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By Markus A. Reuter, Yongxiang Yang, James R. Post

The packed coke bed in the lower part of an iron making blast furnace, the dead man, dissolves slowly in a pool of hot metal, which is tapped regularly. The coke particles of the dead man not only exhibit a size distribution, but also their size distribution is non-uniform throughout the dead man and as a result, the porosity of the dead man is non-uniform. This causes the flow of hot metal through the dead man to be irregular and non-uniform, bringing about channelling in the coke bed. Channelling is detrimental to the refractory lining life of the hearth of a blast furnace. Using population balance modelling and a porosity model it is possible to keep track of the local changes in size distribution and bed porosity during dissolution of coke particles. Numerical simulations show that carbon dissolution from a packed coke bed (with particles which exhibit a size distribution) increases the average porosity, decreases the mean particle size and changes the size distribution to a distribution with a smaller size range. Influence of the type of initial size distribution (mean, variance) is investigated. The calculated changes in porosity are used to dynamically adapt the flow and the mass transfer (kinetics) during calculations. This approach provides the possibility to implement dynamic porosity calculations for CFD applications, and thus simulate the results of various coke types and particle size distributions on dissolution and flow behaviour.

Jan 1, 2003

By M. Paymardi, A. Foroutan, T. P. Oladele, M. Abbaszadeh

"Reducing the amount of zinc and iron in lead concentrate is one of the important aspects of processing in lead and zinc flotation plants which results in improvement of lead concentrate quality and prevents zinc loss. In mineral flotation industries, lignin sulfonates are known for their depressant properties for both non-metallic and sulfide minerals such as pyrite and pyrrhotite.This paper investigates the effect of lignin sulfonate on flotation of galena, sphalerite and pyrite in sulfidic lead and zinc bearing ores. Batch flotation tests were carried out on a high pre-activated zinc samples. The feed contains 0.9% lead, 2.3% zinc and 7.5% iron. The dosage of all reagents such as sodium cyanide, zinc sulfate, ethyl xanthate and methyl isobutyl carbinol (MIBC) were kept constant for lead flotation step except calcium lignin sulfonate (CLS) that was varied between 0 and 80 gr/ton.Results for lead rougher concentrate showed that the grade of lead increased by 2.7% while the recovery decreased around 4 % at the highest dosage of CLS. Furthermore, zinc recovery decreased by 6.3% with no significant change in grade. Iron recovery in lead rougher concentrate decreased by 2.3 % while the grade changed around 1%. In sphalerite flotation step, CLS dosage was changed in the range of 0 to 80 gr/ton while the dosage of other reagents such as copper sulfate, lime, amil xanthate and MIBC were kept constant. In this step, no decreasing in grade and recovery of zinc was observed, while iron recovery decreased. It was suggested that CLS has a depression effect on sphalerite in conjunction with other zinc depressants such as zinc sulfate and sodium cyanide. CLS was further used in plant with non-pre-activated zinc minerals. Similar trends were observed in plant.INTRODUCTIONlead-zinc sulfide minerals play an important role in the production of lead and zinc metals in the mineral processing industry (Luo, Feng et al. 2016). Due to complexity of the lead-zinc ores mineralogy, in some situations, their flotation properties vary significantly from one deposit to another one even in itself (Bulatovic 2007)."

