High Deposits Research Articles

Incorporation of three different creep models into large-strain consolidation analysis of a clayey tailings deposit

Soft soils and clayey tailings deposits can exhibit substantial creep during consolidation. Creep can strongly influence the consolidation and strength development of tailings deposits but is rarely considered in existing large-strain consolidation analyses for design purposes. This paper presents an analysis of a 13 m high deposit of soft clayey tailings using large-strain consolidation coupled with three alternate creep formulations: the Yin–Graham, Vermeer, and overstress formulations. Predictions of settlement and excess pore water pressure using all three consolidation–creep models have better agreement with the measured data compared to predictions from a large-strain consolidation model without creep. The overstress model is more difficult to calibrate for young soft soils in an initially normally consolidated state, owing to the strong dependency on the initial ratio between an unknown small preconsolidation stress and the initial small effective stress. The models calibrated to the pilot study were then used to extrapolate the full-deposit behavior, and the implications of using such consolidation–creep models and their limitations are discussed.

Studi Karakteristik Propertis Tanah di Kecamatan Polen Kabupaten TTS

Knowing soil characteristics is very important for an engineer to ensure the safety of buildings above the ground. Therefore, conducting a soil investigation in the laboratory and field testing The island of Timor, especially in the Polen sub-district, Timor Tengah Selatan district, has fine-grained soil deposits. In the sub-district area, a large dam is being built, namely the Temef Dam and the main road link connecting one city and four regencies on the island of Timor also. This study aims to determine the characteristics of the soil both physically and mechanically through laboratory testing. The results showed that the location in Puna Village was clay of low plasticity, while the Loli Village had high plasticity clay deposits. The higher of soil's plasticity index, the higher the potential for swelling of the soil. The increased swelling potential causes the low shear strength of the soil. Clay with low shear strength cannot support the construction load on it. Therefore, before the construction of the building on it, it is necessary to improve the soil. In addition to its weaknesses, on the other hand, impermeable clay is used in the dam core material, where the location of material extraction is still within reach so that the work becomes economical.

Prediction of Potential Acid Mine Drainage Formation in High Sulfidation Epithermal Deposit using Geochemical and Mineralogy Approaches

Identification of acid mine drainage (AMD) can be predicted using a geochemical and mineralogy characterization approach to identify rocks forming and neutralizing acids. Geochemical characterization using static and kinetic tests. The static test is the first step to determining the potential for acid formation in rocks by comparing the potential for forming and neutralizing acids, which are characterized by uncertain behavior that causes predictions to be inaccurate. Kinetic tests were carried out to predict the long-term acid-producing potential better. Furthermore, mineralogical characterization is needed to assess the importance of sample mineral content in predicting AMD. Tests were conducted on rock samples from high sulfidation epithermal (HSE) deposits in North Sulawesi, Indonesia. The samples represent the different geological domain conditions found in HSE deposits. The main acid-producing components are pyrite and secondary minerals (alunite) capable of buffering acidity. The results showed a lower change in leachate pH (from day 30 to 180) and were accompanied by the release of species (high dissolved metals).

LA-ICP-MS analyses of trace elements in zoned sphalerite: A study from the Maoping carbonate-hosted Pb-Zn(-Ge) deposit, southwest China

