5-2026

CONTENTS # 5/2026

All-Russian Research Institute of Mineral Resources named after N.M. Fedorovsky (VIMS)

CRITERIA FOR CLASSIFYING MINERALS AS CRITICAL: A REVIEW OF INTERNATIONAL EXPERIENCE

The article analyzes the interpretation of the concept of “critical mineral” (CM) in the leading economies of the world, systematizes the criteria used for the formation of national lists of CM and identifies common features and differences in approaches. The criteria for inclusion in the CM and the lists of such adopted in countries that collectively provide about 80 % of global GDP are considered: Australia, Brazil, Great Britain, EU countries, India, Canada, China, the Republic of Korea, USA, South Africa, Japan. A comparison is also made with the approaches to the problem adopted in the Russian Federation. The analyzed lists are current as of May 2026.

Keywords: world experience, critical types of mineral raw materials, strategic types of mineral raw materials, criteria for attribution.

Р. 4

The All-Russian Geological Research Institute of A.P. Karpinsky

GEOCHEMICAL EXPLORATION AND PREDICTION OF BLIND DEPOSITS BASED ON MASF TECHNOLOGY

A brief overview of international and domestic geochemical exploration technologies in covered and semi-closed areas is provided. Testing results obtained in the course of experimental and methodological studies with the method of superfine fraction analysis (MASF) in comparison with other methods are considered. The positive experience of more than 20-year work with of MASF application makes it possible to recommend its wider implementation in geochemical exploration, both in covered areas and in areas characterized by a combination of different landscape settings.

Keywords: covered territories, geochemical exploration, superimposed halos, MASF.

Р. 13

LLC INPK «ADAMANT», Vilyuy Geological Exploration Expedition «ALROSA», St. Petersburg

PREDICTING LARGE TYPE IIa DIAMONDS IN KIMBERLITES BASED ON C–O–H FLUID COMPOSITION RECONSTRUCTED FROM PYROPE XENOCRYSTS

The article presents a mineralogical-petrological method for assessing the potential for the presence of large type IIa diamonds (CLIPPIR diamonds) in kimberlites. The method is based on a fluid-magmatic model, according to which such diamonds form at the final stages of crystallization of magmatic melt from water-carbon dioxide (H2O-CO2) fluids in the websterite solidus zone. An algorithm has been developed for calculating P–T–fO2 parameters and the equilibrium composition of C–O–H-fluids based on the compositions of pyrope xenocrysts. It is shown that the nitrogen content in diamonds is inversely correlated with the oxidation state of the fluid. Testing of the method on materials from pipes in South Africa, Yakutia, and the Arkhangelsk province (the V. Grib pipe) confirmed that pipes with an oxidized water-carbon dioxide fluid, unlike reduced methane-bearing ones, have a high potential for giant nitrogen-free diamonds. The identified fluid composition serves as a reliable prospecting criterion.

Keywords: large diamonds, type IIa, kimberlites, pyrope xenocrysts, fluid-magmatic model, C–O–H-fluid, oxygen fugacity, websterite solidus, nitrogen in diamonds, prospecting criterion.

Р. 24

1 — JSC Rosatom Nedra; 2 — JSC Khiagda; 3 — Lomonosov Moscow State University (MSU); 4 — JSC VNIPIPT; 5 — LLC Geotechnologies; 6 — Institute of Geology of Ore Deposits, Petrography, Mineralogy and Geochemistry of the Russian Academy of Sciences (IGEM RAS)

NEW DATA TO SUBSTANTIATE THE INFILTRATION-EXFILTRATION MODEL OF URANIUM ORE FORMATION AT THE PALEOVALLEY DEPOSITS OF THE KHIAGDA ORE FIELD AND ADDITIONAL PROSPECTING CRITERIA

A summary of the results of research work that accompanied prospecting, evaluation, and exploration in 1991–2012, supplemented by studies in recent years (2017–2025), made it possible to substantiate the infiltration-exfiltration model of ore formation at Vitim-type uranium deposits. Additional criteria for searching for ore deposits of this type are proposed: carbonic bicarbonate-magnesium groundwater containing petroleum-type hydrocarbons; contrasting reducing properties of the hydrogeochemical environment (Eh < –300 mV); bleached and whitened ore-bearing terrigenous sediments; manifestations of solid and liquid hydrocarbons in crystalline and sedimentary rocks of the ore-bearing horizon; bitumen content in the soil cover > 600 mg/kg.