Jan 1, 2018

By V. E. Vigdergauz

Possibilities of the analysis of potential energy of bubble-particle interaction on the basis of extended DLVO theory are discussed. Interaction energies of mineral silica, coal and pyrite particles with contact angles from 20 to 100 degrees and air bubbles in neutral and alkaline solutions are analyzed. It is shown that for hydrophilic silica, the formation of particle-bubble complexes (either in the area of primary or secondary potential minima) is impossible due to the high potential barriers (from 6000 to 140000 kT)and low values of the attraction force. There is shown that for coal and pyrite particles the energy of interaction vs. particle-bubble distance strongly depends on pH value. Improvement of floatability of minerals by the hydrophobization of their surface by collectors leads to the eliminating of potential barriers and the formation of the stable complexes of minerals and air bubbles in the area of primary potential minimum. In addition, due to hydrophobization of coal and pyrite changing pH has practically no influence on the energy of interaction. There are discussed results of the numerical calculations of normalized interaction forces in particle-bubble systems on the nanometer distances for pyrite, sphalerite, and chalcopyrite at contact angles up to 85° in comparison with the experimental data. The values of adhesion force for hydrophobized particles of coal and pyrite to air bubbles are about 10-5 N, that indicates stability of the formed flotation complexes. Examples of using the long-range and high-energy effect of hydrophobic interactions for improving minerals floatability are discussed. There are illustrated minerals wettability changes induced by the adsorption of thiol collector and hydrophobic polymer. Possibilities of flocculation and flotation of mineral slimes due the polymer-collector hydrophobic interactions are shown. Keywords: bubble-particle interaction, contact angle, extended DLVO theory, floatability

Sep 1, 2012

By S. H. Morar

Froth stability is widely recognized as a key driver of flotation selectivity. It is well known that froth stability is affected by the type and quantity of surface active reagents present (frothers), and the concentration and hydrophobicity of solid particles present. While some studies have been performed on the effect of frothers on froth stability in three-phase systems and the hydrophobicity of particles present, very little work has been performed on the effect of solids loading on froth stability. This may be due to insufficiently robust measurement techniques. This paper investigates the use of a new machine vision measurement to measure solids loading, and the relationship between this measurement, bubble size, and bubble burst rate on the froth surface. Keywords: froth flotation, machine vision, solids loading

Sep 1, 2012

By Marzio Piller, Girolamo Belardi, Jure Mencinger, Paolo Bozano, Gianni Schena

"The hydrodynamics of the Tri-Flo™, a two stage cylindrical cyclone used in dense media separation, is studied using Computational Fluid Dynamics. The flow field is simulated with an Euler-Euler Volume of Fluid two-phase approach and the Reynolds stress turbulence model.A unique feature of the device is that the separation medium suspension is pumped and introduced tangentially into the two cylindrical compartments while the raw feed is conveyed to the feed hopper and fed at the axial inlet. This feature allows to use less pumping energy and limits the unavoidable production of fines. The Tri-Flo™ complex flow pattern is little known but central to the efficiency of the separation.The velocity field is computed within the two compartments of the separator. The interface of the air-core that forms in the inner axial part of the cylindrical sections is identified and visualized. The numerical results for a reduced-size 100 mm ID Tri-Flo™ are compared against laser Doppler measurements on a transparent acrylic model (Chinè, 1995) operated with water. The robustness of the model and its prediction capability are verified.The possibility to accurately predict the velocity profiles within the vessel and their dependence on the main Tri-Flo™ operating and geometrical variables paves the way to a better understanding of the functioning of the separator, its design improvements and scale-up."

Jan 1, 2014

By I. V. Shadrunova

Annually it is formed more than 95 Mt of clinkers in iron and steel industry of Russia, including 79 Mt of clinkers in blast-furnace, steelmaking, foundry and ferroalloy productions. Complex development of clinkers will provide not only extraction of valuable components, but also preservation of ecosystems. Processing of solid slags is realized, as a rule, in a cold condition by mechanical methods only including stage-by-stage crushing of slag on devices, working on principles of compression and shift (jaw and roll crushers). However it doesn?t provide the complete extraction of metals from clinkers. The intensification of decomposition, in our opinion, can be provided under the use of the devices working on a principle of free kick. At such influence on a material, its destruction occurs on micro cracks, sides of cohesion that is there is a selective destruction of the components possessing various resistances to impact. Decomposition of a piece on the basis of free kick about a material or metal is realized in centrifugal-shock crushers and mills of research-and-production association ?Ural Center?. The share of the joints sharply lowering the efficiency of enrichment thus is minimal. The efficiency of application is proved by morph-metrical measurements with the help of system of image analysis ?SIAMS-600? and physical-mechanical tests of clinkers and their components (impact strength, micro hardness). The experience of application the devices of centrifugal-shock crushing for processing clinkers in blast-furnace, martin and converter productions of Open Society MMC, clinkers of rough-edged copper melt of Joint-Stock Company "Karabashmed" and aluminium clinkers of Joint-Stock Company « Samara plant of aluminium alloys » has allowed to confirm the efficiency of application these devices for selective decomposition of metallurgical clinkers and the opportunity of using clinkers as resource of ferrous and nonferrous metallurgy.

