Minerals

18 pages, 2593 KiB

Open AccessArticle

In Situ Hydrophobization of Lithium Aluminate Particles for Flotations by Dry Grinding in the Presence of Punicines

by Frédéric Steiner, Ali Zgheib, Maximilian Hans Fischer, Lukas Büttner, Andreas Schmidt and Sandra Breitung-Faes

Minerals 2024, 14(7), 650; https://0-doi-org.brum.beds.ac.uk/10.3390/min14070650 (registering DOI) - 25 Jun 2024

Abstract

The engineered artificial mineral (EnAM) lithium aluminate (LiAlO₂) is a promising candidate for the recycling of lithium from slags, which can originate from the reprocessing of batteries, for example. Derivatives of the natural product Punicine (1-(2′,5′-dihydroxyphenyl)-pyridinium) from Punica granatum have been [...] Read more.

The engineered artificial mineral (EnAM) lithium aluminate (LiAlO₂) is a promising candidate for the recycling of lithium from slags, which can originate from the reprocessing of batteries, for example. Derivatives of the natural product Punicine (1-(2′,5′-dihydroxyphenyl)-pyridinium) from Punica granatum have been proven to be effective switchable collectors for the flotation of this mineral as they react to light. In the present study, three Punicines were added to a planetary ball mill before grinding LiAlO₂ to particle sizes suitable for flotation. We investigated the influence of Punicine and two derivatives with C10 and C17 side chains on the grinding results at different grinding times and conditions as well as on the yields in flotations. SEM images of the particles, IR and ICP–OES measurements provided insights into the Punicine–particle interactions. They showed that Punicines not only prevent the formation of hydrophilic and thus undesirable lithium aluminate hydroxide hydrate (LiAl₂(OH)₇ ▪ x H₂O) surfaces in this process, as is unavoidable in aqueous flotation without this pretreatment, they also prevent the undesired release of lithium cations into the aqueous phase. Due to considerable hydrophobization of the particle surface of LiAlO₂, nearly quantitative recovery rates of this engineered artificial mineral are achieved using the process described here. Full article

(This article belongs to the Special Issue Artificial Engineered Minerals: Synthesis, Characterization, Metallurgical and Mechanical Processing)

11 pages, 648 KiB

Open AccessCommunication

Synthesis of an Antipyrine-Based Fluorescent Probe with Synergistic Effects for the Selective Recognition of Zinc Ion

by Yan Gao, Dezheng Chang, Yuyang Luo, Haojie Yu, Jinhui Li and Kunming Liu

Minerals 2024, 14(7), 649; https://0-doi-org.brum.beds.ac.uk/10.3390/min14070649 (registering DOI) - 25 Jun 2024

Abstract

A novel fluorescent probe containing an imine structure was synthesized through a condensation reaction based on the skeleton of antipyrine. Due to the synergistic effect of photoinduced electron transfer (PET), excited-state intramolecular proton transfer (ESIPT), and E/Z isomerization, the probe itself [...] Read more.

A novel fluorescent probe containing an imine structure was synthesized through a condensation reaction based on the skeleton of antipyrine. Due to the synergistic effect of photoinduced electron transfer (PET), excited-state intramolecular proton transfer (ESIPT), and E/Z isomerization, the probe itself has weak fluorescence. When zinc ions are added to the ethanol solution of the probe, the formed complex inhibits PET, ESIPT, and E/Z isomerization while activating chelation-enhanced fluorescence (CHEF), resulting in fluorescent “turn-on” at 462 nm. Under optimal detection conditions, the probe can rapidly respond to zinc ions within 3 min, with a linear range of 60–220 μM and a lower limit of detection (LOD) of 0.63 μM. It can also specifically identify zinc ions in the presence of 13 common metal ions. Full article

(This article belongs to the Special Issue Recent Advances in Extractive Metallurgy)

15 pages, 1360 KiB

Open AccessArticle

Preparation of Humic Acid from Weathered Coal by Mechanical Energy Activation and Its Properties

by Xiujuan Feng, Rilong Xiao, Sékou Mohamed Condé, Chengliang Dong, Yanping Xun, Dalong Guo, Hui Liu, Kunpeng Liu and Mingzhi Liang

Minerals 2024, 14(7), 648; https://0-doi-org.brum.beds.ac.uk/10.3390/min14070648 (registering DOI) - 25 Jun 2024

Viewed by 59

Abstract

Humic acid (HA) is rich in functional groups with high activity, which can effectively improve the soil environment. The large reserves of weathered coal in China provide sufficient raw material guarantee for HA extraction and utilization. At present, the activation side of weathered [...] Read more.

Humic acid (HA) is rich in functional groups with high activity, which can effectively improve the soil environment. The large reserves of weathered coal in China provide sufficient raw material guarantee for HA extraction and utilization. At present, the activation side of weathered coal is still the main technical difficulty that restricts HA extraction. In this study, the weathered coal from Inner Mongolia was used as the raw material, and the mechanical energy was used to activate the weathered coal through a planetary ball mill, which improved the extraction rate of HA and optimized the molecular structure and composition of HA. The effects of four parameters, namely, ball material ratio, ball milling time, ball milling speed, and ball size, on the free HA content of weathered coal were investigated, the HA was extracted by alkaline extraction method, and the activated weathered coal and the extracted HA were characterized. The results showed that a ball material ratio of 9:1, a ball milling speed of 200 r/min, a ball milling time of 200 min, a milling ball size of Ф5:Ф10:Ф15 = 48:42:45 and 56:42:37 are the optimal parameters for the mechanical energy activation, and the HA extraction rate of activated weathered coal under these conditions reached 82.3%, which was 15% higher than that of the unactivated one. Moreover, the aroma of the ball-milled weathered coal increased, the content of oxygenated functional groups increased, and the molecular weight and aroma of HA increased. This provides scientific theoretical guidance for the preparation of HA with high aromaticity and large molecular weight from weathered coal. Full article

