Nepheline Ore Research Articles

Extraction of Valuable Components in the Process of Recycling of Technogenic Materials of Alumina Production

In the process of recycling man-made resource-saving additives into alumina raw materials, waste fireclay refractory bricks used for lining rotating furnaces and other thermal units were tested. A sufficiently high level of aluminum oxide extraction from fireclay lining has been experimentally confirmed. It has been established that when more than 95 000 tons of stored refractory fireclay brick waste is involved in the technological process, savings on a natural raw material resource are achieved: about 56 700 tons of nepheline ore.

Rare Earth Element Resource Potential of Super-Large Deposits in Eastern Fennoscandia

This work has been carried out to assess the rare-earth potential of the main ore minerals of the Lovozero and Khibiny deposits. The loparite and eudialyte deposits are associated with the giant Lovozero intrusion (Eastern Fennoscandia, Kola Peninsula). There are several deposits of apatite–nepheline ores in the Khibiny complex. All these ores take the leading position in the structure of the raw material base of Russia. The highest contents of the sum of rare earth metals (REMs) are typical of loparite ores (the content of ΣREE in loparites is about 28 wt %), light rare earths sharply dominate over heavy ones (the Ce/Yb ratio is about 78000). The sum of REEs in eudialytes is about 2 wt %. A remarkable feature of eudialyte ores is the high concentration of the heavy REM group (the Ce/Yb ratio is about 14). The apatites of the Khibiny deposits occupy an intermediate position: the Ce/Yb ratio is 680, and the average concentration of the REE sum is 0.9 wt %. The conditions of formation of apatite, loparite, and eudialyte ores are considered.

Pre-activation of nepheline before the enrichment

Due to limited reserves of bauxite, nepheline can be used in the industrial production of alumina in Kazakhstan. The most promising deposit is the nepheline syenites of the Kubasadyr deposit. Currently, there is no effective technology for processing nepheline ores. High energy intensity, capital intensity and significant emissions into the atmosphere are the main drawbacks of the conventional technology of nepheline ore processing by sintering method. Efficient hydrochemical processing of nepheline requires pre-enrichment with the separation of a part of silica. According to the existing technology of chemical enrichment in an alkaline solution at a temperature of 280⁰С, the silica extraction degree is no more than 36%. A pre-roasting at 500⁰C is used to increase the extraction rate of silica and this process permits an increase in the extraction rate to 65%. The paper presents the results of the chemical activation of nepheline syenites in a solution of sodium hydrogen carbonate. The optimum conditions of activation are determined. Activation at a temperature of 280 ⁰C resulted in a change in the phase composition of the feedstock and increases the degree of silica extraction up to 65,5%. The results obtained showed the possibility in principle of using hydrochemical enrichment technology for the resulting high-quality nepheline concentrate and replacing the energy-intensive roasting process.

Express Assessment of Apatite Content in Apatite–Nepheline Ores of Ultrabasic Alkaline Complexes Based on Its Luminescent Properties (The First Study Stage)

The article presents the results of the first study stage aimed at analyzing the luminescent properties of the main and minor minerals composing the apatite–nepheline ores and host rocks in the deposits of the Khibiny rock massif (Kola Peninsula, Russia). The main purpose of the work was a search of a stable identification feature providing fast and safe determination of fluorapatite in the mineral mixture of apatite–nepheline ores and solving technological tasks, namely sampling the borehole walls in open pits. The first stage includes studies carried out on pure mono-fractions of four minerals occurring in fluorapatite deposits and possessing obvious luminescent properties: fluorapatite, nepheline, calcite, and sodalite. The authors have revealed luminescence spectra of these minerals and established correlation of their spectral characteristics with the literature data and their consistency. However, the high intensity of sodalite luminescence in a wide band can complicate identification of fluorapatite by the luminescence spectrum in many cases. Therefore, it is reasonable to use the color and intensity of luminescence rather than spectral characteristics.

