Nonmetallic Deposits Research Articles

The ecological and sanitary-hygienic assessment of the river systems located in the technogenic polluted zone of the Caucasus

The Caucasus is characterized by the large and at the same time increasing load from exploited metal and non-metallic mines. The sanitary-hygienic and toxic danger to people and the environment is quite high. There are 44 metal ores in the Syunik Region, and more than 90 non-metal deposits. In 2018, 12 metal and 29 non-metallic deposits were granted with the use rights for the purpose of mineral extraction. Also, geological survey permission was granted for 12 metal deposits. Currently, there are 12 operating and conserved tailings filled with about 400 million m3 of tailings, which are equipped with many heavy metals and other dangerous substances, as the result of the exploitation of the metal mines in Syunik. The present study focuses on the ecological assessment of the waters of the Voghji and the Khalaj Rivers that are located in the technogenic polluted zone of the Caucasus. The research revealed that along with the increase of the volumes of the Kapan-Qajaran copper-molybdenum mines, as well as the increase of the rock dumps and tailings, the organoleptic-chemical indicators of the waters of the Voghji and the Khalaj Rivers had increased. The quantity of the suspended particles and the heavy metals in the waters of these rivers had increased 1.5 and 2.0 times or by 58–100 % and 19.5 − 29.8 %, respectively, in the last 10 years. The trends are also observed in the values of the sulfates, the total dissolved salts, and the electrical conductivity, which are due to the chemical composition of the ores and the improper management of the acid drainage. The content of the heavy metals in the waters of the mentioned rivers is 9 − 20 times higher than the permissible limit density, and the degree of the mineralization is above the permissible limit. Thus, the waters of these rivers, after mixing with the effluent from the mining industry, are not guaranteed to be used for irrigation. Considering that the mobility of the heavy metals decreases several times in the alkaline environment (pH 8.5 − 9.0), it is recommended that the mining industry constantly adds lime (CaO) to the acid drainage of the mines so that the pH of the water become lower: from acid to alkaline (pH 8.5 − 9.0) and only after that, the water could be used for irrigation of the agricultural crops. This is possible for many types of heavy metals, including when using other wastewater treatment measures: engineering, physicochemical and biological.

A case study of the Yanshanian fluorite mineralization in South China: Fluid inclusion, element and isotope geochemistry and zircon U-Pb geochronology of the Kantian fluorite deposit in southern Jiangxi Province

The Yanshanian events have led to the development of South China as a unique granite province globally. Within South Jiangxi, numerous metallic and non-metallic deposits have a close association with Mesozoic granite formations. The Kantian fluorite deposit, a newly discovered non-metallic deposit in southern Jiangxi Province, is one such deposit that is linked to Mesozoic granites. The orebody at the Kantian fluorite deposit is identified as occurring in veined structures within the silicification fracture zone of Mesozoic granites, with strict control exerted by fault systems. Fluorite ore can be classified into two categories based on the amount of quartz and fluorite. The first category is the fluorite quartz type, which has a higher amount of quartz than fluorite. The second category is quartz fluorite type, which has more fluorite than quartz. Among these two categories, the quartz fluorite type is precipitated during the primary mineralization stage. Through the analysis of fluid inclusions within the fluorite, it was determined that the homogenization temperature is relatively low, ranging from 133 to 236℃. The fluid inclusions also display low salinity (0.18–3.39 wt% NaCl eqv.) and low density (0.75–0.96 g/cm3). Laser Raman spectroscopy revealed that the primary components of the fluid inclusions are H2O, with minor C3H6. Isotope analysis indicated δDVSMOW values of fluorite ranging from −61.9 ‰ to −54.8 ‰ (average −59.8 ‰), while δ18OVSMOW values varied from 1.3 ‰ to 3.1 ‰ (average 2.0 ‰). This study presents chronological, petrological and geochemical data that suggest several processes. The metallogenic age is 135.6 ± 0.7 Ma. The mineralizing fluids were identified to the NaCl-H2O system, with heated meteoric water identified as the primary source; The ore-forming materials originated from the granite, and water–rock interactions are proposed as the primary mechanism for fluorite precipitation. Based on a tectonic setting characterized by stretching, which is closely linked to the subduction of the Pacific plate, we proposed a model for the Kantian fluorite deposit.

