Nonmetallic Deposits Research Articles

A Review of the Non-metallic Industrial Minerals of Mongolia: The Impact of Geological and Geographical Factors on their Formation and Use

Mongolia is one of the countries of the Asian continental interior rich in ore and non-metallic deposits. Non-metallic commodities of high-unit and high-place value commodities are found throughout the country. Some reference types are discussed in this paper: (1) feldspar-quartz pegmatites; (2) graphite-bearing skarns; (3) contact-metamorphic marbles; (4) igneous and sedimentary gemstone deposits; (5) coarse-grained aggregates (alluvial-fluvial); (6) fine-grained aggregates (fluvial-aeolian); (7) arenaceous-argillaceous byproducts of coal mining; (8) and argillaceous deposits. (Paleo)geography and climate were decisive for the accumulation (e.g., clay and sand deposits) and alteration (e.g., calcareous and gemstone deposits) of many of the non-metallic deposits. The recent geographical and climatic situation is responsible for the poorly developed infrastructure and especially affect the high-value commodities. Acquisition of digital data in the field is a must in a country of the continental interior of Eurasia, in order to save time and space for the transport of samples to accelerate data acquisition. A portable IR mineral analyzer (PIMA) is essential in exploration for industrial minerals and its applicability may be rated as follows, in order of decreasing applicability for different commodities: (1) carbonates, (2) sulfate-bearing rocks, (3) argillaceous rocks, (4) claybearing arenaceous rocks, and (5) rocks abundant in alumosilicates/framework silicates.

Aqueous electrodeposition of iron group–vanadium binary alloys

Electrodeposition of binary iron group (IG)–vanadium (V) alloys from aqueous citrate solutions was investigated. Addition of NH 3(aq.) and increasing solution pH resulted in increased deposit V content, but non-metallic deposits were obtained at solution pH > 7. Increasing current density resulted in an almost linear decrease in V content and a sharp increase in hydrogen evolution (decreased current efficiency). In general, the amount of V deposited with the IG metal increased as follows: Ni < Fe ≪ Co. XRD spectra indicated that preferred orientations from 25 °C solutions were not displaced by elevated temperature deposits. Changes in orientation may contribute to the deposit magnetic properties; e.g., Co–V deposits with (1 0 0) planes exhibit harder magnetization than deposits with (0 0 2) planes.

Sedimentology and paleogeographic evolution of the intermontane Kathmandu basin, Nepal, during the Pliocene and Quaternary. Implications for formation of deposits of economic interest

The Kathmandu Valley is an intermontane basin in the center of a large syncline of the Lesser Himalayas. The sedimentary basin fill comprises three units of Plio-Pleistocene to Holocene age. The study aimed at modeling the paleogeographic evolution of the basin, with emphasis on sedimentary series of fossil fuels and non-metallic deposits. The lithological setting of the basin and the tectonic framework were instrumental to basin subsidence. Alluvial through lacustrine sedimentation during incipient stages is a direct response to uplift in the hinge zone of the synclinorium. Axial parallel sediment dispersal gave way to fluviodeltaic sedimentation mainly from the limbs of the synclinorium. Ongoing compression and renewed uplift in the core zone of the synclinorium drove the uplift of a NW–SE running divide and a subdivision of the mono-lake into two basins. This ridge blocked the flow of transverse rivers and the northern subbasin became gradually choked. Ongoing uplift of the entire basin during the recent geological history caused a reorganization of the drainage pattern and triggered linear erosion in the southern mountain range. Step-by-step the remaining lacustrine basins disappeared. Fan aggradation coincide with cold dry or warm seasons, fluvial dissection and discharge increased during warmer and more humid periods. High lake levels exist during phases of increased humidity. The results of this basin analysis may be used predictively in the exploration for coal, natural gas, diatomaceous earths and quarrying for sand or clay. The gas potential is at its maximum in the lacustrine facies, sand and clay for construction purposes may be quarried economically from various fluvial and deltaic deposits. Diatomaceous earths predominantly accumulated in marginal parts of the lake and some landslide-dammed ponds. Lignitic brown coal can be mined together with combustible shales from poorly drained swamps.