Ore hardness properties evaluation based on industrial comminution circuits surveys

The paper addresses determination of ore hardness and grindability parameters using the data obtained from the industrial comminutions circuits survey campaigns. The calculations use the earlier obtained relations between the high-energy impact fracture parameters A and b from JK DWT and SMC tests and the energy efficiency indices used in the Morrell method for the conventional grinding, coarse grinding and high pressure grinding roll milling. Using the simulation modeling of comminution circuits for two types of sulfide copper–nickel ore and one type of apatite–nepheline ore, it is shown that the relative error of the theoretical determination of the JK DWT and SMC testing data is never higher than 16.1%. The calculation method is recommended for application in design and optimization studies of process plants for various genesis minerals, including iron ore. The study was supported by the state contract for research activity in 2021, Grant No. FSRW-2020-0014.

The Molecular Weight Distribution of Occluded Hydrocarbon Gases in the Khibiny Nepheline–Syenite Massif (Kola Peninsula, NW Russia) in Relation to the Problem of Their Origin

The origin of hydrogen–hydrocarbon gases present in the rocks of the Khibiny massif in unusually high concentrations has been the subject of many years of discussion. To assess the role of potential mechanisms and relative time of formation of gases occluded in inclusions in minerals, the molecular weight distribution of C1–C5 alkanes in the main rock types of the Khibiny massif was studied. For this purpose, the occluded gases were extracted from rocks by mechanical grinding and their composition was analyzed on a gas chromatograph. It is established that the molecular weight distribution of occluded hydrocarbon gases in the Khibiny massif corresponds to the classical Anderson–Schulz–Flory distribution. In addition, the slopes of the linear relationships are relatively steep. This indicates a predominantly abiogenic origin of the occluded gases of the Khibiny massif. At the same time, a small proportion of biogenic hydrocarbons is present and is associated with the influence of meteoric waters. It was also found that in the Khibiny massif, the proportion of relatively high-temperature gases decreases towards the Main foidolite Ring in the following sequence: foyaite and khibinite–trachytoid khibinite–rischorrite and lyavochorrite–foidolites and apatite–nepheline ores. In the same sequence, an increase in the proportion of heavy hydrocarbons and the increasing role of oxidation and condensation reactions in the transformation of hydrocarbons occurs.

Calculation and experimental determination of equilibrium composition of liquors in certain instances of the Na2O – К2O – Al2O3 – H2O System

Presently, one can definitely state a rising interest to potassium-bearing aluminium ores, which is due to a gradual depletion of conventional raw materials and the fact that the ores that are mined today are leaner and have a more complex composition. At the same time, soda-potassium products, potassium fertilizers, aluminium hydroxide, alumina and alumina materials are in high demand and sell at high prices. Today, the focus is on new deposits of urtite rock and nepheline ores, as well as those of ultrapotassium rischorrite and synnyrite rock. That’s why it is very important to have a basic understanding of the nature and properties of the technically important system Na2O – К2O – Al2O3 – H2O, which defines the performance of the key processes involved, as well as the output and quality of the final product. In this regard, studying phase equilibria in the above system, the information about which is lacking or inconsistent, can be pointed out as one of the current research priorities. Two methods were tested aimed at reducing the time necessary to reach equilibrium in the Na2O – K2O – Al2O3 – H2O system. One involves hydrolytic decomposition of aluminate liquors with aluminium hydroxide used as seed; the other involves a mathematical description of the curves characterizing the kinetics of gibbsite solubility in alkaline liquors with a given mole fraction of K2O. Similar laboratory equipment and materials were used in the experimental study regardless of the way equilibrium was reached and identified. Through experiments, it was established that the process of approaching equilibrium in predominantly potassium aluminate liquors has complex kinetics and mechanics impeding rapid identification of equilibrium composition of liquors. With regard to the technique that involves gibbsite dissolution in weak sodium-potassium liquors, the authors demonstrate how asymptotic approximation functions can be effectively used to determine maximum solubility of aluminium oxide. The results of experiments aimed at defining the equilibrium compositions of liquors at 60 oC in certain instances of the Na2O – К2O – Al2O3 – H2O system have a good and satisfactory correlation with the modelling data based on the additivity principle, which suggests that the modelling technique can effectively be applied to other temperatures and instances of the 4-component system in view. This research was funded by the Russian Science Foundation under the Agreement No. 18-19-00577-П dated April 28, 2021 on granting funds for basic scientific research and exploratory research.

