Mineral Collection Research Articles

Study on low-rank coal flotation collector screening and performance based on molecular polarity index.

Extensive studies using a trial-and-error approach have been conducted on low-rank coal flotation collectors. However, screening efficient collectors remains a considerable challenge due to the lack of suitable screening principles. It has proven that polar compounds such as carboxylic acids and esters are effective collectors for low-rank coal flotation. In this work, the effects of carboxylic acid, alcohol, and methyl ester on the floatability of low-rank coal were compared, the flotation performance of the polar collector was evaluated with theoretical calculations, a suitable evaluation parameter was determined and a screening principle based on this parameter was determined. The results show that the enhancement effects of polar collectors on low-rank coal floatability follow the order of methyl decanoate > methyl laurate > methyl octanoate > sec-octanol > methyl oleate (or methyl oleate > sec-octanol) > n-octanoic acid. Compared with the molecular polarity index, the hydrophobicity indices log P and dipole moment cannot be used to accurately evaluate different types of collectors and the same type of collectors, respectively. At room temperature, liquid polar compounds with molecular polarity indices in the range of 6.0 ~ 8.0kcal/mol effectively enhance the floatability of low-rank coal. The molecular polarity index of the collector is used for the first time to screen effective collectors of low-rank coal in this work. This parameter is anticipated to be highly important for the development and research of low-rank coal and other mineral collectors. To obtain reasonable and accurate molecular structure, geometry optimization and frequency calculations of the studied collectors were conducted via the Gaussian 09 software package based on density functional theory at the B3LYP/6-311 + G (d, p) level. The integral equation formalism for the polarizable continuum model (IEF-PCM) was utilized with water as the solvent (dielectric constant = 78.36, T = 298K) for all the calculations. Then, the atomic charge distributions (MPA and NPA) and electrostatic potential maps, the dipole moment and molecular polarity index, and the log P and water solubilities of studied collectors were shown or calculated by Gauss View 5.0, Mutiwfn program and website ( https://www.molsoft.com/mprop/mprop.cgi ), respectively.

Metallography of tailings from the Mansfeld copper mining area

Abstract The copper slate deposit of the Mansfeld copper mining area was mined in the 19th and 20th century. Mineral collectors can still find traces of copper smelting activities on the slag heaps of the various copper smelters. A piece from the Krug smelter slag heap mainly consists of Cu and Fe sulfides. The piece in question might be the intermediate product copper matte. The pieces from Hettstedt and the August Bebel smelter contain clearly visible metallic copper. The Hettstedt specimen might be a piece of furnace lining with adhering slag. Cr and Mg could be found, suggesting that chromium magnesia was used as refractory material. The piece from the August Bebel smelter contains up to 18 wt. % Cu. It does, however, not contain any sulfur. It is most likely Fe2SiO4 slag (fayalite) with a high proportion of FeO. The presence of Sn and Zn suggests that this slag was formed during the processing of bronze or brass.

Radioprotection issues in uraniferous minerals collections with reference to an actual case.

Our work investigated the radioprotection implications associated with the possession of a collection of uraniferous minerals. Considering different scenarios, we developed (and applied to an actual collection) specific formulas for radiation doses evaluation. We discussed the shielding necessary to reduce the gamma irradiation down to the required values. A mathematical model was developed to estimate the minimum air flow rate to reduce the radon air concentration below the reference values. The radiation risks associated to the handling of single specimens was also addressed, including hand skin irradiation and shielding capabilities of surgical lead gloves. Finally, we discussed the radiation risks associated to the exhibition of a single specimen. The results, compared to the safety standards of the EU Directive 13/59, show that the exhibition of uraniferous samples with activity of a few MBq do not need specific radioprotection requirements nor for the involved personnel nor for visitors.

