Concentration of alunite ore

Within the scope of this thesis, researches has done to Kütahya – Şaphane field alunite ore, which's license belongs to Eti Mine Works. The researches has aimed to produce high alunite concentrate by separating quartz. Details and results of the laboratory tests are presented with this thesis. Studies were performed on two different samples which were crushed and bagged by Eti Maden from the region. These samples are named as high grade sample and low grade sample. The high-grade alunite ore sample contains 40-42% alunite by weight, 55-56% quartz and 2.5-4.5% by weight of other minerals formed by mostly kaolin mineral. The low-grade alunite ore sample contains 29-31 % alunite by weight, 53-55 % quartz and 14.5-16.5 % by weight of other minerals formed by mostly kaolin minerals. In the mineralogical studies, it is determined that both samples of alunite ore are formed in fine size and the samples are required to be ground below -106 μm to liberate the alunite grains from the silicate minerals. Although no significant difference has been achieved with scrubbing and dispersion for these ores, an extremely successful enrichment has been achieved with flotation. The flotation enrichment method which is widely used in quartz separation from alunite is studied in detail in the scope of this study and the results obtained are presented in this thesis. The different test parameters are tested and the best separation conditions are determined. Fatty acids were used as collector in the flotation study. Sodium carbonate (Na2CO3) was used to adjust the pH and to take advantage of the depressant effect. Sodium silicate (Na2SiO3) was used as another depressant chemical. At the end of the study, a product containing 97.59 % alunite and 2.60 % SiO2 in high-grade ore with 5-step cleaning flotation was obtained with 45.61 % alunite recovery. In low grade ore, a product containing 85.36 % alunite and 5.50 % SiO2 by weight with 4-step cleaning flotation was obtained with 69.73 % alunite recovery. Also alunite recoveries in the rougher flotation stages are 95-96 % in both samples. For the high grade alunite ore sample, the product characteristics obtained by returning the cleaning wastes in the system are calculated with the help of simulation. Simulation results showed that the final alunite product's grade reduces to 86 %. However, 94.9 % of alunite in the feed was thus obtained. After flotation tests, water and caustic leach were applied to both samples, but no detailed testing was carried out. 99.55% purity of potassium sulphate (K2(SO4)) has been obtained with 99.56% recovery with water leach. After caustic leaching carbon dioxide gas applied to solition to obtain precipitation. XRD (X-Ray Diffraction) Analysis has done to products and these analyzes are showed that some peaks are matched with aluminum hydroxide (Al(OH)3) and aluminum oxide (Al2O3).