cause both neurological and developmental problems and it bioaccumulates in the ecosystem.  Thus, the vaporized mercury initially affects the miners and their families, then continues to build up along the food chain concentrating in the larger fish and birds.  Then the mercury finds its way back to the people of Madre de Dios in the larger fish sold in the local markets. 

Each gold mining operation vaporizes between 1-2 kilograms of mercury each week.  This is about the size of one 16 oz. soda.  Based on a 2002 report, the World Wildlife Fund estimated that between 10-30 tons of mercury are released in the Madre de Dios region each year.  By eliminating mercury from the mining process everyone wins.  The miners no longer purchase mercury, saving them money the first day.  Also, miners are no longer breathing the mercury vapor eliminating the health threats along with reducing mercury’s cumulative impact on the environment.

David Plath reported that, based on preliminary testing, the CleanGold process was also more efficient recovering a higher percentage of the finer gold particles, gold that is missed using current mining methods.  David also estimates that each miner’s initial investment from their purchase of CleanGold equipment will be paid for in less than three months.  Kristina Shafer also reported that “Artminers” has been organizing an international market for gold that is mined using mercury free methods.  Buyers and consumers are willing to pay top prices for clean gold.  So as the number of clean gold miners grows, so does their capacity to earn more money from their work.

All of the partners felt that these first demonstrations were very successful and were encouraged by preliminary results and comments from participants.  Funding for this project was provided by Artminers, ACA, and the ACEER.

--Thanks to Joe Bishop and ACEER for allowing us to re-publish his report from ACEER’s Summer 2008 Newsletter, titled: ACA and ACEER Sponsor Workshops to Explore New Gold Mining Technologies Along the Madre de Dios