Elemental analysis of phosphorus ores using the tagged neutron method

The results of the pilot operation of the AGP-F facility in determination of mass fraction of phosphorus pentoxide in phosphorus ores are discussed. The facility operates by the tagged neutron method, irradiates ore with fast neutrons with an energy of 14 MeV and records the characteristic emission of gamma rays from inelastic neutron scattering reactions. The pilot operation of the AGP-F facility at Vostochny Mine of Apatit JSC well demonstrated the main features of the elemental analysis of apatite–nepheline ores using the tagged neutron method. This is primarily the absence of any sample preparation and the ability to determine the elemental composition of samples of large mass (3–5 kg) and size (up to 100 mm). Based on measurements of 75 ordinary samples with a particle size of -10 0 mm, the measurement accuracy was estimated. The absolute value of the standard deviation in the range of P2O5 contents of 2–25% is RMSabs = 1.17% P2O5 (RMSrel = 8.3%) with a measurement time of 10 minutes. Measurements of the calibration collection of 69 samples with a size of -3 mm showed RMSrel = 3.33% in the range of P2O5 of 1-40%. The minimal concentration of P2O5 was determined. It was 1.71%. Measurements of 58 samples with size of -100 mm made it possible to determine a transient response that relates the values of the AGP parameter for samples with size of -100 mm and with size of -3 mm. An important result was obtained on the simple linear dependence of this characteristic. It shows that due to the high penetrating power of fast neutrons with an energy of 14 MeV, a natural averaging of the elemental concentration over the entire sample material occurs and the value of the AGP parameter becomes the same for both the large-sized sample and small ones. This result is important to for the future use of TNM for a conveyor system. The tests have fully confirmed the consistency of the tagged neutron method for determining the elemental composition of phosphorus ores. The applicability of the tagged neutron method for determining mass concentrations of 25 chemical elements (Na, Mg, C, N, O, F, Al, Si, P, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Zr, Pb, Sn, Bi, Sb) is verified.This article is devoted to the memory of Dr. Phys.-Math. V. M. Bystritsky who greatly contributed to the tagged neutron method development and the AGP-F facility engineering.The authors express their deep gratitude to: S. A. Zhurba and Skolkovo Innovation Center for the sponsorship of the pilot facility manufacturing; V. B. Melnik, I. V. Salnikov, I. Yu. Rybin, A. A. Skryabin, E. V. Persiyanov, N. B. Domosevich and D. A. Mikhailov from Apatit’s Division in Kirov for the help in experimentation; E. A. Andreev, E. V. Zubarev, P. P. Reunov, A. B. Sadovsky and O. G. Tarasov from Diamant LLC for the participation in engineering and testing of AGP-F facility.

Development of a human-machine interface for cascade control mills in obtaining nepheline ore charge

Development of a human-machine interface for cascade control mills in obtaining nepheline ore charge

Design and operation of SOMEX column flotation machines for processing the Khibiny apatite–nepheline ore

The article discusses design variables and operation, as well as control and adjustment of process flows in column flotation machines of the same size from four different manufacturers. The relevance and key features of the column flotation method are shown. The main directions of modernization of column flotation machines with justification and comparison of operational characteristics are revealed. The technological performance indicators of the Russian flotation column, developed on the basis of a comparative analysis, are given. In Russia, column flotation machines are widely used in the flotation of phosphate raw materials. They are used at the processing plants of Apatit and North-Western Phosphorus Company, processing apatite–nepheline ores of the Khibiny deposits, and ensured a reduction in the number of refining operations from three to one. Column flotation machines of four manufacturers are used at these enterprises: CPT (Canada), BGRIMM (China), Metso Minerals (Finland), SPA SOMEX (Russia). Brief results of technological tests comparing the performance of two parallel sections, one performed on equipment manufactured by Metso Minerals, the second on the equipment of SPA SOMEX, are presented. It is established that the column flotation machine manufactured by SPA SOMEX takes into account the experience of operating columns from various manufacturers and is the most advanced version of column apparatuses.