The minerals of Jules Verne

Many rock and mineral collectors have roots in the movies and books of Jules Verne, such as Journey to the Centre of the Earth (1864). It seems only fitting that the mineral verneite was recently named after him, one of only three writers (Verne, Goethe and Theophrastus) to have a mineral named after them. Verne was an active amateur geologist, visiting sites throughout Europe. Of Verne's 80 novels, many have geological themes, subthemes or backgrounds second only to the sea. Like in his Journey to the Center of the Earth, Verne's lesser geological novels offer a remarkable literary guide to rocks, minerals and geology. Verne's geology‐based novels and writings are extensive and provide a means to re‐energize your childhood love of mineral collecting.

The historical collection of minerals and rocks from Egypt preserved at the Regional Museum of Natural Sciences (Torino, Italy)

The historical collection of minerals and rocks from Egypt preserved at the Regional Museum of Natural Sciences (Torino, Italy)

Network analysis of the herbarium collection of the Moravian Church from the 18th century

The Herbarium Dresdense (DR), Germany, houses about 500 000 specimens of worldwide origin. One of the oldest collections is the Herbarium Barbiense of the Moravian Church from the mid to the late 18th century. On their mission to spread Christianity, the Moravians settled on many continents and took the advantage of exploring culture and nature of their new home countries. Being excellent observers and documentarists, they left a barely explored corpus of objects and texts of tremendous importance for natural sciences and humanities. Since 1754 the educational centre of the community was located in Barby, Saxony-Anhalt, Germany. To support the scientific training and to gather objects send home by the missionaries, a cabinet of natural curiosities was established in 1756. The collections of minerals, fossils, conchylia and plants were unique and soon attracted other European academics.

Identification of Some Gem Quality Blue to Green Li-Tourmalines

Due to their appealing colors, gem quality tourmalines, particularly the blue to green Cu- and Mn-bearing Li-tourmalines known as the Paraíba type, have been of significant interest since their discovery at the end of 1980s. At the same time, the demand of other similar colored tourmalines increased. Most Paraíba-type tourmalines belong to the elbaite species; however, liddicoatite gems can also be found. Recognizing and classifying various tourmaline species, especially these valued Paraíba-type tourmalines, are important for geologists, mineralogists, mineral collectors, and gemologists. This study explores the application of Raman spectroscopy in random crystal orientations to distinguish between the elbaite and liddicoatite tourmaline species. Raman spectra were collected from faceted blue to green Li-tourmalines alongside chemical analysis using EDXRF (Energy Dispersive X-ray Fluorescence), UV-Vis-NIR (Ultraviolet-Visible-Near InfraRed Spectroscopy), and PL (Photoluminescence spectroscopy) to provide comprehensive characterization. The results show that Raman spectroscopy, particularly in the OH stretching region, is a useful tool for differentiating elbaite from liddicoatite, and this identification remains consistent regardless of crystal orientation. The fingerprint region in the Raman spectra, on the other hand, is orientation-dependent and can only differentiate the two species when detected in specific orientations. Furthermore, Paraíba-type tourmalines can be identified by visible-near infrared (Vis-NIR) spectroscopy, although not by Raman spectroscopy.

Flotation behavior and mechanism of smithsonite under the system of bidentate ligand sulfide sodium thiocyanate

The sulfuration pretreatment is essential in enhancing the floatability of zinc oxide ore during the flotation process. The conventional vulcanizing agent employed in the sulfuration process, however, has proven to be ineffective and environmentally unfriendly. The dosage of this agent must be strictly regulated to ensure optimal flotation efficiency of zinc oxide ore, as excessive or insufficient amounts can have a negative impact. To address these issues, a more efficient and environmentally friendly vulcanization agent called sodium thiocyanate (NaSCN) has been introduced to enhance the sulfuration flotation of smithsonite. It also demonstrated the effective sulfidation of smithsonite by sodium thiocyanate, which also exhibits superior vulcanization effects compared to sodium sulfide. By applying NaSCN at a concentration of 6 × 10-4 mol/L, the recovery rate of zinc ore can achieve 88.75 %. Moreover, the vulcanization conditions utilizing sodium thiocyanate offer greater ease of management. The vulcanization mechanism of smithsonite was investigated through FTIR, Zeta potential, and XPS analysis. The findings indicate that the dentate ligand SCN– derived from sodium thiocyanate can undergo chemical adsorption onto the surface of smithsonite through either sulfur (S) or nitrogen (N) elements. The interaction leads to the formation of zinc-thiocyanate anions, which enhance the surface hydrophobicity and expand the mineral collection sites. The overall findings suggest that sodium thiocyanate exhibits promising potential as a highly efficient vulcanization agent for smithsonite, providing valuable insights for the flotation of this mineral.

