Major Minerals Research Articles

Application of infrared spectroscopy and its theoretical simulation to arsenic adsorption processes.

Accurate detection and analysis of arsenic pollutants are an important means to enhance the ability to manage arsenic pollution. Infrared (IR) spectroscopy technology has the advantages of fast analysis speed, high resolution, and high sensitivity and can be monitored by real-time in situ analysis. This paper reviews the application of IR spectroscopy in the qualitative and quantitative analysis of inorganic and organic arsenic acid adsorbed by major minerals such as ferrihydrite (FH), hematite, goethite, and titanium dioxide. The IR spectroscopy technique cannot only identify different arsenic contaminants but also obtain the content and adsorption rate of arsenic contaminants in the solid phase. The reaction equilibrium constants and the degree of reaction conversion can be determined by constructing adsorption isotherms or combining them with modeling techniques. Theoretical calculations of IR spectra of mineral adsorbed arsenic pollutant systems based on density functional theory (DFT) and analysis and comparison of the measured and theoretically calculated characteristic peaks of IR spectra can reveal the microscopic mechanism and surface chemical morphology of the arsenic adsorption process. This paper systematically summarizes the qualitative and quantitative studies and theoretical calculations of IR spectroscopy in inorganic and organic arsenic pollutant adsorption systems, which provides new insights for accurate detection and analysis of arsenic pollutants and arsenic pollution control. PRACTITIONER POINTS: This paper reviews the application of infrared spectroscopy in the qualitative and quantitative analyses of inorganic and organic arsenic acid adsorbed by major minerals such as ferrihydrite, hematite, goethite, and titanium dioxide, which can help identify and evaluate the type and concentration of arsenic pollutants in water bodies. In this paper, theoretical calculations of infrared spectra of mineral adsorbed arsenic pollutant systems based on density functional theory reveal the adsorption mechanism of arsenic pollutants in water at the solid-liquid interface and help to develop targeted arsenic pollution control technologies. This paper provides a new and reliable analytical detection technique for the study of arsenic contaminants in water bodies.

Potential Uses of Local Clay Materials for the Production of Porcelain Electrical Insulators, Ethiopia

AbstractClays are extremely variable materials with different mineral compositions, and they are the main ingredients in ceramics applications. Their properties play specific roles in influencing the technological properties and performance of ceramics products. Evaluating the various properties can help to determine the best way to utilize clay materials, such as the locally available Bombawuha (BC) and Denkaka (DC) clays mined from Ethiopia's Bombawuha and Denkaka areas, respectively. The objective of this study was to examine these materials for the purpose of using them to produce quality electrical porcelain insulators. The clay samples were characterized for their chemical composition, mineralogy, thermal properties, plasticity, and particle-size distribution, using atomic absorption spectrometry (AAS), X-ray diffractometry (XRD), differential thermal analysis coupled with thermogravimetric analysis (DTA-TGA), the Atterberg plasticity test, and sieve hydrometer analysis. Based on the characteristics, suitable clay materials were selected and mixed with feldspar and quartz to formulate various porcelain body compositions which were fired at three different temperatures (1200, 1250, and 1300°C) and dwell times (1.5, 2.0, and 2.5 h). The mineralogy, water adsorption, apparent porosity, bulk density, dielectric strength, flexural strength, and microstructure of the fired bodies were measured. The results revealed that, compared to DC, BC contains kaolinite as the major mineral with appreciable amounts of silica (46.72 wt.%), alumina (35.32 wt.%), and fluxing oxides but smaller amounts of CaO. BC contains greater clay fractions (20.58 wt.%); and has a middle-range plasticity index (PI = 11.2 wt.%), thus making BC suitable for producing porcelain insulators. A test-body composition of 40 wt.% BC, 40 wt.% feldspar, and 20 wt.% quartz, fired at 1250°C for 2 h, exhibited water adsorption of 0.17 wt.%, apparent porosity of 0.42 wt.%, bulk density of 2.45 g/cm3, a dielectric strength of 8.22 kV/mm, and flexural strength of 43.63 MPa and, thus, satisfied the required properties for quality porcelain insulators.

