Mine Waste
Metals mining in the Eastern Alps primarily ceased at the end of the 18th century. At the time of mining metals prices and primitive processing technologies meant that lower grade sulfide ore was discarded on waste rock piles. With todays metals prices and demand these waste rock piles represent an underappreciated source of Cu-Au-and associated critical metals. Additionally, they represent a large source of arsenic contamination. Research has been pushing for an industrial application of mine waste mining for precious and critical metals, while simultaneously remediating these heavily contaminated sites.
For more details see our grant homepage.
Keweenaw Copper Belt
The Keweenaw Copper Belt is one of the most incredible mining district in the world. Therein we have the only native copper deposits in the world. Copper grades below ~10 % native copper where considered waste rock, and disposed of on large waste rock piles near the mine sites, which stretch almost 100km through the middle of the Keweenaw Peninsula in Northern Michigan.
Most of the mining ceased at the turn of 19th century, and the ore processing was rudimentary compared to today. Large stamp mills on the the shores of Lake Superior crushed the ore to sand size particles, but the processing was poor so a large portion of the copper remained in the waste which was dumped as stamp sands into the lake. While copper is an incredibly important element for modern technology, it is also toxic to certain animals especially fish. These stamp sands (especially those offshore of Gay, Michigan) have destroyed the local fisheries (Buffalo Reef), wish served as a major local industry and a traditional food source of the native communities of Chippewa that life in/around the Keweenaw.
Reprocessing these stamps sands would not only mean billions of dollars worth of copper and associated silver for the US, but also improve the environment and hopefully restore the fish stock.
REE elements in Iron Oxide Apatite Deposits, Sweden
Iron Oxide-Apatite (IOA) deposits like the famous Kiruna Mine in Northern Sweden, have been an incredibly important source for European steel industry for hundreds of years. Apatite, while an important part of the deposit formation, the phosphorous in this mineral is an incredibly deleterious element. To make sure that the steel didn't end up crumbly steel, great care was taken to separate the apatite from the iron ore. These Northern and Central Swedish IOA therefore have huge quantities of apatite rich mine waste, and therefore represent a readily accessible source of REE elements for Europe. The REEs elements are primarily present as monazite which is intergrown with the apatite.
For more details see our grant homepage.
CRMs in Pb-Zn deposits, Eastern US and Eastern Alps
Alpine type Pb-Zn deposits in Austria and MVT deposits in the Eastern US represent some of the largest mining operations their respective regions. Historically, the Zn ore (sphalerite) was unimportant, and only the Pb ore (galena) was won. Sphalerite has been shown to be incredibly good at incorporating a variety of important critical metals, most notably Ge. We have been working with a local mining company (Biominex) in Austria that which is interested in re-processing these mine wastes to extract the critical metals that remain.
The MVT districts in the Eastern US (especially Tennessee and Kentucky) are significantly different than those in the Alps, and we have shown them to be a potential source of Ga (in collaboration with partners at Austin Pey State University). Recent redevelopment of the smelters in Eastern Tennessee means that there is a reemergence of interest in the critical metals in these ores, and a realistic possibility to win them for the US industry.
