Kryvyi Rih Iron Ore Basin Research Articles

Application of remote sensing techniques for estimation and mapping of iron oxides and iron-containing minerals in open pits of the Kryvyi Rih iron ore basin

The purpose of this study is to use remote sensing data to map the deposits of the Kryvyi Rih iron ore basin. Several methods for estimating iron oxide content have been applied and tested. Using image processing techniques, color composites, band ratios and supervised classification, a map of rocks with different iron oxide contents in the Inhulets and Skeliuvats-Magnetite deposits was create. The proposed method uses six Landsat 9 bands to map iron-bearing minerals and rocks (spectra 1, 3, 4 and 5) and hydroxyl (spectra 1, 5 and 7), which are easily visible in the pictures of the operation land images. The final identification of iron deposition was based on the difference in reflectivity of iron oxide content. The Kryvyi Rih iron ore basin is an excellent environment for remote sensing experiments for iron ore identification. Quite large-scale outcrops of ore bodies with pronounced reflection spectra are observe at the deposits. The large extent of development of ferruginous horizons makes them easy to diagnose using Landsat series satellites.

Reduction of ore losses on the footwall by improving ore breaking

When mining steep deposits of Kryvyi Rih iron ore basin (Ukraine), a significant part of the reserves is lost in the “triangle” of the footwall. Complete extraction of reserves requires increased costs for mining ore. At present, there are options for mining reserves from the “triangle” of the footwall. However, all the proposed options lead to an increase in the cost of mining or increased ore losses and the reduced iron content in the mined ore mass. To reduce the cost of mining, an option is proposed with concentrated charges to break ore located between the footwall and the caved massif. In order to improve indicators of reserve extraction from the “triangle” of the footwall in the massif, it is advisable to place inclined concentrated charges at an angle of 58 – 78 degrees. To reduce broken ore dilution with waste rocks on the boundary, it is advisable to create an overcompacted layer of the broken ore mass by reducing the calculated value of the line of least resistance by a factor of 0.5 – 0.75. Application of this method of mining reserves from the block increases the content of iron in the mined ore mass by 1.2%, reduces discounted costs for driving workings and for drilling and blasting. Thus, due to application of the bulk level caving system with improved ore breaking by the use of concentrated charges located in the “triangle” of the footwall, the expected economic effect of mining of 718.2 kt makes 5.20 k USD.

Study of rock massif strains when creating an internal dump in the zone of transition from open pit to underground mining

The work explores technologies for transitioning from open pit to underground mining of minerals, focusing on stress-strain analysis of the rock mass during this process. It enhances methods for studying these stress-strain states, particularly in the context of combined technologies for iron ore extraction. The study proposes environmentally safe techniques for extracting magnetite quartzite, involving the use of internal dumps in open pits to dispose of mining waste. It develops and suggests efficient design schemes for managing stress-strain states during the transition and proposes using protective barrier pillars formed from artificial consolidating backfill for subsequent underground mining. Strains in these barrier pillars and the rock mass are calculated for various scenarios of waste filling. The study, exemplified by the Kryvyi Rih iron ore basin, demonstrates the environmental benefits of using abandoned open pits for waste disposal and underscores the economic advantage of these technologies. This innovative approach plays a crucial role in preserving the valuable Ukrainian agricultural chernozem. By implementing this method, there is a significant reduction in the amount of land required for agricultural use and minimizing environmental impact.

Improvement of the transitional technology from open pit to underground mining of magnetite quartzite

The paper analyzes the disadvantages of the technology of iron ore open pit mining and current environmental problems of open pit mining. The paper also addresses problems of possible displacement and strains of rocks in the classical open pit mining method with extraction of minerals exclusively by open pit mining, studies current transitional technologies from open pit to integrated open pit-underground and subsequent underground mining, and presents an improved methodology for studying the stress-strain state of the massif during transition from open pit mining to integrated open pit-underground and subsequent underground mining. There are studied, developed and proposed options of environmentally friendly technologies of integrated open pit-underground mining with mining waste disposal in the worked-out space of underground mines and open pits, highly efficient calculation schemes for studying the stress-strain state of a rock massif during transition from open pit to underground mining with formation of protective barrier pillars, an option with the development of the lower room of stage II under protection of an ore pillar left within the contours of the upper room of stage I, and an option with the development of the lower room of stage II under protection of an artificial pillar made of the consolidating backfill in the upper room of stage I. The stress-strain state of the massif and possibilities of forming internal waste rock dumps when applying integrated open pit-underground mining technologies are studied and substantiated. Transition technologies from open pit to underground mining of iron ore raw materials under the bottom of an operating open pit are developed and proposed on the example of Kryvyi Rih iron ore basin.

