Guest Commentary: Lower sulfide should ease mining fearsI am cautiously in favor of granting PolyMet a permit to mine for the reasons explained below.
By: Roger A. Anderson, Two Harbors, Lake County News Chronicle
I am cautiously in favor of granting PolyMet a permit to mine for the reasons explained below. I say cautiously because the copper-nickel deposits in northeastern Minnesota are low sulfide ores. They contain 1to 2 percent sulfur.
The ores in Butte, Mont., contained much higher levels of sulfur. They have leached sulfuric acid and many poisonous metals into lakes and rivers. The cleanup for Butte is costly. We want to avoid that problem.
I attended the Institute of Lake Superior Geology annual meetings in Ely last May. I was able to get on a “Copper Nickel Deposits of the Duluth Complex” tour. According to the field trip guide, every American born today will need 1,309 pounds of copper during his or her life.
Serious exploration for copper-nickel began in 1948 about eight miles south of Ely when the Spruce Road was built. Areas of strong copper mineralization were uncovered in an excavation used for road material. That area was explored in the 1960s.
The area south of the Peter Mitchell mine was explored in the 1980s. The ores range from 0.5 percent to 1.5 percent copper, 0.1 percent to 0.5 percent nickel and parts per million gold, platinum and palladium. Most copper-nickel ores presently mined contain under 5 percent copper-nickel.
Northern Minnesota has world class deposits of copper and nickel. “World class” means it is among the top 10 percent of the deposits of the particular metal. We have the second largest copper-nickel resource in the world. The largest is in South Africa.
At present there are four areas of interest for development in Minnesota. Starting in the east is the Nocomis (Duluth Metals) deposit south of the Kawishiwi River and Birch Lake on either side of Highway 1. The Birch Lake deposit goes under Birch Lake about three miles miles east of Babbitt. Both the proposed Nokomis and the Birch Lake operations would mine ore more than 1,000 feet underground. The third is the Mesaba deposit south and east of the Peter Mitchell mine. The last is the NorthMet deposit which is owned by PolyMet and located south ot the Peter Mitchell Mine and west of the Mesaba deposit. The last two deposits would be mined above ground.
The NorthMet deposit/mine is the closest to opening. PolyMet purchased the old LTV taconite plant, tailings basin, and related properties several years ago. The planned NorthMet mine is about two miles south of the Northshore Mining pit. The plan is to mine about 32,000 short tons of ore per day. The ore would be ground to a fine powder in the old LTV taconite plant. A new building will be built to concentrate the ore. The valuable minerals contain most of the sulfur and it would be separated from the wastes rock. The waste rock will be deposited in the present LTV tailings basin. The water will be treated and reused in the operation.
PolyMet has a great interest in designing and running an environmentally safe operation because they are seeking a 20-year permit on a deposit that has 100 years worth of ore in it. They will be the lead operation for the three other potential mines. One of them has at least 88 billion dollars worth of copper. They want to do it right.
The copper and nickel be mined somewhere. Will it be mined in northeastern Minnesota with strict environmental standards or will it be mined in a third-world country with no regulation and possibly produce a great environmental disaster?
Anderson was born and raised in Two Harbors and graduated from Two Harbors High School in 1962. He is a UMD graduate in chemistry. He was a teacher in Milwaukee from 1967 to 1998.