(This article belongs to the Special Issue Waste Minerals, Sediments and Their Environmental Mineralogy)

33 pages, 21747 KiB

Open AccessArticle

Mineralogy and Geochemistry of Jasperoid Veins in Neoproterozoic Metavolcanics: Evidence of Silicification, Pyritization and Hematization

by Mohamed Zaki Khedr, Mahmoud A. Sayed, Shehata Ali, Mokhles K. Azer, Yuji Ichiyama, Eiichi Takazawa, Ali Y. Kahal, Kamal Abdelrahman and Ali M. Mahdi

Minerals 2024, 14(7), 647; https://0-doi-org.brum.beds.ac.uk/10.3390/min14070647 (registering DOI) - 25 Jun 2024

Viewed by 79

Abstract

The Wadi Ranga sulfidic jasperoids in the Southern Eastern Desert (SED) of Egypt are hosted within the Neoproterozoic Shadli metavolcanics as an important juvenile crustal section of the Arabian Nubian Shield (ANS). This study deals with remote sensing and geochemical data to understand [...] Read more.

The Wadi Ranga sulfidic jasperoids in the Southern Eastern Desert (SED) of Egypt are hosted within the Neoproterozoic Shadli metavolcanics as an important juvenile crustal section of the Arabian Nubian Shield (ANS). This study deals with remote sensing and geochemical data to understand the mechanism and source of pyritization, silicification, and hematization in the host metavolcanics and to shed light on the genesis of their jasperoids. The host rocks are mainly dacitic to rhyolitic metatuffs, which are proximal to volcanic vents. They show peraluminous calc-alkaline affinity. These felsic metatuffs also exhibit a nearly flat REE pattern with slight LREE enrichment (La/Yb = 1.19–1.25) that has a nearly negative Eu anomaly (Eu/Eu* = 0.708–0.776), while their spider patterns display enrichment in Ba, K, and Pb and depletion in Nb, Ta, P, and Ti, reflecting the role of slab-derived fluid metasomatism during their formation in the island arc setting. The ratios of La/Yb (1.19–1.25) and La/Gd (1.0–1.17) of the studied felsic metatuffs are similar to those of the primitive mantle, suggesting their generation from fractionated melts that were derived from a depleted mantle source. Their Nb and Ti negative anomalies, along with the positive anomalies at Pb, K, Rb, and Ba, are attributed to the influence of fluids/melt derived from the subducted slab. The Wadi Ranga jasperoids are mainly composed of SiO₂ (89.73–90.35 wt.%) and show wide ranges of Fe₂O₃t (2.73–6.63 wt.%) attributed to the significant amount of pyrite (up to 10 vol.%), hematite, goethite, and magnetite. They are also rich in some base metals (Cu + Pb + Zn = 58.32–240.68 ppm), leading to sulfidic jasperoids. Pyrite crystals with a minor concentration of Ag (up to 0.32 wt.%) are partially to completely converted to secondary hematite and goethite, giving the red ochre and forming hematization. Euhedral cubic pyrite is of magmatic origin and was formed in the early stages and accumulated in jasperoid by epigenetic Si-rich magmatic-derived hydrothermal fluids; pyritization is considered a magmatic–hydrothermal stage, followed by silicification and then hematization as post-magmatic stages. The euhedral apatite crystals in jasperoid are used to estimate the saturation temperature of their crystallization from the melt at about 850 °C. The chondrite (C1)-normalized REE pattern of the jasperoids shows slightly U–shaped patterns with a slightly negative Eu anomaly (Eu/Eu* = 0.43–0.98) due to slab-derived fluid metasomatism during their origin; these jasperoids are also rich in LILEs (e.g., K, Pb, and Sr) and depleted in HFSEs (e.g., Nb and Ta), reflecting their hydrothermal origin in the island arc tectonic setting. The source of silica in the studied jasperoids is likely derived from the felsic dyke and a nearby volcanic vent, where the resultant Si-rich fluids may circulate along the NW–SE, NE–SW, and E–W major faults and shear zones in the surrounding metavolcanics to leach Fe, S, and Si to form hydrothermal jasperoid lenses and veins. Full article

(This article belongs to the Special Issue Advances in Mantle–Crust Interactions for Petrogenesis and Ore-Forming Processes)

21 pages, 2871 KiB

Open AccessArticle

New Understanding of the Early Cambrian Uplift–Depression Framework and the Large-Scale Source–Reservoir Distribution along the Margin of the Awati Sag in Tarim Basin, NW China

by Yongjin Zhu, Jianfeng Zheng, Chunbo Chu, Qiqi Lyu, Haonan Tian, Tingting Kang, Tianfu Zhang and Lili Huang

Minerals 2024, 14(7), 646; https://0-doi-org.brum.beds.ac.uk/10.3390/min14070646 (registering DOI) - 25 Jun 2024

Viewed by 100

Abstract

The uplift–depression framework controls the source–reservoir assemblage. However, the exploration breakthrough is restricted by an insufficient understanding of the uplift–depression differentiation framework in the Early Cambrian Keping–Wensu area. In this paper, based on field outcrops evaluations, thin section analysis, logging data, drilling data, [...] Read more.

