I was amazed at some of the things Tim Vanderpool said in his piece about Cananea ("Hard Rock, Hard Times," September 16). In it, he worries about the dangerous tailings ponds with their "rising cocktail of cyanide, sulfates and other copper-leaching by-products." But before all you anti-mining activists out there get your sustainable, fair-wage, family farmed, cruelty-free, unbleached, organic cotton Underoos in a bind, you should know that Vanderpool is completely ignorant about mining.
First, he doesn't know the difference between a gold mine and a copper mine. Cyanide is used to leach disseminated gold at gold mines. Cyanide never has and never will be used to leach copper. At copper mines, it is a weak solution of sulfuric acid, about the same strength as vinegar, that is used to leach the copper out of low-grade ore. The rocks from which copper is leached are in walnut- to watermelon-sized pieces, not the fine-grained material found in tailing ponds.
Cyanide not only does not dissolve copper minerals, but it is incompatible with an acidic environment, such as found in a sulfide-based copper deposit like Cananea. In the presence of the slightest amount of acid, a cyanide solution will generate hydrogen cyanide gas. Where Vanderpool's toss-a-bomb-and-run reference to cyanide at a copper mine came from, I don't know.
Furthermore, tailings ponds have nothing to do with leaching. Tailings ponds store the leftovers (called tails) from the milling process of treating ore. In that process, higher-grade ore is crushed to sand-size or finer particles and the copper minerals are physically separated by flotation. The concentrated copper minerals are then sent to a smelter. There is no leaching involved in the milling-smelting process. Again, no cyanide.
Vanderpool tries to scare us by mentioning sulfates as a by-product of the leaching. Although sulfuric acid is a sulfate (hydrogen sulfate), it poses no threat to the environment. In the days before sulfuric acid started being used in large quantities for copper leaching, it was used by farmers as an excellent fertilizer. You can make your own natural sulfuric acid fertilizer by using Ironite (crushed iron sulfide), available at any hardware or garden store.
The weak sulfuric acid solution used in leaching is instantly neutralized in the environment by reaction with calcium carbonate, which is common in the bedrock at Cananea and in the basin-fill alluvium of the San Pedro Valley. The reaction forms gypsum, which is calcium sulfate. Gypsum is used in wallboard and is the ingredient added to the boiled extract of soybeans to form tofu. I'm not afraid of gypsum wallboard or tofu, but Vanderpool wants us to shudder at the thought of sulfates occurring in association with a sulfide mine.
Vanderpool mentions "other copper-leaching by-products" in the tailings ponds, but just what other by-products these are, he doesn't have the courtesy to tell us. Maybe he just doesn't know. There are things in a tailings pond that can be of importance at a copper mine. Things like copper, arsenic, lead, molybdenum and cadmium. These metals, not sulfate, are among the potentially hazardous by-products of copper mining. It's too bad he is completely clueless about copper mining, or he could have been even more effective at his attempt at fear-mongering!
Of course, when throwing around the word "toxins" to describe everything found at copper mines, it helps to keep things in perspective. I already mentioned that "dangerous" sulfate is used to make tofu. And if you want to know how dreadfully "toxic" copper is, read the label on a roll of Certs breath mints or a bottle of vitamins. Don't forget that a concentrated mass of lead and sulfuric acid is also known as an electric car, something environmentalists are all hot-to-trot to call environmentally friendly. (See the September 21, 1995 and December 19, 1996 editions of the Tucson Weekly for articles about how environmentalists are demanding we use more lead and sulfuric acid because they are good for the environment!)
Even after consulting with Daniel Patterson, "point man" on Cananea from the litigious group of activists with savior complexes and self-appointed experts on everything, known as the Center for Frivolous Lawsuits (formerly the Southwest Center for Frivolous Lawsuits), Vanderpool is still completely ignorant about mining practices at Cananea. He doesn't know gold from copper, nor leaching from milling, nor tailing ponds from leach piles, but that won't stop him from engaging in anti-mining scare-mongering. It's like yelling "CYANIDE!" in a crowded movie theater. Just once, I'd like to see an activist group or a journalist covering activist issues who actually knows even the most basic facts about the industries they rally against. Vanderpool's article proves you don't have to know anything to be an environmental activist.
-- Ray Harris
Tim Vanderpool replies: Oops. Sorry Ray. Before you get your metallurgical panties all in a bunch, I'll concede that you're right -- copper processing doesn't involve cyanide. My mistake. Of course, that doesn't mean traces of the poison haven't been found in the waters around Cananea.
As for those wonderful sulfates, they're really not bad, unless you have an aversion to the occasional bout of severe diarrhea. Ingesting the chemical can be especially dicey for babies and seniors. But it seems you wouldn't mind quenching your thirst with a big ol' schooner of brisk, sulfate-enhanced water. Actually, I prefer mine with a twist of lemon and a wisp of vermouth. Cheers!
Concerning the rest of that "toxic cocktail" restrained behind Cananea's earthen dams, like you say, it's only tainted with arsenic, lead and a few potentially lethal acid solvents. I'm sure that clarification will let folks down-let them sleep a lot easier.
Finally, with regards to the "Center for Frivolous Lawsuits," isn't it something how that bunch just keeps winning in federal court? Why, only last month they bamboozled a judge into forcing the Fish and Wildlife Service to designate critical habitat for two endangered minnow species. That zany ruling could change the face of development in rural Southern Arizona.
Don't it beat all? And from "self-appointed experts" with "savior complexes" no less. Hey, wait a minute! That sounds vaguely fam -- aw, never mind.