National Geographic Society Newsroom

Mercury Reduction in Xinjiang’s Gold Mines: Fieldnotes from an Eco-entrepreneur

Artisanal and small-scale gold mining (ASM) continues to be a major user of metallic mercury worldwide. During the past six months the National Geographic Air and Water Fund for China has supported an applied research project with Dr. Lanhai Li based at the Xinjiang Institute of Geography and Ecology (a Chinese Academy of Sciences institute)...

A Uyghur child in the Urumqi bazar – children are most impacted by mercury pollution. Photo by Kristina Shafer

Artisanal and small-scale gold mining (ASM) continues to be a major user of metallic mercury worldwide. During the past six months the National Geographic Air and Water Fund for China has supported an applied research project with Dr. Lanhai Li based at the Xinjiang Institute of Geography and Ecology (a Chinese Academy of Sciences institute) to test a novel technique to extract gold without using mercury. In this article, the eco-entrepreneur Kristina Shafer shares her experiences of the field visit to Xinjiang to test the technique at a gold mine near the capital Urumqi. Ms. Shafer is the executive director of the Institute for Sustainable Mining (a.k.a Artminers) that has worked with metal technologist David Plath and his patented CleanGold method in various parts of the world. So far, the economic incentives to move from mercury to other techniques have been scant. However, the signing of the Minamata Convenetion  in October 2013 provides an opportunity to revisit such innovative techniques for reducing pollution while providing livelihoods from mining in some of the most remote locations.

Guest article by Kristina Shafer

Our first surprise when we arrived in Urumqi was the public stir we created. Our work has taken us to remote places, but we’d never stopped people on the street in open-mouthed shock at seeing our Western features.

In the far-flung, northwestern province of Xinjiang, China, Urumqi is an ancient/modern paradox. With a population of 3.2 million, its center is like Times Square on steroids with upscale malls, minarets, baijiu and bazaars. Here, everyone has smart phones, texts incessantly and wifi is everywhere, but people still wash clothes by hand. Ice, vacuum cleaners, and other conveniences haven’t arrived, but infomercials have. The only english speaking TV program we saw (and often we needed subtitles) was a reality show about redneck gator hunters in the deep Southern US.

Cranes jammed the skyline while high-rise construction workers acrobatically assembled scaffolding by hand to install stories at breakneck speed.

Rush hour traffic near the Axi mine - photo by Kristina Shafer
Rush hour traffic near the Axi mine – photo by Kristina Shafer

Southeast of the city is one of the largest wind farms in the world. We drove along miles upon miles of turbines on the way to a Buddhist version of Machu Picchu at Turpan (video link to come). It was over 100 degrees the day we hiked its hills, yet it’s below sea level.

We would soon learn that no Americans involved with mining had ever been granted entry to the Yili Kazakh Autonomous Prefecture.

Yili is where we went to introduce Cleangold, a toxin-free fine gold mining technology invented by US scientist David Plath.

With funding from National Geographic, our NGO Artminers came to show miners how to reduce environmental threats to the watershed habitat of the endangered Snow Leopard.

At the Institute in Urumqi, in preparation for our field work, we soon discovered that we wouldn’t be doing our usual work with artisanal or small scale gold miners dependent on mercury. Instead, we would be visiting a modern, state-run gold mine, which was already using every state-of-the-art technology available—from centrifuges and flotation cells, to bacterial processes and cyanide.

Big, rich industrial mines weren’t part of our mission. The main focus of our work is with miners at the bottom of the supply chain. However, communities impacted by mining are at the bottom of the supply chain, including the wildlife. Cleangold had never gone up against cyanide before, widely regarded as the ultimate chemical for extracting gold dust from rocks. This gave us a chance to concentrate and examine gold being lost by the final cyanide-based recovery process used on the concentrates from their centrifuges and flotation.

Oregon, our home state, shares the same latitude as Yili, with similar agriculture and natural resources, but that’s where any similarities end.

The Axi mine was a ten-hour drive from Urumqi over the jagged face of the Tian Shan mountains, which dropped into a lush, Central Asian wonderland.

The mountain highway was modern, and our driver attacked it with his SUV like an avatar in a video game without real lives at stake, recklessly spinning out his back wheels on hairpin turns in the wake of mini landslides while our guides napped in the back. At the summit, when we pulled over for a break, I was stunned by all the trash the previous tourists had left behind.