The uplift–depression framework controls the source–reservoir assemblage. However, the exploration breakthrough is restricted by an insufficient understanding of the uplift–depression differentiation framework in the Early Cambrian Keping–Wensu area. In this paper, based on field outcrops evaluations, thin section analysis, logging data, drilling data, and 3D seismic data, Wensu low paleo-uplift was discovered in the northern Tarim Basin, and the planar distribution was demonstrated in detail, generally shown as a SW–NE trending nose structure, extending roughly 114 km in length to the southwest, about 35 km in width to the northeast, and with the overall characteristic of being high in the west and low in the east. During the Early Cambrian, the Tabei paleo-uplift evolved into the Wensu low paleo-uplift and largely died out by the Middle Cambrian, with the development of ramps and rimmed carbonate platforms. The tectonic-sedimentary evolution of the uplift–depression framework controlled the development of a set of main source rocks and two sets of large-scale effective reservoir rocks in the Lower Cambrian, constituting two sets of effective hydrocarbon accumulation in the upper and lower stratigraphic parts of the basin. Among them, the upper assemblage holds more potential for hydrocarbon exploration, and is expected to be a next strategic target area for hydrocarbon exploration of Cambrian subsalt in the Keping–Wensu area. Full article

(This article belongs to the Special Issue Sedimentology and Geochemistry of Carbonates)

21 pages, 903 KiB

Open AccessArticle

Mineral Components, Organic Matter Quality and Soil Enzymatic Activity under the Influence of Differentiated Farmyard Manure and Nitrogen Fertilisation

by Joanna Lemanowicz, Agata Bartkowiak, Bożena Dębska, Edward Majcherczak and Agata Michalska

Minerals 2024, 14(7), 645; https://0-doi-org.brum.beds.ac.uk/10.3390/min14070645 (registering DOI) - 25 Jun 2024

Viewed by 114

Abstract

Research was carried out on the impact of long-term use of cattle manure (30 t ha⁻¹ FYM) and various doses of N (0, 40, 60 and 120 t ha⁻¹) in the form of ammonium nitrate on the following soil parameters: [...] Read more.

Research was carried out on the impact of long-term use of cattle manure (30 t ha⁻¹ FYM) and various doses of N (0, 40, 60 and 120 t ha⁻¹) in the form of ammonium nitrate on the following soil parameters: salinity, hydrolytic acidity, total exchangeable base cations, cation exchange capacity, degree of base saturation of the sorption complex, total organic carbon and total nitrogen content, dissolved organic matter, fractional composition of organic matter and content of bioavailable macroelements: phosphorus, potassium and magnesium in the soil of a multi-year static field experiment. The activities of dehydrogenases, catalase, alkaline and acid phosphatase and proteases were also tested. A significant effect of FYM and N fertilisation on the content of bioavailable macroelements was found. The application of manure at a dose of 30 t ha⁻¹ mitigated the negative effects of the application of N at a dose of 120 kg ha⁻¹. A higher content of total organic carbon (8.42 g kg⁻¹) and humic acid fraction (1761 mg kg⁻¹) and higher values of the CHA/CFA ratio (0.79; parameters that are indicators of soil quality) were found in the soil fertilised with manure compared to the soil without manure added (TOC—7.00 g kg⁻¹; CHAs—1285 mg kg⁻¹; CHAs/CFAs 0.66). The activity of the tested enzymes was also significantly determined by the applied fertilisation. Enzyme activity was highest in the soil to which manure had been applied. Nitrogen fertilisation varied in its impact on the activity of enzymes according to the specifics of each enzyme. The content of humic acids and CHA/CFA values correlated positively with the content of soil minerals and the activity of dehydrogenases, catalase, alkaline and acid phosphatase and GMea and TEI indices. Dehydrogenases and acid phosphatase can be considered enzymes that take part in transforming organic matter towards the formation of FAs. Full article

(This article belongs to the Special Issue Adsorption and Precipitation of Phosphorus by Minerals in Soil)

19 pages, 7050 KiB

Open AccessArticle

Sources and Ore-Forming Environment of the Jinchanghe Pb-Zn Polymetallic Skarn Deposit, Baoshan Block, SW China: Constraints from Cu-S Isotopic and Trace Elemental Compositions of Sulfides

by Xiaolin Cheng, Yunman Zhou, Jiyuan Wang, Chengfeng Zhao, Jing Huang, Pengju Li, Hai Wang and Fuchuan Chen

Minerals 2024, 14(7), 644; https://0-doi-org.brum.beds.ac.uk/10.3390/min14070644 (registering DOI) - 25 Jun 2024

Viewed by 117

Abstract

The Jinchanghe Pb-Zn polymetallic deposit is a representative distal skarn deposit in the Baoshan block. Due to limited research on the sources of ore-forming metals and trace elemental geochemistry of sulfides, the sources and mineralization environments of the Jinchanghe skarn Pb-Zn polymetallic deposit [...] Read more.

