A new generation of mining

Recent metallurgical research by Natural Resources Research Institute (NRRI) and Process Research Ortech (PRO) on an area ilmenite deposit has shown to produce high quality titanium dioxide.

Ilmenite is the mineral from which titanium dioxide and eventually titanium metal comes. The challenge of this study has been to remove magnesium oxide impurities.

According to “Pilot-Scale Demonstration of Ilmenite Processing Technology,” the peer-reviewed report of this study, “The mineral ilmenite is an iron-titanium oxide (FeTiO3) which is locally concentrated within small oxide-bearing ultramafic intrusions (OUI) associated with the DC [Duluth Complex]...”

In a phone interview, George Hudak, initiative director of Mining, Minerals and Metallurgy at NRRI, described ilmenite as the mineral from which we get titanium dioxide and titanium metal. “It is an iron and titanium bearing oxide mineral,” Hudak explained, “and is one of the major ore minerals for the element titanium.”

The pilot study shows how a hydrometallurgical process can be used to remove magnesium oxide and produce nearly pure titanium dioxide concentrate — resulting as a white powder. The team of researchers were able to achieve titanium purity of 99.8 percent and pure iron oxide at 98.5 percent (unoptimized) purity.

The pure iron oxide percentage was not the focus of this study and it is possible for future research to yield a higher purity percentage.

“The findings of this study are important because Minnesota has a significant resource that we hadn’t been able to extract valuable products from,” explained Matthew Milnar, NRRI research coordinator of Mineral Processing and program manager for the project, “and now we can.”

During this year-long project, the Longnose deposit in Hoyt Lakes was studied. American Shield Titanium Group, LLC., owner of the Longnose deposit and its president, Bill Ulland, authorized the test program.

Findings of this pilot study are important because of the market value of this high-quality material. According to NRRI, titanium dioxide’s market value is approximately $3,200 per ton. Iron Range taconite pellets is about $70 per ton, by comparison.

For decades NRRI has done varying degrees of research on the Longnose deposit. The years of these studies were 1990, 1994, 1996, 2002 and 2013. This most recent research, finished May 2017, shows possible future growth and diversification in area mining activity. But more research needs to be done before the local economy notices any changes.

“Through this research we have been able to show that ilmenite from Longnose can produce very pure powders,” said Hudak. “Before it can be mined, further research needs to be completed.”

Hudak said that better understanding of the deposit is needed, including tonnage and grade information along with environmental studies before this could lead to jobs in the region. This type of work, which would need to be completed for permitting, is not done by the NRRI team but by the owners of the deposit.

“As a trained geologist, I’ve known about the ilmenite there for 30 years,” Ulland in a news release from NRRI. “This process demonstrated by NRRI and PRO appears to be very cost effective with commercial potential. There’s a very strong market now for titanium oxide.”

UMD’s Center for Economic Development conducted a preliminary marketing study of titanium dioxide and found that there are few U.S. producers and that this product is highly marketable as it is used in a wide variety of products. Titanium dioxide is especially used in paints, coatings, plastics and paper. After titanium dioxide is processed into titanium metal it is used in electronics and energy storage.

“This is especially exciting because we have an opportunity to process the ilmenite to an end product, titanium dioxide, here in Minnesota,” said NRRI Executive Director Rolf Weberg. “NRRI’s role is to define the state’s portfolio of mineral opportunities. That is how we retain wealth, add value to our resources and take care of our environment.”

As far as the effect ilmenite will have on the region’s iron ore mining, Milnar expressed little concern. “As far as competition, there shouldn’t be any. Ilmenite and titanium dioxide are different products” from other material mined in the region.

There were three funding sources for this research: $300,000 from the Iron Range Rehabilitation Board, $150,000 from the University of Minnesota Vice Chancellor for Academic Affairs and $150,000 University of Minnesota Office of the Vice President of Research.

There were two project partners for this research: the University of Minnesota Duluth Natural Resources Research Institute and Process Research Ortech from Mississauga, Ontario, Canada.

Project manager was Matthew Milliner. The pilot-scale peer-reviewed article was co-authored by Milnar, Shashi Rao and Tom Petersen (technical manager).

“Matt and his team were able to produce ahead of schedule and under-budget and that speaks of the skills of Matt and the technicians,” congratulated Hudak. “It was an outstanding team and Matt deserves all of the credit for getting it done.”


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