MANGANESE DEPOSITS OF THE LAKE SUPERIOR DISTRICT, AND POTENTIAL METHODS FOR EXTRACTING THEM

Even though manganese is a critical mineral for both the iron/steel industry and battery manufacture, there are currently no active manganese mines in the US. While manganese deposits exist, they are normally considered either too small or too low-grade to be competitive for mining. The authors are developing a new approach to manganese mining that is particularly suitable for economically extracting small deposits, and so potential sites in the US deserve new scrutiny. There are a number of known deposits in the area around Lake Superior, including the Cuyuna Range in central Minnesota, and locations near Copper Harbor, Alberta, and Negaunee in the northwestern Upper Peninsula of Michigan. The potential application of this new extraction technology to these deposits, and to similar deposits that may remain to be discovered, will be discussed.