Chemistry Professor Al Denio seeks to illuminate us non-chemists on how sulfide metallic mining creates pollutants that threaten Wisconsin's environment in his short piece, "A Tale of Three Elements."
Hydrogen is a gaseous element under normal conditions. This is given the atomic number one since it is the smallest atom known, based on a single heavy proton as the core. This positively charged particle is surrounded by an "electron cloud" composed of a single electron with a negative charge. Thus, the hydrogen atom is electrically neutral. Hydrogen atoms pair up to form more stable hydrogen molecules, referred to as H2. If you buy a tank of hydrogen, this is what you get.
Oxygen is also a gaseous element under normal conditions, and makes up about 20% of our air supply. It is essential for our bodies to function - without it, we die. An oxygen atom is much larger and more complex than hydrogen. It is given the atomic number eight, since it has eight protons in the nuclear core and eight electrons in the "electron cloud." The nuclear core of protons in stabilized by eight neutrons which have no charge. Oxygen atoms alone are unstable so they also pair up to form more stable molecules, referred to as O2. These are what we need for life.
A third nonmetallic element is sulfur, normally a yellow solid. This element has an atomic number of sixteen since it has sixteen protons and sixteen electrons. The nuclear core containing the protons also has sixteen neutrons to help provide stability. Sulfur atoms prefer to bond together into eight atom rings to give the molecule S8.
Each of these elements alone is not a problem. However, their chemical combinations can cause very significant problems. Sulfur and oxygen can form sulfur dioxide (SO2) and sulfur trioxide (SO3). If these compounds are then combined with water, obtained by reacting hydrogen and oxygen, the products are sulfurous acid (H2SO3) and sulfuric acid (H2SO4). These two acid compounds are capable of causing enormous damage to the environment when deposited as "acid rain."
The chemistry is different when we talk about sulfide ore tailings. The copper sulfide ore contains sulfur not as the free element S8, but rather as the negatively charged sulfide ions. The ore removed from the mine would be ground into a fine power which is then mixed with water, air and detergent-like chemicals designed to help float the metal containing particles so they can be skimmed off. The waste sediment would still contain small amounts of copper, zinc, silver, gold, lead, mercury, arsenic and other elements. A large supply of sulfide ions would be combined with these metals and arsenic.
These mine wastes or "tailings" would be discarded near the proposed Crandon mine in a 355 acre pile that would be 90 feet high. The problem then becomes one of keeping air and water away from the tailings until the end of time. This is due to the ability of oxygen to convert the sulfide ions into sulfurous and sulfuric acids when water is present.
Thus, there is the potential for the release of very substantial quantities of these acids into the mine area. Some would pollute lakes and streams nearby, then be transported a short distance to the famous Wolf River, noted for its brown, brook and rainbow trout. Perhaps before long the acid levels in the Wolf River would lead to a new fish species, the "pickled trout."
Fish are quite sensitive to both acid levels and the resulting higher levels of copper, zinc, lead, mercury, etc. that are leached from the soil by the sulfur based acids. If you wipe out the fish populations, you destroy an important food source for Native Americans and others who live in the area. The Lake Superior Chippewa retain the rights to "hunt, fish and gather" on that land under their 1842 treaty with the U.S. If the fish die, part of the treaty is broken.
Tourism is also involved in this debate. If there are not fish, perhaps there will be no tourists. That means lost jobs and falling real estate values. I thought Gov. Thompson liked to fish and tried to lure those Chicago Bears up north to spend money. So who wants to see a tailings pile?
How about the proposed "FIX" by the Crandon Mining Company? They propose adding lime (calcium oxide, CaO) to the tailings to neutralize the initial acid formation, just as you add lime to a lawn or garden with acidic soil. To be truly effective over the long haul, they would need to add massive amounts of lime and have a uniform mixture throughout. Given the economics of mining where waste treatment and cleanup are regarded as profit killers, I am not willing to bet the farm on this proposal. If it fails - then what do we do? How about a chain link fence 100 miles in diameter? Or we could get it declared a "Superfund Site" and be put on a waiting list forever.
There are many other concerns about this proposed Crandon Mine. The 38 mile pipeline to transport wastewater to the Wisconsin River is interesting. Since this river is already polluted to the max, how can more be added? No problem folks - a DNR waiver can be granted by Secretary Meyer, compliments of the Guv. Let’s bring this up if he runs again.
I worry about all the wells and lakes to be sucked dry due to pumping huge amounts of water from the mine. How do you live in your home without water? No doubt those good folks from the Crandon Mining Company would provide some bottled water.
Gold is extracted from the ore using sodium cyanide, a highly dangerous compound. It is estimated that 14,000 pounds per month would be used. If sodium cyanide comes into contact with an acid, hydrogen cyanide gas is formed - the stuff formerly used in "gas chambers" on bad guys.
The Mining Moratorium Bill makes a lot of sense. The Senate passed it 29-3. The Assembly must act on it next. Rumor has it that the mining lobby wants to amend it to death. I hope that our Assembly Representatives will pass the bill in its present form. Let us learn from past mistakes and keep the Crandon area as a pristine area.
- Al Denio
(Professor Denio recently retired from the UW-EC Chemistry Department. If you would like to reach him, his phone number is 715-839-9082 or by writing him at 433 McKinley Ave, Eau Claire, WI 54701.)
