Online Analysis Methods for the Extraction of Mineral Resources

As part of the project "Online Analysis Methods for the Extraction of Mineral Resources" (OFUR) funded by InnoNet (Promotion of Innovative Networks), the AMT (formerly IMR) in cooperation with several small and medium-sized companies and the Fraunhofer Institute for Laser Technology (ILT) developed a system for real-time elemental analysis of raw materials during the extraction process. Laser emission spectroscopy is used to analyze the material to be mined and determine the concentrations of various substances. In contrast to previous analyses, the results are immediately available and can be used to optimize the degradation process.

Laser technology for underground rock analysis

The advantage of OFUR is obvious: The constantly increasing demand for mineral raw materials means that responsible and efficient handling of existing deposits is indispensable. At present, cutting mining machines are still largely controlled manually in the extraction of raw materials. The boundary layer between the valuable mineral and the surrounding rock can only be detected visually and very inaccurately by the operator. This leads to an increased mining of worthless rock, a higher wear of the cutting tools and thus to increased costs and a poor deposit yield.

The objective for the use of OFUR on cutting mining machines underground was therefore to develop a method with which an automatic and targeted control of mining machines can be guaranteed by early detection.

Laser technology for rock analysis during drilling or blasting

Another advantage of OFUR is that even in the extraction of raw materials by drilling and blasting, an analysis of the material to be extracted can currently only be carried out by examining the drill cuttings. As a result, the results are only available with a time delay and adaptation of the drilling and extraction process to the changing rock compositions is only possible to a very limited extent.

The use of OFUR in drilling extraction now makes it possible to detail deposit models and control quality quickly. In addition, time-consuming and costly core drilling can be partially replaced by online analysis.

A particular challenge was the integration of the laser-based sensor technology into the operating field of the mining industry. Dust, moisture and vibrations are factors that had to be taken into account when designing the sensors.