Improvement of the stoping technology in mining magnetite quartzite by underground methods

The ore deposits in Kryvyi Rih iron ore basin are mined using bulk ore and overlying rocks caving systems. These mining systems have a significant drawback, namely a 2 – 5% reduction in the iron content of the mined ore mass when mining rich ores and up to 15% when mining poor ores. Current technological solutions enable improvement of ore extraction values while increasing economic costs by 15 – 20%. Therefore, the present article proposes a technological solution that will improve extraction values for poor ores. The study conducted results in determining the optimal distance between drawpoints of the receiving level and substantiates location of additional workings in the footwall, which reduces ore losses and increases ore mass extraction values. The proposed technological solution will reduce ore losses by 10 – 15% of the standard losses and increase ore extraction values by 5 – 15%, while reducing iron content by 5 – 7% of the initial one. Thus, the study conducted proves that the use of an additional level located 30 – 35 m above the main receiving level allows reduction of ore losses from 27.39% to 21.19%, and the iron content in the extracted ore mass – by only 3% instead of 12%.

Earthquake prediction based on the analysis of water level fluctuations in the control well

This study examines the methodology and results of earthquake forecasting based on the assumption that the earthquake preparation process can be linked to the development of rupture mechanisms. The analysis focuses on water fluctuations in a control monitoring well, which provides valuable information about the earthquake’s preparation period well in advance. Studies on the territory of the Kryvyi Rih iron ore basin (Kryvbas) confirmed that the underground waters in a deep well (815 m deep) depend on the processes of the current lithosphere deformations evidenced by the changing elastic-deformation state of the crust in tectonic areas. The Kryvyi Rih-Kremenchuk crust-mantle fault produces a system of different-scale faults in the crystalline basement which determine the hydrodynamics of the Kryvbas underground filtration. The earthquake preparation process exhibits clear indicators of the rupture process, characterized by a periodic component of water fluctuations superimposed on the main level-changing process during the preparatory phase. The frequency of the periodic component increases as the date of the earthquake approaches. With this approach, an earthquake with a magnitude of 4.1 inKryvbas was successfully predicted one and a half year before the event, based on monitoring water level fluctuations for 120 days between February and June 2016. The efficacy of forecasting local earthquakes was evaluated using the retro-forecast of earthquakes in Kryvbas on July 29, 2017. The methodology was validated through testing, confirming the initial assumptions. This technique was tested to predict the exacerbation of the seismic situation in the iron ore mining area caused by powerful blasting activities.

Kryviy Rih as the center of heavy industry of the USSR: the role of Kryvbas scientists in the development of the mining industry

The article completes the cycle of investigations within the framework of the historical and foundational research of the State Printing Archive "Printed editions of the 1970s: thematic and content priorities", planned for 2023. The object of the research was the priority topics that were covered in domestic printed editions of the specified period , the subject of which is the periodical and continuing editions published in Kryvyi Rih during the 1970s, namely: the yearbook "Mining ore production", published by the Scientific and Research Mining and Ore Institute (SRMOI) of Kryvyi Rih, and materials of all-Union and republican scientific and technical forums (seminars, conferences, etc.). Relying on the specified primary source base, the author considered the main directions of development of mining science in Kryvyi Rih during the researched period. The purpose of the proposed exploration is to form conclusive generalizations about today's little-known local prints, conduct a content analysis of their content, update important historical events from the past of Kryvyi Rih and personify the mining science of the Kryvyi Rih iron ore basin. Having achieved the set goals, the author claims that in the 1970s, Kryvyi Rih became an all-Union recognized center of scientific and practical mining. In the city, despite its modest (district) administrative-territorial status, powerful scientific schools were formed, higher, secondary special and vocational-technical mining education flourished. Having a closed cycle: from mining (Kryvyi Rih mines, quarries) and beneficiation of iron ore (five mining and beneficiation plants operate on the territory of the city) to the production of the best types of iron and steel (Metallurgical Plant "Kryvorizhstal", Kryvyi Rih Coke Chemical Plant) — Kryvyi Rih became the industrial pearl of the Soviet Union. In modern Ukraine, the city has rightly earned the name "iron heart of the state".

