Cochise College             Student Papers in Geology     
Geology Home Page                     physical geology  historical geology  planetary  gems
Roger Weller, geology instructor
wellerr@cochise.edu       


Bisbee Copper Mining
Maria Ramos
Physical Geology
Spring 2006

 

The Worries of a Bisbee Copper Miner

A Little History

            In 1877, Bisbee's Copper Queen Mine opened where miners would extract over eight billion ponds of copper, almost 3 million ounces of gold and over 7.5 million ounces of silver before the close of the mine in 1975.  Sometime around 1951, Phelps Dodge Corporation took a stab at the more cost effective open-pit mining and started work in the Lavender Pit, named for mine manager Harrison Lavender (not its lavender-tinted walls).  The Lavender Pit produced an estimated billion tons of copper (along with substantial amounts of gold, silver and "Bisbee Blue" turquoise) and was closed in December 1974.  In 1976, almost one hundred years after mining began there, the Copper Queen Mine opened to the public for tours.  Miners who once worked the mine themselves guide the tours and offer insight to mine life.






 

 










Equipment troubles
 

            A copper miner's "office" is a cool (47o year-round in upper levels), dark, damp, cramped space, but these are minor discomforts compared to some of the other costly, time consuming, or life-threatening problems one can encounter in the mine.  One problem that arose in the Bisbee mine was the obstruction of piping due to dense selenite crystal growth.  Bisbee water, rich in calcium sulfate, would flow through the pipes where the crystals had a place to form.  Under the right conditions, a pipe such as the one pictured could become completely obstructed in as little as a few years.  A large-scale version of this occurs in Mexico's cave of swords where the result is awe-inspiring, not a nuisance.  



 

           














cave





 
Another equipment problem resulted from a chemical reaction that was actually beneficial when extracting copper from the mined ore.  In a process called copper cementation, pieces of scrap iron are placed in a copper rich solution, and the iron is dissolved away and replaced with copper.  This handy method for extracting valuable copper could wreak havoc on iron track rails, nails and tools that were consistently exposed to the copper-rich mine water.












"The Committee"

            Dynamite blasts are an obvious source of danger in the mine, but not only for obvious reasons.  Of course premature blasts, fire, shooting rock and cave-ins were on a miner's mind as he blasted away, but he had to drill his blasting holes carefully so as not to damage support structures and displease "The Committee".  In a copper mine, where the real money is made for every ton of bonus material you produce above the base, time really is money.  If the next shift (The Committee) has to waste time repairing what you've broken, they might very well meet you for an inspirational chat in the parking lot.
 

Lung Trouble

            In the early days of copper mining, when the work was done mostly by hand, drilling into the silica-rich walls of the mine gave rise to even more dangers and health hazards.  Using a stoper (a machine aptly nicknamed the widowmaker) a miner drilled into overhead rock.  Any loose material of substantial size could be the immediate end to the miner's life, but the tiny, airborne particles were just as dangerous over the long term.  Long-term exposure to silica dust resulted in silicosis, a progressive, sometimes fatal lung disease.  Even if it didn't kill you, silicosis, which causes scarring in the lungs, could be disabling.  Later, wet drilling eliminated this problem by soaking the silica dust, therefore eliminating the possibility of breathing it.
 

Surprising Allies

            Many people would immediately call pest control experts if they discovered rats in their workplace, but the crazy copper miners actually befriended them.  Actually, it wasn't so crazy to become friends with a rat when you realized they could detect dangers you couldn't.  Similar to the canaries that coal miners kept in their work areas, rats were more susceptible to a rise in dangerous gas levels or a drop in oxygen levels.  They could also sense ground movements that might signal a cave-in.  The support beams within the work area, could not keep the ceiling from coming down- they were designed to let out enough warning creaks and moans to give you time to get out, hopefully.  If the rats started running towards the entrance, you'd better follow close behind.













 

           
             As if the aforementioned problems weren't enough, the addition of electricity to the mines, brought additional hazards.  The trolley wires overhead could do some serious damage to a damp miner.  The trains that ran within the mine to carry material could also jump their tracks and crush a miner.
 

The Statistics

            While mining is very dangerous work, the Bisbee Copper Queen mine maintained a more than decent safety record.  Between 1950 and 1975 approximately 16 miners were lost in all Bisbee mines combined (China may currently lose 16 miners a day!).  Some of this can be credited to Bisbee being one of the first western mining towns to use wet-drilling to prevent silicosis.  The U.S. Department of Labor's Mine Safety and Health Administration keeps daily fatality reports and it was amazing to see the number of mining fatalities there have been in recent years.  Even as we become more safety-conscious and technology advances, mines are still a dangerous place to be.

 

Website sources:

U.S. Department of Labor Mine Safety and Health Administration

            http://www.msha.gov
            http://www.msha.gov/S&HINFO/SILICO/SILICO.HTM     (Silicosis Info)
19th century copper leaching process

            http://www.derbyscc.org.uk/alderley/mining_f.htm
John Decker, gypsum pipe

Phelps-Dodge Corporation

            http://www.phelpsdodge.com
Copper cementation process

            http://rotapan.com/rcopper.htm
 

Personal Interview:

            Ron McGinnis, Miner/Tour Guide, Bisbee Copper Queen Mine

 

Photo Credits:

1. Crystal obstructed pipe given to Roger Weller, Cochise College, by John Decker of Bisbee

2. Passage through the Cave of Swords, Naica, Chihuahua, Mexico.  Photo by Vladamir Dinets,             http://dinets.travel.ru/caves2.htm
3. Iron track railing turned to copper through copper cementation.  Photo courtesy of Roger  Weller, Cochise College