Investigation of recovery of rare earth elements from Eskişehir Sivrihisar Beylikahır complex ores

There is a complex ore deposit containing fluorite, barite, and REE in Eskişehir province, Sivrihisar district, Beylikahır region. Enrichment studies were carried out on the composite samples prepared in order to investigate the possibilities of recovering rare earth elements in this ore deposit.The sample to be studied was weighed and determined to be approximately 120 kg. With the sample preparation processes, all of the material was crushed to -1 cm and representative samples of 1 kg were prepared. Mineralogical and chemical analyzes of the prepared samples were made. According to the results of the chemical analysis, it was determined that 27.24% BaSO4, 28.05% CaF2, 1.31% CeO2, 0.87% La2O3, 0.21% Nd2O3, 0.084% ThO2 and 0.001% U3O8. Considering the general characteristics of the ore, for enrichment, it was predicted that the scrubbing method could be used for pre-enrichment due to the differences in work index values and mineral grain sizes. In the experiments, abrasion tests were carried out on representative -1 cm grain size samples at 75% pulp density at 1000, 1500, 2000, and 2500 rpm mixing speeds for 5, 10, and 15 minutes. Grade and yield distributions were determined by separating the abraded samples into fractions by wet sieving. According to the analysis results of the samples obtained from these experiments, it was decided to apply the 2000 rpm stirring speed and 15 min abrasion condition corresponding to the highest yield of rare earth oxides.In the scope of this study, a -10 μm grain size was studied after the scrubbing. After the abrasion tests, the flotation sample was prepared with a particle size of -10 μm at the mixing speed of 2000 rpm. After flotation sample preparation, the effects of collectors and suppressors on yield and grade were investigated. For the depression of barite and fluorite and for the flotation of rare earth oxides, different depressants and their dosages were tested. Because of the experiments, REE minerals could not be floated. For this reason, after the flotation of barite, the method of separating fluorite and rare earth minerals from each other was applied. In the best condition, barite was floated using 1000 g/t Na-silicate, 600 g/t citric acid, and A-845 as the collector. After three stages of cleaning, BaSO4 with 93.69% grade was obtained with 57.01% efficiency. There was no discrimination in the experiments for fluorite and REE minerals remaining in the waste.