Jan 1, 2014

By J. Zou

With the increasing applications of the Chinese metal magnetic liners, the requirement for their technical specifications has become stricter and stricter. It is necessary to deeply analyse the metal magnetic liners in order to improve their reliability and economics. The key issue of metal magnetic liners is magnetic forces: their attractions to mill shell and protection layer. Mathematical models were developed using finite-element analysis software and systematic simulation analyses of the two most critical indexes of magnetic liners were performed to find out the most important parameters and their effect on the liner?s characteristics. The relationships between magnetic forces and installation gaps, thickness of permanent magnets and thickness of protection layer may be used to guide the design of metal magnetic liners for ball mills in order to achieve good economic indexes.

Jan 1, 2014

By D. Szyszka

During passing gas bubbles through mineral suspensions, some mechanical carryover of fine particles to the froth layer always takes place. The entrainment of mineral particles is influenced by many parameters, mostly by the particle size and the concentration of the frother. The paper deals with influence of selected frothers (methylisobutylcarbinol (MIBC), a-terpineol, and hexadecane tricosaethyleneglycol ether (C16E23)), common laboratory flotation frothers, on the mechanical car-ryover of quartz, a typical gangue mineral component of ores. Entrainment tests were carried out in a laboratory Mechanobr flotation machine with quartz particles suspended in aqueous frother solu-tions. The mechanical recovery of quartz in the presence frother was increasing with time and reached plateau after about 20 minutes of flotation. The plateau level of quartz recovery depended on the frother concentration. Initially an increase of the plateau with frother concentration was observed until the plateau reached the highest level called the maximum recovery emax. The emax can be used as a parameter to characterize the ability of frothers to entrainment. In the studied quartz-frother flotation system the maximum entrainment was 32%, 50% and 80% for methylisobu-tylcarbinol (MIBC), a-terpineol, and monohexadecane tricosaethylene glycol ether (C16E23), re-spectively. A comparison of the maximum entrainment factor emax with other, known from literature, indices such as bubble critical coalescence concentration (CCC), dynamic foamability index (DFI), Jw, e =25%revealed, except DFI, their similarity.

Jan 1, 2014

By M. Guo

Coal-based Direct Reduction in Interior-combustion Shaft Kiln (CDR/ISK) is a brand-new technique. Compared with the traditional Coal-based Direct Reduction (CDR) technique, its main character is to use Interior-combustion Shaft Kiln (ISK) as the reactor of direct reduction. After being crushed and grinded, iron ore is made into green pellet, which will be surface-coated by coal fines. Then, the surface-coated green pellet can be directly reduced in ISK. The pellet should not be too dry and should be charged from the top of ISK. Oxygen-contained air should be blasted into ISK to keep the temperature in it higher than 1000 degrees centigrade, at which iron oxide will start direct reduction. The reduced pellet will be discharged from the bottom of ISK and after de-surface-coated, spherical Direct Reduced Iron (DRI) can be gained. The volume of carbon monoxide in the off-gas discharged from ISK is less than one per cent. By using this technique to get one tonne DRI, the consumption of coal is about 300kg of fixed carbon, which is much lower than the energy consumption by using other CDR techniques. There is a lot of complex refractory iron ore in China, which remains unexploited. The iron-bearing minerals in this kind of the iron ore can not be beneficiated economically by present technique of gravity, magnetic, flotation or magnetic roasting because the iron minerals are too very finely disseminated to be liberated, or, the iron minerals are too similar to gangue to be separated each other. By using CDR/ISK, complex refractory iron ore can be directly reduced in lower temperature and all kinds of iron mineral can be turned into iron metal. As the grains of iron metal growing larger during direct reduction, magnetic separation can be used to separate iron metal from gangue mineral, thus high-grade iron metal fines can be gained. According to the experiments, the grade of iron metal fines is above 90 percent and the recovery of iron is higher than 90 percent. The consumption of coal to process one tonne of complex refractory iron ore is only about 90kg of fixed carbon.