THE IRON MINERAL DEPOSITS OF ELBA ISLAND: STATE OF THE ART

A number of metallic (Fe, Cu, Mn, Sb) and non-metallic deposits (Mg silicates, magnesite, sericitized aplites, granite, pegmatites) have been the target of exploration and exploitation in Elba Island since the The iron deposits of Elba Island have been the target of intense exploitation since the 1st Millennium BC up to present1981. Elba is especially famous worldwide for its iron deposits and the pegmatitic minerals from Monte Capanne. All iron mines are now closed, but in the last years several steps were taken in order to preserve and promote such a valuable heritage: the inclusion of Elban mining and mineralogical areas into the UNESCO’s World Heritage provisional list of geological sites (1990), the project of the “Elba Island Mineralogical and Mining Park” (started in 1991 and now underway), and the establishment in 1996 of the “Tuscan Archipelago National Park”. In this paper we summarize the state of the art of the research on Elba Island’s mineral iron ore deposits, with particular focus onto the iron ores of eastern Elba. In the course of almost three thousand years of exploitation, not less than 60 million tons of Fe ore have been won. Fe. Notwithstanding the many studies on these deposits carried out by Italian and foreign scholars over more than two hundred years, many aspects of their setting, genesis and evolution still need to be clarified and better constrained. This is due to various factors, including the complex (and only partially understood) geological framework of the island, and the closure of mining activity, with consequent inaccessibility to many mine-workings. We stressand emphasize the some mostproblematic aspects, which are fundamental clues not only for the understanding ofof the oreforming genetic processes of and evolution of Elban’s mineral deposits, but also for the reconstruction of the overall geologic evolution of the Apenninic chain.

Minerogenic System of Magnesian Nonmetallic Deposits in Early Proterozoic Mg‐rich Carbonate Formations in Eastern Liaoning Province

Abstract In the early Proterozoic the Li'eryu Formation and Dashiqiao Formation of eastern Liaoning province, China, there are distributed Mg‐rich carbonate rock formations, in which large to superlarge deposits of boron, magnesite, talc, Xiuyan jade etc. occur. The formation of these magnesian nonmetallic deposits was related to early Proterozoic evaporates; then these deposits underwent reworking of regional metamorphism and hydrothermal metasomatism during the Lüliang orogeny and tectono‐magmatism during the Indosinian‐Yanshanian. Among other things, the Mg‐rich carbonates formations, minerogenetic structures and ore‐forming fluids played a controlling role in the formation of the mineral deposits. Therefore, it can be concluded that the mineral deposits are products of combined processes of the coupling of ore source field, fluid field, thermal field (energy field) and stress field under certain time‐space conditions in the early Proterozoic and the late‐stage superimposed reworking of tectono‐magmatism.

Mineralogical and Chemical Studies of Volcanic-RelatedArgillaceous Industrial Minerals of the Central American Cordillera(Western El Salvador)

The western provinces of El Salvador, which are covered almost exclusively by igneous rocks, offer favorable conditions to study the entire suite of volcanic-related, nonmetallic deposits involving accumulations of zeolite-feldspar, smectite, kaolinite, and diatomite. Formation of nonmetallic deposits, which is still going on in the active geothermal field near Ahuachapan, began during the late Pliocene. This age is based on micropaleontological data obtained during the study of lacustrine sediments laid down in volcanogenic depressions. Judging by their regional distribution and geological setting, the deposits may be subdivided into regional deposits (T <100°C) and structurally controlled deposits (T = 140°–250°C). Both types of volcanic deposits can be further subdivided into various stages:(1) zeolite-feldspar stage, (2) smectite stage, (3) quartz-kaolinite stage, (4) kaolinite-cristobalite stage, and (5) kaolinite stage. Stages (4) and (5) are characterized by the presence of alunite-, woodhouseite-, and crandallite-group minerals and some minerals of the aluminite-alunogen group. Within the deposits, gradual changes (progressive vs. regressive trends) may be attributed to various alteration processes. The progressive trends are correlative with the differentiation of the mineralizing fluids throughout hydrothermal activity and supergene alteration. The regressive trends are caused by hot-spring diagenesis. Knowledge of the minerostratigraphy in a geothermal field and of the intracrystalline processes within minerals such as siliceous compounds and aluminum-phosphate-sulfate minerals may help to answer the question of whether hypogene or supergene processes have triggered nonmetallic mineralization. The major and trace element compositions (Ag, As, Be, Co, Cr, Cs, Cu, Ge, Hf, Hg, Mo, Nb, Ni, Pb, Rb, Sb, Se, Sr, Tl, Th, U, V, Y, Zn, Zr, and REE) for several argillaceous deposits are presented in this paper. Cross plots using the couples Ba + Sr vs. Ce + Y + La, Ti + Fe vs. Cr + Nb, and Zr vs. Ti may help discriminate hypogene and supergene kaolin concentrations in these epithermal argillaceous deposits. The nonmetallic deposits represent a subtype of high-sulfidation-type deposits . The Salvadorian deposits formed distally to the arc-trench gap and belong to the most recent stages of the Cenozoic Ando-Caribbean mineralizing processes.

Anoxic environment and formation of superlarge ore deposits

The formation of many metallic and non-metallic ore deposits is a result of coupling of mineralization, related to anoxic environment and regional, or global background. Inter act~on, concordance and continual development of the mineralization and environmental background control the large to superlarge scale of ore deposits. Three kinds of ore-forming models related to anoxic environment and three important background patterns are suggested. The turning period of geological history is favorable to the formation of large to superlarge ore deposits.