Theoretical substantiation of water inflow into the mined-out space of quarries mining hard-rock building materials

This paper covers topical issues of groundwater and surface water inflow depending on the quarry field spatial dimensions, which leads to an increase in the costs of dewatering and drainage. The spatial dimensions of a quarry field are one of the key indicators in determining the appropriate depth of mining the deposits of hard-rock building materials. The theoretical research is performed using the following methods: statistical and analytical research method for analyzing the hydrological characteristics of non-metallic deposits and their parameters; graphic-analytical method for determining the area of the quarry walls from which water flows due to groundwater and atmospheric precipitation; technical-economic method for assessing the patterns of changes in costs for dewatering the quarry depth; and method of options for selecting the type of water drainage equipment. As a result, patterns have been obtained that characterize the change in the normative inflow of atmospheric precipitation depending on the quarry field area and the change in the unit costs for dewatering depending on the type of the studied quarry field. The practical significance of the conducted research is to use the obtained results of developed design solutions, tested and implemented in the scientific-technical (project) documentation for the mining conditions of Sofiivskyi, Mykytivskyi, Boleslavchykskyi, Chaplinskyi, and Lyubimivskyi fields of non-metallic hard-rock minerals.

Radiometric characteristics of some metallic ores and nonmetallic deposits: an example, Wadi Al-Allaqi, South Eastern Desert, Egypt

Hydrothermal alteration processes are connected to many mineral formations, particularly auriferous deposits. In this study, airborne gamma-ray spectrometry (GRS) data and the analysis of radioactive materials (eU, eTh, and K) are applied to search for regions with hydrothermal alteration activity. An example is presented from Wadi Al-Allaqi, South Eastern Desert, Egypt. GRS was used to analyse various radiometric data to address potential mineral deposit areas, to map regions potentially showing metallic ore mineralisation, and to point out new geological mineral resources. The Kd (potassium deviation), “F” parameter and Th-normalisation of the K and eU anomalies were calculated, and locating new exploratory targets in the study area that exhibit high F-parameter, Kd, and K/eTh values was recommended. Additionally, the research region has a few isolated enriched spots of (K). Therefore, GRS data was used to characterise and estimate potential metallic ores, nonmetallic deposits, and gold ore zones associated with the alteration zones. Results show that most of the known mineral deposits and gold occurrences in the area, according to the metallogenic map of Egypt, are located in zones with a ratio value of (0.25–0.30) (K%/(U or Th ppm)) maps which may suggest a moderate degree of alteration. Also, most mineral deposits and gold occurrences are found in intermediate altered zones, or K-enriched sites, with a Kd% of (0.2. The work represents an attempt to map hydrothermal alteration zones associated with mineral deposits in the Wadi Al-Allaqi area. Generally, natural radiation characteristics and attributes suggest criteria that can be used globally for regional mineral exploration.

Mining of non-metallic mineral deposits in the context of Ukraine’s reconstruction in the war and post-war periods

Purpose. The research purpose is to study the conditions for mining deposits of metamorphic and igneous origin to produce crushed stone products in conditions of limited electricity supply. Methods. The research uses an integrated approach, including data analysis on quarry field spatial dimensions and the overburden rock thickness, which provides the basis for identifying deposits into basic groups. For the identified groups of deposits, taking into account the hydrological characteristics of non-metallic deposits and their parameters, patterns have been determined that characterize the change in the normative atmospheric precipitation inflow, based on the quarry field area and the change in the specific costs for water drainage depending on the studied quarry field type. Based on data on technical characteristics of mobile and semi-stationary units and aggregates, the parameters of physical-mechanical properties of granites and diorites, technical-technological solutions for the formation of complexes for processing raw materials for the production of crushed stone products are proposed. Findings. Problems arising during mining operations under conditions of limited electricity supply, which is caused by mass attacks on Ukraine’s energy infrastructure, have been revealed. A systematization of deposits of igneous and metamorphic origin for mining of rock building materials, which are the basis for the production of crushed stone products, has been developed. The rates of water inflow into the mined-out space depending on the quarry field spatial parameters and the depth of mining operations have been studied. Technological schemes of the apparatuses of a complex for processing raw materials for production of crushed stone products and the apparatuses of a complex for processing siftings are proposed. Originality. Dependences of possible water inflow into the mined-out space of the quarry and change in energy consumption for water drainage have been determined, taking into account the accepted classification criteria, namely the quarry field spatial dimensions, the overburden rock thickness and the quarry depth. Practical implications. The obtained data on the possible water inflow into the mined-out space of the quarry and change in energy consumption for water drainage make it possible to assess the efficiency of pumping units. The proposed technical-technological solutions on formation of complexes for processing raw materials to produce crushed stone products have been developed in accordance with the fundamental provisions of the Law of Ukraine “On approval of the National program for the development of the mineral resource base of Ukraine for the period up to 2030”.