Collection security: low-cost measures for mineral collections

A series of high-profile thefts of museum specimens in recent decades highlights the vul- nerability of collections to such incidents. With the increasing value of mineral specimens, mineral collections may increasingly become the target of such thefts. Although system- ic funding and staffing issues at many institutions limits the practicality of implementing more sophisticated security measures, there are a number of low-cost measures that can be implemented to augment existing security measures and increase relative collection se- curity. These include physical actions such as limiting access to collection specimens and space by using locking cabinets, safes, and locking collection spaces, as well as behavioural approaches such as controlling information, escorting visitors, and restricting what items can be brought into collection spaces. Knowing the value of specimens can also allow one to understand where to concentrate security measures. As outreach is used to teach the public about collections and specimens, measures should be taken to limit the distribution of monetary value and the security measures implemented.

The fiscal effects of armed conflicts in Africa

AbstractThis study examines the impact of armed conflicts on the fiscal capacity of African governments. It made use of a data set covering 1997–2021 for 50 countries, as well as the system dynamic generalized method of moment estimation technique. The results show that, in the short run, conflicts undermine tax revenue, mount pressure on military expenditure, and force governments to rely more on mineral resource rents for their fiscal needs. As conflicts persist, this fiscal feature changes to a pattern that reflects a decline in mineral resource earnings and an increase in tax revenue. The impact on public health expenditure also changes from an increasing to a decreasing pattern, whereas the positive impact on military expenditure and external borrowing persists over time. The findings suggest that African countries in conflict can address their fiscal challenges by observing these patterns and putting in place policies that protect public resources (e.g., the adoption of digital financial technology protocols to facilitate remote revenue collection and strategic protection of mineral resource‐endowed zones from insurgents' control). Overall, enhancing government effectiveness and strengthening the institutions of governance is important to facilitate a quick return to normalcy in the event of conflict and to prevent future conflicts.

Из архива профессора Д. П. Григорьева: к 250-летию Горного музея

The article continues the series on the history of geology and is devoted to the Natural Science Museum of the St. Petersburg Mining University, namely its mineral collection. From the letters found by the author in the archive of Professor D. P. Grigoriev’s
 archive, kept in the Russian Mineralogical Society we can learn, interesting information about the circumstances of the acquisition of certain collections and exhibits, and about people worthy to remain in the history of mineralogy. At the same time, wide connections of D. P. Grigoriev with industrial and academic organisations and his active work on the creation and dissemination of the doctrine of mineral ontogeny, which eventually became a section of the university course of mineralogy, were revealed. The letters were accompanied by photographs from the same archive. The aim of the article was to cover the history of Russian mineralogy as fully as possible, including the role of organisations and individuals, and to reconstruct details of their biographies. Some of the problems discussed in the letters are still relevant today. The reader's attention should be attracted by the names of statesmen Prince G. Orbeliani, Prime Minister of India J. Nehru, Emperor of Ethiopia H. Selassie, mineralogists A. E. Fersman, G. N. Vertushkov, Yu. S. Kobya­shev, name of the Ural historical deposits Gumeshevka and Vatikha, enterprise «Russian precious stones» mentioned in one context. The article is timed to coincide with the 250th anniversary of the Mining Museum.