In southwest China, many Pb-Zn deposits are described as low temperature carbonate-hosted deposits or Mississippi Valley-type (MVT) deposits. But trace element distribution and concentration in sphalerite between deposits may significantly vary and could possibly imply alternative deposit-types. An investigation was carried out on sphalerite (Sp-II) in the main ore stage of the Maoping carbonate-hosted Pb-Zn(-Ge) deposit (Southwest China), based on laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Here, Sp-II is divided into the dark red, yellow–brown, and light-yellow zones. Principal component analysis revealed element clusters distributed within distinct zoning types in Sp-II: the dark red zones are enriched in Mn, Fe, and Cd; the yellow–brown zones are enriched in Cu, Ge, Ag, and Sb; the light-yellow zones are enriched in Ga. Trace elements in Sp-II record temperature and sulfur fugacity (fS2) evolution of ore-forming fluid system, which tends to decrease from the dark red to yellow–brown to light-yellow zones. The formation of Sp-II may be an external process resulting from the varieties of temperature and fS2 in the ore-forming fluid, which may be driven by rock buffer. Here, Manganese, Fe, and Cd are preferentially incorporated in the relatively higher temperatures and fS2, whereas Ga is preferentially incorporated in the relatively lower those. Regardless of the zoning type, strong binary correlations between Ge and Cu as well as the high similarity of their concentration distribution in mapping images suggest coupled substitutions as Ge4+ + 2Cu+ ↔ 3Zn2+ and/or Ge2+ + 2Cu+ ↔ 2Zn2+ + vacancy. A trace element comparison of various Pb-Zn deposits in the world, including our new data from Maoping shows a distinctive signature for the Maoping deposit. Homogenization temperatures (217–430 ℃, mean 298 ℃) of the newly discovered ore body (No. VI) support that Maoping is a medium–high temperature carbonate-hosted deposit.

Global green hydrogen-based steel opportunities surrounding high quality renewable energy and iron ore deposits

The steel sector currently accounts for 7% of global energy-related CO2 emissions and requires deep reform to disconnect from fossil fuels. Here, we investigate the market competitiveness of one of the widely considered decarbonisation routes for primary steel production: green hydrogen-based direct reduction of iron ore followed by electric arc furnace steelmaking. Through analysing over 300 locations by combined use of optimisation and machine learning, we show that competitive renewables-based steel production is located nearby the tropic of Capricorn and Cancer, characterised by superior solar with supplementary onshore wind, in addition to high-quality iron ore and low steelworker wages. If coking coal prices remain high, fossil-free steel could attain competitiveness in favourable locations from 2030, further improving towards 2050. Large-scale implementation requires attention to the abundance of suitable iron ore and other resources such as land and water, technical challenges associated with direct reduction, and future supply chain configuration.

Geochemistry of ore minerals from Chelopech deposit: II. Trace-elements in enargite-luzonite

The concentrations of trace elements in enargite-luzonite from blocks 8, 19-SE, 19-NW, 19-NE, 19-SW, 103-W, 103-E, 144, 146, 147, 149-south, 150, and 151 of copper-gold high sulphidation Chelopech deposit were determined by LA-ICP-MS. It was found that the enargite-luzonites from the individual blocks are enriched in different degrees of “impurity” elements: those from block 19-SW are enriched in Ge, Ga, and W; from block 146 of Bi; from block 147 of Se, Sb, Sn, and In; from block 149-south of Zn, Pb, Tl, and Cd; from block 8 of Fe, Mn, and Ti; from block 103-Е of Au and Hg; from block 103-W of V, Ga, and Mo; from block 150 of Ag and from block 151 of Те. In addition, a preferential distribution of trace elements between pyrite and enargite-luzonite is observed. For example, silver, lead, manganese, nickel, cobalt, thallium, molybdenum, chromium, and titanium are concentrated in the first, while germanium, gallium, indium, tin, zinc, antimony, tellurium, bismuth, mercury, vanadium, tungsten in the second, and in most cases they are structurally related. Both minerals are concentrators of gold, but it reaches its highest values in the latter (309 ppm from block 103-Е and 118 ppm from block 151), and in both cases its presence is mainly due to microinclusions of native gold and/or electrum and tellurides.

Influence of Lithium Metal Deposition on Thermal Stability: Combined DSC and Morphology Analysis of Cyclic Aged Lithium Metal Batteries

Safety properties of lithium metal batteries (LMBs) are key for potential commercialization. The few studies reported focus predominantly on pristine materials or as-assembled cells disregarding potential safety risks induced by cyclic aging and the associated formation of high surface area lithium deposits. Herein, LMBs using organic carbonate-solvent electrolyte were investigated to decipher the influence of the lithium metal deposition behavior on the thermal stability. For this purpose, cells were cycled to different states of health, states of charge and at varied current densities during charging before analyzing the thermal stability on material and cell level via differential scanning calorimetry. In combination with cryogenic-focused ion beam-scanning electron microscopy it is possible to correlate the lithium metal deposition morphology with the thermal stability. Therein, accumulation of highly porous lithium metal deposits during cycling leads to a significant increase of released heat caused by highly exothermic reactions between deposited lithium and the electrolyte. Consequently, a denser deposition morphology shifts the onset for exothermic decomposition reactions to higher temperatures. Overall, this study introduces the combination of different analytical techniques to evaluate LMB safety properties and reveals the safety-relevant impact of cyclic aging on thermal stability.

