Development of an Evaluation Method for Processing Bauxite Ores to be Applied in the Refractory Industry
Research output: Thesis › Doctoral Thesis
Bauxite is used as raw material in many different industry fields. Whereas most of the bauxite mined worldwide is fed into the Bayer process, only about 5 % are used directly in the refractories, abrasive, cement, chemical, steel and proppant industry. In the refractory industry very stringent requirements for the chemical composition of the applicable bauxites are valid. Therefore, until now only very high quality bauxite deposits are used to cover the demands. In order to make deposits of lower quality useable in the refractory industry as well, physical processing techniques will be necessary to reach the expected requirements. Four different bauxite samples from deposits in Brazil, India, Hungary and Turkey were used to investigate the processability by means of physical beneficiation methods. The analyses and experiments covered three topics: First, the required pre-treatment processes for a subsequent successful separation step were investigated. Second, a fractional analysis with regard to the density, the optical properties and the susceptibility was accomplished. In cases where promising processes had been found, pilot-scale tests were conducted in the third place. Those bauxite samples, which could not be enriched sufficiently by physical processing techniques alone, were investigated regarding the reduction of accompanying impurities by leaching in hydrochloric acid. On basis of these results, a ‘Bauxite Analysis Scheme’ was developed to facilitate the future evaluation of any additional bauxite samples, which were not analysed within the framework of this thesis. Thereby, those beneficiation methods can be identified, which are most promising. The ‘Bauxite Beneficiation Matrix’ supports the finding of potential processing methods. This matrix was developed on the basis of a thorough literature research and of the findings from the conducted analyses and experiments. It is classified according to the main bauxite mineral and the main impurity which has to be lowered. The ‘Bauxite Processing Tests’ in pilot-scale should further complete the investigation routine and can be deduced from the ‘Bauxite Analysis Scheme’ on the one and the ‘Bauxite Beneficiation Matrix’ on the other hand.
|Translated title of the contribution||Entwicklung einer Beurteilungsmethode zur Aufbereitung von Bauxiterzen in der Refraktärindustrie|
|Publication status||Published - 2012|