Characterization and Provenance of Carbonate Rocks for Quicklime and Dololime Production in Twin-Shaft Regenerative Kilns from the Arabian Peninsula and Neighboring Countries

This study analyzes high-grade carbonate rocks from several strategic deposits in the Arabian Peninsula and neighboring countries. The rocks are used locally for quicklime and dololime production in twin-shaft regenerative kilns. Stable C-O-Sr isotopes, along with chemical, mineralogical-petrographic analyses, micropaleontological investigations, cathodoluminescence microscopy, organic carbon speciation, and electron paramagnetic resonance spectroscopy, were used to trace the provenance of these rocks from economically significant non-metallic deposits. The resulting database can help identify and differentiate industrial raw materials that may appear similar chemically and/or macroscopically but have different textures/microstructures that can affect the properties of the derived burnt lime products. Various technological tests, including slaking reactivity, sticking tendency at high-temperature (i.e., 1300 °C), and physico-mechanical behavior of the lime, were performed to evaluate their suitability and predict lime performance in twin-shaft regenerative kilns. Comparison of laboratory and plant results validated the resulting database.

Обоснование области и опыт применения однорядного взрывания в условиях повышенных требований к качеству полезного ископаемого

The paper justifies the application area of single-row blasting at nonmetallic deposits characterized with a complex structure and low cost of mineral resources, but with a high value of recoverable fractions. It describes the reasons for decreasing value of the end products mined in quarries developing marble reserves to produce microcalcite. Ways of upgrading the quality characteristics of rock preparation for excavation using single-row blasting are described for conditions of increased requirements towards the quality of minerals. Drilling and blasting plans are developed to achieve the required quality characteristics of rock crushing. A simulation of single-row blasting in conditions of varying parameters of the borehole grid and specific consumption of explosives has been carried out. The article presents the results of pilot blasting as well as technical and economic comparison of multi-row and single-row blasting in terms of maximized profitability of the mining company and minimized cost of the end product. The parameters of the mining system that are changed when single-row blasting is used are indicated.

Substantiation of resource-saving technology when mining the deposits for the production of crushed-stone products

Purpose. Scientific substantiation of the expedient depth of mining the non-metallic deposits of rocky minerals on the basis of mathematical and statistical methods, which will ensure resource-saving and rational use of natural resources. Methods. To solve the purpose set, the following methods are used: graphical-analytical – when optimizing the maximum depth of mining the deposits of building materials, and the method of mathematical modeling – for determining the maximum depth of mining the non-metallic deposits with internal dumping. By means of statistical processing according to systematized types of deposits, the patterns of a change in the maximum depth of mining the basic deposits, depending on the main parameters of the quarry field, have been studied. Findings. A new methodology, which is distinguished by taking into account in-pit dumping, has been developed for calculating the maximum depth of granite quarries, which most of all influences the efficiency of mining operations and the value of economic indicators while ensuring the maximum economic effect with the achievement of a rational maximum depth of mining the deposit. A new, theoretically substantiated methodology has been created for determining the maximum depth of mining the mineral deposits for the production of crushed-stone products while providing the resource- and land-saving during the quarry operation. Originality. For the first time for these deposits, the dependence of their maximum mining depth on the main parameters of the quarry field and the place of internal dumping of overburden rocks has been determined. This has become a determining factor in the appropriate mining of deep non-metallic deposits of building materials with internal dumping, which provides a minimal land disturbance. Practical implications. The research results have been tested and implemented in working projects for mining the Liubymivske, Chaplynske, Pervomaiske, Mykytivske, Trykratske and Novoukrainske granite deposits; as a result of additional mining of mineral reserves, their additional increment in the volume from 1 to 48 million m3 is possible, which will ensure 5-40 years of sustainable operation of the mining enterprise.

