Laser analysis used for mining

As demand for minerals and other natural resources increases, so does the need for optimizing mining techniques. Fraunhofer Institute for Laser Technology has developed a laser analysis system that can identify potential mineral reserves.

As part of the InnoNet project OFUR (Online Analysis for Minerals Extraction), funded by the German Federal Ministry of Economics and Technology, the Fraunhofer researchers, in collaboration with the Institute for Mining and Metallurgy Machinery at RWTH Aachen University and seven partners from industry, have developed a demonstrator with an inline analysis module for use in mining.

The demonstrator directly analyzes rock in real time as it is being drilled. Using a conventional rig fitted with the analysis module, a 10-cm-diameter hole is drilled up to 24 m deep. The system can measure the chemical composition of the rock during drilling to make the evaluated data available immediately.

Fraunhofer Institute for Laser Technology’s laser analyzer in use on a drilling rig. Courtesy of the Institute for Mining and Metallurgy Machinery at RWTH Aachen.

Using laser-induced breakdown spectroscopy, scientists can analyze various elements within a rock by passing a laser pulse through the particles. This can provide information about the overall composition of the rock, while the chronology of the data sequence will show how the deposit is layered.

Because the data can be evaluated and presented in a matter of seconds, mine operators can determine the quality of a deposit immediately and adjust the mining process accordingly. The method has been used to detect magnesium, calcium, silicon, iron and aluminum. The researchers hope soon to be able to detect copper and other metals using a different spectrometer.

In the long term, this real-time procedure for multielement analysis could make it possible to automate extraction machinery. Work has already begun on a follow-up project that aims to make the analysis system fit for industrial application.