Jan 1, 2014

By M. Q. Xu

During the flowsheet development for a potential commercial Cu/Ni separation plant at the In-co?s Sudbury operation, extensive laboratory and miniplant studies were carried out. There are two potential feed streams for Cu/Ni separation at the existing operation. It is shown that Cu/Ni separation from the rougher concentrate is relatively simple without need of regrind. However, Cu/Ni separation can be difficult from the bulk concentrate because of the presence of excess flotation reagents in the bulk concentrate slurry and locked particles. Excess flotation reagents created excess froth increasing entrainment. By replacing the slurry water with tap water and with addition of some hydrogen peroxide, entrainment is minimized and good Cu/Ni separation is achieved on the bulk concentrate. Fine regrind is required to increase liberation of the locked particles for ultimately high copper recovery at the minimal nickel content.

Jan 1, 2014

By M. V. S. Cavalcante

The quality of iron ore pellets, represented in terms of parameters such as cold compressive strength (CCS) and Tumble Index (TI), has a strongly influence on the productivity and energy of reduction furnaces like the blast furnace and on the quality of hot metal or liquid iron. The main objective of pelletization operations is to produce iron ore pellets of desirable specifications and ensure high levels of plant productivity and energy efficiency. Advanced process control of an industrial iron ore pellet induration process using a soft sensor for pellet quality and fuzzy-logic based control algorithm is described in this paper. The pellet quality soft sensor consists of a rigorous mathematical model of the induration process and a statistical model for the pellet quality parameters. The mathematical model is based on the fundamental principles of heat and mass transfer between gases and pellets, kinetics of drying and condensation of moisture, combustion of coke, calcination of limestone, and melting and solidification of pellets. The predictions of wind-box temperature profiles are in close agreement with the measured profiles. The time-temperature profiles of the pellets during induration, along with raw material characteristics and induration process operating conditions, are used as inputs to the quality model to predict cold compressive strength and the Tumble Index. The predictions of the quality soft sensor along with the rules based on fuzzy-logic derived from simulation results and operator experience are then utilized to control the induration process to achieve precise control of the quality parameters and to optimize the induration process in terms of fuel efficiency and productivity. The mathematical model is also utilized as a soft sensor for temperature, moisture and composition profiles of pellets and gases. Results of implementation of this model-based control strategy on an industrial scale induration process will be presented. Keywords: iron ore, pelletization, simulation, process control, optimisation

Sep 1, 2012

By Deirdre Bradshaw, Cornelius Vos

"The detailed understanding of the variability in process performance parameters within an ore body forms a key aspect of ensuring that proper decisions are made with regards to the economic viability of that ore body. To gain this understanding, various tools have been developed over the years, of which the batch flotation test is the most well-known and applied technique for investigating the flotation separation of ores. In this paper, the Julius Kruttschnitt Mineral Separability Indicator (JKMSI) is put forward as a small-scale test, suitable for the characterization of the flotation separability of copper porphyry ores. It is demonstrated that the JKMSI can be a complementary technique to the batch flotation test, with the capability to further improve the knowledge of ore body variability. The response from this test has been shown to be sensitive to particle size and modal mineralogy, providing a critical link between flotation and upstream comminution activities. The trade-off between the fineness of grind and the recovery target can thus be evaluated to determine the minimum energy application required for optimal separation economics. The test is designed to utilize small sample quantities of various sizes, providing an opportunity to increase our understanding of ore variability through increased tests. This complements our ore body knowledge and combining this with efforts in comminution (Powell, 2013) provides a platform for extending the concept of flexible circuit design."

