Taconite

Taconite is a hard, low-grade iron ore rock found in large deposits, most famously in the Lake Superior region of Minnesota and Michigan. Because the iron content is low, taconite must be crushed into powder and processed into pellets before it can be used to make steel. Some taconite deposits contain amphibole minerals that can occur in fibrous, asbestos-like forms.

Origin

The name was coined in the nineteenth century by a Minnesota state geologist, reportedly after the Taconic mountains of the northeastern United States. Large-scale taconite processing grew after the richer natural iron ores of the Mesabi Range were depleted in the mid-twentieth century.

Significance in Asbestos Context

For patients, taconite matters because mining and processing certain taconite ores released amphibole fibers, including grunerite and cummingtonite, that resemble commercial asbestos. Workers on Minnesota's Iron Range and communities near processing plants faced questions about elevated rates of mesothelioma and other lung disease. The most famous example is the Reserve Mining case, where a company dumped taconite tailings containing amphibole fibers into Lake Superior, contaminating drinking water for the city of Duluth. If your exposure history includes taconite mining, milling, or living near these operations, the specific fiber types found in that ore can be central to identifying the source of your disease.

Example Sentence

His decades working at a taconite processing plant on the Mesabi Range put amphibole fiber exposure at the center of his mesothelioma claim.

Related Terms

Amphibole, Grunerite, Cummingtonite, Mesabi Range, Reserve Mining, Fiber Burden Analysis

Notes

• If your work or home was near taconite operations, note the specific mine or plant and the years, since ore composition varies by deposit.
• Ask whether fiber analysis distinguished the amphibole types tied to taconite from commercial asbestos products.
• Preserve any employment or union records from Iron Range mining and processing work.