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A new substance could expand Northern Minnesota’s mining industry and create jobs near Hoyt Lakes, according to findings of a technical report prepared by UMD’s Natural Resources Research Institute (NRRI).
Ilmenite could profitably be mined and processed into titanium dioxide, NRRI researchers found during laboratory testing. The ultra-white value-added product is typically used as a paint and plastics pigment, incorporated into pharmaceutical products and as titanium metal, said Dr. Rolf Weberg, NRRI executive director. The system would produce a concentrated titanium worth about $3,000 a ton, said Bill Ulland, president of American Shield Titanium Group LLC, which provided 10 tons of ore to NRRI for the demonstration project. Ulland also is CEO and board chair of Duluth-based IKONICS Corp.
A geologist, he became interested in ilmenite during the 1970s, Ulland said at a Thursday news conference. He owns the mineral rights at the high-grade “Longnose” deposit northeast of Hoyt Lakes, where the mineral is just below the surface. It is located near nonferrous precious metal deposits that PolyMet proposes to mine, but ilmenite contains no sulfides.
“I think this is a very important day in northern Minnesota. I believe we’re on the cusp of a new mining industry,” Ulland said. Drilling samples have established 100 million tons of the material is available, he added.
Development of the industry, until now, has been delayed by the presence of magnesium impurities in the ore and the lack of a way to remove them. The raw ore is only worth about $100 per ton, according to Ulland. That compares with about $70 a ton for taconite pellets.
To study that challenge, Iron Range Resources allocated a $300,000 grant in February of 2016. It was matched by $300,000 from the University of Minnesota to fund a pilot-scale demonstration of ilmenite processing technology. Researchers also collaborated with Process Research Ortech, near Toronto, to develop a process.
“To go from $100 a ton to $3,000 a ton is a pretty big jump,” Ulland said.
The method involves both physical and chemical processing. First, silica is removed. As a by product, it could be used as a road patch material, said NRRI Research Coordinator of Mineral Processing Matt Mlinar. Then magnetite is removed. It could be used in the process of making iron nuggets, and for other products. Then, the ilmenite concentrate would be treated with acids to remove iron oxide. The 98.5 percent pure iron powder can be used by the pigment industry. The extracted titanium oxide powder would be 99.8 percent pure.
The closed-loop system would recycle water and the acids involved in processing, Mlinar said, minimizing environment impacts near the ore body, which is located in the Lake Superior watershed.
“We know we can do more to improve the purity of the products produced from ilmenite,” he said.
The Longnose deposit is spread across 160 acres. Ulland said he believes Minnesota Power Co. owns the surface rights, although it has changed hands over the years.
Titanium is mined and processed elsewhere in the United States, including the southeastern states of Georgia and Florida. It also is produced in South Africa.
The next step will be to investigate what opportunities might exist for the mineral, and to determine how it could best be incorporated into marketable products. Mlinar noted there would also have to be environmental studies, economic feasibility studies and a search for project investors.
Weberg said interest has been expressed by potential developers.
“People are very interested in what’s going on here,” he said. But because taxpayer money was involved in the processing research, the findings must be provided to the public at large. The full report is posted online at www.nrri.umn.edu.