Jan 1, 2014

By P. Somasundaran, Tarun Bhambhani, D. R. Nagaraj, P. Patra

"Certain non-sulfide gangue minerals are known to have a detrimental impact on flotation performance. When present in large amounts, they can negatively affect recoveries, grades and throughput at current operations, and dictate the viability and economics of a greenfield project. While the problem has been investigated for a long period of time, a scientific understanding of the mechanisms by which these minerals affect performance has not been obtained, and no acceptable solutions have been developed. This study focused on the role of physical aspects (e.g. shape, size and morphology) of these minerals as the underlying factors for poor performance. Flotation tests were conducted using model mineral systems to understand the impact of one phyllosilicate mineral (muscovite) on flotation kinetics, recoveries and grades. The study reveals that there is minimal impact on flotation kinetics, no impact on recoveries, but a very strong detrimental impact on concentrate grade. The traditional mechanisms of transport such as true flotation and entrainment are not sufficient in describing the extent of transport. The transport is attributed to the unique platy morphology of muscovite, which allows for action of buoyancy forces. Data also shows that the muscovite transport to the froth phase depends on particle size; coarser sized muscovite (100-150@) report to the froth phase in much larger amounts than medium sized muscovite (50-100@). At finer size fractions (<50@) the transport is also increased, and this is likely due to entrainment."

Jan 1, 2014

By R. Imhof, S. E. Sánchez-Pino, H. Sprenger, S. A. Sánchez-Baquedano

"In 1992, Ingeniería de Minerales started with the introduction of pneumatic flotation technology in Chile and South America. This technology consists of vertical cells and gyratory cells, used mainly under actual operational conditions, with pilot units directly installed in the concentrator circuits of the industrial process. Successful industrial applications have been observed at Los Pelambres, in the molybdenum plant; at Codelco Andina in the molybdenum plant as pre-rougher to produce directly a final concentrate; in the copper circuit at Las Luces as pre-rougher producing final concentrate using sea water; at Minera Valle Aconcagua where a full automatic plant produces pre-concentrate from fresh tailings as feed; at the silica and silicate reverse flotation circuit of Compañía Minera del Pacífico; in cleaning the final concentrate of Zn by reverse flotation removing ultrafine carbonate; and in a plant that reprocesses fresh tailings from a copper slag flotation process. Positive operational changes in the design of the flotation circuit have been seen in plants using G-cells and V-cells, improving the performance of flotation circuits and the quality of final products. The high concentration of bubbles and micro turbulence produced by the pneumatic aeration units provide a high probability of collision and attachment, reducing dramatically the residence time. Though it is a pneumatic flotation, no compressed air is needed, and the equipment is characterized by low maintenance costs, full automation, savings in investment and energy."

Jan 1, 2014

By Hans-Åke Häggblad, Bertil I. Pålsson, Jan Stener, Kent Tano, Andreas Berggren, Pär Jonsén

Numerical modelling of grinding in tumbling mills is traditionally done with the discrete element method (DEM). The grinding balls are then represented by DEM particles and the mill structure is considered rigid. To include more physical phenomena several numerical methods can be combined. One important improvement is to include the mill structure response, using the finite element method (FEM). The interaction between charge and lining can then be studied in detail. The pulp can also be included using a particle-based continuum method e.g. smoothed particle method (SPH). The strength of SPH lies in modelling of free surface flows and very large deformations and it is suited to model simultaneous fluid and granular flow. Still, the coarse particles (grinding balls) in the charge are suitable to be model using DEM. Each of these methods has their strength and weaknesses, but combined they can successfully mimic the main features of the charge movement. With these numerical tools the complex interaction between the different components of the grinding process; pulp, charge, lining and the mechanical behaviour of the mill, can be studied together. This work will present novel numerical approaches to model, simulate and validate charge behaviour in tumbling mills. These numerical models give possibilities to better understand the physical and mechanical behaviour of particulate material systems during grinding in a tumbling mill. This is important in order to develop and optimise future high-capacity grinding circuits and save energy.

