Dr.-Ing. Graduates

Dr.-Ing. Katja Schaldach (22nd June 2022)

Dr.-Ing. Medhanie Tesfay Gebrekidan (17th January 2022)

Dr.-Ing. Leo Bahr M.Sc. (9th July 2021)

Dr.-Ing. Simon Stehle M.Sc. (20th November 2020)

Dr.-Ing. Juian Schuster M.Sc. (6th March 2020)

Dr.-Ing. Tobias Klima M.Sc. (17th December 2019)

Dr.-Ing. Christine Holzammer M.Sc. (18th October 2019)

Dr.-Ing. Arite Werner (23th November 2018)

Dr.-Ing. Arite Werner defended her doctoral examination successfully on November 23rd, 2018.

The title of her doctoral thesis is:
Entwicklung eines membranbasierten Trenn- und Anreicherungsverfahrens zur selektiven Gewinnung von Indium und Germanium aus Laugungslösungen.

The elements indium and germanium are among the economic-strategic elements due to the steadily rising demand and the strong fixation on the nearly sole producer China. Against this background, an alternative method of biohydrometallurgical recovery was investigated at the 2nd Krüger Research College. The focus of this work is the selective separation of indium and germanium from complex model solutions through the application of nanofiltration. By developing a systematic methodology, the pH-dependent separation behaviour of the target elements, with variation of the process parameters and the process control, was specifically investigated. The variation of the pH allows the selective separation of indium and germanium from the model solutions. The transferability to real concentration ratios was successfully implemented by indium enriched in the retentate and germanium was selectively separated with the permeate.


Dr.-Ing. Franz Fehse (1st June 2018)

Dr.-Ing. Franz Fehse defended his doctoral examination successfully on June 1st, 2018.

The title of his thesis is “Granulierung von Weichbraunkohle für die stoffliche Nutzung” (Granulation of brown coal for material usage).
For the material usage of brown coal the mechanical refinement of the coal is an important process step. One example is the production of granules from brown coal with a narrow particle size distribution and high mechanical strength.
In the thesis the granulation of a brown coal from Central Germany was systematically investigated using different procedural approaches. One of the approaches used an intensive mixer for granulation of the coal. In laboratory-scale investigations the influence of the different process and machine parameters was determined independently. Using different sizes of mixers the scale-up behaviour of the granulation process was determined successfully. Thereby it is possible to produce high-quality granules with customised properties e. g. for montan-wax extraction or gas purification.