Fe(III) Biomineralization in the Surface Microlayer of Acid Mine Waters Catalyzed by Neustonic Fe(II)-Oxidizing Microorganisms

The formation of thin mineral films or encrustations floating on the water surface of low-flow or stagnant zones of acid mine drainage (AMD)-affected streams is probably among the most exotic features that can be found in mining areas. However, most fundamental questions about their origin (biotic vs. abiotic), structure, mineralogy, physical stability and metal-retention capacity remain unanswered. This study aims to reveal the factors promoting their formation and to clarify their composition in detail. With this purpose, the major mineral phases were studied with XRD in surface film samples found in different mine sites of the Iberian Pyrite Belt mining district (SW Spain), and the major oxide and trace metal concentrations were measured with XRF and/or ICP-MS. Fe(III) minerals dominated these formations, with mineralogy controlled by the pH (jarosite at pH~2.0, schwertmannite at pH 2.5–3.5, ferrihydrite at pH > 6.0). Other minerals have also been identified in minor proportions, such as brushite or khademite. These mineral formations show an astounding capacity to concentrate, by orders of magnitude (×102 to ×105), many different trace metals present in the underlying aqueous solutions, either as anionic complexes (e.g., U, Th, As, Cr, V, Sb, P) or as divalent metal cations (e.g., Cu, Zn, Cd, Pb). These floating mineral films are usually formed in Fe(II)-rich acidic waters, so their formation necessarily implies the oxidation of Fe(II) to Fe(III) phases. The potential involvement of Fe(II)-oxidizing microorganisms was investigated through 16S rRNA gene amplicon sequencing of water underneath the Fe(III)-rich floating mineral films. The sequenced reads were dominated by Ferrovum (51.7 ± 0.3%), Acidithiobacillus (18.5 ± 0.9%) and Leptospirillum (3.3 ± 0.1%), three well-known Fe(II)-oxidizing genera. These microorganisms are major contributors to the formation of the ferric mineral films, although other genera most likely also play a role in aspects such as Fe(III) sequestration, nucleation or mineral growth. The floating mineral films found in stagnant acidic mine waters represent hotspots of biosphere/hydrosphere/atmosphere interactions of great value for the study of iron biogeochemistry in redox boundaries.

Adsorption of textile dyes from aqueous solutions onto clay: Kinetic modelling and equilibrium isotherm analysis.

The commercial activated carbon commonly uses to reduce of dye amount in the textile industry effluents. In this study has focused on the use of a natural clay sample as low cost but potential adsorbent. For this purpose the adsorption of commercial textile dyes, Astrazon Red FBL and Astrazon Blue FGRL, onto clay was investigated. The physicochemical and topographic characteristics of natural clay sample were determined by scanning electron microscopy (SEM), X-Ray fluorescence spectrometry (XRF), X-Ray diffraction (XRD), thermogravimetric analysis (TGA), and cation exchange capacity measurements. It was determined that the major clay mineral was smectite with partial impurities. The effects of several operational parameters such as contact time, initial dye concentration, temperature, and adsorbent dosage on the adsorption process were evaluated. The adsorption kinetics was interpreted with pseudo-first order, pseudo-second order, and intra-particle diffusion models. The equilibrium adsorption data were analyzed using Langmuir, Freundlich, Redlich-Peterson, and Temkin isotherm models. It was determined that the adsorption equilibrium was reached in the first 60min for each dye. The amount of adsorbed dyes onto clay decreased with increasing temperature, similarly, it decreased with increasing sorbent dosage. The kinetic data were well described by pseudo-second order kinetic model, and adsorption equilibrium data was followed both Langmuir and Redlich-Peterson models for each dyes. The adsorption enthalpy and entropy values were calculated as -10.7kJ.mol-1 and -13.21J.mol-1.K-1 for astrazon red and those for astrazon blue -11.65kJ.mol-1 and 37.4J.mol-1.K-1, respectively. The experimental results support that the physical interactions between clay particles and dye molecules have an important role for the spontaneous adsorption of textile dyes onto the clay. This study revealed that clay could effectively be used as an alternative adsorbent with high removal percentages of astrazon red and astrazon blue.

