Chile A Story of Gold and Quicksilver
By Dr. Ralph E. Pray
That's the upside. At the same time I've been forced to realize that not one relave contains much material that assays at over five grams per ton. Most, in fact, assay at about two grams per ton or less. Given the current low price of gold this does not bode well for the project.
The despondency I encounter among the trapiche operators is, I think, linked to this low price of gold. The Chilean govemment;-out of greed and a lack of good sense, places a heavy tax on the sale of raw gold. The small, gold producers and trapiche operators get around the tax by selling to jewelers' at just below market. My L.A. associates repeatedly try get in on this business in a big way.
Brinks is standing by to transport bullion to a Waiting U.S. refinery. But in Chile, gold selling is a secretive business with its own cultural norms. The gold melts, untaxed into the national economy.
During this second trip to Chile I make a surprising discovery. What I had first taken to be dejection over the low price of gold, is not that at all. It has to do with mercury. After more than 400 years the gold-processing trapiches of Chile are being shut down by government edict. The reason? Mercury! Trapiche amalgamation plants have contaminated the environment with so much mercury that it's now viewed as a national disgrace. The result - Public health agencies, and other social forces, have pressured federal legislators to take action. Throughout Chile mercury poisoning of land and water is all but banned. This development just happens to coincide with my visits.
In all this public and government outcry, no mention is made of air pollution. On any hot day a trapiche gold relave will exhaust toxic fumes of pure mercury into the atmosphere. The concentration is often measured in micrograms per cubic meter. I have brought a state of the art "mercury sniffer" with me, that I rented from Arizona Instrument Company for $1,000 per month. A pump sucks in air across a gold gauze hooked to a resistivity meter. As I walk around a 300,000-ton relave in the Los Negritos District of Andacollo with owner Luis Donoso Garcia, we take readings of the invisible mercury vapor.
"Look at that!" Luis says. "On a hot day 1 don't want to be standing here." I ask him about all those families living in houses built on the relaves in nearby Andacollo.
"Shouldn't they move to safer ground?"
"They'll all die before they move."
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June, 2001.
Reprinted with permission of the author. Dr. Ralph Pray,
Mining & Metallurgy
805 S Shamrock Ave
Monrovia, CA 91016
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