Relationship between physical and mechanical properties of jointed rocks in Central Iran (Bafgh Block)

Central Iran is one of the active mining zones of Iran and has great mining potential. Large iron mines such as Choghart, Chadormalu, Sechahoon, Chahgaz, Lake Siah, Mishdavan, etc. are located in this zone. Other metals also exist in this zone Like lead and zinc in Koushk, Chahmir and Taj-Kooh mines. Also, non-metallic deposits such as Fahraj limestone mines and building stone mines such as Bishedar marble, Taft travertine, Shirkooh granite, etc. are being extracted in this zone. Considering mineral resources and current explorations, the mines continue to develop and one of the important topics in the exploration and exploitation phase is the study of geomechanical conditions in the zone under study. The relationship between the physical and mechanical properties of rocks makes it possible to predict the strength of intact rock which can be used in preliminary designing of the mine at less cost and less time and just with some simple tests on exploratory boreholes and surface samples. It can also be used in mines under extraction to gain more comprehensive knowledge of the mechanical properties of mine rocks. In this study, mechanical properties such as uniaxial compressive strength, point load, indirect tensile strength (Brazilian) as well as physical properties of rock such as density, porosity, compressive wave velocity (P-wave) and electrical resistivity were measured on selected samples taken from Choghart, Sechahoon, Lakeh Siah, Koushk, Bishehdar marble, Taft travertine, Ravar sandstone and the cores of 5 geotechnical boreholes from the Anomaly VI of Central Iran Iron Ore and 4 geotechnical boreholes of Chahgaz iron ore mine. The purpose of these measurements is investigating the relationship between mechanical and physical properties of the samples, especially electrical resistivity. In the first step, 300 surface and depth samples were collected from the mines mentioned above. After preparing the cores, effective porosity and density were recorded according to the standards (weighing the saturated and dry sample method). Also, the electrical resistivity was calculated by measuring the voltage and electrical current in the samples. The results demonstrated that there is a high correlation between P-wave velocity and electrical resistivity in all the samples. Furthermore, both parameters of P-wave velocity and electrical resistivity are dependent on porosity, and electrical resistivity like P-wave velocity, has a good relationship with mechanical properties of sedimentary rocks and volcano-sediments. Hence, the special electrical resistivity can be used as a non-destructive test to estimate the mechanical properties of rocks. Additionally, the presence of metal ores in the samples in low percentages does not cause errors in estimating physical and mechanical parameters as long as density is less than 2.8 gr/cm3. For samples with high metal content, induced polarization measurements can reduce uncertainty of the electrical resistivity.

Element Accumulation Patterns of Native Plant Species under the Natural Geochemical Stress.

A biogeochemical study of more than 20,000 soil and plant samples from the North Caucasus, Dzungarian Alatau, Kazakh Uplands, and Karatau Mountains revealed features of the chemical element uptake by the local flora. Adaptation of ore prospecting techniques alongside environmental approaches allowed the detection of geochemical changes in ecosystems, and the lessons learned can be embraced for soil phytoremediation. The data on the influence of phytogeochemical stress on the accumulation of more than 20 chemical elements by plants are considered in geochemical provinces, secondary fields of deposits, halos surrounding ore and nonmetallic deposits, zones of regional faults and schist formation, and over lithological contact lines of chemically contrasting rocks overlain by 5–20 m thick soils and unconsolidated cover. We have corroborated the postulate that the element accumulation patterns of native plants under the natural geochemical stress depend not only on the element content in soils and the characteristics of a particular species but also on the values of ionic radii and valences; with an increase in the energy coefficients of a chemical element, its plant accumulation decreases sharply. The contribution of internal factors to element uptake from solutions gives the way to soil phytoremediation over vast contaminated areas. The use of hyperaccumulating species for mining site soil treatment depends on several external factors that can strengthen or weaken the stressful situation, viz., the amount of bedrock exposure and thickness of unconsolidated rocks over ores, the chemical composition of ores and primary halos in ore-containing strata, the landscape and geochemical features of sites, and chemical element migration patterns in the supergene zone.