Jan 1, 2014

By Skinner. W.

"Introducing cutting-edge development work, which aims to simplify mineral processing flow-sheets, reduce costs and address environmental issues. Over the past four years Innovative Mineral Processing Technologies Pty. Ltd (IMPTEC) Australia have developed a Super-fine Crusher and a Planar Magnetic Separator which offer low cost, wet or dry alternatives to conventional grinding and conventional magnetic separation. Each of these machines has been successfully trialed at pilot scale and are now in the process of transitioning to commercial scale. This paper reports on the progress made in each of these fields. The potential scope for application of super-fine crushing technology as an alternative to grinding is potentially expansive and could include beneficiation of metalliferous ores, precious metal ore processing, hydrometallurgical processing, industrial minerals and coal processing, plastic fillers and ceramics processing as well as processing of cementitious slags and fly-ash. IMPTEC have recently achieved outstanding results at pilot scale with a dry combination of super-fine crushing and planar magnetic separation, which offers an alternative to the wet processing of magnetic iron ores. The dry combination has set new laboratory performance benchmarks when compared with the industry standard wet Davis Tube Tester. The test results have also established a strong evidence base showing that super-fine crushing achieves liberation of value minerals at coarser sizes when compared with grinding. The dry combination of super-fine crushing and planar magnetic separation also addresses environmental issues and completely eliminates grinding. An IMPTEC super-fine crusher is currently undergoing commercial trials, generating ultra-fine products from granulated lead blast furnace slag for use as cement substitutes. The performance of the super-fine crusher on this extreme duty highlights the potential benefits of super-fine crushing over the wide range of industries and applications where conventional grinding is employed.INTRODUCTION Present day mineral processing practices can become anchored in convention, where, inefficient methodologies are recognized and accepted as “best practice” or “industry standard”. Motivated by this challenge, IMPTEC has undertaken the development of radically different and improved methodologies in the fields of fine comminution and magnetic separation. Whilst, crushing is much less energy intensive and generally less capital and maintenance intensive than grinding, the technology has stalled due to the lack of crushing devices, which have the capacity to adapt to fine and ultra-fine duties. Grinding practice advances have been achieved through major increases in machine size and power. However, these advances are also accompanied by major escalations in capital, operating and maintenance costs. The economics of this strategy has become increasingly questionable. A typical example is the viability of low-grade magnetite beneficiation, which can hinge largely on the cost of grinding to fine and ultra-fine liberation sizes."

Jan 1, 2018

By G. J. Feng

Based on detailed theoretical analysis of coarse floatation and three-phase froth, a laboratory system which contains a new type of froth floatation equipment is established. Through water experiment, the relationship among floatation dynamics parameters of the equipment is studied and the best work parameters are educed too. Based on all of above, Slurry test is carried out in a copper concentration plant. Granule between 0.28~0.45mm can be reclaimed successfully. The slurry test proves that to separate coarse minerals in froth floatation equipment is a kind of effective method, it is well worth to make a further study.

Jan 1, 2014

By D. B. Mazzinghy, D. C. Rocha, H. B. Miller

"The use of ball mills for fine grinding is an inefficient process and has contributed to the increasing popularity of vertical stirred grinding mills in the minerals industry. Over the last decade, the performance and energy efficiency of stirred milling technology has become a preferred alternative to ball mills for fine and regrinding operations. The difficulty encountered in fine grinding is the increased resistance to comminute small particles when compared to coarse particles. Therefore, increased energy inputs are then necessary to raise the number of stress events in a mill to contribute to the comminution of fine particles. This work discusses the effect of operating conditions on the amount of fines produced and torque readings in a screw type batch laboratory vertical stirred mill. A time-based population balance model (PBM) was used to empirically analyze the performance of a vertical mill and to calculate mill breakage parameters for the different operating conditions tested. The results indicate the possibility of applying population balance model to the vertical stirred mill to predict product size distribution with acceptable accuracy. The obtained breakage function shows that the main breakage mechanism in this vertical stirred mill is by attrition, and that the selection function changes with experimental conditions within the mill. Higher agitator velocities are also seen to promote an increase in the degree of attrition between grinding media hence particle selection and fines generation increase.INTRODUCTION Stirred milling technology has been firmly established in the last 20 years as superior to ball mills for fine and regrinding operations due to its superior energy efficiency (Jankovic, et al., 2006). Stirred mills are now commonly used in many sectors of the mining industry, though they have been used in other industries for many years (Stehr & Schwedes, 1983). This technology has proven to be more energy efficient with greater opportunities for future optimization in both fine and coarse grinding."