Linking the Gawler Craton and Mount Isa Province through hydrothermal systems in the Peake and Denison Domain, northeastern Gawler Craton

Tectonic reconstructions of Proterozoic Australia commonly place the Peake and Denison Domain of the northeastern Gawler Craton at the interface between the North and South Australian cratons prior to the reconfiguration of Australia’s main tectonic components in the Mesoproterozoic. However, this reconstruction is largely based on palaeomagnetic data as the geological correlations between these regions are currently limited, particularly during the Mesoproterozoic. The early Mesoproterozoic period is significant as it corresponds to major IOCG mineralization in the eastern Gawler Craton between 1600 Ma and 1575 Ma, and IOCG mineralization in the Mount Isa Province largely between 1550 Ma and 1490 Ma. Therefore, determining the relationship of the Peake and Denison Domain to the Gawler Craton and Mount Isa Province during this period is essential to evaluating mineral prospectivity in the northeastern Gawler Craton. New U–Pb LA-ICP-MS geochronology on zircon and titanite improves our understanding of the tectonothermal and hydrothermal history the Peake and Denison Domain during the late-Palaeoproterozoic, early-Mesoproterozoic and the Cambrian–Ordovician periods. Titanite formed within largely calc-silicate alteration assemblages indicates the Peake and Denison Domain has a protracted history of hydrothermal activity, recording events at c. 1565 Ma, 1530–1515 Ma, c. 1500 Ma, c. 1465 Ma and c. 490 Ma. The highly calcic nature of the c. 1565–1500 Ma alteration in the Peake and Denison Domain shares strong similarities in age and character to the regional calcic-sodic alteration recorded in the Mount Isa Province. We suggest the two regions were influenced by similar hydrothermal systems during the early Mesoproterozoic, supporting reconstruction models that place the Peake and Denison Domain near the Mount Isa Province during the early-Mesoproterozoic. This highlights the prospectivity of the Peake and Denison Domain for Isan-style IOCG mineralization, but requires consideration of the post-1500 Ma rotation of prospective structures.

Alteration of sulfide ore of the Samolazovskoe deposit, Aldan shield, in an experimental bioleaching heap

The article contains the results of a mineralogical study of sulfide ores of the Samolazovskoe deposit (Aldan Shield) and the products of their experimental bacterial oxidation in a heap. Pyrite and marcasite are the major minerals of primary ores. They form fine-grained crystalline and micrometer-grained to cryptocrystalline aggregates. Sphalerite, galena, chalcopyrite, pyrrhotite, fahlore, luzonite, bournonite and other Sb sulfosalts, antimonite, arsenopyrite are minor minerals. Tiemannite, coloradoite, calaverite, hessite, petzite and native gold are rare. The ores in the experimental biooxidation heap are mostly altered in its upper parts. The secondary products of the alteration of ores include fine-grained Mg- and S-bearing calcite, smectites after feldspars, and films of Fe3+oxyhydroxides on the surface and in fractures of ore. In the lower part of the heap, technogenic processes are weak and mainly include the formation of gypsum . The sulfides are preserved throughout the heap vertical profile including very fine crystalline, colloform and botryoidal aggregates with a nonstoichiometric ratio of cations and anions and the presence of As, Ni and Cu. The botryoidal aggregates of the Fe disulfides contain galena, which forms a “microseptary” structure, which was not found in primary ores. The high-fineness native gold was found in assemblage with coloradoite and calaverite as inclusions in fine-grained aggregates of Fe disulfides. The conclusion is made on an insufficient impact of the bioleaching of refractory ores in the irrigation regime used, and forming of the secondary minerals that prevent the extraction of gold. Keywords: Samolazovskoe deposit, Aldan Shield, coloradoite, calaverite, native gold, refractory ores, bio-oxidation.