The ecologically safe development of solid non-metallic deposits with transporting by conveyor

The ecologically safe development of solid non-metallic deposits with transporting by conveyor

Substantiating Systems of Open-Pit Mining Equipment in the Context of Specific Cost

The purpose of the paper is to substantiate optimum mechanization systems of extraction and transportation equipment in terms of unit costs while open-pit mining of nonmetallic deposits. Statistical and analytical methods were applied to obtain the results; they were used to analyse the systems of open-pit extraction and transportation equipment. A technique to determine specific power intensity of operations by the equipment systems in the course of production processes and their processing into the end product has been represented. Possibility to use specific power intensity of operations while planning and developing the open-pit mining method has been proved in terms of assessment of extraction–loading–transportation equipment operating in nonmetallic open pits. The obtained results follow through with the conclusions concerning the use of wheel loaders in the context of mining enterprises. The proposed universal criteria for evaluation can be used as the index of energy consumption of open-pit extraction and transportation systems in the context of calculation techniques while designing and planning a technology of open-pit mineral mining and their processing into the end product. The criterion can be used expediently while selecting the rational facilities in the links of mining-processing complexes used industrially in terms of open-pit mining of mineral raw materials.

Organization of geomechanical monitoring for non-metallic deposits chambers roofs

The purpose of the work is the development and implementation of methods and monitoring equipment and diagnostics of the mine workings roof state of non-metallic deposits for providing of long safety operation of large section chambers. The task was solved by the organization and performance of geomechanical monitoring of working roofs state. Experience of a three-level system monitoring creation on the gypsum deposit in the city Bakhmut (Ukraine) is described. Monitoring included visual inspection, filing of roof deformations and vibroacoustic diagnostics. Examples of the long overseeing results by dangerous sites of the working roof are given.

Assessment of the ecological efficiency of the open development of non-metallic deposits of useful minerals

The object of research is the environmental safety of the functioning of mining enterprises. One of the most problematic places there are significant differences in the mining and geological conditions and geometrical parameters of the quarries, the type and technical condition of the mining and transportation equipment used in mining enterprises, as well as the need to refine reserves in a reduced sanitary protection zone. Changes in the procedure for assessing the environmental impact of a planned activity by mining enterprises should include the development and implementation of additional technological solutions that will help reduce pollution in the adjacent territories. Therefore, there is a need to develop standardized approaches, the use of which will allow analyzing the technological processes of mining enterprises and be more dangerous from an environmental point of view, where significant amounts of pollutant emissions are generated.In the course of the study, three typical technological schemes for the development of deposits of rocky building materials, differing in productivity and emissions of pollutants to adjacent territories, have been analyzed. It has been established that the use of belt conveyors allows reducing the zone of influence of an enterprise on the ecological state of adjacent territories and minimizing the environmental risks of the functioning of mining enterprises.For the localization of emissions of pollutants in the mining enterprise, it is reasonable to place mobile and portative crushing and screening plants in a quarry directly in the faces or at work sites. This will reduce environmental pollution levels and increase the comfort of living in the mining regions.Thanks to the use of modern research methods, methods of cartographic modeling and scientific forecasting and the use of computer programs, optimal environmental-friendly field development technologies have been developed. Their use will reduce emissions of pollutants outside the sanitary protection zone and improve the environmental image of the mining enterprise. Such approaches will contribute to the successful passage of the environmental audit of mining enterprises, obtaining international environmental certificates and the development of new markets for products.

Organization of non-metallic deposits development by steep excavation layers

Дана робота виконана в рамках розробки робочого проекту відпрацювання Одарівського родовища мігматитів, розробленого за госпдоговірною тематикою №110027, виконаною Інститутом з проектування гірничих підприємств Державного ВНЗ “НГУ”, а також у рамках виконання науково-дослідних робіт за держбюджетною тематикою “Розробка технологічних, управлінських рішень, нормативної документації, системи екологічного моніторингу щодо природоохоронної діяльності гірничих підприємств” (№ держреєстрації 0112U000875) та “Розробка екологобезпечних технологій ведення гірничих робіт з урахуванням потреб в ліквідації та консервації гірничодобувних підприємств” (№ держреєстрації 0115U002301).

