Base and Non-Ferrous Metals

Since prehistoric times, base metals have served – quite literally – as the building blocks of society, providing the materials for many of life’s most basic needs. From structures such as homes and skyscrapers, to tools such as farming implements and cooking utensils, to providing the means for electric power generation and transmittal, base metals such as iron, zinc, nickel, lead and copper have proved their worth over generations.

Base metals, as opposed to precious metals (gold, silver and platinum group metals) are more abundant and consequently less valuable than precious metals, and are thus the metals most commonly used by people.

Non-ferrous metals, a sub-group of base metals, are distinguished from ferrous metals (generally iron and certain ferro alloy metals). The common non-ferrous metals encountered in everyday existence are copper, nickel, zinc, lead, aluminum and tin. In Minnesota, the mineral deposits of non-ferrous metals currently being explored and developed by projects such as PolyMet’s and Franconia’s and principally being sought by other exploration groups are focused primarily on copper and nickel, and on accompanying precious metals of the platinum group.

Copper is a critical metal because of its wide use in essential applications. Copper is an excellent electrical conductor, which makes it essential in electrical power generation, transmission and distribution; and in electrical motors. Because of its corrosion resistance, copper also has wide application in water supply – most fresh water piping in modern homes is copper. The same corrosion resistance makes it useful in roofing and gutters. Other uses include cookware, as components of a wide variety of electric and electronic applications, hardware (as in brass – an alloy of copper and zinc) or bronze (an alloy of copper and tin).

World copper consumption has risen steadily throughout history and especially in the last 150 years. As living standards gradually rise in underdeveloped countries, the per capita copper consumption of developing countries can be expected to rise 10- or 15-fold to a level approaching that of Japan, Europe and North America. The United States, a large producer and consumer of copper, is now no longer self-sufficient and has become a net importer of copper. Minnesota’s copper deposits in the Duluth Complex are perhaps the largest currently undeveloped copper resource in the United States.

For the United States, nickel is both a critical and a strategic metal, in the sense that the United States imports all of its primary nickel supply. The chief use of nickel is in an alloy of nickel and steel – commonly known as stainless steel. Stainless steel has myriad applications where strength and corrosion resistance are required, ranging from scalpels and other medical instruments to armor plate. Nickel is used in the chemical industry where resistance to caustics or saline solutions is required, such as in hospital and kitchen equipment, aircraft engines, gas and power plant turbines, hard facing of construction equipment parts, and many other industrial and consumer applications.

At present, rapidly increasing use of stainless steel and other nickel applications especially in the developing world has created a major shortage of nickel in world markets resulting in supply shortages and rapidly rising prices. Duluth Complex ores represent the only known major potential source of nickel in the United States; however some other possible geologic targets for nickel in Minnesota may also warrant testing.

Precious Metals