A New Mineral Hanauerite, AgHgSI, and Common Crystal Chemical Features of Natural Mercury Sulphohalides

A new mineral, hanauerite, ideally AgHgSI, was found in the oxidation zone of Ag- and Hg-bearing ores at two old, abandoned mines in Rhineland-Palatinate, Germany. In a holotype specimen originating from the Schöne Aussicht Mine, Dernbach, Westerwald, it is associated with plumbogummite–hinsdalite series of minerals and goethite. In cotype from the Friedrichssegen Mine, Bad Ems, it is associated with perroudite, goethite, and quartz. At both localities, hanauerite occurs as a prismatic crystal up to 0.15 mm long and up to 0.02 mm thick. The mineral is yellow, transparent, with an adamantine lustre. It is brittle, and cleavage was not observed. The calculated density values are 6.671 and 6.575 g cm−3 for holotype and cotype, respectively. The empirical formulae calculated (from electron microprobe data) based on the sum of all atoms = 4 apfu are Ag0.95Hg1.00S1.01(I0.83Br0.19Cl0.03)Σ1.05 for holotype and Ag0.97Hg0.97S1.05(I0.76Br0.25)Σ1.01 for cotype. Hanauerite is orthorhombic, space group Pmma; the unit cell parameters (from single-crystal X-ray diffraction data; holotype/cotype) are: a = 9.932(2)/9.9256(8), b = 4.6219(19)/4.6209(2), c = 9.891(4)/9.9006(4) Å, V = 454.0(3)/454.19(5) Å3, and Z = 4. The crystal structure was studied on single crystals extracted from both holotype and cotype specimens; R1 = 0.0416 (holotype) and =0.0544 (cotype). In hanauerite, Hg2+ cations centre strongly distorted octahedra with two short Hg–S bonds (Hg and S atoms build “crankshaft-type” chains) and four strongly elongated Hg–I bonds. The Hg-centred octahedra are connected via common edges and faces to form corrugated layers; Ag+ cations are located between these layers. Hanauerite is named in honour of the German mineral collector Dr. Alfred Hanauer (1912–1988). The common crystal chemical features of mercury sulphohalide minerals are discussed.

Composite Collectors for the Flotation of Refractory Alkaline Rock-Type Rare-Earth Ores

Alkaline rock-type rare-earth (RE) ores have significant utilisation value. However, the exploitation of such resources faces great challenges owing to the complex mineral and element assemblages. Composite collectors exhibit excellent performances, which may provide solutions to the flotation problem of alkaline rock-type RE ores. Therefore, 16 collectors typically used in RE ores flotation were selected. Flotation tests were performed to identify collectors with high selectivity and collection ability for RE minerals, then nine composite collectors were prepared by combining the satisfactory collectors. The flotation performances of single and composite collectors for RE minerals were examined, and the composite collector FA301 with different carbon chain lengths was identified as the best one. When FA301 was applied in optimal conditions of slurry temperature, grinding size, collector and inhibitor dosage, RE concentrate yield of 6.29%, REO grade of 32.013%, and recovery of 59.02% were achieved. According to the results of the zeta potential, FTIR, and XPS test, the functional groups (dominated by carboxyl groups) in FA301 chemically adsorbed onto the main active sites (La, Ce, Y, etc.) on the surface of RE minerals. The findings can provide scientific basis for the development of efficient collectors to facilitate the exploitation of RE resources.