The physical–chemical regime of argillaceous interseam sediments in the Emet borate district, Turkey: A transition from non-metallic volcano-sedimentary to metallic epithermal deposits

Among the world-class borate deposits, the borate deposits at Emet Espey and Hisarık in Western Anatolia, Turkey, stand out by their enrichment in As-bearing minerals realgar and orpiment. In terms of abundance these Turkish deposits are on a par with the world-class borate deposits in North America. In Turkey As-bearing base and precious metal deposits of epithermal low-sulfidation type developed adjacent to these non-metallic deposits under consideration. The borate deposits formed during the Miocene under arid climatic conditions within intermontane basins. The latter were filled with volcano-sedimentary series, which host a playa lake at the center. If we use the non-borate minerals, mainly phyllosilicates, as marker minerals and as a link to the equivalent shallow metal deposits, we can distinguish six paragenetic mineral associations (PAS). They reflect the following intrabasinal processes responsible for the formation of the deposits: (1) siliciclastic detrital input into the depocenter, (2) basic volcanic input into the depocenter, (3) felsic volcanic input into the depocenter, (4) evaporation in the depocenter, (5) hot brine activity in the depocenter and at its rim, and (6) oxidation. The physical–chemical regime of the various stages, including the temperature of formation, and the Eh and pH conditions are discussed in the current study indicating the interaction of intrabasinal and extrabasinal fluids:PAS-1: The alluvial–fluvial drainage systems delivered siliciclastics into the playa lake, which is a result of the weathering and denudation from the crystalline footwall rocks. The phyllosilicate association may be described as “kaolinite-in” and “pyrophyllite-out” bearing witness of a true supergene siallitic weathering, unaffected by hydrothermal activity (Eh>0, pH<7, T≈30°C).PAS-2: The phyllosilicate association which features chlorite and saponite is indicative of a reducing environment during smectitization. A moderate activity of basinal hot brines can be recognized, affecting the mineralogical input derived from basic magmatic rocks into the Neogene borate basin (Eh<0, pH6–7, T=30°–100°C).PAS-3: The alteration within the felsic tuffaceous rocks is marked by two discrete trends, the Mg trend with smectite as the diagnostic mineral (pH>7, T<100°C), and the K trend with sanidine and zeolite (clinoptilolite) being typical of this trend (pH>5.5, T<100°C). The temperature of alteration in the tuffaceous interseam pyroclastic deposits was higher than during alteration of stage (2).PAS-4: The borate minerals resulted from the combined action of evaporation and hydrothermal activity. The temperature of formation increased relative to the afore-mentioned processes. As far as the phyllosilicates are concerned, muscovite can be considered a marker mineral of this stage (pH=7–13, T≪100°C) (≪ means significantly lower than).PAS-5: Although dominated by As sulfides, the sheet silicate muscovite can be referred to as a marker for stage 5. This mineral association most strikingly shows the genetic relationship between the low-sulfidation epithermal metal and volcano-sedimentary non-metallic deposits, which developed within an ephemeral lacustrine environment of deposition (Eh<0⇒>0, pH=3–7, T≈100°C).PAS-6: A side-effect of a rising Eh is also observed among the Fe-bearing phyllosilicates. Nontronite, the diagnostic element acts like an umbrella, which covers the low-sulfidation epithermal metal and volcano-sedimentary non-metallic deposits (Eh>0, pH>5.5, T<100°C).A comparison of non-metallic and metallic shallow or epithermal systems reveals that the borate–smectite–muscovite system is the distal or non-metallic part of the low-sulfidation-type epithermal system when it comes to the accumulation of precious and base metals in a region under semi(arid) climatic conditions. Both systems show the largest overlap in stages (5) and (6). At the opposite end of this metallic–non-metallic catena, the alunite (APS mineral)–pyrophyllite–kaolinite system takes a position similar to the borate–smectite–muscovite system for the high-sulfidation metallic epithermal system.

Review on the monograph Historical Minerageny volumes 1–3, 2005–2008 by N. N. Zinchuk, A. D. Savko, and L. T. Shevyrev; Voronezh State University