Internal Flesh Browning in Apple and Its Predisposing Factors—A Review

This review article is focused on internal flesh browning (IFB)-related physiological disorders affecting apple (Malus domestica Borkh.) fruit. The expression of different physiological and metabolic IFB-related disorders during post-harvest storage are investigated along with the pre-harvest factors contributing to development. The effectiveness of commercially available pre-harvest technologies for preventing IFB-related disorders are also examined. Internal flesh browning-related disorders are erratic and devastating disorders that result in post-harvest deterioration of fruit quality in apples. Internal flesh browning-related disorders can result in severe economic losses to the apple industry through reduced consumer trust and market acceptability of susceptible cultivars. There are several IFB-related disorders and incidence can range from 0 to 100% of a crop, with severity ranging from no brown flesh to browning of the entire fruit flesh. While IFB-related disorders are found in several apple cultivars, some cultivars are more prone than others. The development of IFB-related disorders involve complex mechanisms depending upon the different types and causes, or factors involved in loss of structural integrity and functional stability of the cell membranes and cell components. Membrane disruption followed by enzymatic oxidation of fruit phenolic compounds by polyphenol oxidases and the production of brown polymers is considered to be the general underlying mechanism causing the browning of flesh tissue. It can be observed in different patterns based on the injured portion of the fruit flesh and the cause of membrane disruption. Three broad categories of IFB-related disorders, including chilling injury, internal CO2 injury, and senescent-related browning disorders, are discussed along with their sub-types. The development of IFB-related disorders can be influenced by both pre-harvest factors and post-harvest conditions and their interactions. Although commonly associated with storage, IFB can also be found immediately after harvest and sometimes in unharvested fruit prior to full maturity. As pre-harvest conditions are a strong contributor to IFB-related disorders, the influence of several pre-harvest orchard conditions, including fruit size, crop load, maturity at harvest, cultivar, climatic conditions, seasonal temperatures, growing degree days, and major mineral nutrients, such as nitrogen (N), phosphorus (P), potassium (K), and calcium (Ca) are reported. Although there are contradictory findings in the studies reported, in general, factors such as larger fruit size, light crop load and delayed harvesting, along with cool temperatures after bloom and warmer temperatures before harvest, increase the risk of IFB-related disorders. In relation to fruit mineral concentrations, high N and low Ca have been associated with increasing IFB, while there is conflicting evidence in relation to the impact of both P and K. This review also examines the effectiveness of commercial pre-harvest technologies such as 1-methylcyclopropene, aminoethoxyvinylglycine and diphenylamine in the prevention of IFB-related disorders, but none of these technologies were found promising due to varied and contradictory results.

Assessing the quality of octopus: From sea to table

AbstractOctopuses (scientific order Octopoda under the scientific class Cephalopoda) are a group of aquatic species with economic importance as a food product in many countries around the world. Octopus products are consumed in many different geographic locations around the world, including East Asia, the Mediterranean region, the Caribbean region, and South American coastal regions. To‐date, a comprehensive scientific review of octopus with direction toward procurement, food processing, and food quality has not been published. The purpose of this review was to provide a practical overview of the nomenclature, procurement (i.e., catching), processing, quality, and shelf‐life of octopus. The objective was accomplished by strategically searching for scientific literature on the topic of octopus and octopus‐derived food products. Octopus‐derived food products have a high protein content (70%–85% on a dry matter basis), significant levels of important major and trace minerals, and significant levels of essential vitamins. In addition, octopus‐derived food products are highly sought after in some areas of the world. However, recognized standards for procurement of octopus and preparation of octopus‐derived food products vary around the world and are frankly inconsistent and under reported. The octopus industry would greatly benefit from greater levels of practical information becoming available, especially as the industry experiences growth and heightened levels of demand.

Molecular modelling of cementitious materials: current progress and benefits

Developing new sustainable concrete technology has become an urgent need, requiring faster and deeper insights into the fundamental mechanisms driving the cement hydration reactions. Molecular simulations have the potential to provide such understanding since the hydration reaction and the cement chemistry are particularly dominated by mechanisms at the atomic scale. In this letter, we review the application of two major approaches namely classical (including reactive) molecular dynamics simulations and density function theory calculations of cementitious materials. We give an overview of molecular simulations involving the major mineral and hydrate phases.

