The Chilean sun beats down on the Atacama Desert as Dr. Manuel Paneque readies himself for another day of monitoring plant growth. The sandy landscape stretches for hectares in every direction, with Barrick’s Zaldivar copper mine providing the backdrop. Rows of plants are carefully marked by wooden spikes and soaker hoses are woven between each specimen to supply them with water.
Paneque, a professor of biochemistry and molecular biology at the University of Chile, visits the site weekly to monitor the plants, which are the basis of an ambitious research project between Barrick, the University of Chile and the National Chilean Forestry Corporation (NCFC). The long-term goal is to use the plants, 10 species in all, to produce bioenergy, such as biodiesel. The challenge is whether the plants are durable enough to grow and thrive at an oxygen-deprived altitude of 3,300 meters above sea level in the second-driest region on Earth. The potential pay-off is significant if the experimental project is successful, as biodiesel can be used to power equipment at the Zaldivar mine, reduce green-house gas emissions and cut the operation’s fuel costs. While it is too early to determine potential cost savings, biodiesel can be mixed with regular diesel fuel in concentrations as high as 20 percent.
“We’re adding value to the land since we’re enriching degraded soil and otherwise generating agriculture in a place where it typically hasn’t existed,” says Paneque, who is overseeing the project.
If the project is successful, it could spawn a new industry in the region, Paneque adds. “Isolated communities would be able to produce these plants, produce their own energy and even sell biofuels internationally,” he says.
The three-year project launched in 2010 and was recently extended for a second three-year term. To date, Barrick has invested nearly $600,000 in the project, which is being implemented on the ground by the University of Chile and Agroenergía SA, a Chilean green energy company. The NCFC has donated some of the plants and is providing input. The plants, which include jatropha, goat nut, saltbush and the castor oil plant, are grown at a Desert Agricultural Center near the Zaldivar mine. None of the plants are native to the Atacama Desert, and whether they can grow at high altitude and cold temperatures will be critical to the project’s success.
All 10 plant species endured the 2011 winter. The jatropha and goat nut need another two to three years to grow and produce seeds from which to extract oil, but the castor oil crop is already harvested. Soon scientists will be able to provide initial results on the oil content of the castor oil plant seeds and, in another year, researchers will have enough data on seed quality and volume of oil production to determine if it is viable to continue growing the plant in the harsh Atacama Desert conditions.
The water and fertilizer used to feed the plants are by-products of an innovative water filtration system used at the Zaldivar mine. The water itself is treated wastewater that comes from the mine’s operations and mining camps. It is passed through a series of filters, including a wood-chip filter filled with earthworms that eliminate particulate matter in the water. The filter system cleans the water and produces worm “humus,” a nutrient-rich fertilizer. Thanks to this process, Zaldivar is able to recycle 99 percent of its wastewater at a rate of approximately 20 liters per second.
“We didn’t have much use for the treated waste water and, having worked with the University of Chile before, we consulted them about alternative uses for it,” says Robert Mayne-Nicholls, Executive General Manager for Barrick Chile.
Mayne-Nicholls says he is excited about the project’s potential to have both a positive environmental and economic impact, and pleased that the mine is contributing the necessary water, fertilizer and support for the project.