Scientific and technical problems of transition from open pit to combined technologies for raw materials mining

In Kryvyi Rih iron ore basin, long-term and intensive mining of deposits applying open pit methods have resulted in significant areas disturbed by open pits, dumps and tailings storage facilities. Hundreds of thousands of hectares of fertile arable land are already unsuitable for agriculture and sometimes for living. Thousands of tonnes of dust from dumps and tailing ponds deteriorate the surrounding nature every year and pollute the atmosphere in mining basins. Industrial ore breaking in open pits using bulk blasting causes emissions of a significant amount of harmful dust and carcinogenic substances. The environmental situation in open pit mining areas is often close to critical. In addition, bulk blasting forms a seismic wave, which in some cases destruct civil buildings and industrial facilities. The article proposes ways of gradual transition from mining mineral deposits by open pit methods to environmentally friendly technologies of open pit-underground and underground mining. It is established that such transition is a forced and at the same time choiceless way of developing mining areas, in particular Kryvyi Rih iron ore basin. The paper notes that the main problems of this transition include geomechanical stabilization of the rock massif during construction of underground mines in areas of possible impacts of open pit fields. The paper develops the fundamental study of the problems of controlling the stress-strain state of the massif during transition from the open pit to combined technology of deposit mining. Technologies of combined mining that involve formation of a transition belt with backfilling the worked-out space with compound mixtures are studied as well. It is proved that development of theoretical foundations for controlling the stress-strain state of the massif during transition from the open-pit to combined technology of deposit mining, study and design of technological solutions that contribute to transition to open pit-underground and underground mining, is an urgent scientific, technical and practical problem of great importance.

Implementation of sustainable development approaches by creating the mining cluster: the case of MPP “Inguletskiy”

The article provides the basic foundations of the implementation of sustainable development approaches in the world society and their interpretation in mining activities. The study also analyzes the regulatory framework and organizational mechanisms for the implementation of these principles in the Ukrainian mining industry. An analysis of the current state of rational subsoil use and solid industrial waste management in Ukraine is given. The concept of a mining cluster and prospects for its formation in the region of the Kryvyi Rih iron ore basin are substantiated. An algorithm designed to optimize the schedule of mining operations in the mining cluster is described. The Ingulets iron ore deposit was analyzed from the standpoint of integrated development. The reserves of talc shale extracted from the open-pit and stored in a man-made deposit for further sale are separately allocated. The order of mining works for the development of man-made deposits is given.

Enhancement of the technology of caved ore drawing from the ore deposit footwall “triangle”

In mining iron ore, over 60% of underground mines at Kryvyi Rih iron ore basin apply a system with the bulk caving of ore and overlying rocks. However, when the deposit dip is 45-60 degrees, application of this mining system leads to losses of about 30-40% of the footwall ore. Available methods of the loss reduction result in an increase in production costs or a decrease in the iron content in the mined ore mass. After analyzing the mechanism of forming the figure of drawing, it is proposed to change its parameters without significant costs due to the use of an inclined plane and an overcompacted ore layer. The presented study enables stating that with an increase in the inclined plane angle from 45 to 75 degrees the draw crater radius increases from 2 to 7.5 m, and a decrease in the factor of first loosening of ore leads to an increase in the radius of the crater to 10 m. Thus, for the first time it is proved that a decrease in the first loosening factor leads to the increased semi-minor axis of the ellipsoid of drawing and the width of the active drawing area, which will reduce losses of caved ore when drawing it from the stoping block in the footwall area. It is established that in order to minimize losses and dilution of ore when using level mining systems, the drawpoint should be located in the block sill at a distance ensuring formation of the 20 to 25 m high ellipsoid of drawing. In case of an overcompacted 22 m thick ore layer, it is possible to significantly reduce ore losses from 14 to 10% and ore dilution from 16 to 9%, thereby enhancing ore mass extraction indices without additional costs.