Combined analysis of resistivity and induced polarization tomography for 3D modelling and preliminary volume estimation of the possible gold mineralization zones in the Simi locality, Adamawa, Cameroon

AbstractThe present study attempts to combine direct current and induced polarization methods for 3D geological modelling and preliminary volume estimation of gold mineralization targets in the Simi locality, Adamawa, Cameroon. To begin, resistivity and chargeability data were collected along seven profiles oriented in N150E using the electrical tomography technique. A geological investigation was also carried out and allowed in addition to the geological formations to highlight the existence of gold mineralization in the study area. The interpretation of the inversion results was done by taking into consideration the geological field data and the existing resistivity charts. The 3D distribution of the interpreted sections allowed us to make a horizontal correlation between the different sections and to elaborate the 3D geological model of the study area by using the deterministic inverse distance method. The estimated model indicates a volume of 621,130.625 m3 of the possible gold complex. The gold complex was then divided into two mineralization domains based on chargeability ranges (mV/V): A first domain is associated with a major mineralization zone (39–60 mV/V) with a volume of 10,842 m3, and a second domain is associated with secondary mineralization zone (18–39 mV/V) with a volume of 610,288 m3. This model allows to compartmentalize the gold complex and can be used as a base model for the gold investigation in the study area.

Effects of neutron irradiation on densities and elastic properties of aggregate-forming minerals in concrete

The aggregate-forming minerals in concrete undergo volume swelling and microstructure change under neutron irradiation, leading to degradation of physical and mechanical properties of the aggregates and concrete. A comprehensive investigation of volume change and elastic property variation of major aggregate-forming minerals is still lacking, so molecular dynamics simulations have been employed in this paper to improve the understanding of the degradation mechanisms. The results demonstrated that the densities of the selected aggregate-forming minerals of similar atomic structure and chemical composition vary in a similar trend with deposited energy due to the similar amorphization mechanism. The elastic tensors of all silicate minerals are almost isotropic after saturated irradiation, while those of irradiated carbonate minerals remain anisotropic. Moreover, the elastic modulus ratio versus density ratio of irradiated minerals is roughly following the density–modulus scaling relationship. These findings could further provide basis for predicting the volume and elastic properties of irradiated concrete aggregates in nuclear facilities.

Retraction Note: Salinity-induced changes in the morphology and major mineral nutrient composition of purslane (Portulaca oleracea L.) accessions

Retraction Note: Salinity-induced changes in the morphology and major mineral nutrient composition of purslane (Portulaca oleracea L.) accessions

Towards the Sustainable Exploitation of Salt-Tolerant Plants: Nutritional Characterisation, Phenolics Composition, and Potential Contaminants Analysis of Salicornia ramosissima and Sarcocornia perennis alpini.

Increasing soil salinisation represents a serious threat to food security, and therefore the exploitation of high-yielding halophytes, such as Salicornia and Sarcocornia, needs to be considered not merely in arid regions but worldwide. In this study, Salicornia ramosissima and Sarcocornia perennis alpini were evaluated for nutrients, bioactive compounds, antioxidant capacity, and contaminants. Both were shown to be nutritionally relevant, exhibiting notable levels of crude fibre and ash, i.e., 11.26-15.34 and 39.46-40.41% dry weight (dw), respectively, and the major minerals were Na, K, and Mg. Total phenolics thereof were 67.05 and 38.20 mg of gallic acid equivalents/g extract dw, respectively, mainly p-coumaric acid and quercetin. Both species displayed antioxidant capacity, but S. ramossima was prominent in both the DPPH and ß-carotene bleaching assays. Aflatoxin B1 was detected in S. ramosissima, at 5.21 µg/Kg dw, which may pose a health threat. The Cd and Pb levels in both were low, but the 0.01 mg/Kg Hg in S. perennis alpini met the maximum legal limit established for marine species including algae. Both species exhibit high potential for use in the agro-food, cosmetics, and pharmaceutical sectors, but specific regulations and careful cultivation strategies need to be implemented, in order to minimise contamination risks by mycotoxins and heavy metals.