The Jinchanghe Pb-Zn polymetallic deposit is a representative distal skarn deposit in the Baoshan block. Due to limited research on the sources of ore-forming metals and trace elemental geochemistry of sulfides, the sources and mineralization environments of the Jinchanghe skarn Pb-Zn polymetallic deposit are still controversial. In this study, copper and sulfur isotopes and trace elements of sulfides from the Jinchanghe Pb-Zn polymetallic deposit were analyzed to reveal the sources of ore-forming materials and the ore-forming environments. The trace elemental analysis results show abundant Co, Ni, Mn and Se elements, and less As, Tl and Sb elements dominantly enter pyrite by isomorphic substitution, except for some Zn and Cu that occur as sulfide inclusions in Py1. Abundant Fe and Mn elements could substitute Zn to enter the sphalerite crystal lattice by the isomorphic substitution mechanism of (Fe²⁺ + Mn²⁺) ↔ 2Zn²⁺, and less Ag and Sb elements could enter the sphalerite by the isomorphic substitution mechanism of (Ag⁺ + Sb³⁺) ↔ 2Zn²⁺. The Cu-S isotopic and trace elemental compositions jointly suggest that the Jinchanghe distal skarn Pb-Zn polymetallic deposit formed from magmatic hydrothermal fluids with a sedimentary host-rock contribution, under mesothermal conditions (260 °C on sphalerite). Full article

(This article belongs to the Special Issue Mineralogical and Geochemical Characterization of Zn-Pb Ore Deposits: Insights into Their Genesis, Implications for Exploration, and Environmental Issues)

14 pages, 2988 KiB

Open AccessArticle

Adsorption of the Herbicide Endosulfan by Newly Discovered Zeolitic Tuffs in Mexico

by Juana Deisy Santamaria-Juarez, Miguel Ángel Hernández, Gabriela Itzel Hernández, Karin Monserrat Álvarez, Efraín Rubio, Roberto Portillo, María de los Ángeles Velasco, Josue Fernando Aquino and Vitalii Petranovskii

Minerals 2024, 14(7), 643; https://0-doi-org.brum.beds.ac.uk/10.3390/min14070643 - 24 Jun 2024

Viewed by 196

Abstract

The study presents experimental results on the adsorption of endosulfan in new natural zeolite deposits from Mexico. The adsorption of this herbicide was evaluated using inverse gas chromatography with a thermal conductivity detector and helium as the carrier gas. The experimental adsorption data [...] Read more.

The study presents experimental results on the adsorption of endosulfan in new natural zeolite deposits from Mexico. The adsorption of this herbicide was evaluated using inverse gas chromatography with a thermal conductivity detector and helium as the carrier gas. The experimental adsorption data were analyzed using the Langmuir and Freundlich equations in their linear form over a temperature range of 413–573 K. The study also estimated thermodynamic parameters such as the Free Energy of Gibbs (ΔG), isosteric enthalpy of adsorption (ΔH), and entropy change (ΔS) within this temperature range. The results indicated that the zeolites studied had a low adsorption capacity for this herbicide under the experimental conditions. The study also quantitatively determined the presence of starting minerals, with Na-Mordenite and Na-Clinoptilolite being the most prevalent, followed by Ca-Chabazite, Ca-Clinoptilolite, and Montmorillonite, with Quartz being present in low amounts. The NMOR zeolite underwent ion exchanges with AgNO₃ to produce the Ag-MOR zeolite and assess its herbicide adsorption capacity. Another mineral, Ca-Stilbite, was present in higher quantities than Ca-Clinoptilolite and Quartz. Full article

(This article belongs to the Special Issue Zeolite: From a Boiling Stone to the Applicable Minerals in Various Industrial Processes: 2nd Edition)

► Show Figures

Figure 1

19 pages, 21581 KiB

Open AccessArticle

A Review of the Genetic Mechanism of Megacrystalline Uraninite in the Kangdian Region, China

by Minghui Yin, Zhengqi Xu, Chengjiang Zhang, Youliang Chen, Hao Song and Jian Yao

Minerals 2024, 14(7), 642; https://0-doi-org.brum.beds.ac.uk/10.3390/min14070642 - 24 Jun 2024

Viewed by 173

Abstract

Naturally occurring granular uranium particles are typically fine and are often found as accessory minerals. However, reports of megacrystalline uraninite are rare. The discovery of megacrystalline uraninite is a significant achievement in uranium prospecting and mineralogy in the Kangdian region and China. Our [...] Read more.

Naturally occurring granular uranium particles are typically fine and are often found as accessory minerals. However, reports of megacrystalline uraninite are rare. The discovery of megacrystalline uraninite is a significant achievement in uranium prospecting and mineralogy in the Kangdian region and China. Our team’s research and review of previous studies have led to a systematic summary of the formation age, genetic types, relationship with migmatization, and metallogenic dynamic background of megacrystalline uraninite in the Kangdian region. The key findings are as follows: (1) the formation age of megacrystalline uraninite is Neoproterozoic (790–770 Ma); (2) migmatization preceded uranium mineralization; (3) the formation of megacrystalline uraninite is linked to high-temperature, low-pressure metamorphism caused by partial melting; (4) and the formation of megacrystalline uraninite may be associated with the Rodinia rifting event. This review aims to enhance our understanding of uranium mineralization during the Neoproterozoic in China and worldwide. Full article

(This article belongs to the Special Issue Advances in Uranium Metallogenic Theory, Exploration and Exploitation)

27 pages, 7075 KiB

Open AccessArticle

Middle Silurian–Middle Devonian Magmatic Rocks in the Eastern Segment of the Northern Margin of the North China Craton: Implications for Regional Tectonics

by Bin Li, Jingsheng Chen, Fan Yang, Miao Liu, Yanqing Zang and Chao Zhang

Minerals 2024, 14(7), 641; https://0-doi-org.brum.beds.ac.uk/10.3390/min14070641 - 23 Jun 2024

Viewed by 248

Abstract

This paper presents a detailed study including LA-ICP-MS zircon U-Pb dating, geochemical, zircon Hf isotope, and whole rock Sr-Nd isotope analysis of magmatic rocks from the Yitong County, Jilin Province, NE China. These data are used to better constrain the Middle Silurian–Middle Devonian [...] Read more.

