Grant: Alliance Grants

The services of commercial laboratories are required throughout the development of a mine of critical minerals. This includes the analysis of: a variety of samples collected during grassroots exploration campaigns, drill cores to map out the ore body and determine where to mine, and mine tailings and effluent discharges to mitigate environmental risks. Currently, each solid sample is pulverized and usually put in solution through treatment with several acids. The latter step may take several days, depending on resilience of the sample to acid attack. This process is widely adopted because it results in homogeneous solutions that can be correctly analyzed with good precision if nothing interferes during the analysis. Unfortunately, the analysis technique is susceptible to interferences from sample components in large concentration. Furthermore, the numerous steps involved in the dissolution process may lead to contamination or the loss of important components, resulting in incorrect results and requiring a repeat of the whole process. All these problems delay the release of results to customers (one month is not unusual). Swifter methods are required to provide results within a day or two of receiving samples so that, for example, people performing exploration may take more samples in the area of suspected deposits to confirm their presence or move elsewhere if no deposit is indicated. The time window for such exploration is limited, as it is difficult with snow and ice on the ground. The aim of this project is to develop methods that enable the direct analysis of solids, mine tailings, effluent discharges, etc., without any sample preparation step, thereby avoiding all the aforementioned problems. One approach involves heating the sample in a small furnace while transporting vaporized components to the instrument for detection. With this approach, a sample can be analyzed in 80-100 seconds. Another approach involves the use of a laser for bulk analysis, depth profiling or mapping of the surface composition of a sample. Both approaches have been used mostly by researchers and require improvements to make them robust enough for implementation in a commercial laboratory.