Keywords: uranium deposit, infiltration, exfiltration, bleaching of rocks, carbonated groundwater, hydrocarbons, airborne geophysics, bitumen in the soil cover, ore formation model, search criterion.

Р. 29

1 — Institute of Geology of Ore Deposits, Petrography, Mineralogy and Geochemistry
of the Russian Academy of Sciences (IGEM RAS), 2 — Sergo Ordzhonikidze Russian State University for Geological Prospecting (MGRI), 3 — All-Russian Research Institute of Mineral Resources named after N.M. Fedorovsky (VIMS)

MICROINCLUSIONS, IMPURITY ELEMENTS IN CASSITERITE CRYSTALS OF THE VALKUMEY DEPOSIT (CHUKOTKA AUTONOMOUS OKRUG)

Cassiterite crystals from the Valkumey deposit, located on the coast of the Chaunskaya Bay of the East Siberian Sea (Chukotka Autonomous Okrug), were studied. It belongs to the tin-silicate industrial type (tourmaline mineral type) of the ferrous-polymetallic-tin formation and was exploited until 1996. The study of cassiterite crystals included electron microscopic studies, determination of the contents of trace elements and their mathematical processing. Microinclusions of rutile and aluminosilicates were found, formed simultaneously with the growth of cassiterite crystals and as a result of their recrystallization. Eleven trace elements with a content above 0.0001 wt. % were identified in cassiterite, the main ones being Ti, V, Fe, Zr, Nb, W, and U. Correlation analysis revealed two associations of trace elements: (Ti, V, Fe) and (Nb, W, U). Elements can be present in the cassiterite structure and as microinclusions. The deposit is located in an economically developed region, and its significant tin reserves allow for the resumption of its exploitation.

Keywords: tin deposits, cassiterite, microinclusions, trace elements, Chukotka Autonomous Okrug

Р. 50

1 — LLC “Almazintech — Consulting and Engineering”, 2 — All-Russian Scientific Research Institute of Mineral Resources n.a. N.M. Fedorovsky (VIMS), 3 — LLC “Siberian Mining Company”

LUMINESCENCE CHARACTERISTICS OF DIAMONDS FROM THE INGASHET AND CHUKSHA-KOVINSKAYA-2 AREAS AS EVIDENCE FOR THE EXISTENCE OF THE CHUNA-BIRYUSA DIAMOND-BEARING DISTRICT

The article considers the history of searches for primary diamond sources in the Irkutsk region. Studies of photo- and X-ray luminescence of a representative collection of diamonds from the Ingashet and Chuksha-Kovinskaya-2 areas have been conducted. The features of the distribution of photoluminescence image processing results, in comparison with the distributions of diamonds from the Arkhangelsk (M.V. Lomonosov pipe) and Yakutian (Mir, Udachnaya, Yubileynaya, Komsomolskaya, Nyurbinskaya pipes) diamond-bearing provinces, suggest that several primary diamond deposits can be discovered in the Chuno-Biryusa diamond-bearing district (Irkutsk region).

Keywords: photoluminescence, X-ray luminescence, diamonds, prospecting and exploration, processing algorithms, Irkutsk region.

Р. 57

JSC Elkon MMC, Aldan, Republic of Sakha (Yakutia)

THE DRUZHNOE DEPOSIT IN THE ELKON GOLD-URANIUM ORE DISTRICT: PROSPECTS AND CHALLENGES IN THE PROCESSING OF MOLYBDENUM-BEARING URANIUM ORES

A brief overview of the works performed at the Druzhnoe deposit is presented, which, according to its mineral composition, is analogous to other deposits of the Yuzhnaya zone (Elkon, Elkon plateau, Kurung, Neprokhodimoe). At the deposit, the carrying out of geological exploration works is planned with the delineation of a detailed site, the study of the complex composition and degree of oxidation of ores, the assessment of the refractoriness of ores for uranium and gold, the character of the distribution of rhenium and platinum-group elements, and the sampling of ore. The main directions of research into ore processing methods are determined: radiometric separation and X-ray radiometric separation, the separation of sulfide concentrate by flotation, and sulfuric acid leaching with the extraction of uranium, gold, molybdenum, and vanadium. Based on the results of the work, a feasibility study of permanent exploration criteria will be prepared.