This paper presents a detailed study including LA-ICP-MS zircon U-Pb dating, geochemical, zircon Hf isotope, and whole rock Sr-Nd isotope analysis of magmatic rocks from the Yitong County, Jilin Province, NE China. These data are used to better constrain the Middle Silurian–Middle Devonian tectonic evolution in the eastern segment of the northern margin of the North China Craton (NCC). Zircon U-Pb dating results show that the Ximangzhang tonalite formed in the Late Silurian (425 ± 6 Ma); the basalt, andesite, and metamorphic olivine-bearing basalt in the Fangniugou volcanic rocks formed in the Middle Silurian (428 ± 6.6 Ma) and Middle Devonian (388.4 ± 3.9 Ma, and 384.1 ± 4.9 Ma). The Late Silurian tonalites are characterized by high SiO₂ and Na₂O and low K₂O, MgO, FeOT, and TiO₂, with an A/CNK ratio of 0.91–1.00, characteristic of calc-alkaline I-type granite. They are enriched in Rb, Ba, Th, U, and K, and depleted in Nb, Sr, P, and Ti, with positive ε_Nd(t) (+0.35) and ε_Hf(t) (+0.44 to +6.31) values, suggesting that they mainly originated from the partial melting of Meso–Neoproterozoic accretionary lower crustal material (basalt). The Middle Silurian basalts are characterized by low SiO₂, P₂O₅, TiO₂, and Na₂O and high Al₂O₃, FeOT, and K₂O, enriched in Rb, Ba, Th, U, and K and depleted in Nb, Ta, Sr, P, and Ti, indicative of shoshonitic basalt. The Late Silurian tonalites have positive ε_Nd(t) (+4.91 to +6.18) values and primarily originated from depleted mantle magmas metasomatized by subduction fluids, supplemented by a small amount of subducted sediments and crustal materials. The Middle Devonian volcanic rocks exhibit low SiO₂, TiO₂, and Na₂O and high K₂O, and MgO, enriched in Rb, K, and LREEs and depleted in Nb, Ta, Sr, and HREEs, characteristic of shoshonitic volcanic rocks. Their ε_Nd(t) (+2.11 to +3.77) and ε_Hf(t) (+5.90 to +11.73) values are positive. These characteristics indicate that the Middle Devonian volcanic rocks primarily originated from depleted mantle magmas metasomatized by subduction fluids, with the addition of crustal materials or subducted sediments during their formation. Based on regional geological data, it is believed that the study area underwent the following evolutionary stages during the Silurian–Devonian period: (1) active continental margin stage of southward subduction of the Paleo–Asian Ocean (PAO) (443‒419 Ma); (2) arc-continent collision stage (419‒405 Ma); (3) post-collision extension stage (404‒375 Ma); (4) active continental margin stage, with the PAO plate subducting southward once again (375‒360 Ma). Full article

(This article belongs to the Special Issue Tectonic–Magmatic Evolution and Mineralization Effect in the Southern Central Asian Orogenic Belt)

21 pages, 1777 KiB

Open AccessArticle

Characteristics and Mechanism of the Ore-Forming Fluids in the Shimensi Tungsten Polymetallic Deposit in Southeastern China

by Peng Wang, Zhanghuang Ye and Xiaohua Zong

Minerals 2024, 14(7), 640; https://0-doi-org.brum.beds.ac.uk/10.3390/min14070640 - 23 Jun 2024

Viewed by 220

Abstract

The Shimensi super-large tungsten polymetallic deposit is located in the Late Jurassic–Early Cretaceous Porphyry–Skarn tungsten ore belt in the south Yangtze metallogenic belt. There are three types of mineralization: veinlet-disseminated type, thick quartz vein type and hydrothermal cryptoexplosive breccia type. Based on geological [...] Read more.

The Shimensi super-large tungsten polymetallic deposit is located in the Late Jurassic–Early Cretaceous Porphyry–Skarn tungsten ore belt in the south Yangtze metallogenic belt. There are three types of mineralization: veinlet-disseminated type, thick quartz vein type and hydrothermal cryptoexplosive breccia type. Based on geological studies, this paper presents new petrographic, microthermometric, laser Raman spectroscopic and hydrogen and oxygen isotope research on the fluid inclusions from the deposit. The results show that there are five different types of fluid inclusions: liquid-rich inclusions, vapor-rich inclusions, pure liquid inclusions, pure vapor inclusions, and fluid inclusions containing a solid crystal. The homogenization temperatures of the fluid inclusion range from 140 °C to 270 °C, the salinities are 3 wt.%–5 wt.% NaCl_eq and the densities of ore-forming fluid range from 0.64 g/cm³ to 0.99 g/cm³. For the analyses of laser Raman spectroscopy, the ore-forming fluids can be approximated by a Ca²⁺-Na⁺-SO₄²⁻-Cl⁻ fluid system with small amounts of CO₂, CH₄ and N₂. Otherwise, the data of the pressure, pH and Eh show a fluid metallogenic environment of low pressure, weak acid and weak reduction. The values of the homogenization temperature in the three types of orebodies suggest that the mineralization is characterized by a decrease in temperature under the conditions of fluid immiscibility. The H-O isotope values are interpreted to indicate that the ore-forming fluids are mainly composed of magmatic water, and meteoric water is added with the process of magma rising. Full article

25 pages, 7560 KiB

Open AccessArticle

New Strategies in Archaeometric Provenance Analyses of Volcanic Rock Grinding Stones: Examples from Iulia Libica (Spain) and Sidi Zahruni (Tunisia)

by Lluís Casas, Roberta Di Febo, Anna Anglisano, África Pitarch Martí, Ignasi Queralt, Cèsar Carreras and Boutheina Fouzai

Minerals 2024, 14(7), 639; https://0-doi-org.brum.beds.ac.uk/10.3390/min14070639 - 23 Jun 2024

Viewed by 224

Abstract

Archaeometry can help archaeologists in many ways, and one of the most common archaeometric objectives is provenance analysis. Volcanic rocks are often found in archaeological sites as materials used to make grinding tools such as millstones and mortars or as building materials. Petrographic [...] Read more.

