Inhaltszusammenfassung

Among other raw materials, bauxite is an important resource for the production of refractories. In 2020 the European Commission added bauxite to the list of critical raw materials. This illustrates that availability of sufficient raw material qualities will become increasingly difficult, not only for the aluminum producing industry. In the refractory industry, particularly iron contents > 2 % in calcined raw material cause problems. For some years, therefore, various studies have already been...Among other raw materials, bauxite is an important resource for the production of refractories. In 2020 the European Commission added bauxite to the list of critical raw materials. This illustrates that availability of sufficient raw material qualities will become increasingly difficult, not only for the aluminum producing industry. In the refractory industry, particularly iron contents > 2 % in calcined raw material cause problems. For some years, therefore, various studies have already been carried out on the reprocessing of these high iron non-refractory grade bauxites. In this study, the use of an acid leaching process with HCl to decrease the iron content in raw bauxites, even with different grain sizes, is specifically investigated on a laboratory scale. It is shown that, in addition to the leaching parameters used and the chemical composition, mineralogy of the raw material also plays an important role. Al2O3 and Fe2O3 contents obtained after leaching of bauxite previously thermally treated at T = 300 °C, T = 500 °C and T = 1000 °C and as well as untreated bauxite are compared. Together with the investigation of the mineralogical composition by means of powder X-ray diffraction (PXRD), conclusions could thus be drawn about the leachability of the bauxite and the containing iron phases. In addition to the optimization of the leaching parameters used, this would provide a further opportunity to improve process efficiency or selection of suitable raw material sources.» weiterlesen» einklappen

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Klassifikation

DFG Fachgebiet:
Materialwissenschaft

DDC Sachgruppe:
Ingenieurwissenschaften