Nonmetallic Mineral Deposits of China and Plate Tectonics

Abstract The Chinese continent is a component part of the present Eurasian plate. The history of its geological development is a process of the convergence of palaeo‐plates, the oceanward migration of volcanic belts and volcanic island‐arcs, and the accompanying growth of the intracontinental rifts in the later stage. So the Chinese continent abounds in nonmetal resources. Based on the plate‐tectonic settings in which those deposits were formed, the nonmetallic deposits can be generally classified into those related to the sutures and ophiolites, those related to the volcanic island‐arcs, those related to the back‐arc epicontinental sea, those related to the intracontinental rifts and those within the plate interior. They all show certain characteristic regularities of distribution. The evolutionary process of the Chinese continent is so complicated that some nonmetallic deposits have various origins and are characterized by multi‐stage mineralization, multiplicity of types and superimposition of mineralization. All these are of great significance in deepening the understanding of the formation and modes of occurrence of the nonmetallic deposits and in prospecting for mineral resources.

Surface characterization of iron and steel prior to coating

This report presents the latest knowledge on surface properties by which the mechanism and intensity of the adhesion of organic coatings can be influenced on iron materials. By this, it is to be made clear above all that these surface properties depend on a large number of single factors. Since, however, their complex combined action has not been quite clear, it is not yet possible to reconcile the partly different conceptions of the most favourable condition of steel surfaces for a subsequent coating [1 -14]. On the basis of experimental results there are given reasons for the conclusion that greater attention than has been the case so far should be paid to the hydroxyl group-containing primary oxides being formed spontaneously on steel surfaces following the mechanical or chemical pretreatment during contact with air, when coating materials and techniques are selected. If such a continuous, homogeneous primary oxide layer exists, its amphoteric surface hydroxyl groups can be utilized for the chemical adhesion of suitable organic film-formers. On steels whose surface is heterogeneous due to the island-shaped distribution of primary oxides, non-metallic deposits and pollutants, homogenization can be achieved by producing a conversion layer. Usually, phosphate and oxide layers have amphoteric surface hydroxyl groups, too, whose isoelectric point (IEPS) varies with the composition, so that it is possible to select thermodynamically favourable conditions for the chemical adhesion of organic coatings.

Studies of Epitaxial Growth of Metallic and Nonmetallic Films by Means of High-Resolution Ciné and Still-Electron Microscopy

Growth processes of metallic vacuum deposits, Ag and Au, and nonmetallic deposits, PbS and PbSe, on MgO and MoS2 substrates have been studied by means of direct cine recording of electron micrographs resolvable down to 17 A moire spacing. The detailed kinetics of the film growth as revealed by the moire fringes are discussed in the light of growth mechanisms. The main differences between the metallic and nonmetallic film growths are the absence, in the cases of nonmetallic film growth, of “liquid-like” behavior during coalescence, and lack of the secondary nucleation, which are known to be very important in metallic film growth. Growth processes of so-called multiply-twinned particles and twin formation and release in the metallic film growth have also been studied. The direct observation of formation of pseudomorphic interfacial dislocations was carried out in the case of PbSe on PbS. The lattice spacing anomalies in pseudomorphic overgrowth have been examined by means of high-resolution still-electron m...

Paleoclimatologic and Paleobiologic Implications of Louann Salt Deposition: ABSTRACT

On the assumption that the Louann Salt mass extends below the Gulf of Mexico basin, its volume is calculated at about 4 million km3. If such an amount of salt is added to the volume of present ocean water, together with other post-Paleozoic salts in Africa and the Middle East, the ocean water at the close of the Paleozoic is found to be at least 20 percent saltier than that of the present. The evidence of extinction of many forms of marine life at the close of the Paleozoic probably reflects the inability of marine animals to survive in such salty waters, but it also suggests that such saltiness was not typical of Paleozoic seas and was a consequence of Permian climatic and weathering conditions. The extraction and accumulation of the Louann Salt mass required prolonged continuance of evaporating conditions. The extensive presence of eolian sandstone in the Triassic System of North America, South America, Africa, Antarctica, Australia, and Europe indicates that desert and semiarid regions probably were far more extensive then than now, and that highly evaporative winds were the agencies affecting the return to normal oceanic salinity as the Louann Salt was deposited. In turn, surviving animal stocks were able to proliferate and fill the Jurassic seas. It is probable that these conditions also exercised significant control in accumulation of such nonmetallic deposits as phosphates, uranium, potash, sulfur, and bauxite. End_of_Article - Last_Page 1833------------

Non-Metallic Deposits of The U.S.S.R.

Non-Metallic Deposits of The U.S.S.R.