Archaeometry can help archaeologists in many ways, and one of the most common archaeometric objectives is provenance analysis. Volcanic rocks are often found in archaeological sites as materials used to make grinding tools such as millstones and mortars or as building materials. Petrographic characterization is commonly applied to identify their main mineralogical components. However, the provenance study of volcanic stones is usually undertaken by comparing geochemical data from reference outcrops using common descriptive statistical tools such as biplots of chemical elements, and occasionally, unsupervised multivariate data analysis like principal component analysis (PCA) is also used. Recently, the use of supervised classification methods has shown a superior performance in assigning provenance to archaeological samples. However, these methods require the use of reference databases for all the possible provenance classes in order to train the classification models. The existence of comprehensive collections of published geochemical analyses of igneous rocks enables the use of the supervised approach for the provenance determination of volcanic stones. In this paper, the provenance of volcanic grinding tools from two archaeological sites (Iulia Libica, Spain, and Sidi Zahruni, Tunisia) is attempted using data from the GEOROC database through unsupervised and supervised approaches. The materials from Sidi Zahruni have been identified as basalts from Pantelleria (Italy), and the agreement between the different supervised classification models tested is particularly conclusive. In contrast, the provenance of the materials from Iulia Libica remained undetermined. The results illustrate the advantages and limitations of all the examined methods. Full article

(This article belongs to the Special Issue Mineralogical and Geochemical Characterization of Geological Materials)

20 pages, 813 KiB

Open AccessReview

Technological Advancement in Solar Photovoltaic Recycling: A Review

by Monserrat Martínez, Yahaira Barrueto, Yecid P. Jimenez, Dennis Vega-Garcia and Ingrid Jamett

Minerals 2024, 14(7), 638; https://0-doi-org.brum.beds.ac.uk/10.3390/min14070638 - 22 Jun 2024

Viewed by 166

Abstract

This review examines the technological surveillance of photovoltaic panel recycling through a bibliometric study of articles and patents. The analysis considered the number of articles and patents published per year, per country, and, in the case of patents, per applicant. This analysis revealed [...] Read more.

This review examines the technological surveillance of photovoltaic panel recycling through a bibliometric study of articles and patents. The analysis considered the number of articles and patents published per year, per country, and, in the case of patents, per applicant. This analysis revealed that panel recycling is an increasingly prominent research area. However, the number of patents filed annually has varied in recent years, averaging fewer than 200 per year. The state-of-the-art review identified three main types of treatment for photovoltaic panel recycling: mechanical, chemical, and thermal. Among these, mechanical treatment serves as a preliminary stage before the recovery of valuable elements, which is achieved through chemical or thermal processes. The articles reviewed cover a range of processes, including hydrometallurgical and pyrometallurgical methods, and explore various classification processes, solvents, and oxidizing agents. In contrast, patents predominantly focus on pyrometallurgical processes. This analysis is supplemented by a survey of market-ready technologies, many of which include stages such as size reduction or delamination followed by pyrometallurgical processes. Additionally, the review highlights the collection processes implemented by some companies, noting that the volume of panels considered waste is currently insufficient to maintain a continuous and year-round operational process. This study identifies key challenges such as (i) reducing solar panel size due to the EVA polymer complicating conventional machinery use, (ii) high process costs from the need for high temperatures and costly additives, (iii) the environmental impact of thermal treatments with high energy consumption and air pollution, and (iv) the necessity for environmentally friendly solvents in hydrometallurgical treatments to reduce contamination during recycling. Future directions include developing specific machinery for panel size reduction, either creating or modifying a polymer to replace EVA for easier treatment, adopting hydrometallurgical treatments with green solvents proven effective in recycling minerals and electronic waste, and addressing the lack of detailed information on industrial processes to make more precise recommendations. Full article

(This article belongs to the Section Mineral Processing and Extractive Metallurgy)

20 pages, 9384 KiB

Open AccessArticle

Petrogenetic Implications of the Lithium-Rich Tongtianmiao Granite Pluton, South China: Evidence from Geochemistry and Geochronology

by Xinhui Yu, Yongzhang Zhou, Wei Cao, Hanyu Wang, Can Zhang, Lifeng Zhong, Wu Wei, Zhiqiang Wang, Jianying Yao, Zhiqiang Chen and Qinghe Xu

Minerals 2024, 14(7), 637; https://0-doi-org.brum.beds.ac.uk/10.3390/min14070637 - 21 Jun 2024

Viewed by 291

Abstract

The South China Block, a region renowned for its extensive granite distribution and rich metal deposits, serves as a natural laboratory for the study of granite-related mineralization. This research focuses on the Tongtianmiao granite pluton, which is located at the intersection of the [...] Read more.

