Talking Points

Talking Points

Talking Points on Banning Cyanide at Mines

(Published: March 04, 2002)

The Examples Used by Supporters of the Ban Do Not Apply at Crandon

* Supporters of the ban point to mine disasters at gold mines around the world. These mines used heap leaching, a process where huge piles of ore are sprinkled with a cyanide solution outside in order to extract the gold. By contrast, Crandon will only use the “froth flotation” process, which occurs completely indoors in a contained and controlled environment and uses dramatically less cyanide.

* Crandon is a zinc/copper mine, not a gold mine. There is no recorded environmental incident involving cyanide at any copper/zinc mine using the froth flotation process.

* Supporters of the ban point to a ban on cyanide passed in Montana. However, that ban only relates to cyanide used at heap leaching operations and, therefore, would not ban cyanide use at a facility like the Crandon mine.

The Transportation of Cyanide will be Safe

* The transportation of cyanide is completely regulated by the U.S. Department of Transportation.

* The cyanide will be transported in briquette (like charcoal) form, not liquid form.

* There is no recorded spill or release of cyanide during its transportation in the United States.

* Fifty other Wisconsin companies transport cyanide into Wisconsin, and our local governments spread it on our roads every time they use road salt.

Use of Cyanide at the Crandon Mine will be Safe

* Crandon will use approximately 69 grams of sodium cyanide per ton of ore processed which translates into seven tons of cyanide per month, or about one truckload every three months.

* The cyanide will be stored and handled inside the mill, in an enclosed and well-regulated environment. Advanced spill containment safeguards and protocols will be in place (and employees will be trained on the handling of cyanide, and all other hazardous substances). The mill building itself is designed to prevent any release of any chemical reagent.

Why Crandon needs Cyanide

* Cyanide is used as a reagent in the “froth flotation” process at the mill. It helps separate the zinc and copper from the ore.

* At this time, there are no proven substitutes for cyanide for the Crandon orebody.

* Any substitutes would require the use of other chemicals that might require much higher consumption and transportation volumes and the substitutes may pose unknown and serious environmental dangers. By contrast, the use of cyanide is well understood.

The Cyanide is Destroyed in the Mill Process

* 99.75% of the cyanide used at the mill will be actively destroyed in the froth flotation process.

* There will be no detectable levels of cyanide in the tailings deposited in the company’s landfill. Any residual amounts that may be left in the tailings will quickly break down into harmless compounds and pose no threat to the environment.

* The only detectable level of cyanide “exposed” to the environment will be in the backfill that goes into the underground mine. That level, at its highest, will be .011 milligrams per liter. That is four times lower than the state’s extremely conservative preventative action limits for groundwater, and nearly twenty times less than the level of cyanide allowed in bottled drinking water (.2 milligrams per liter).

Cyanide is used extensively in Wisconsin

* EPRCA data shows that 50 other companies use cyanide in Wisconsin as an industrial chemical, mostly in the metal finishing and electroplating industries.

* The largest user of cyanide in Wisconsin is, by far, the government spreading of road salt. Millions of pounds of road salt are spread in Wisconsin every winter. Road salt contains 350 parts per million (ppm) cyanide.

* The citizens of Wisconsin ingest cyanide every day: Table salt contains 13 ppm cyanide, lima beans 31 ppm, almonds 100 ppm and coffee 6 ppm. All these amounts are vastly larger than the trace concentrations left at the Crandon mine.