Keywords: uranium, gold, silver, molybdenum, vanadium, technological schemes for processing ores of the Druzhnoe deposit.

Р. 68

All-Russian Research Institute of Mineral Resources named after N.M. Fedorovsky (VIMS)

PROSPECTS FOR THE DEVELOPMENT OF WEAKLY LITHIFIED URANIUM ORES IN MESOZOIC DEPRESSIONS OF TRANSBAIKALIA USING GEOTECHNOLOGICAL METHODS

The prospects of developing off-balance uranium reserves in weakly lithified Mesozoic deposits of Transbaikalia (Imskoye deposit, Badin depression) are considered. Earlier attempts to exploit these sites by in-situ leaching (ISL) were unsuccessful due to the low permeability of the rocks. Based on laboratory studies, a new geotechnological concept is proposed: the action of weakly acidic sulfuric acid solutions causes the destruction of carbonaceous-clay cement, transforming the rock into a loose state. Filtration leaching experiments confirmed the possibility of uranium extraction with an efficiency of up to 70 %. The fundamental feasibility of involving such ores in exploitation by the ISL method is proven. It is proposed to include these sites in the list of hard-to-recover reserves to conduct new pilot-scale operations.

Keywords: in-situ leaching (ISL), weakly lithified uranium ores, Transbaikalia, Imskoye deposit, cement destruction, filtration leaching, geotechnological methods, hard-to-recover reserves, rock permeability, sulfuric acid.

Р. 74

DEVELOPMENT OF SORPTION TECHNOLOGY IN HORIZONTAL COLUMNS FOR URANIUM RECOVERY FROM PREGNANT SOLUTIONS OF IN-SITU LEACHING

Development of a Mobile Sorption Unit (MSU) is a relevant task for all uranium ore districts with a large number of small deposits that remain undeveloped due to the low profitability of using expensive stationary units. As a result of the conducted research and pilot-industrial tests, the feasibility of uranium recovery from pregnant solutions (PS) by sorption in packed bed columns of SNK type, arranged in a horizontal position, at a linear PS velocity in the column exceeding 25 m/h has been substantiated. It is proposed to mount the SNK-2000 sorption column on a 9835-77-2 road trailer. Calculations of the technological parameters of sorption columns have been performed, and initial data for the MSU design have been provided. According to estimates, the net discounted income from the implementation of the MSU will amount to about 1 billion rubles compared to the use of a local sorption unit.

Keywords: Productive solution processing unit, local sorption unit, modular sorption unit, mobile sorption unit, sorbent, uranium sorption, sorbent regeneration, equilibrium concentration front, sorption pressure column, productive solution, total dynamic exchange capacity of the sorbent.

Р. 82

GEOLOGY IN SCHOOLS: THE MISSING LINK IN THE TRAINING SYSTEM FOR MINING AND GEOLOGICAL PROFESSIONALS

The history of teaching natural sciences in secondary schools shows the importance of geological education. The reintroduction of this subject has become especially relevant in the context of the escalating shortage of qualified specialists in the mining and geological industry of Russia. Today, geology is taught in a fragmented manner, teachers lack specialized education, and therefore the general level of geological knowledge remains low. Comprehensive measures are required for the development of a new curriculum, the creation of a modern textbook, and the expansion of geological training for teachers. Enhanced interdepartmental coordination will be of decisive importance. Restoring geology to the school curriculum is regarded as a fundamental first step towards solving the problem of staff shortage and raising the geological literacy of the population.

Keywords: history of geology, geology in secondary school, geology textbook, personnel shortage in mining and geological specialties, All-Russian Congress of Geologists, geology teaching methods.

Р. 88