Geochemistry of ore minerals from Chelopech deposit: I. Trace elements in pyrite

The concentrations of trace elements in pyrite from blocks 8, 19-SE, 19-NW, 19-NE, 19-SW, 103-W, 103-E, 144, 146, 147, 149-south, 150, and 151 of copper-gold high sulphidation Chelopech deposit were determined by LA-ICP-MS. It was found that the pyrites from the individual blocks are enriched in different degrees of “impurity” elements: the highest contents of Ag, Au, Zn, Hg, and In are typical to block 19-NE; Se, Bi, and Ti to block 19-SE; As, Mn, Tl, V, and Cd to block 19-SW; Co and Ni to block 144; Sb and Sn to block 146; Cu to block 149-south; Pb, Te, and Ga to block 103-E and Cr to block 103-W. The obtained results also show that in collomorhic pyrites the variations in the contents of trace elements are always very large and are rather due to adsorption processes than isomorphism. In addition, pyrites are also enriched in poisonous trace elements, especially from the lower level of the northern blocks, which, however, also have the highest values of gold and silver.

Caspian transgressive-regressive cycles across the Lower Volga region during the Quaternary reconstructed from the borehole at Ulan-Khol (Kalmykia, Russia)

During the Quaternary, the Lower Volga region was typically a shallow shelf of the Caspian Sea. This region regularly and distinctively responded to sea level fluctuations by changing both sediments and biota. This region is therefore a key to understanding the history of the transgressive-regressive cycles of the Caspian Sea during the Quaternary. There is a wealth of information about the Quaternary deposits of the Lower Volga region; however, their diversity of facies, erosional processes, and fragmented sections create difficulties in stratigraphic interpretation and the development of paleogeographic models. The studied 500-m section of borehole 8 Ulan-Khol is among the few in the Caspian region that allows for the sequential reconstruction of the Quaternary history of the region in one section. These borehole data offer a unique opportunity to reconstruct transgressive-regressive cycles in Pleistocene basins located in the most southeastern part of Europe (the Caspian region). Based on biostratigraphic, sedimentological, and paleomagnetic methods, we were able to define main Early, Middle, and Late Pleistocene units, which were correlated with regional stratigraphical units. Each unit corresponds to regional paleogeographic events and sedimentation modes characterized either by basinal (brackish water) or continental conditions when lagoons and fluvial landscapes dominated. The borehole interpretation integrated with regional data demonstrates a complex history of Caspian basin development during Apsheronian time (MIS 63–20) with the presence of a strong regression in its final stage, accompanied by a previously unknown advance of the Paleo-Volga valley to the latitude of Astrakhan city and further south. This regression and the formation of the Paleo-Volga valley continued during Tyurkyanian time (MIS 19). By the end of the Tyurkyanian, the regression was followed by a transgressive stage, which culminated in Bakunian time (MIS 18–12). The Khazarian stage (MIS 11–5) of Caspian Sea development was characterized by a constant change from alluvial-marine to marine and estuarine environments. The borehole data support our earlier conclusion that the Singilian deposits separate the lower (MIS 11–7) and upper (MIS 5) Khazarian units. New data support the existence of only one transgression of the Caspian Sea during Khvalynian time (MIS 3–2); after its maximum stage the sea level gradually decreased with the formation of coastlines at several terrace levels. Due to its high deposit thickness and rich paleontological, stratigraphic and lithological information, Ulan-Khol borehole 8 can be considered a key site for the Northern Caspian area.