Increasing the efficiency of phosphate ore processing using flotation method

The paper presents flotation of two phosphate ore samples of different origin. Statistical analysis was used to study the effect of operating parameters on flotation efficiency. The paper proposes to increase the efficiency of flotation processing of magmatic phosphate ore with a low grade of the valuable component (P2O5 = 10.88 %), containing nepheline and feldspars, by means of direct anionic flotation. Authors present an optimization of anionic flotation using tall oil fatty acids mixed with anionic phospholane as an anionic collector. The effect of adding soda ash to compensate for the influence of calcium cations on technological parameters of P2O5 flotation was examined. The results of studying the flotation of nepheline ore (flotation tailings of magmatic phosphate ore) showed that replacement of phospholane with oxyethylated isotridecanol allowed to obtain a high-quality concentrate. It was estimated that with the addition of Na2CO3 in the amount of 2,000 g/t, a concentrate was obtained with the grade and recovery of phosphorus pentoxide equal to 39.15 and 94.19 %, respectively. The paper proposes to increase the efficiency of flotation processing of sedimentary phosphate ore with a low grade of the valuable component (P2O5 = 22.5 %), containing gypsum and quartz, by means of desliming followed by anionic or cationic reverse flotation. Tall oil fatty acid with anionic phospholane was used as a collector in anionic reverse flotation, and amine was used in cationic reverse flotation. Sodium tripolyphosphate was used as a P2O5 depressant. It was found to be an effective depressant in both anionic and cationic flotation. When analyzing the statistical plan, it was estimated that the maximum grade of the valuable component in the concentrate (P2O5 = 31.23 %) and the recovery to concentrate of 95.22 % were obtained in the chamber product at amine consumption of 950.88 g/t and sodium tripolyphosphate consumption of 500 g/t.

Effect of phase type in the alumina precursor on the flash calcination synthesis

Economical alumina precursors, derived from bauxite or nepheline ores, were calcined through a very short time process. Results showed that phases of the precursor are a key parameter on the flash calcination process. The number of structural water molecules is the dominant phenomenon. A porous and fine structure of activated alumina was developed as the hydroxyl groups are explosively driven off and establish a hydrothermal condition. The presence of gibbsite phase with larger particle size and most structural water molecules has better product properties in comparison of other alumina precursors phase with small particle size because water vapor pressure achieves a critical value for splitting particles and developing nucleation desirable phases. The changes rate of properties reaches to its maximum value for gibbsite phase at lower calcination temperature. FESEM images showed the precursor phase forms different morphologies of products like, nanodimensional, a coral-like co-continuous or loose particles surrounded with macropores.

Software for Efficient Chemical Technologies for Processing of Apatite–Nepheline Ore Waste

Aspects of the methodological support of digital twins were presented by the example of the chemical and energy engineering process of phosphorus production from apatite–nepheline ore waste. Algorithmic support was developed for one of the levels of the hierarchy of the information structure of a self-refining digital twin. This support is intended for the complex optimization of the operation of the phosphorus production plant according to the criterion of the minimum resource consumption. The algorithm is based on the ensemble application of deep neural networks, the training of which can continue during the operation of the plant. The results of a model experiment performed using the created program that implemented the developed algorithmic support of the self-refining digital twin were presented.

Computer-Assisted Decision-Making System of Optimal Control over the Energy and Resource Efficiency of a Chemical Energotechnological System for Processing Apatite–Nepheline Ore Wastes

Some multilevel decision-making algorithms have been developed to provide optimal control over the energy and resource efficiency and environmental safety of a chemical energotechnological system designed for processing apatite–nepheline ore wastes and composed of a grinder, a granulator, a roasting conveyor machine, and an electric ore-smelting furnace (EOSF). The mutually dependent set of parameters of wet granules at the outlet from the tray granulator, roasted granules at the outlet from the roasting conveyor machine, and granules loaded into the EOSF and the characteristics of initial finely dispersed technogenic raw materials is taken into account alongside the effect of these waste-processing indices on the quality and purity of the finished product, namely, yellow phosphorus. Descriptive and mathematical formulations are given for the problem of optimal control over the energy and resource efficiency of a complex multistage chemical energotechnological system for processing apatite–nepheline ore wastes with the production of yellow phosphorus with consideration for the spatial and temporal interdependence between the chemical and energotechnological processes occurring in this system. One complex energy and resource efficiency criterion is the prime cost of electrical and heat energies, water, and coke spent on processing apatite–nepheline ore wastes in the considered chemical energotechnological system. It has been established that the optimal system functioning regime intensifies all the chemical energotechnological processes, decreases the energy and coke consumption, and increases the quality and purity of the finished product (i.e., yellow phosphorus). This study has resulted in a solution for the urgent scientific and practical problem of improving the energy and resource efficiency and environmental safety of a complex system for processing technogenic apatite–nepheline ore wastes via intensifying the chemical energotechnological processes occurring in this system.