The South China Block, a region renowned for its extensive granite distribution and rich metal deposits, serves as a natural laboratory for the study of granite-related mineralization. This research focuses on the Tongtianmiao granite pluton, which is located at the intersection of the Qin-Hang and Nanling metallogenic belts and has been confirmed as a significant lithium mineral resource. Despite its discovery and ongoing development, the lithium-rich Tongtianmiao pluton has been understudied, particularly concerning its petrogenesis, which has only recently come to the forefront of scientific inquiry. By integrating an array of petrogeochemical data with geochronological studies derived from zircon and monazite dating, this study provides insights into the magmatic processes related to lithium enrichment in the Tongtianmiao granites. The Tongtianmiao granites are classified as A-type granites characterized by high SiO₂ contents (69.18–78.20 wt.%, average = 74.08 wt.%), K₂O + Na₂O contents (4.59–8.34 wt.%, average = 6.86 wt.%), A/CNK > 1.2, and low concentrations of Ca, Mg, and Fe. These granites are enriched in alkali metals such as Li, Rb, and Cs but are significantly depleted in Ba, Sr, and Eu. They show no significant fractionation of light or heavy rare-earth elements but present characteristic tetrad effects. A finding of this study is the identification of multiple ages from in situ zircon U–Pb dating, which implies a prolonged history of magmatic activity. However, given the high uranium content in zircons, which could render U–Pb ages unreliable, emphasis is placed on the monazite U–Pb ages. These ages cluster at approximately 172.1 ± 1.1 Ma and 167.9 ± 1.6 Ma, indicating a Middle Jurassic period of granite formation. This timing correlates with the retreat of the Pacific subduction plate and the associated NE-trending extensional fault activity, which likely provided favorable conditions for lithium enrichment. The study concluded that the Tongtianmiao granites were formed through partial melting of crustal materials and subsequent underplating by mantle-derived materials, and were contaminated by strata materials. This process resulted in the formation of highly differentiated granite through magmatic differentiation and external forces. These findings have significant implications for understanding the petrogenesis of lithium-rich granites and are expected to inform future exploration endeavors in the Tongtianmiao pluton. Full article

(This article belongs to the Special Issue In-Situ Microanalytical Techniques in Geological and Geochronological Research)

► Show Figures

Figure 1

16 pages, 5196 KiB

Open AccessArticle

Optimization of Flotation Conditions for Long-Flame Coal Mud by Response Surface Method

by Linfang Ao, Hongbo Zhang, Jingkun Zhang and Guoping Li

Minerals 2024, 14(7), 636; https://0-doi-org.brum.beds.ac.uk/10.3390/min14070636 - 21 Jun 2024

Viewed by 183

Abstract

With the application of modern coal mining technology and the fact that there are fewer and fewer high-quality coal seams, the quality enhancement and utilization of low-rank coal are gaining more and more attention. To solve the problems of high consumption of chemicals [...] Read more.

With the application of modern coal mining technology and the fact that there are fewer and fewer high-quality coal seams, the quality enhancement and utilization of low-rank coal are gaining more and more attention. To solve the problems of high consumption of chemicals and low recovery of refined coal in the flotation separation process of low-rank coal, the long-flame coal from the Inner Mongolia Autonomous Region of China was selected as the research object, and the factors affecting the flotation process were analyzed and optimized by adopting the response surface method and establishing a regression model with high precision and reliability. The test results showed that the primary and secondary relationships of the factors on the fine coal yield were as follows: slurry concentration > frother dosage > collector dosage; and the primary and secondary relationships of the factors on the flotation refinement index were as follows: slurry concentration > collector dosage > frother dosage. The optimal conditions for flotation were 2453.09 g/t of collector, 795.84 g/t of frother, and 50.04 g/L of slurry concentration. Under these conditions, the fine coal yield was 51.51%, and the relative error of 53.71% was 4.27%. The flotation refinement index was 21.34%, and the relative error with the predicted value of 21.58% was 1.12%. The relative error of the experimental results was within a reasonable range, which indicated that the regression model obtained by the response surface method was highly reliable. The research results are of great significance to strengthen the comprehensive utilization of long-flame coal in full particle size and improve the economic benefits of coal enterprises. Full article

(This article belongs to the Special Issue An Overview of Applications and Types of Flotation Reagents: Performance, Efficiency and Optimization)

► Show Figures

Figure 1

18 pages, 11286 KiB

Open AccessArticle

Paleo-Sedimentary Environment and Formation Mechanism of the Organic-Rich Shale of the Permian Lucaogou Formation, Jimsar Sag, Junggar Basin, China

by Zhongying Zhao, Senhu Lin, Xia Luo and Lijun Zhang

Minerals 2024, 14(7), 635; https://0-doi-org.brum.beds.ac.uk/10.3390/min14070635 - 21 Jun 2024

Viewed by 171

Abstract

The Jimsar Sag is an important shale oil exploration target area in the Junggar Basin, northwestern China. The Permian Lucaogou Formation, with a thickness of 200–300 m, is the primary exploration target. High-frequency variation in lithology is a typical feature of the Lucaogou [...] Read more.

