Bor Zenginleştirme Tesisi Ara Ürünlerinin Flotasyon İle Kazanımının Araştırılması

Abstract

Colemanite is a commercially prominent resource of boron, which is a critical raw material for sectors such as fiber optics, semiconductors, solar cells, etc. In the Bigadic Boron Plant, which is one of the important boron production points of our country, products with particle sizes of -25 and -3 mm, which are characterized as low-grade products, are stocked. Within the scope of this study, considering the environmental effects and stock costs of stocking these products, it is aimed to investigate the improvability of this stock to usable grades by applying additional methods to the existing boron enrichment methods of the plant. In the current process at the facility, three quality products are obtained as a result of washing and classification processes in general. Experimental studies have been carried out in order to obtain usable products from the low grade material that is produced and stocked as a result of this process. The -3+0.2 mm stock is problematic in terms of clay content and impurities and it is approximately 3 times the amount of -25+3 mm stock. Due to content of -25+3 mm stock, it can be mixed and sold with high grade products. However, some additional methods are required for the -3+0.2 mm stock. Therefore, studies were performed based on the -3+0.2 mm stock. Within the scope of the experimental studies, characterization tests, washing and attrition scrubbing tests, heavy liquid tests to examine the suitability for gravity enrichment, teetered bed separation and hydrocyclone tests for classification purposes and also flotation tests for enrichment were carried out. As a result of the experimental studies, it has been seen that the B2O3 content of the stocks is approximately 25-30% and it can reach the usable grade with the removal of impurities such as calcite, talc, silicate and dolomite from low grade products. Chemical analysis showed that Al2O3, CaO, MgO, etc. contents tend to increase towards fine fractions by size classification after attrition scrubbing process. MLA (Mineral Liberation Analyzer) results revealed that the degree of colemanite liberation is at the level of 93% in -300 µm size fraction. Detailed qualitative clay XRD (X-ray Diffraction) analysis showed that -25 µm fraction of the material dominated by montmorillonite mineral. According to the results obtained, the clay mineral in the low grade products were removed from the colemanite surface by attrition, and after this stage grade values 40% and recovery values up to 90% were reached by flotation. With the data obtained, the flowsheets including the combination of gravity enrichment methods and flotation methods are also evaluated in this thesis.