The Paleozoic-Aged University Foidolite-Gabbro Pluton of the Northeastern Part of the Kuznetsk Alatau Ridge, Siberia: Geochemical Characterization, Geochronology, Petrography and Geophysical Indication of Potential High-Grade Nepheline Ore

Geological, geochemical and ground magnetic techniques are used to characterize the University alkaline-gabbroid pluton and crosscutting N-S trending alkaline dikes, located northeast of the Kuznetsk Alatau ridge, Siberia. Trace element concentrations and isotopic compositions of the igneous units were determined by XRF, ICP-MS and isotope analysis. The Sm-Nd age of subalkaline (melanogabbro, leucogabbro 494–491 Ma) intrusive phases and crosscutting alkaline dikes (plagioclase ijolite, analcime syenite 392–389 Ma) suggests two stages of activity, likely representing separate events. The subalkaline and alkaline rocks are characterized by low silicic acidity (SiO2 = 41–49 wt %), wide variations in alkalinity (Na2O + K2O = 3–19 wt %; Na2O/K2O = 1.2–7.2 wt %), high alumina content (Al2O3 = 15–28 wt %) and low titanium content (TiO2 = 0.07–1.59 wt %). The new trace element data for subalkaline rocks (∑REE 69–280 ppm; La/Yb 3.7–10.2) of the University pluton and also the crosscutting younger (390 Ma) alkaline dikes (∑REE 10–1567 ppm; La/Yb 0.7–17.8 ppm) both reflect an intermediate position between oceanic island basalts (OIBs) and island arc basalts (IABs). The presence of a negative Nb–Ta anomaly and the relative enrichment in Rb, Ba, Sr, and U indicate a probable interaction of mantle plume material with the lithospheric mantle beneath previously formed accretion complexes of subduction zones. The isotopic signatures of strontium (εSr(T) +3.13–+28.31) and neodymium (εNd(T) +3.2–+8.7) demonstrate the evolution of parental magmas from a plume source from moderately depleted PREMA mantle, whose derivatives underwent selective crustal contamination.

Resource-saving technologies in the processing ofnepheline ores by sintering

To solve ecological problems in alumina production, ecological measures were implemented to reduce the consumption of mineral natural resources and by involving secondary technogenicmaterials in the production. In the processing ofnepheline ores, a number of technologies were tested and implemented into production for the introduction of various additives of technogenic raw materials into the raw alumina charge: spent chamotte refractory bricks, ferrotitanium production slag, and combined heat and power plant ash. The introduction of technology for processing oftechnogenic raw materials provided the use of spent chamotte bricks of more than 70,000 tons, while saving natural raw materials: nepheline ore of about 42,000 tons. In addition to saving mineral resources, work was carried out to reduce waste water discharges into open water basin and reduce the water intake of treated water for production needs. For this purpose, the technological equipment for water supply of the combined heat and power plant was replaced. As a result of the introduction of new cooling towers, the waste water discharges into an open water basin was eliminated and the intake of treated water from the river was reduced by 40.07 millionm3per year.