Development of an Efficient Process Scheme for Breaking High-Grade Iron Ores of Low Strength and Stability During Sublevel Caving

Introduction. The main part of rich iron ores (73%) is mined in the Kryvyi Rih iron ore basin, most of which(160.5 million tons) are characterized by a low strength and stability.Problem Statement. One of the most important operations of slope excavation, which significantly affects the productivity of delivery vehicles and a crushing and processing complex, the quality and completeness of extraction of rich iron ores of a low strength and stability, is drilling and blasting operations to form a compensationspace with maximum, in terms of stability, dimensions and to hammer the main stock of the panel into it.Purpose. The purpose is to develop an efficient process scheme for breaking off reserves of rich iron ores of a lowstrength and stability, given the stress-strain state, efficient length of wells, and the quality of ore mass crushing.Material and Methods. The structural and functional analysis of the systems for the development of sublevel caving, the numerical calculations with the analysis and assessment of the parameters of outcrops of compensation chambers, the analysis and assessment of practical experience and scientific achievements in the field of increasing the efficiency of the ore breakage process, the analysis of techniques for the calculation of the parameters of drilling and blasting operations in the extraction of iron ores, the design of process schemes for breaking rich iron ores and their feasibility assessment.Results. For the first time, in this study, there has been developed a resource-saving version of the process schemefor the formation of a triangular-shaped compensation chamber and the hammering of the main stock of a breakage panel on it in the course of developing rich iron ore deposits of a low strength and stability, which allowspractically raising the efficiency by 7.8—18%, depending on the conditions of the breakage panel operation.Conclusions. The author has established the dependences of the angle of inclination of the inclined outcrop of thecompensation chamber and the line of least resistance. given the stress-strain state, the breakage energy intensity coefficient, the specific costs of breakage, and the efficiency on the distance of the breakage panel to the rocks of the hanging side across the strike of the ore deposit with one and two contacts of the breakage panel with collapsed host rocks.

Technological grades of iron ores as a basis for identification of stratigraphic horizons of the Saksaganska Formation of the Ingulets deposit of the Kryvyi Rih Iron Ore basin

Characterisation of technological varieties of iron ores of Ingulets deposit is given. It is marked that each technological grade corresponds to a certain stratigraphic horizon of the Saksaganka Formation. It is suggested to use this fact for identification of ferruginous and shale horizons of the Saksaganska Formation at the Ingulets deposit

Enhancement of the quality of marketable iron ore products of Kryvyi Rih iron ore basin

The main indicators of the iron ore quality are the content of iron, silica, phosphorus and other components. It is ascertained that the quality of ore depends on its grain-size composition. The article proves that when crushing 16-0 mm fraction ore to 5-0 mm, Fe content is reclassified by sizes due to liberation of both martite and hematite at this grain size. To reduce energy consumption during grinding, it is recommended to install high pressure grinding rolls for crushing the 16-1 mm fraction and consider this operation as the first stage of grinding. Martite liberation in the -1.0+0.0 mm material shows that significant predominance (87.0 vs. 13.0%) of free grains over aggregates is observed in the -0.071+0.05 mm fraction material. Free martite aggregates make 57.12% in the -0.16+0.071 mm material. Complete (100%) liberation of martite is observed in the -0.05 mm material. Sieve analysis of the A56 sinter ore sample crushed to 5-0 mm in the industrial roll crusher enables ascertaining that the greatest increase in recovery (Fetot = 60.05%) of sinter ore occurs at the -0.16+0.071 mm grain size.

Можливість використання амфіболітів Інгулецького родовища (Кривий Ріг) для виробництва декоративного та рядового щебню.

The suitability and degree of utilisation of amphibolites of Ingulets iron ore deposit (Kryvyi Rih iron ore basin) as a raw material for crushed stone production has been estimated.

Особливості геологічної будови Первомайського родовища Криворізького басейну.

The article considers the features of the geological structure of the Pervomaysk deposit of the Kryvyi Rih iron ore basin. Attention is paid to the stratigraphic division of rocks of the Kryvyi Rih series, tectonic structure and processes that contributed to the formation of the iron ore deposit.

