Earth Talk: The ‘green-ness’ of mining for boron
From the Editors of E/The Environmental Magazine
Dear EarthTalk: I’ve heard so much about using Borax for green housecleaning. But if this mineral has to be mined, doesn’t that negate some of its “green-ness?”
—Elsa, Lincoln, Neb.
Mining for minerals such as boron (the key ingredient in the “Borax” we use for cleaning, pest control and other household tasks) is an activity that typically leaves behind a big environmental footprint. Mining degrades the local landscape and destroys wildlife habitat, while polluting both air and water. It also usually consumes large amounts of water, which can be taxing in already arid regions, such as the Mojave Desert, one of two regions of the world (along with parts of Turkey) with large boron deposits.
Typically, boron is extracted in open-pit mines by drilling, blasting, crushing and hauling—all activities fueled by petrochemicals. The refining process then uses a significant amount of water. Finally, the waste product—known in the industry as “tailings”—is deposited in man-made ponds where further refining is done before the water is then discharged into the local watershed.
The mining industry has long been criticized as an environmental baddie, but the leading company that mines Borax, Rio Tinto, has actually been given high marks for environmental stewardship. Jared Diamond’s 2005 book, Collapse: How Societies Choose to Fail or Succeed, called the British mining giant the exception in its industry. Because of “a strongly supportive CEO and British stockholders,” he wrote, the company moved forward with the 2002 environmental recommendations of the mining industry’s Mining Minerals and Sustainable Development project that were, for the most part, ignored by the rest of the industry.
“Rio Tinto foresaw business advantages to being seen as an industry leader in social responsibility,” said Diamond. “Its Borax mine in Death Valley, Calif., is now perhaps the most cleanly-operated mine in the U.S.”
Boron, oxygen and sodium make up sodium tetraborate, which is sold as “20 Mule Team Borax” (the name comes from the teams of 18 mules and two horses that would haul large wagons of processed borax from mines in the late 1800s to the nearest railroad spur). The powdered detergent is considered a least-toxic recipe as a natural disinfectant and household cleaner. Beyond cleaning formulations, boron is also used in a variety of other products, including the manufacture of fiberglass and Pyrex.
Pest control is another use. One boron compound is used to treat wood to prevent fungal decay and repel carpenter ants, roaches and termites. Boric acid is included on the national list of allowed substances for structural pest control in organic food production (as long as there is no direct contact with food or crops). The U.S. Environmental Protection Agency has determined that pesticide products containing boric acid and its salts are of low toxicity. (However, ingesting it or applying large amounts to the skin can cause acute poisoning, so parents should be vigilant about where they store and use products containing Borax.)
Emerging uses of boron, and new ways to recycle its waste, may make this mineral even more valuable. A Turkish researcher notes that borax waste added to red bricks and cement products increases strength and lifespan. And at the National Boron Research Institute in Turkey, it is being studied as an element to produce fuel cells and to aid in cancer treatment.
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From the September 2-8, 2009 issue