Hybrid Composites Based on Silica and Titanium(IV) Phosphate for Sorbents

Using a titania–silica precursor with the composition SiO2 ∙ TiO2 ∙ хH2O, isolated via hydrochloric acid treatment of a process waste from the dressing of apatite–nepheline ore, we have prepared a hybrid composite containing silica as a matrix for an α-Ti(HPO4)2 ∙ H2O functional filler (STP). The key step of the synthesis process is a solution-phase reaction of the precursor with phosphoric acid. Our results demonstrate that a preferable sequence of steps begins with the mechanical activation of the components of the precursor, with their phase transformations. Using a combination of subsequent heat treatment with phosphoric acid with different concentrations under atmospheric conditions and in an autoclave, we have found conditions for chemical reactions that change the composition and structure of the final product and, accordingly, its sorption activity for cesium and strontium cations. The synthesized hybrid inorganic material can be effectively used to remove radionuclides and heavy nonferrous metal cations from liquid discharges. The proposed technology significantly surpasses known processes in economic and environmental characteristics.

Raw material composition at Rusal Achinsk and its impact on the production indicators

It is well known that an unstable composition of ore and auxiliary materials creates the need to manage material flows and their composition in order to ensure the required productivity and achieve the desired qualitative and quantitative characteristics of the final products. The above problem was decided to find a solution for through analysis and mathematical processing of the RUSAL Achinsk database containing data on the incoming nepheline ore and limestone. Thus, one could analyze variations in the ore composition and carry out a statistical analysis by calculating the root-mean-square (standard) deviation and the variation coefficient. A digital model of the alumina and soda product production process employed by RUSAL Achinsk was used as the main tool for calculating production indicators as a function of the raw material composition. The model was built by RUSAL ETC on the basis of lumped parameters modelling. It is shown that the chemical composition of the raw materials supplied to RUSAL Achinsk and their variability in the current operating conditions of the Kiya-Shaltyr nepheline mine and Mazoul limestone mine have a significant impact on the alumina and by-product production process and some adjustment of the process flows is required. It was estimated how the output and the consumption of soda-sulfate mixture and potash are likely to change depending on the concentration of Al2O3, K2O, Na2O and SO3 in the feed material. Based on the obtained results, one can identify the most innovative process solutions that would enable to raise the output of by-products while maintaining the output of alumina due to the introduction of appropriate corrective ingredients. In this case, the output of potassium sulfate is expected to rise from 1.22 to 5.78%, and that of soda ash — from 1.27 to 6.5%, which determines a significant increase in profit for these two products. This research study was funded by the Russian Science Foundation under the Grant Agreement No. 18-19-00577 dated 26th April 2018 on fundamental scien tific research and exploratory scientific research.

Применение оперативного метода контроля и управления на основе компьютерного физико-химического моделирования в процессах спекания глиноземной шихты

The present study is aimed at the development of a method for computer control and management of mineral formation and emissions of hazardous compounds during processing of nepheline ore by sintering in tubular rotary kilns. Technological, mathematical and mineralogical research approaches taken when developing the method included physical and chemical modelling using the Selector software package. In accordance with the technological stages of obtaining sintered mass (drying, dehydration, decarbonisation, reflow, sintering and cooling), the developed physical and chemical model is conventionally divided into six thermodynamic tanks (furnace zones) with simulation of mutual mass and energy transfer. Coordination of the simulation results with the production and statistical data of RUSAL Achinsk JSC was carried out by analysing a furnace operation with a processing volume of 120 tons of charge per hour. During the processing of nepheline charge with the production of alumina and sodium products (having a standard analysis methodical accuracy of 1-5%), the deviation of production indices for the extraction of Al 2 O 3 from the predicted results was shown to comprise 0.1-0.6 and 1.5-2.1% for physical and chemical modelling and thermophysical field controlling, respectively. The applied sintering process modelling using the Selector software package provides for a significant increase in the degree of control and management of the raw material processing cycle. The proposed method of thermodynamic analysis is shown to provide high-precision control of the mineral formation processes in technological zones of the alumina charge sintering furnace and to guarantee a deviation of Al 2 O 3 content in the sintering mass from the predicted data of no more than 0.1-0.6%. The 85.8% rate of Al 2 O 3 extraction calculated using the physical and chemical modelling corresponds closely with the average value of 85.7% according to production data.

Improvement of apatite recovery from the Khibiny apatite–nepheline ore in flotation

Improvement of apatite recovery from the Khibiny apatite–nepheline ore in flotation