How do strategic mineral resources affect clean energy transition? Cross-sectional autoregressive distributed lag (CS-ARDL) approach

In the transition to a low carbon economy, minerals are crucial. The demand for the minerals required to create and install green energy technology, such as solar panels, wind turbines, electric vehicles, and energy storage, is rising along with it. In particular, the countries that hold these mineral reserves should be thought of as thriving economically from the rising demand for essential mineral resources (such as cobalt, lithium, and others). This study uses import demand function analysis to look at how the major mineral importing countries’ mineral import demand changed in response to the clean energy transitions between 2000 and 2021 for selected 14 countries. In the study, the cross-sectional autoregressive distributed lag (CS-ARDL) method was used. Findings show that long-term renewable energy production has a largely favorable impact on mineral import demand. Additionally, CO2 emissions have a long-term negative impact on mineral import demands, but energy intensity and exchange rate are favorable for mineral imports. The findings have significant ramifications for using the mineral trade to speed up the transition to sustainable energy around the world. Therefore, the study’s key proposed policy is to emphasize the value of mineral resources in clean energy while maximizing their use in the transition to carbon-free energy.

Characterization of a carbonatite-derived mining tailing for the assessment of rare earth potential

Depletion of high-grade deposits of rare earth elements (REEs) has led to increased interest in reprocessing mining tailing, particularly from carbonatite-related deposits. This is because most of the world’s REEs are produced from such deposits. The objective of this study was to physically, geochemically, and mineralogically characterize a carbonatite-related tailing from an Australian mine site to assess the REEs recovery potential. The tailing sample sourced from the mine site was analyzed by dry screening, laser particle size analysis, X-ray fluorescence (XRF), X-ray diffraction (XRD), Inductively Coupled Plasma Mass Spectrometry, and Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS). The results revealed that tailing consisted of mainly fine particles with 50 wt% below 61 µm. The geochemical results showed that the tailing consisted mainly of iron (Fe), and REE accounted for over 50% and 9% of the mass, respectively. The identification of major mineral phases by XRD followed by verification by SEM-EDS found monazite and florencite were the main REE-bearing minerals. The main gangue mineral is identified as goethite. The metallurgical balance showed that over 70% of the mass, REE, and Fe were concentrated in finer particle fractions below 63 µm. The SEM-EDS-based mineral liberation analysis found that REE-minerals were primarily associated with goethite and were locked within the latter in larger particle sizes over 100 µm. However, the smaller (<50 µm) REE-mineral grains were mostly liberated. The findings of this study suggest that light grinding of the particle fractions above 63 µm would potentially liberate the locked REE-minerals and subsequent separation by gravity, magnetic, and flotation processes can be tested to make REE concentrate. Because the sample is fine-grained, direct hydrometallurgical processing could potentially be effective to recover REE from this tailing.

APATITE VOLATILE CONTENTS OF PORPHYRY Cu DEPOSITS CONTROLLED BY DEPTH-RELATED FLUID EXSOLUTION PROCESSES

Abstract Porphyry Cu deposits are formed by Cu- and volatile (e.g., Cl, S)-rich fluids exsolved from underlying magma reservoirs. Intuitively, higher magmatic Cl and S contents likely correspond to higher magma fertility. However, the Cl contents of syn-ore magmatic apatite, one of the major Cl-bearing mineral phases in magmas, are highly variable among deposits (from &amp;lt;0.1 to &amp;gt;2 wt %). These variations may be controlled by different timing of apatite crystallization relative to fluid saturation among deposits, but the causes of these different relative timings remain obscure. Here we compile existing chemical data of magmatic apatite and amphibole phenocrysts from 25 porphyry Cu deposits worldwide and use these data to calculate magmatic physical-chemical conditions, such as water contents and magma reservoir depths. We find that the porphyry Cu deposits associated with deeper magma reservoirs are characterized by systematically higher magmatic H2O contents and apatite Cl, but lower apatite F contents and F/Cl ratios compared to shallower deposits. These correlations are best explained by early fluid exsolution and Cl loss that predate apatite crystallization in shallower porphyry Cu systems, which leads to elevated apatite F/Cl ratios. This is supported by the common occurrence of primary fluid inclusions in apatite from shallower systems. Postsubduction porphyry Cu deposits are normally associated with lower apatite Cl contents and shallower magma reservoirs, which is attributed to their formation under relatively extensional tectonic regimes. Our results demonstrate that the magma reservoir depth exerts an important control on the timing of fluid exsolution and accompanying Cl loss. In contrast, relatively high and constant apatite S content among deposits is minimally affected by fluid exsolution, possibly due to buffering of early-saturated sulfate in oxidized and S-rich magmas, and therefore might be used as a better potential fertility indicator than Cl.

