The recovery of all possible useful components from ores corresponds to modern approach to the mineral raw materials processing and provides a reduction in the amount of waste sent to tailings dumps. The increasing complexity of the mineral composition of the ore leads to the fact that the existing beneficiation methods and regimes do not provide the necessary quality of the obtained concentrates. This study shows the peculiarities of nepheline recovery from apatite flotation tailings of apatite-nepheline ores with low nepheline fraction.
Two reagent regimes were tested for nepheline reverse flotation: a mixture of pine and foliate tall oil, a mixture of tall oil and polyalkylbenzene sulfonic acid, which previously showed high selectivity of separation of nepheline and dark-coloured minerals. On the studied apatite-nepheline ore samples the necessary selection of flotation separation was not observed. Mineralogical analysis shows that losses of nepheline with froth products occur both at the expense of nepheline in intergrowths with associated minerals and at the expense of liberated minerals. Nepheline is quite actively floated, which is associated with a change in the surface properties of the mineral. The quality of flotation nepheline concentrates is reduced due to liberated grains of amphiboles, pyroxenes, and mica.
The high content of feldspar in the ore, which during flotation predominantly remains in the chamber product, also affects the quality of the nepheline concentrate. It was possible to increase the Al2O3 content in the concentrate to the required values only after magnetic separation in a strong field.