Environmental Hazards Associated with Copper

by Jake Stevenson

http://www.emporia.edu/earthsci/amber/go336/stevenson

for GO 366 Mineralogy in fulfillment of course requirements

Copper is a mineral that has been mined for use by man for thousands of years. Many people like to think that mining copper is "for the good of mankind" but in reality it is for the profit of a few.

Copper Ore from the Bingham Canyon Copper Mine

Image taken from
http://www.rockhounds.com/rockgem/articles/bingham_canyon.html

Table of Contents

Introduction

Properties

Conclusions

References

Related Links

Introduction

There are many harmful aspects of copper, both in terms of how you mine for the mineral and also the environmental aspects. Bingham Canyon Mine, which is located south of Salt Lake City in Utah, is the largest hole in the earth with a rim measuring "2 miles wide and a depth of .5 miles" (Voynick, 2002). This means that you could stand two Sears towers (1353 feet each), one on top of the other and still not make it to the top of the hole. Astronauts in space now can see this hole, which was once a mountain. (Voynick, 2002). In order to mine copper you must extract much more rock than copper. What this means is that there are huge areas of ground and wildlife habitat destroyed during the mining for copper. The excess rock that has no value to the mine is tossed into a pile called "tailings." These tailings piles create mountains where there was once a valley. In these tailings harmful minerals such as asbestos, even radioactive minerals, such as uraninite, thorianite and autunite could be found. When rain falls on the tailings the water reacts with the waste material from this copper sulfide mineral, chalcopyrite, to produce sulfuric acid, which then runs into the streams, contaminating the water and harming the fish amd other wildlife. Humans are harmed when they eat fish or animals that have been tainted with sulfuric acid (United States Environmental Protection Agency).

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Image taken from
http://www.the-copper-pot.com

Properties

Copper in its metallic form is shiny red-brown with very malleable aspects, which creates a wide range of uses (Klein, 2002, p. 344). Copper is used in wires, pots (as shown above), and tubes, because of its good conduction of electricity and heat. Those same items when left exposed to the air turn a dull red-brown compared with the shinny appearance as before. When copper turns this dull red-brown it has gone through a process known as oxidation. During oxidation oxygen molecules react with copper atoms and actually break down or combine with the copper to form malachite. Oxygen is not the only element that copper reacts with. When copper is in a liquid form, it is a component of many metal alloys such as brass and bronze. When combined with other chemicals, copper reacts to form salts.
There are two main types of copper-bearing minerals sulfides (those that contain sulfur and have not been affected by oxygen) and oxides (those that have been affected by oxygen and contain little or no sulfur). Typical sulfide copper minerals are bornite, chalcocite, chalcopyrite and covellite. Oxide copper minerals include azurite, chrysocolla, cuprite, and malachite. Many copper-bearing rocks also contain molybdenite, lead, zinc, gold, platinum, nickel, iron, and silver (Lichtenhan).
Cuprite, Cu2O, is isometric with crystals commonly occurring in cubes. The composition of cuprite is 88.8% Cu and 11.2% O. Atacamite is copper paired chlorine, hydrogen and oxygen, and is another minor ore of copper. The chemical composition of atacamite is Cu 14.88, CuO 55.87, Cl 16.60, H2O 12.65%, with an orthorhombic crystal system. Copper, when found in nature, has a face-centered cubic (FCC) crystalline structure (Klein, 2002, p. 345).
Copper salts and other combined copper forms can vary greatly in their behavior. Since some forms of copper are extremely soluble in water they pose a serious human hazard. When dissolved copper normally imparts a blue or blue-green color to the material in which it is dissolved. If your drinking water was blue or your tiles, sink, or other fixtures are green there is a very high chance that you have copper in your water.
A way to tell if your food has copper in it is to taste it. If your food or water has a sharp or bitter taste it would indicate dissolved copper in the range of 1 –5 milligrams per liter. According to the Oregon Department of Human Services, when copper occurs in food or water in levels greater than 1 part per million (ppm), stomach irritation and vomiting result. Chronic injury results if levels are 1.3 ppm or higher. The Oregon Department of Human Services goes on to say that if infants or children are exposed to levels of copper above the action level for weeks or months they may suffer liver and kidney injury (Oregon Dpeartment of Human Services).

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Bingham Canyon Copper Mine

Image taken from
http://www.rockhounds.com/rockgem/articles/bingham_canyon.html

Conclusion

Over time, copper in the environment is neither degraded nor destroyed, but goes through a series of chemical reactions. Generally copper tries to return to a less soluble and more stable form, which can be found in soil.
The mining process is becoming a cleaner and more productive process at Bingham Canyon's Kenecott Mine. Although there are harmful aspects with mining and many potential environmental problems, technology and geoscientists help improve the process to produce more environmentally safe mining.

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References

Klein, C. 2002. The 22nd edition of the manual of mineral science. John Wiley & 

Sons, Inc, NYC, 378, 402pp.

Lichtenhan, G. Dec.1, 2001. Copper the mighty metal: Arizona's gift to the

world. Arizona Mining Association. Journal Web page 
http://www.azcu.org/cumightymetal/textversion.html.  

McChesney, S. 2001. Copper: The star of Arizona. Arizona Mining 
Association. Journal Web page 
http://www.azcu.org/custarofaz/textversion.html. 

Oregon Department of Human Services. Copper. Retrieved on 10-29-03. World 
Wide Web homepage URL: 
http://www.dhs.state.or.us/publichealth/dwp/docs/fact/copper.pdf.
 
United States Environmental Protection Agency. Iron Mountain Mine. Retrieved 
on 10-8-03. World Wide Web Homepage URL: 
http://yosemite.epa.gov/r9/sfund/overview.nsf/0/7a8166ef298804808825660b007ee6
58?OpenDocument. 

Voynick, S. 2002. Bingham Canyon copper finding chalcopyrite at "the richest hole on Earth." 
Rock & Gem Magazine. World Wide web Homepage URL: 
http://www.rockhounds.com/rockgem/articles/bingham_canyon.html. Retrieved on 10-8-03.

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Related Links

Kyle's Positives Aspects of Copper

GO 336 WebPage Project Assignment

GO 336 Student WebPages

Mineral and Gemstone Links

World of Amber

For more information email stevenson18jake@hotmail.com.
Webpage creation November 25, 2003; last update December 5, 2003.

Copyright 2003 © Jake Stevenson. All rights reserved.