Survival of whole-rock Sm–Nd isotope system from REE redistribution and mineral-scale isotopic resetting amid hydrothermal alteration in REE-rich Fe-Cu deposit

The 147Sm–143Nd isotope system has long been used as a powerful tracer and geochronometer for a wide range of geological process, yet the robustness of Sm–Nd system has been questioned in the presence of multistage hydrothermal alteration. Here we provide robust evidence for the survival of whole-rock Sm–Nd isotopes from REE redistribution and mineral-scale isotopic resetting during multistage fluid infiltrations in the Lala Fe-Cu-REE deposit in Kangdian region, southwestern China.The Lala deposit is hosted in the ∼1.72–1.68 Ga rift-related Hekou Group and contains variable proportions of REE-rich apatite and fluorite in the ores. Both of the apatite and fluorite grains show textures of extensive metasomatic alteration, during which large amounts of REE, especially LREE, were leached out and mostly re-incorporated into newly-formed monazite, bastnäsite, and xenotime. Quantifying REE distribution budget at thin-section scale confirms that the amounts of REE (1583–5403 ppm) leached from primary apatite and fluorite are compatible with those (1636–5526 ppm) incorporated in the newly crystallized REE minerals, indicating that REE are internally redistributed within investigated samples. The whole ores yield an 18-point 147Sm–143Nd errorchon date of ∼1.71 Ga, which is in accordance with the other analogous Fe-Cu deposits in Kangdian region, and supports a ∼1.71 Ga primary mineralization at Lala. By contrast, SHRIMP 232Th–208Pb dating of texturally constrained monazite yield a crystallization age of ∼0.92 Ga, which corresponds well with the combined monazite-bastnäsite-apatite Sm–Nd isochron ages of representative samples, demonstrating a major REE redistribution and Sm–Nd isotopic resetting event at this time. The results suggest that Sm–Nd mobility was limited to within the whole-rock scale or even within the thin-section scale in the vast majority of cases, such that the whole-ore Sm–Nd isotopic system largely remained closed, despite complete resetting of the major REE minerals during younger fluid infiltration events. Our study exemplifies the apparent “decoupling” of Sm–Nd isotopic systems between macro- and microscales, which can advance our understanding of the complex history of hydrothermal systems. Our findings of a major transition (80–96%) in REE repositories also highlight the economic significance of hydrothermal alteration for modifying ore mineral assemblages, which resembles a natural REE refinement process and helps create beneficial REE resources to meet the society increasing demands.

Effects of adding pyrochar and hydrochar to calcareous soil on nutrient uptake by maize

The patterns and mechanisms underlying the effects of different types of biochar on crop dry matter accumulation and uptake of major soil minerals are uncertain. This study demonstrated the positive effects of adding pyrochar (PC) and hydrochar (HC) to calcareous soils on nutrient uptake by maize seedlings and revealed the important role of mycorrhizal colonization. The effects depended on the type of biochar added and the type of nutrient evaluated. The dry weights of maize seedlings were higher in the HC and PC groups than in the control group, and the P accumulation was 17% higher than that of the control. Adding PC significantly increased Zn accumulation and the concentration and accumulation of Cu in maize seedlings, whereas adding HC increased the Fe concentration. Applying PC and HC also promoted mycorrhizal colonization of maize roots, and P, Zn, and Cu accumulations in the plant were positively correlated with the mycorrhizal colonization rate. This study found that applying PC and HC to calcareous soil at the tested application rate promotes the uptake of some mineral nutrients by maize at the seedling stage, and this effect was at least partially influenced by an increased mycorrhizal colonization rate in the plant root system.

