The Treibacher Industrie AG produces ferromolybdenum according to a metallothermic production procedure. In the past there were irregularities at the production, which should be removed in this project. The primary intention was to realise preparatory work and investigations for a new and extensive calculation of the burden, on basis of empirical data which is capable to calculate an ideal burden composition in dependence of the present raw materials. In order to capture the actual state of the production plant, a characterization of the raw materials and the products occurred at the beginning. In further consequence the burden mixing plant was analysed with regard to the running periods. The realization of numerous burnup attempts allowed to estimate the homogeneousness of the burden. Further investigations were carried out concerning the deposition behavior from molybdenum in the slag. After the realization of pilot experiments in the relation 1:10, which delivered excellent results concerning the molybdenum yield, test runs took place in the production plant. Subsequent a study of the possibilities of the utilisation of ferromolybdenum slag was carried out, whereby the depository might be avoided in future.