Минералы Приполярноуральской хрусталеносной провинции в фондах Геологического музея им. А. А. Чернова

The article provides information about a wide variety of crystal-bearing deposits in the Subpolar Urals. Unique collections of minerals from crystal-bearing nests are collected in the Geological Museum named after A. A. Chernov. The cadastre contains 84 minerals and makes up 65 % of the total cadastre of deposits. Crystal-bearing minerals of the locality and occurrences of the Subpolar Urals of all classes are represented in the Museum funds to varying degrees. The minerals of silica, fluorite, layered silicates and carbonates are most fully represented. A high proportion of fund representativeness is established for the Kozhim, Skalistoye, Pelingichey-3, Puiva, Khasavarka, Vodorozdelnoye, Omega-Shor and Severnaya Lapcha fields. The subsequent study of minerals to replenish the museum funds and form a reference mineralogical collection of unique crystal-bearing objects of the Subpolar Urals is prognosed.

Anthropic Vulnerability of a Hydrothermal Mineral Deposit and Related Mining Heritage, a Case Study from a Medieval Gold-Silver Mining Area, Telkibánya, Hungary

The movable geoheritage elements (minerals, fossils, rocks) are important part of geodiversity. Their anthropic vulnerability includes collection by geo-amateurs and professionals which has become a very popular activity in the last decades. The in situ protection of such geoheritage elements preserves their authenticity and integrity, but needs detailed inventory and assessment providing recommendation for geoconservation. The aim of this study is to investigate a medieval mining site of the Carpathians (Telkibánya, Hungary) where recent anthropic vulnerability related to mineral collecting. Earlier works emphasized the scientific, aesthetic, and geo-educational potential of the mineral association and mining heritage of the study area. Our field survey gives a review of medieval mining works and the current state of the surviving infrastructure identifies the major areas of mineral collecting disturbances and the integrity of the main and additional geological elements. Based on the degradation risk assessment, further conservation management initiatives are proposed by open collecting outcrops (exposure sites) and declared protection with controlled collecting (finite sites).

The use of pracaxi oil collector in the selective flotation of xenotime from silicates

Rare earth elements have played a key role in technological advancement, attracting great visibility in the global commodity market. Xenotime, a heavy rare earth resource (YPO4), can be found associated with granitic rocks, as in the Pitinga deposit, located in the Brazilian Amazon region, where the main gangue minerals are quartz, microcline and albite. This research investigates the application of a new collector produced from pracaxi oil, an Amazon oil abundant in Brazil, in the selective flotation between xenotime and its main gangue minerals. The study conducted the synthesis and characterization of the collector, the chemical, mineralogical and surface characterization of minerals, as well as the evaluation of collector adsorption and flotability via microflotation tests, zeta potential measurements, surface tension determination and XRD, WDXRF, ICP-MS, FTIR and XPS analyses. The pracaxi collector was found to be mainly composed of oleic acid (56.2%), linoleic acid (14.1%) and behenic acid (10.6%), in addition to exhibiting a critical micelle concentration (CMC) of approximately 150 mg/L. Microflotation tests indicated that the best condition for selective recovery of xenotime occur at alkaline condition (pH 9.0), presenting selectivity of approximately 90% with collector concentration of 10.0 mg/L. The zeta potential data confirmed a selective adsorption of pracaxi collector onto xenotime, with an increase in the surface charge from −30 mV to −68 mV, whereas no significant changes were detected in the silicates. The FTIR spectra showed the appearance of a band at 1545 cm−1 on the surface of the xenotime after collector adsorption, which indicates, along with the zeta potential data, the chemical nature of the adsorption. The presence of small amounts of iron in the lattice structure of silicate gangues can act as an activator, and therefore, may be responsible for the small flotability of these minerals. The performance of the pracaxi oil collector presented in this study indicates the great potential of this Amazonian oil for application in the selective flotation of xenotime ores found in the region.