ЗАГАЛЬНА ГЕОЛОГІЧНА ІСТОРІЯ ЯК ОСНОВА ЄДИНОЇ СТРАТИГРАФІЧНОЇ ШКАЛИ ДОКЕМБРІЙСЬКИХ ПОРІД ПЕРШОТРАВНЕВОГО ТА ГАННІВСЬКОГО РОДОВИЩ КРИВОРІЗЬКОГО ЗАЛІЗОРУДНОГО БАСЕЙНУ

Hannivske deposit of poor magnetite ores is part of the Kryvyi Rih iron ore basin. The deposit is located in the southern part of the Eastern-Hannivka belt at the Northern iron ore district of Kryvbas. Two sets of rocks are involved in the geological structure of the Hannivske deposit: crystalline rocks of the Archaean and Proterozoic, as well as rocks of the Cenozoic sedimentary cover. Archean rocks are represented by plagiogranites and plagiomigmatites of the Dnipropetrovsk Complex (AR2dn) and amphibolites of the Konkska Series (AR3kn). The Proterozoic complex of rocks is formed by the Kryvyi Rih Series (PP1kr), which is divided into five Formations (from bottom to top): Novokryvorizka (PR1nk), Skelyuvatska (PR1sk), Saksaganska (PR1sx), Gdantsivska (PR1gd) and Gleyuvatska (PR1gl). The productive stratum of the Hannivske deposit is the overlying pack of the first ferrous horizon of the Saksaganska Formation of the Kryvyi Rih Series, which, according to the generally accepted stratigraphic scheme of Kryvbas, corresponds to the fifth-sixth ferrous horizon of Saksaganska Formation of Kryvyi Rih Series. Crystalline rocks of the Archaean and Proterozoic are covered by a layer of sedimentary rocks of the Cenozoic: Paleogene (P), Neogene (N) and Quaternary (Q) periods. In the southern part, the Eastern-Hannivka belt (Hannivske deposit) connects with the Pervomayka deposit by a series of numerous sublatitudinal and diagonal faults. In the north-northwest direction, there is a gradual decrease in thickness and wedging of the Eastern-Hannivka belt, including the iron ore stratum. Metasomatic processes in their intense display are observed in the productive stratum of the Hannivske deposit locally, but a significant part of it is covered by weak metasomatic changes. A feature of metasomatic processes was the formation of metasomatic bodies along linear tectonically weakened zones or at their intersection nodes. Multi-stage formation of the Hannivske deposit, active display of various geological processes in the productive and containing stratums (sedimentation, metamorphism, tectogenesis, metasomatosis, hydrothermal, astroblemic phenomena, syngenetic and epigenetic magmatism, hypergenesis, etc.) determined the mineralogical and chemical diversity of the Hannivske deposit ores, the presence in its productive and capacious layers, the manifestation of many metallic and non-metallic minerals, the formation of a complex mineral and raw material base of the deposit.

БРЕКЧІЇ ОБРУШЕННЯ – "НОВИЙ" ТИП ТЕХНОГЕННИХ ГЕОЛОГІЧНИХ УТВОРЕНЬ/ТІЛ/РОДОВИЩ КРИВОРІЗЬКОГО ЗАЛІЗОРУДНОГО БАСЕЙНУ

On the basis of geological mapping, structural, mineralogical, petrographic, geochemical, petrophysical studies in the Pivdennyi and Pivnichnyi iron ore quarries of the Saksahansk district of the Kryvyi Rih iron ore basin (Kryvbas), a "new" morphological and genetic type of anthropogenic formations – collapse breccias formed as a result of rock masses displacement over underground mining zones – has been identified. These breccias make up huge volumes within the quarries, forming virtually new large-scale anthropogenic geological bodies with morphology, material composition and physical properties that differ from the original parent rocks. They occupy almost 100 % of the axial areas of the quarries, as well as significant volumes of their western ("hanging") sides. Together with the remnants of ferruginous quartzite and rich ore leftover from underground mining, they are the subject of modern industrial mining. Breccia collapses are new anthropogenic geological rocks. Genetically and morphologically, they fully correspond to the essence of anthropogenic formations and it is quite legitimate to apply the conceptual and legal framework of anthropogenic deposits to them in case of their economically feasible extraction, just as it is generally recognised for bulk dumps and sludge dumps. All this raises the question of the relevance of including these formations in the modern classifications of anthropogenic deposits of Kryvbas as a separate type.