Combination model-based numerical simulation of the mineralizing processes within iron oxide-apatite systems

Iron oxide-apatite (IOA) deposits are high grade iron magmatic-hydrothermal mineral deposits having significant economic values and extremely complex and coupled forming processes. The combination model of ore deposits is a model integrating characteristics of several deposits with the same genetic type or sharing close temporal-spatial correlations. This research highlights the usage of numerical simulation method and combination model of deposits in quantitatively analyzing ore-forming processes during the formation of IOA systems and views the future developments of numerical modeling in ore geology research. Our numerical model couples heat transfer, pressure, fluid-flow, chemical reactions and migration of ore-forming materials. Results match the fact that temperature reduction and pressure variation are two key factors controlling the temporal-spatial distribution of iron mineralization, and results of cooling process indicates that a single period of ore formation of IOA deposits may last no more than 12,200 years, a timespan much shorter than previously estimated. These results are obtained based on the concept of combination model of IOA systems, providing quantitative information reflecting the generation of IOA deposits. However, the methods in our research are stills limitations remained, such as uncertainty of pre-metallogenic conditions and restriction from elementary reactions. Future advances in analytical methods and mathematical models will definitely improve the practicality of combination model of deposits and numerical modeling of ore formation, and provide quantitative answers for existing problems related to mineral deposits.

Study on Mechanism of Oxygen Oxidation Leaching with Low Acid for High Acid Consumption Sandstone Uranium Deposit

In view of the problems of high acid consumption, the blockage of ore-bearing beds caused by iron ion precipitation and a low leaching rate in the conventional acid leaching of a sandstone-type uranium deposit, the author put forward “low-acid and oxygen leaching technology” research. In order to further clarify the mechanism of leaching sandstone-type uranium ore with low acid and oxygen, the oxidation mechanism of ferrous ion under acidic conditions, the influencing factors of ferrous ion oxidation process, the kinetic simulation of oxygen oxidizing uranium minerals, and the interaction of uranium and iron precipitation in acidic solution were analyzed and studied, and the mechanism of oxygen oxidizing uranium and uranium leaching under low acid conditions was explored. The results show that under the condition of low acidity, the kinetics that ferrous oxidized by oxygen is between the first-order and second-order reaction, which can reduce the iron ion precipitation and then reduce the influence of iron ion precipitation on uranium leaching, so as to improve the uranium leaching rate. This study confirmed the feasibility of the oxygen oxidation of uranium and uranium leaching under low acidity conditions, which has a good guiding significance for the effective leaching of uranium deposits with a high acid consumption.

Stability evaluation of the high fill deposit slope subjected to rainfall considering water deterioration

Stability evaluation of the high fill deposit slope subjected to rainfall considering water deterioration

The Cretaceous of the Cameroon Atlantic Basin (Central Africa): sediment provenance, correlation, paleoenvironment and paleogeographic evolution of the Eastern Proto-Atlantic margin (Central Gondwana)

An integration of geochemistry, mineralogical and palynological data is used to depict the sediment provenance and distribution, the sedimentary environment and the paleogeographic evolution of the Cretaceous Atlantic Basin of Cameroon. The basin is located along the African western coast, in the heart of the Guinea Gulf, and includes the Campo, Douala, and Rio-del-Rey sub-basins from South to North. The sediments of the Campo sub-basin are derived from rocks of intermediate composition, those of the Douala sub-basin from intermediate to mafic rocks in the southern and felsic rocks in the northern parts, and those of the Rio-del-Rey sub-basin from felsic rocks with a contribution of rocks of intermediate composition. The paleoweathering index and Index of Chemical Variability values for Campo, Douala and Rio-del-Rey sub-basins range from 71.26 to 76.88 and 0.98 to 2.12, 67.15 to 99.39 and 0.37 to 0.90, and 73.17 to 92.90 and 0.44 to 10.03, respectively, indicating sub-maturity, high maturity and sub- to high maturity deposits. Al2O3 vs. V and Al2O3 vs. P2O5 plots, and palynologic data such as marine (e.g. dinoflagellates and microforaminifera) and continental (e.g. Classopollis sp., Ephedripites sp., Botryococcus sp.) species suggest a deposition in more or less deep lacustrine (Campo sub-basin), fluvio-deltaic to shallow marine (Douala sub-basin), and marginal to shallow marine (Rio-del-Rey sub-basin) environments. The paleoweathering index values, the clay minerals (kaolinite, illite and chlorite/vermiculite) distributions, and the palynological data point to arid to semi-arid climate in the Campo sub-basin and semi-arid to periodically humid conditions in the Douala and Rio-del-Rey sub-basins. The tectonic setting diagram suggests collision tectonic events that are inconsistent with the classic geological history of the Atlantic Basin. The situation is in fact related to Precambrian events that affected the basement rocks from which the studied sediments were derived, and probably to the compressional tectonics during the evolution of the South Atlantic Ocean. Although these sub-basins share the same geological history, there are some differences, such as the degree of sediment maturity, the diagenetic effects, the lithology of rock sources, the paleoenvironments of deposition and their fluctuation, depending on the moment the tectonic of Atlantic opening reached them (northward progression of the W-E extension) and the northern shearing along the southern area of the Benue through axis (Rio-del-Rey). The geological history of the Cameroon Atlantic Basin is similar to those of Gabonese and Nigerian basins, along the African western coast, and of those of the Brazilian basins along the eastern coast (Santos Basin to Pernambuco-Paraiba Basin).