Jan 1, 2018

By Danilo Zim, Matheus Paschoalino, Denis Guimarães, Jasbir Gill

The shortage of water supply in some regions of the globe is particularly problematic and forces mining companies to adopt alternatives like pumping sea water from the ocean up to the mining sites. Although deaeration of sea water or the use of lined pipelines are known options to prevent corrosion during pumping, a recent development of a new corrosion inhibitor allowed the use of simple mild steel pipelines for this purpose. The objective of this study is to demonstrate the recent advances of this technology in protecting against not only general corrosion but localized corrosion, main cause of corrosion-related pipeline failures. Corrosion studies were carried out using electrochemical techniques, weight loss balance as well microscopy surface analysis in order to measure and therefore evaluate the treatment efficiency. The right dosage of corrosion inhibitors may vary depending on water composition and characteristics of each system. Differences were observed depending on the sea water source. Pretreatment of metallic surface impacts the observed corrosion rate which can be as low as 3.6 mpy. The absence of pitting or localized corrosion was achieved in aerated seawater.

Jan 1, 2014

By S. V. Bogdanov, S. I. Grishaev

"The article presents the materials about the appropriateness of the use of rental indices to assess the effectiveness of the use of deposits of rare earth elements (REE). The authors suggest from the standpoint of rent payments to rate for the owner the possibility of using the anticipated rental income as the indicator for the analysis of preferences and economic significance of enrichment of extracted raw materials in the emerging field of rare earth metals (REE). Usually from ore mined at the fields, for flotation technology to produce concentrates with collective REE, then they are subjected to chemical-metallurgical processing of the received products are divided into pure oxides, chemical compounds or isolated from them pure metals and alloys. This commercial product is shipped to the buyer. REE were a non-renewable natural resources, so the calculations for determining differential and specific rent showed that during the development of the technologies of mineral processing of a specific field it is necessary to consider what the expected rental income depends on the magnitude of differential rent is related to the volume of production of REE for the whole planned period of exploitation of natural resources. This income is determined by the amount of stock field. For long-term exploitation of the deposit is observed in almost direct proportional dependence between the annual differential rent and the rental income. The decrease in rents in the long run is determined by the change in the composition of ores included in the extracted raw materials and the balance between light and heavy REE. The largest 70% reduction of the rent projected for ""cerium"" fields, while for ""yttrium"" these losses are considerably smaller. Tomtor, Chuktukon and Katuginskoye Russian deposits are characterized by a level of rent that is comparable to the mastered foreign sources of REE. Thus, the enrichment of minerals with REM in the domestic deposits is quite competitive at the world level. INTRODUCTION Deposits of rare earth metals (REE) are non-renewable resources that should be developed and used so that it would be possible to provide a reduction due to payment of appropriate resources for future generations. This compensation, due to the reduction of natural resources, can be carried out both in natural and in economic terms (1). When analyzing economic compensation options, particular attention should be paid to rental income in assessing the attractiveness of using different REE deposits. It is known that absolute and differential rents are summands when calculating the value of natural rents. The value of the absolute natural rent is proportional to the unit price of the product obtained from mineral raw materials and sold on the commodity market. Limitations, as well as the use in production processes and business, contribute to the gradual reduction of natural resources, which increases their consumer value and affects the price of commodity products from primary raw materials."

Jan 1, 2018