Abstract Bauxite is the main raw material in primary aluminum production and its reactive silica content and mass ratio of Al2O3 to SiO2 (A/S) has a critical role in the economic viability of Bayer process. As a major source of the reactive silica, clay impurities should be removed from the ore as much as possible by a beneficiation method such as froth flotation before the Bayer processing. The success of the beneficiation method largely depends on geological origin and mineralogical composition of the bauxites. In this study, low-grade bauxite ore from Seydisehir (Konya, Turkey) containing 57.33% Al2O3 and 9.01% SiO2, (A/S = 6.36) was investigated to determine the modal mineralogy and mineral liberation with regard to the removal of reactive silica by flotation. Mineralogical studies showed that the principal bauxite mineral was boehmite interlocked with clay minerals (kaolinite and illite), ferruginous minerals (hematite and goethite) and titanium bearing minerals (e.g. rutile and ilmenite). By reverse flotation of the ore, a high-grade bauxite concentrate with A/S ratio 8.54 was obtained, however the Al2O3 recovery remained low at 42.87%. Although the A/S rate achieved by the flotation was adequate for the Bayer process, Al2O3 recovery was considered to be low for flotation process. It was deduced that the separation of reactive silica by flotation with plausible recovery was difficult, largely due to the complex mineralogy and poor mineral liberation.

中文翻译：

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Seydişehir（土耳其科尼亚）低品位勃姆石铝土矿的表征和浮选

摘要 铝土矿是生产原铝的主要原料，其活性二氧化硅含量和Al2O3与SiO2的质量比(A/S)对拜耳法的经济可行性至关重要。作为活性二氧化硅的主要来源，粘土杂质应在拜耳处理前通过泡沫浮选等选矿方法尽可能多地从矿石中去除。选矿方法的成功在很大程度上取决于铝土矿的地质来源和矿物组成。在这项研究中，研究了来自 Seydisehir（土耳其科尼亚）的低品位铝土矿，其中含有 57.33% 的 Al2O3 和 9.01% 的 SiO2（A/S = 6.36），以确定与去除活性二氧化硅有关的模态矿物学和矿物释放通过浮选。矿物学研究表明，主要的铝土矿矿物是勃姆石，与粘土矿物（高岭石和伊利石）、铁质矿物（赤铁矿和针铁矿）和含钛矿物（例如金红石和钛铁矿）互锁。通过矿石的反浮选，获得了 A/S 比为 8.54 的高品位铝土矿精矿，但 Al2O3 回收率仍然很低，仅为 42.87%。尽管浮选达到的 A/S 率对于拜耳法来说是足够的，但认为浮选法的 Al2O3 回收率很低。据推断，通过浮选分离反应性二氧化硅并具有合理的回收率是困难的，这主要是由于复杂的矿物学和较差的矿物释放。通过矿石的反浮选，获得了 A/S 比为 8.54 的高品位铝土矿精矿，但 Al2O3 回收率仍然很低，仅为 42.87%。尽管浮选达到的 A/S 率对于拜耳法来说是足够的，但认为浮选法的 Al2O3 回收率很低。据推断，通过浮选分离反应性二氧化硅并具有合理的回收率是困难的，这主要是由于复杂的矿物学和较差的矿物释放。通过矿石的反浮选，获得了 A/S 比为 8.54 的高品位铝土矿精矿，但 Al2O3 回收率仍然很低，仅为 42.87%。尽管浮选达到的 A/S 率对于拜耳法来说是足够的，但认为浮选法的 Al2O3 回收率很低。据推断，通过浮选分离反应性二氧化硅并具有合理的回收率是困难的，这主要是由于复杂的矿物学和较差的矿物释放。