The effect of sediment density parameter values on the debris flow velocity parameters

Debris flow is a phenomenon where the material from the eruption is carried away by the flow of water due to rain in the upstream area of the river and usually crashes into watersheds around the volcano. The potential for large debris flows can be caused by high rainfall and sediment deposits that occur during debris flows. Rainfall and sediment carried by water flow can affect the volume and velocity of debris flows. A debris flow simulation was carried out to anticipate casualties and damage using SIMLAR V2.1 by modifying rain intensity and the density of sediment carried by the debris flow. Based on the result, we can obtain the results of the velocity, volume, and area affected by the debris flow. The flow velocity values obtained for testing with rainfall intensity of 162 mm with a density of sediment 1370 kg/m3, 2340 kg/m3, 2635 kg/m3, and 2820 kg/m3, respectively, were 2.72 m/s, 2.16 m/s, 2.50 m/s, and 2.57 m/s. The volume values with the same intensity and density of sediment are 186,381 m3, 311,116 m3, 274,030 m3, and 294,987 m3. Based on the test results, it can be concluded that sediment density significantly affects the velocity and volume of the debris flow. Where sediment density is inversely proportional to the flow velocity, the higher the sediment density, the slower the flow velocity, while the volume is directly proportional to the sediment density. The higher the density of the sediment, the higher the volume.

Tomografía Computarizada Espectral y unidades Hounsfield: bases para una correcta interpretación

Dual energy CT is a recent upgrade to this diagnostic imaging technique. The purpose of this critical narrative review is to lay out the clinical applications of Hounsfield Units and their variation across the x-ray energy spectrum using DECT. We explore new reconstruction methods and parametric maps helpful for the diagnosis of prevalent pathologies such as fatty liver disease, urolithiasis, and to identify complications after interventions or determine the aggressiveness of tumoral lesions. The energy-resolving capabilities of DECT make it a reliable method for the characterisation of tissue and lesion composition. Lower energy monoenergetic images allow us to increase soft tissue contrast and easily identify tissues with higher contrast uptake. Higher energy monoenergetic images are useful to distinguish between contrast uptake and high attenuation calcium deposits and for metal artifact reduction. Parametric images showing uric acid, iodine, calcium, and other material decompositions can be obtained from spectral data for the diagnosis of tumoral or metabolic diseases, vascular lesions and characterisation of deposition arthritis and urolithiasis.

Influence of facies and tectonic structure on the reservoir properties distribution

The lithofacies features influence of productive strata and a system of tectonic faults on the reservoir properties distribution of Jurassic deposits one of the area of Western Siberia was analysed. Main productive strata in this place is Tyumen suite. The facies model of field was updated according reconstruction of sedimentation environment by electrometric facies models (by Muromcev V. S), interpretation results of seismic and core descrition. Dedicated sedimentation zones show main conception of Western Siberia basin evolution in Jurassic. Lithofacies analysis allow to identify main features of sedimentation zones, find out a reasons of uneven reservoir properties distribution. Also influence of tectonic faults system on reservoir properties of productive layers was found. Data summation help update fault model and highlight new low-amplitude faults. Next comparing maps of initial and remaining recoverable reserves of oil with lithofacies and fault model of reservoir rock help identify reason of zones with high density deposits forming and develop most effictient stimulation of oil recovery.

