Central Mineral and Environmental Resources Science Center
There has been much discussion about the growing need for rare metals, which include elements such as lithium (Li), indium (In), gallium (Ga), germanium (Ge), rhenium (Re), tellurium (Te), the rare earth elements (REEs) and others. The proliferation of new metal-based technologies such as energy related technologies (solar, semiconductor, magnets, batteries, turbines, etc.) has led to the need for identifying new sources of rare metals. As there has been little organized effort to conduct a systematic national assessment of historical, existing, and new mineral deposits for a wider range of elemental content including the rare metals, the task of a national-scale assessment for rare metals is daunting. These elements are typically produced as low-cost byproducts from conventional mining operations, which met the past lower demand, but the current increased demand pressures the limited supply chain. Identification of new significant rare metal sources that may be produced at economical levels is required to augment current sources.
A USGS pilot study on historical ore samples, rocks, soils and other bulk powders has demonstrated the effectiveness of a simplified methodology for the rapid screening of rock powders for rare and critical metals. The method is a direct laser ablation ICP-MS analysis of powders, a new method that allows for the rapid (< 5 minutes per sample) screening of rock powders for elemental content for the entire periodic table (minus hydrogen (H), helium (He), nitrogen (N), oxygen (O), and fluorine (F)) in a single analysis. The method requires minimal sample handling and preparation and no difficult, slow, acid digestion. It can provide concentration ranges from major element concentrations to trace or even ultra trace (< 10 parts per billion in some cases). During a pilot screening of 150 samples from 100 western mineral localities a number of elevated values of previously not examined metals such as indium, tellurium, gallium, germanium, cobalt, rhenium, and the rare earth elements were identified.
The project objectives are to employ this new rapid analytical method to assess the Nation's inventory of previously mined ore deposits, archived ore collections, and recent samples for rare metals and full elemental chemistry. This project will provide a quick assessment of rare and critical metal resources on federal land and throughout historic mineral deposits.