A major review of the deposits of mineral resources of all ages and all types on the Earth’s surface has recently been published. Data on the main types of metallic and nonmetallic deposits of the world from the Archean to the Cenozoic are systematized. The huge body of data is of considerable importance both for the comprehensive analysis of mineragenic pro� cesses and for revealing geodynamic trends in the crust and mantle, as well. The material is presented in three volumes. Volume 1 is concerned with a global review of the data on the spatiotemporal distribution of mineral resources; Vol� ume 2 is devoted to the mineral resources of ancient platforms; and Volume 3 comprises a description of deposits in mobile belts (fold regions). The descrip� tions of objects (deposits and their groups) are system� atic, complex, and comprehensive. A convenient hier� archic system is elaborated for easy orientation among the multitude of different objects. The succession of “mineragenic process” (forma� tion of metallic and nonmetallic mineral resources) is considered in two dimensions. The first coordinate— type of geodynamic settings—is expressed in the data arrangement by volumes: the first volume is devoted to global trends in the distribution of deposits; the second volume deals with deposits on platforms; and the third volume concerns deposits in orogenic belts. The sec� ond coordinate is distribution in time according to the basic orogenic epochs: Early Precambrian, Riphean (Late Precambrian), Caledonian (Early Paleozoic), Early Hercynian (Middle Devonian–Early Carbonifer� ous), Late Hercynian (Middle Carboniferous–Middle Triassic), Kimmerian (Late Triassic–Jurassic), Early Alpine (Cretaceous), and Late Alpine (Cenozoic). Voluminous factual material is generalized in the

Aqueous Electrodeposition of SmCo Alloys: I. Hull Cell Studies

The Hull cell (HC) is a rapid “economical” method for screening the effects of varying solution composition and operating variables, providing a preliminary parametric study of Sm–Co alloy electrodeposition. HC deposit patterns exhibited three distinct current density (CD) areas: a metallic deposit, a “burnt” deposit, and a nonmetallic oxide/hydroxide deposit. X-ray diffraction spectra indicated the metallic deposits were generally amorphous, essentially free of oxide/hydroxide; the burnt deposits contained varying amounts of Sm–Co, Co hydroxide, and Sm oxide/hydroxide, and the nonmetallic deposits consisted of oxide/hydroxide. Increased temperatures extended CD ranges for metallic deposits , resulting in increased Sm content. The CD for electrodeposition of metallic Co from dilute Co solutions increased with increasing temperature; addition of glycine significantly increased . HC patterns from solutions containing only Sm sulfamate were devoid of metallic deposits. Addition of complexants (glycine) is essential for the electrodeposition of Sm–Co alloys. For pulsed current (PC) electrodeposition, increasing the solution temperatures did not result in increased Sm content as dc, although was extended. Decreasing the duty cycle increased at . PC results at indicate that alloy compositions may be electrodeposited, favorable to subsequent thermal treatments to intermetallic compounds, and .

Electric-discharge cleaning of surfaces of manufacturing equipment from foreign nonmetallic deposits

Processing characteristics of the electric-discharge cleaning of surfaces of manufacturing equipment from foreign nonmetallic deposits of different durability are researched. To expand the capabilities of the cleaning of manufacturing equipment, a complex cleaning method is proposed.

A review of mineral resources in Malawi: With special reference to aluminium variation in mineral deposits

The lithology of Malawi is characterized by Precambrian metamorphic and igneous rocks which form part of the polyphase East African Orogen. Rift-related sedimentation and igneous activity during the late Paleozoic (Karoo System) and the late Mesozoic (Chilwa Province) have produced a great variety of rocks that underwent strong chemical weathering and erosion when the entire region received its final shape by peneplanation and fluvial incision during the Cenozoic under (sub)tropical climatic conditions. Aluminum is a dominating element in minerals (e.g., corundum, kyanite, beryl, gibbsite) in this region. Some minerals were concentrated in deposits bound to Al-enriched host rocks (zircon, pyrochlore, eudialyte, uranium minerals) with high A/CNK ratios, whereas others, e.g., asbestos, chalcedony, monazite, kaolinite, ilmenite and garnet have host rocks of a low A/CNK ratio. Aluminum was used to categorize these various mineral deposits. The abundance of aluminum and accumulations of Nb, Zr, Ti, REE, Sr and Ba point for some mineralisations to similar subcrustal carbonatite-forming systems that were operative during periods of the Precambrian and the Mesozoic in Malawi. Aluminum variation does not only reflect differentiation in the various igneous rock series but it is also visible in the sedimentary realm during transport and weathering. In context with other elements such as Ti and P, Al provides an opportunity to reveal chemical relationships between rocks and mineral deposits. Spinel and Al-enriched silicate minerals can be used as pathfinder minerals in the stream sediments to guide the exploration geologist to non-metallic deposits.