On our descent, soft, green hills embraced us as Kazakh cowboys tended cattle, farmers worked the fields, and, as it was late August, harvest was in full swing—melons, grapes, nuts, raisins, and honey–it was a good time to visit. (video link to come)

When we finally arrived at the Axi mine, after a quick cup of tea and questions from the director, we were led to their lab, where buckets of tailings from various processes were offered with their young techs in attendance. (video link to come)

This is where we always start with Cleangold—on the tailings (refuse ore after all possible gold has been recovered). If Cleangold can recover gold that got past their methods, we’d capture their interest. We did. David asked if they’d ever examined their gold under a microscope, and the answer was no. We were also able to ascertain that despite being run through centrifuges, flotation cells and cyanide, the mine was still losing about two percent of its gold, worth $12,000 US per day.

One of the techs who studied in the US and could speak a little English invited us to spend the night at their guest quarters, to run more experiments and to take a formal tour of the mine the next day. Oh, yes, we said!

Absolutely not, said our guides. We had to leave immediately for our designated hotel three hours away or we’d all be in big trouble. We arranged for more concentrates to be shipped to the lab in Urumqi, then we tore out of there.

We weren’t allowed to shoot photos at the mine, but suffice it to say it was a town-sized hole in the ground with all the modern processing facilities typically attached with same. Apart from a trip to an ore-crushing operation to collect magnetite required for the Cleangold process, our field work was completed.

400 micron gold particle recovered by Cleangold. Nom. Mag 100X - photo by David Plath
400 micron gold particle recovered by Cleangold. Nom. Mag 100X – photo by David Plath

Back at the Institute’s lab in Urumqi, David ran bench extractions on the shipped samples and enjoyed full access to sophisticated crushers, microscopes with digital cameras, grad students and assayers. Under the microscope, David discovered coatings on the micron gold he recovered which likely interfered with the cyanide recovery.

As we shared results with our partners, more mine directors were sent in for demonstrations, and all seemed impressed with our results. David estimated the return on investment at Axi for a scaled-up system was less than a week. Assay results on the sample recovered by Cleangold revealed 790 grams of gold per ton.

Around the world it’s widely perceived that the Chinese care more about industry than the environment. If this is true, why were we brought in? Clearly there was genuine concern and a willingness to engage.

In the past couple of years, some in the artisanal and small scale gold mining community have suggested introducing cyanide to small miners as an alternative to mercury since it decomposes in sunlight and does not bioaccumulate in the environment like mercury. Yet such an approach would merely trade one toxin for another at different time scales. Returning home, we were heartened to learn that lab results had provided positive feedback from the miners. The translation provided by email to us revealed that the miners noted that they were interested in further using this technology because the method is not complex and easy to implement; water consumption is minimal — an important concern in an arid location; the efficiency of mining gold is high; pollution is palpably reduced and less labor is required. Despite all the negativity one often hears about Chinese inertia on environmental concerns, we found the responsiveness of the miners to be remarkably positive. This was particularly heartening in the “Wild West” of China that has often been neglected by mainstream investors. Smart technologies have the potential to provide environmentally sound economic development in this remote but remarkable region.

About National Geographic Society

The National Geographic Society is a global nonprofit organization that uses the power of science, exploration, education and storytelling to illuminate and protect the wonder of our world. Since 1888, National Geographic has pushed the boundaries of exploration, investing in bold people and transformative ideas, providing more than 14,000 grants for work across all seven continents, reaching 3 million students each year through education offerings, and engaging audiences around the globe through signature experiences, stories and content. To learn more, visit or follow us on Instagram, Twitter and Facebook.

Meet the Author

Author Photo Saleem Ali
Saleem H. Ali is Blue and Gold Distinguished Professor of Energy and the Environment at the University of Delaware (USA) and a Professorial Research Fellow at the University of Queensland, Australia. He is also a Senior Fellow at Columbia University's Center on Sustainable Enterprise. Dr. Ali is a National Geographic Emerging Explorer for 2010 and World Economic Forum "Young Global Leader" (2011). His books include "Environmental Diplomacy" (with Lawrence Susskind, Oxford Univ. Press) and "Treasures of the Earth: Need, Greed and a Sustainable Future" (Yale University Press). He can be followed on Twitter @saleem_ali.