Bauxite is, among other raw materials, an important material for the production of refractories. However, the availability of refractory raw material grades is limited worldwide. As high iron contents have a negative influence on the temperature resistance of the refractory material produced, a maximum iron oxide content of 2 wt.-% in the bauxite is acceptable. This means that only native raw materials from a few deposits can be used. In order to counteract the problem of too high iron oxide contents in natural bauxites, the possibility of processing bauxite for the refractory industry by using an acid leaching process was to be investigated within the scope of this work. In previous studies on this topic, some investigations on iron leaching have already been carried out on individual bauxites. However, the resulting bauxite composition was mostly neglected in its entirety and only the influences of individual leaching parameters on the leaching result were investigated independently. Moreover, the results and procedures generated are not generally valid and cannot be transferred to bauxites of other chemical or mineralogical compositions. In order to clarify the open questions in the processing of natural bauxites, leaching tests with hydrochloric acid were carried out on five different bauxites within this work. By using computerized statistical design of experiments, an individual model was generated for each bauxite to predict the optimal factor settings. The factors investigated were acid concentration, solid-acid ratio, leaching temperature, leaching time and grain fraction. The general planning method for bauxite processing developed in this context contains all necessary factors, useful factor settings and the effects to be considered during planning and evaluation. It could be shown that, based on this planning method, a significant, individual model can be created for each of the bauxites investigated, which predicts the optimal leaching settings for the corresponding bauxite. Furthermore, it was found that the transfer of an already created model to another bauxite of similar composition is possible. Based on the results obtained from the leaching tests and model fittings, in combination with further results on the structural analysis of the bauxites, insights into the leachability of various aluminium and iron minerals from bauxite could be gained. To develop a sustainable acid leaching process, the possibility of regenerating the contaminated acid produced was also tested as an example. It was shown that liquid-liquid extraction can extract more than 99 % of the iron present in the solution and that the regenerated acid can then be reused for the leaching process.