ІСТОРІЯ СТАНОВЛЕННЯ СТРАТИГРАФІЧНОЇ ОСНОВИ ДОКЕМБРІЙСЬКИХ ПОРІД ГАННІВСЬКОГО ЗАЛІЗОРУДНОГО РОДОВИЩА (КРИВБАС) ТА ПРИЧИНИ ЇЇ МОДЕРНІЗАЦІЇ

The Gannivske deposit of ferruginous quartzites occupies the northern part of the Kryvyi Rih iron ore basin (Krivbass). This deposit is part of the Northern Ore District of Kryvbas and in structural terms is a continuation in the northern direction of the Central Ore District. There is no doubt about the belonging of the ferruginous rocks of the Gannivske deposit to the Proterozoic Sakxagan Formation of the stratigraphic scheme of Precambrian sediments of Kryvbas. However, so far, the comparison of separate stratigraphic horizons of the Northern and Central Ore District causes great difficulties. The Saksagan Formation of the Northern Ore District has a thickness of 350-600 m and is well divided into two sub-formations – lower and upper. The lower sub-formation consists of biotite-amphibolite and amphibole-biotite schists, which often include garnet. In the central part of this sub-formation there is a bed of magnetite-amphibolite quartzite, which includes interlayers of schists. It was found out that this magnetite-amphibolite quartzite bed within the Pervomayske deposit is divided into two iron-ore beds, which belong to the first and second iron-ore horizons. Thus, it would be logical to name the magnetite-amphibolite quartzite bed of the lower sub-formation of the Saksagan Formation of the Gannivske deposit as the first-second iron-ore horizon, the schists underlying it to correlate with the first schist horizon, and the schists overlying it to correlate with the third-fifth schist horizon. However, according to the stratigraphic scheme used at the Gannivske deposit, this magnetite-amphibolite quartzite bed is referred to the zero iron horizon, the schists underlying it – to the zero schist horizon, and the schists overlying them – to the first schist horizon. The upper iron-ore sub-formation of the Saksagan Formation of the Gannivske deposit is divided into two parts: lower and upper. The lower part of the upper sub-formation (the first ferruginous horizon) is the main productive stratum of the Gannivske deposit. It is composed of various magnetite quartzites, which can be easily compared with the fifth and sixth ferruginous horizons of the Central Ore District. However, at the Gannivske deposit this stratum belongs to the two-membered first ferruginous horizon. The lower part of this stratum is distinguished as an overlying pack, the upper part – as a hanging pack of the first ferruginous horizon. The upper part of the upper sub-formation consists of magnetite-silicate quartzites with almost no layer-by-layer concentrations of magnetite. Such composition of the rocks of the ferruginous horizon at the Pervomayske deposit is typical only for the rocks of the seventh schist and seventh ferruginous horizons. However, it is impossible to assign this part of the upper sub-formation of the Gannivske deposit to the seventh schist and seventh ferruginous horizons, as it contains four quartzite strata (from bottom to top) rather than two strata, as in the Pervomayske deposit: magnetite-amphibole-amphibole quartzite (they are referred to I strata), biotite-amphibole-magnetite quartzite (II strata), magnetite-amphibole-amphibole quartzite (III strata) and magnetite-amphibole-biotite quartzite (IV strata). In the northern part of the Gannivske deposit there are layers of ferruginous quartzites and schists, the analogues of which have not been reliably established in the Central Ore District. However, according to the stratigraphic scheme of the Gannivske deposit they are referred to the second schist, second ferruginous, third schist, third ferruginous and fourth schist horizons. For geologists of the Northern Ore District of Kryvbas the most actual, from all problematic issues of the Gannivske deposit, is the problem of identification of ferruginous and schists horizons of the Saksagan Formation, as well as their correlation with horizons of the Saksagan Formation of the Pervomayske deposit. The current ideas about their correlation are now more and more questioned. Therefore, the question of modernisation of the stratigraphic scheme of the Saksagan Formation of the Gannivske deposit on the basis of generalisation of all available data has now become urgent.

