Student practical training / Bachelor theses / Master theses / Diploma theses

With the energy turnaround, the demand for rare earth elements (REE) for key technologies such as lithium for electromobility or neodymium for wind turbines is increasing. The effective processing and separation of these valuable minerals represent a challenge for the mineral industry. One possibility for separation is flotation. Flotation separates the value mineral particles from gangue material based on their surface wettability. Hydrophobic valuable particles adhere to gas bubbles and rise as agglomerates. These form a froth which can be skimmed off. The efficiency of this process still remains far below the economically and ecologically desired targets for the separation of REE.

One approach to improve the process efficiency is to inhibit coalescence of bubbles so that more interfacial area is available for the attachment of the hydrophobic particles. This is achieved by adding complex organic compounds in the presence of simple salts. Present experimental study focuses on quantifying the effect of inorganic electrolytes on the coalescence behavior. Images of bubble swarm are captured by means shadowgraphy at different electrolyte concentrations. Bubble diameter distribution is then computed by means of image analysis algorithm and analyzed as a function of electrolyte concentration. The results will improve the understanding of the suppression of coalescence in a flotation cell, leading to a higher efficiency in the separation of REE.

FOCUS OF WORK

• Measurement of bubble diameter at varying concentrations of different electrolytes
• Image analysis of bubble images with ImageJ, Matlab or Python
• Summarization and documentation of the obtained data

• Studies in process/energy/mechanical engineering
• Interest in practical work
• Experience in programming with MatLab or Python is beneficial
• Good written and oral communication skills in English and German

• Start: immediately
• Duration: ca. 6 months