High density deposits of binary colloids

Colloids are essential materials for modern inkjet printing and coating technology. For printing and coating, it is desirable to have a high density of colloids with uniformity. Binary colloids, which consist of different size colloidal particles, have the potential to achieve high coating density and uniformity from size effects. We report a strategy to attain high-density deposits of binary colloids with uniform, crack-free, and symmetric deposits through droplet evaporation on micropillar arrays. We modify surfaces of micropillar arrays with plasma treatment to control their surface energy and investigate how binary colloidal fluids turn into well-controlled deposits during evaporation with X-ray microscopic and tomographic characterizations. We attribute temporary surface energy modification of micropillar arrays to the well-controlled high-density final deposits. This simple, low-cost, and scalable strategy would provide a viable way to get high-quality, high-density deposits of colloids for various applications.

Farmers’ willingness to engage in a deposit-refund system for animal manure in biogas production: A discrete choice experiment in Germany

This article reports the results of a discrete choice experiment with 101 German livestock farmers designed to establish the factors affecting the respondents’ acceptance of a deposit-refund system for animal manure. Farmers entering into a manure supply contract with a biogas plant would offer their entire slurry to the plant and pay a deposit which is refunded if and when the farmer takes back the same quantity of nutrients as initially supplied. Such a system can secure the supply of slurry for biogas plants and help farmers reduce greenhouse gas and ammonia emissions. A mixed-logit model revealed a very high overall willingness to participate in such a scheme. The average probability of participation is 70%. With an average of 73% of nutrients taken back the deposit-refund system can be a good way to distribute nutrients regionally. The remaining nutrient quantities are transferred to crop farms - if necessary for a fee, financed by the retained deposit. Low deposit rates and cost-reducing complimentary services offered by the biogas plant in the field of nutrient management improve participation. Free slurry storage with a WTP of €4.15 per m3 and free digestate spreading with a WTP of €7.14 per m³ can be very effective in enticing farmers into the scheme. Less tangible services such as the certification of greenhouse gas reductions appear less important for participation decisions. While high deposit amounts could increase nutrient redemption or additional intake, the probability of choice decreases as the amount increases. Based on the simulated acceptance rate, 8–10 €/t seems to represent a critical deposit level up to which a high probability of participation can be achieved.

Environmental reputation and bank liquidity: Evidence from climate transition

AbstractThis study empirically investigates how a bank's nonfinancial signals of environmental reputation affect its deposits and credit provision in US counties with severe climate transition risks. We find that banks with higher reputational risks associated with environmental issues tend to experience declining deposits in counties exposed to severe climate change risks. Banks with a poor environmental reputation also reduce mortgage origination in such counties and diminish liquidity creation if they have high deposit shares in counties sensitive to climate transition. This study suggests that a bank's reputation regarding environmental, social and governance practices is an important underlying cause of bank liquidity in areas sensitive to climate change.

Experimental study of sediment washout from stormwater sumps.

Sumps are commonly used in urban stormwater systems, which can be considered as a simple pretreatment device for stormwater quality control. However, they may function as pollution sources due to sediment washout under high flow conditions. An experimental study was conducted to investigate the scour process of predeposited sediments from a sump and its influencing parameters. Under conditions with large inflows or high sediment deposit, the sediment particles could be resuspended, entrained and flushed out. The washout mass decreased exponentially with time if the sediment bed surface depth was larger than a threshold value; otherwise, the amount of washout would be much smaller. The same scour pattern was observed for all the testing cases, of which the largest scour depth always occurred below the outlet. The deposit below the inlet might increase under conditions with high flow rates and low levels of sediment bed. Dimension analysis was performed and principal non-dimensional parameters were found, including the Péclet number, the pipe Froude number, and the dimensionless particle diameter, which can be used to determine whether the washout would occur and its intensity in a stormwater sump under given conditions.