Ecological problems of irrigated soils in the south of Ukraine

Problem formulation. Ecological quality of soils and agricultural products depends on the level of irrigation water mineralization. The quality of mineralized irrigation water has a negative impact on soils, agricultural products and ecosystems. This is especially negative in the conditions of Southern Ukraine within the Black Sea territories where the formation of irrigation waters in the Ingulets river basin depends on the influence of the Kryvyi Rih iron ore basin located in the river basin. The aim of the article is to assess the impact of mineralized irrigation waters on soils and natural ecosystems. Materials and methods. Field sampling of water and dark chestnut saline soils and southern chernozem soils to determine the impact of mineralized water quality on soils and ecosystems, statistical analysis of the obtained data. Results. Discharges of highly mineralized mine waters into the river basin lead to a change in the flow velocity in the river from 4 m³/s to 20 m³/s, which negatively affects the flora and fauna living conditions. Depending on the chemical composition of the discharges, the mineralization of irrigation water varies from 1.393 g/dm³ to 1.7608 g/dm³, and sometimes reaches 4.349 g/dm³. In terms of chemical composition, irrigation water is formed as a hydrocarbonate-sulfate-chloride with almost the same content of sulfates and chlorides, calcium-magnesium-sodium with a significant advantage of sodium. The dynamics of irrigation water quality indicators during 2013-2021 testifies to an increase of the most dangerous indicators for soils: hydrogen index of soil solution (pH) from 7.7 to 8.4, chlorine ion content (Cl–) – from 9.52 to 10.77 meq/dm³ and sodium (Na+) from 9.52 to 13.33 meq/dm³. By means of correlation and regression analyzes, the regularities of water hydrochemical composition formation were revealed and a strong functional connection between mineralization and chlorine ions (r = 0.99) and sulfate ions (r = 0.99), between mineralization and hydrocarbonate ions was established (r = 0.47). As the mineralization of water increases, the content of chlorine ions and sulfate ions increases proportionally, and hydrocarbonate ions play a secondary role in the formation of the hydrochemical composition. To prevent the chlorine ions excess of more than 350 meq/dm³ and sulfate ions excess – 500 meq/dm³, irrigation water mineralization should not exceed 1500 mg/dm³, and to prevent the chlorine ions excess of more than 350 meq/dm³, water flow from the canal should be at least 9.0 m³/s. Scientific novelty. New mathematical models of the irrigation water mineralization, its anionic composition, its chloride content dependence on water consumption from the Ingulets river and the interdependence between mineralization and cationic composition of water are offered. Practical significance. The obtained results are of practical importance for the implementation of agro-ameliorative measures for soil and ecosystem conservation.

Peculiarities of the raw material base of the Lykhmanivka iron ore region in Kryvyi Rih basin

Lykhmanivka (Inhulets) iron ore district takes the southernmost position in the Kryvyi Rih iron ore basin. In the north, it is bordered by a series of sublatitudinal faults with the Southern Iron Ore District of Kryvbas. The productive strata of the area are Lykhmanivka iron ore pay streak, in the southern part of which the Inhulets deposit of magnetite quartzites is located in the zone of closing of Lykhmanivka syncline. However, in addition to them in the area, there are more than 20 types of other minerals, which are mined by-products and can be successfully used in the national economy. Syngenetic (sedimentation, diagenesis, dynamothermal metamorphism) and epigenetic processes (tectogenesis, metasomatism, hydrothermal processes, hypergenesis), which occurred during the formation of iron ore and host strata area have contributed to the formation of several minerals and rocks, which can be considered as associated complex useful minerals. The relevance of the work is due to the need for detailed research of the localization, formation conditions, directions of use of metallic and nonmetallic minerals of the area, the geological justification for their priority varieties. As a result of these studies, systematization of minerals of the area has been developed, their priority varieties have been identified. Their involvement in mining and processing significantly expands the spectrum of alternative ways of use of minerals and rocks of iron-banded formation, which will contribute to a significant addition to the mineral resource base as in Kryvyi Rih iron ore basin, and in Ukraine as a whole.