The Jimsar Sag is an important shale oil exploration target area in the Junggar Basin, northwestern China. The Permian Lucaogou Formation, with a thickness of 200–300 m, is the primary exploration target. High-frequency variation in lithology is a typical feature of the Lucaogou Formation, reflecting the fluctuation of the depositional environment and organic matter enrichment. The evolution of the depositional environment and accumulation mechanism of organic matter still need to be elucidated for the Lucaogou Formation. High-resolution sampling of the entire Lucaogou Formation was applied to a 248 m long core from Well JX in the Jimsar Sag to examine the depositional environment and organic matter enrichment. The findings unveiled that the Lucaogou Formation was deposited under a hot and arid climate, within the confines of a closed saline paleo-lake, where sediments endured an extended period of anoxic conditions, displayed periodic oscillations in paleo-temperature and paleo-salinity values over time, alongside a continuous rise in paleo-water depth. The predominant source lithology of the Lucaogou Formation is felsic igneous rock. Small-scale transgression and hydrothermal sedimentation occurred during the deposition of the Lucaogou Formation. The prevailing hot climate and enduring reducing environment fostered ideal circumstances for the enrichment of organic matter in the Lucaogou Formation. Due to different sedimentary environments and enrichment mechanisms, organic matter is enriched in two modes in the Lucaogou Formation. Full article

11 pages, 1534 KiB

Open AccessArticle

The Effect of an Anionic Polyacrylamide on the Flotation of Chalcopyrite, Enargite, and Bornite

by Ginna Jimenez, Pablo Cabrera, Angie Rodriguez, Camilo Cuervo and Leopoldo Gutierrez

Minerals 2024, 14(7), 634; https://0-doi-org.brum.beds.ac.uk/10.3390/min14070634 - 21 Jun 2024

Viewed by 338

Abstract

Water recycling in mining is essential to decrease water usage, which results in the accumulation of high concentrations of inorganic and organic substances in the process water. Consequently, adverse impacts on the flotation process of copper sulfides may arise. High-molecular-weight polymers based on [...] Read more.

Water recycling in mining is essential to decrease water usage, which results in the accumulation of high concentrations of inorganic and organic substances in the process water. Consequently, adverse impacts on the flotation process of copper sulfides may arise. High-molecular-weight polymers based on anionic polyacrylamides (PAMs) are used as tailing flocculants in mineral processing plants. The recirculation of water recovered from the tailing thickeners to the flotation process introduces residual PAMs, which can impact the flotation of important copper sulfides like chalcopyrite, bornite, and enargite. This issue has been rarely studied. In this work, results on the effect of an anionic polyacrylamide (PAM) of medium–low anionicity on the flotation of chalcopyrite, enargite, and bornite are reported and analyzed. The results show that PAM molecules depress the flotation of chalcopyrite, enargite, and bornite under a wide range of pH values. The experimental data indicate that the depressing effect of PAMs on copper sulfides increases with pH. The zeta potential results reveal that this parameter becomes less negative with the addition of PAMs, indicating interactions between PAM molecules and the surfaces of the copper sulfides. PAM adsorption on copper sulfides increases with pH, which correlates with the flotation and zeta potential data. It is proposed that the interactions between PAM molecules and copper sulfides are explained by the presence of surface iron and copper hydroxides that create chemically active adsorption sites. Full article

(This article belongs to the Special Issue Development of Flotation of Chalcopyrite)

► Show Figures

Figure 1

12 pages, 4228 KiB

Open AccessArticle

Application of a Multi-Technique Approach to the Identification of Mineral Polymorphs in Histological Samples: A Case of Combined Use of SEM/EDS and Micro-Raman Spectroscopy

by Alessandro Croce, Donata Bellis, Caterina Rinaudo, Laura Cagna, Giorgio Gatti, Annalisa Roveta, Marinella Bertolotti and Antonio Maconi

Minerals 2024, 14(7), 633; https://0-doi-org.brum.beds.ac.uk/10.3390/min14070633 - 21 Jun 2024

Viewed by 381

Abstract

In the last few years, an increasing interest has developed regarding the application of different techniques for the identification of pollutants inside the tissues deriving from patients affected by benign or neoplastic diseases. Particular attention was paid to neoplasia linked to particular exposures, [...] Read more.

In the last few years, an increasing interest has developed regarding the application of different techniques for the identification of pollutants inside the tissues deriving from patients affected by benign or neoplastic diseases. Particular attention was paid to neoplasia linked to particular exposures, e.g., heavy metals, carbon dusts, silica, asbestos. As regards the last pollutant, a wide body of scientific literature has been collected, considering the severe effects caused by mineral fibers on human health. Optical and electronic microscopies were widely applied to identify the fibers in respiratory and extra-respiratory organs to detect the minerals and to link their presence to an exposure source and to understand their role in cancer development. The main advantage of electron microscopy lies in the possibility of coupling the microscopes with energy dispersive spectrometers and also collecting data on the elemental composition of various inorganic phases. In term of sample preparation and time of analysis, the most utilized microscope technique is Scanning Electron Microscopy with an annexed energy dispersive spectrometer (SEM/EDS), allowing for the morphological and chemical characterization of the observed particles/fibers. Moreover, this technique is envisaged by Italian Law for asbestos identification in air and bulk samples. On the other hand, this technique does not allow a reliable identification of the mineral phase in the case of polymorphs with the same chemical formula but different crystal structures. In this work, the coupling of a spectroscopical technique—micro-Raman spectroscopy—to SEM/EDS is proposed for a sure phase identification of particles, showing EDS spectra with ambiguous phase identification, observed in samples of tissues from patients affected by colorectal cancer and living in an asbestos-polluted area. In these tissues, different particles with EDS spectra that do not allow a sure identification of the phase—in particular calcium-rich particles and titanium oxides—were successively analyzed by micro-Raman spectroscopy. Thanks to this last technique, it was possible to ascribe the mineral phases associated to these particles to “aragonite” (a calcium carbonate polymorph) and to “anatase” (a Ti dioxide polymorph). Full article

(This article belongs to the Section Crystallography and Physical Chemistry of Minerals & Nanominerals)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Minerals, Volume 14, Issue 7 (July 2024) – 18 articles

Further Information

Guidelines

MDPI Initiatives

Follow MDPI