RECOVERY OF NEPHELINE FROM APATITE FLOTATION TAILINGS OF APATITE-NEPHELINE COMPLEX MINERAL COMPOSED ORES

"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."

Mineral Concentrates As a Factor of the Khibiny Apatite-Nepheline Ores Efficiency Improvement

Apatite-nepheline ores of the Khibiny deposits contain the largest phosphorus-bearing resources in the world, and, at the same time, they contain associated valuable components in the rock-forming minerals — apatite, nepheline, sphene and titanium magnetite. Intensive development of the Khibiny deposits with production of only apatite concentrate and a small part of nepheline concentrate resulted in the accumulation of over 1.0 billion tons of wastes in tailing storage facilities and dumps during 90 years of JSC Apatit operation. The possibility of increasing the efficiency of the use of the main concentrates of apatite-nepheline ores of the Khibiny deposits and wastes for their processing is considered through the use of technological developments of the FRC KSC RAS, JSC RIFI and JSC Apatit to obtain traditional and new target products. A fundamentally new approach to the problem of sustainable use of natural resources is focused on establishment of the whole production chain in the region, from mining and processing operations to manufacturers of final high technology products (rare-earth products, welding and construction materials, coloring agents and other materials). They also determine the level of industrial technical progress. Keywords: Khibiny apatite-nepheline ores, mineral raw materials, extraction and processing, new materials

Promising methods of processing the kola nepheline concentrate in the current situation.

The papergives an overview of existing methods for processing the Kola nepheline concentrate into aluminum hydroxide and alumina as the end products. We selected the most promising methods of the Kola nepheline concentrate processing for a possible practical application of them in future.

Research on Obtaining Silica Xerogels from Nepheline and Study of some of their Physical and Chemical Properties

The article presents a method to obtain silica xerogels with developed specific surface based on nepheline concentrate acid decomposition in C2H5OH-H2SO4 system. It was found that the use of ethanol instead of water produces stable and steady silica gels. It is proved that the use of ethanol results in almost complete deposition of soda alum and aluminum potassium sulphate out of nepheline decomposition solution without its additional cooling, due to their extremely low solubility in alcohol solution. The morphology, structural and surface properties of synthesized xerogel sample with ~600 m2/g specific surface area (based on the analysis) were investigated; its mixed micro-and mesoporous structure was established. Electron probe microanalysis showed chemical purity of the resulting SiO2.