Formation Damage Caused by Wax Deposition Results in Shale Production Decline

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 210414, “First Evidence for Shale Production Decline as a Result of Formation Damage Caused by C60+ Paraffin Wax Deposition: A Permian Case Study,” by Amir Mahmoudkhani, SPE, Locus Fermentation Solutions, and Jonathan Rogers and Martin Shumway, SPE, Locus Bio-Energy Solutions, et al. The paper has not been peer reviewed. _ Analysis of production decline curves revealed that three candidate wells in West Texas depleted faster than indicated by a type decline curve, indicating a potentially abnormal permeability-reduction mechanism. A biosurfactant-based squeeze program was recommended and applied in three horizontal wells. The biosurfactant treatment offers an alternative and economical method for remediation of formation damage caused by high‑molecular‑weight paraffin wax deposition in porous media that does not require costly intervention techniques to apply. Introduction The Bone Springs horizontal oil play in the Delaware Basin spans from southeast New Mexico into West Texas. Stacked, multipay reservoirs, each with diverse rock properties, possess upside but also complexity. The initial targets in the play were conventional sandstones. Wells then tapped into carbonate lenses and, ultimately, low-permeability sandstones. As a result of horizontal drilling technology combined with hydraulic fracturing, very thin sands and other facies are now being produced. Generally, reservoir quality of this unconventional hydrocarbon system is controlled by carbonate content, where increased carbonate content typically is associated with lower productivity. Experimental Methods All crude oils exhibited precipitation of organics at ambient laboratory temperatures. Even after storing crudes at the bottomhole temperature of 140°F, a small amount of wax remained insoluble in bulk liquid. Samples of formation drill cuttings were received for various depth intervals between 8,500 and 12,000 ft. X‑ray diffraction analyses of solids revealed quartz as the major mineral phase, with clays and carbonates account for remaining phases. Combined fractions with 160-micron size were used for microcolumn oil-recovery screening tests. Carbon distributions of oils and waxes were performed by high-temperature gas chromatography (HTGC). The Du Noüy ring method was used to measure static surface tensions of biosurfactant solutions at different concentrations and was applied to calculate critical micelle concentrations at ambient temperature. Interfacial tension (IFT) measurements were performed using a drop-shaped tensiometer using the pendant-drop method. Finally, the IFTs of oil in synthetic formation water and in biosurfactant solutions prepared in city tap water were determined. Contact-angle measurements also were performed. The wax-appearance temperature (WAT) of crude and wax samples was determined by the differential scanning calorimetry method. Spontaneous imbibition experiments were performed using the Amott-cell method at reservoir temperature. Berea sandstone core plugs (25×50 mm) with a permeability of 385 md and porosity of 18.4% were used. Core plugs were saturated with homogenized crude oil samples at 140°F for 7 days.

Huge Variation in H2 Generation During Seawater Alteration of Ultramafic Rocks

AbstractWater‐rock reactions liberate bioavailable energy, a necessary condition for chemotrophic habitability and origins of life. The major minerals of ultramafic (UM) rocks: olivine (ol), orthopyroxene (opx), and clinopyroxene (cpx), are of particular astrobiological interest as they are widespread in the solar system and known to produce significant quantities of H2 during aqueous alteration (serpentinization). H2 yields energy to life when oxidized by chemical species common to planetary fluids and is the most deeply rooted metabolite in Earth's phylogenetic tree. However, while field observations and calculations have corroborated the H2‐generating potential of UM rocks, specific formation pathways remain elusive, as the alteration assemblages in natural samples contain substantial heterogeneity. Here we show that variable UM compositions, temperature (T), and the mass ratio of Earth's seawater to rock (w/r) conspire to segregate alteration systems into those that produce supra‐mmol H2, and those that produce sub‐µmol H2. The oxidation of UM Fe(II) to Fe(III) provides the electrons necessary to reduce H2O to H2. However, the Fe(III)‐bearing phases that facilitate this process form together with more abundant phases competing for the same elements, including Ca, Si, and Fe(II). As a result, H2 abundance is determined by non‐redox‐active elements. Maximum H2 at high T requires low Si and is generally supported by Fe(III)‐serpentine and magnetite formation. Andradite formation, which stores Fe(III) but requires elevated Ca abundance, throttles up H2 production as T decreases in aging systems. These conditions are achieved in ol‐ and cpx‐rich rocks while opx‐rich rocks sequester less Fe(III), producing less H2.