The Vámoscsalád-Kavicsbánya Site (Vas County)

The archaeological artefacts of the Vámoscsalád-Kavicsbánya site were discovered, collected and preserved by István Marton and his brother, András Marton, mineral collectors from Mesterháza, in about 2015. The slight elevation on a terrace of the Répce River was mined for the M86 highway in 2012–2013. Apart from knapped stone tools, the main subject of our paper, several polished serpentinite and greenschist tools have been recovered from the site, which could be in use between the Neolithic and the end of the Bronze Age. Only a few potsherds indicated a settlement of the Transdanubian Linear Pottery culture (TLPC). Of the Copper Age, Lengyel III and Baden pottery fragments and a clay spatula are worth mentioning. Almost the entire Bronze Age is represented, the most exciting find being a rim fragment of a bowl, decorated with an encrusted geometric pattern on both sides, of the Somogyvár–Vinkovci culture. Given the presumed mixed character of the knapped stone record of the Vámoscsalád-Kavicsbánya site (as the finds were not recovered from a closed stratigraphic context), we looked for possible cultural analogies and relationships, primarily those corresponding to the system of raw material–technology–typology. Although the pottery fragments of the TLPC recovered from the site are few and uncharacteristic, and the recovered finds may represent more than one phase, the knapped stone assemblage most likely represents the industry of the Middle Neolithic cultural unit, as suggested by raw material composition, technological features, type distribution and characteristics of the retouched tools. It is perhaps even possible that we are dealing with relatively old, if not the oldest TLP finds ever unearthed in the county.

Aleksandr Vasil’evich Kalugin (1857–1933) and former kaluginite (now jahnsite-(CaMnMg))

Aleksandr Vasil’evich Kalugin was a major practical mineralogist and compiled magnificent mineralogical collections from the Ural samples. While working at the Ural Mining Institute, he trained a whole galaxy of mineralogists and donated his unique collection of minerals, on the basis of which the Ural Geological Museum was created in 1937. In honor of him in 1983 B. V. Chesnokov named a new mineral – kaluginite, which was almost immediately rejected by the International Mineralogical Association. At the moment it turned out that kaluginite is jahnsite-(CaMnMg).

Studi Pengaruh Titik Penambahan Sodium Isobutyl Xanthate (SIBX) dan Kecepatan Impeller pada Performa Flotasi Mineral Tembaga

Evaluation of the use of the SIBX addition point and energy consumption in a flotation machine is an optimization effort to increase recovery in a valuable mineral separation process. The purpose of this study was to maximize the use of reagents and energy consumption in flotation machines by looking for the effect of the SIBX addition point and impeller speed variations on copper recovery. In the experiments, the authors vary the impeller speed and the SIBX addition points. The impeller speed is varied into five different speeds. While the SIBX addition point into four different points. From the variation of the experiment, the test must be done within 20 flotation kinetics. Those tests were performed for 8 minutes and will generate 4 concentrates and tailings. From this information, a graph of the relationship between recovery and time is obtained, and it can be seen that the point of adding SIBX and impeller speed is to produce optimal recovery values. From the available tailings and feed, an analysis of particle size and distribution is also carried out to check the effectiveness of changing the impeller speed pattern to provide kinetic energy for particles of various sizes to collide with air bubbles and increase the probability of collection of valuable minerals, so that high recovery is obtained in various areas. particle size. Of all the speed variations used in the impeller, the best kinetic recovery comes from the addition of SBX in the 0 min, 2 min, and 4 min. While the worst comes from the addition in the 6 min. Copper kinetic recovery is only affected by the nature and amount of hydrophobic particles but is not affected by impeller speed. Copper recovery at each end of the experiment showed the same value which is an average of about 94%.

Making it Mine: Sir Arthur Russell and his Mineral Collection by Roy E. Starkey. Published (2022) by British Mineralogy Publications, 15 Warwick Avenue, Bromsgrove, Worcestershire, B60 2AH, England. Hardcover, 27.6 3 21.8 cm, 432 pages; £40 (+£35 shipping to the U.S.; £10 and £20 to the UK and Europe; £40 to Australia and New Zealand). Order from www.BritishMineralogy.com.

Making it Mine: Sir Arthur Russell and his Mineral Collection by Roy E. Starkey. Published (2022) by British Mineralogy Publications, 15 Warwick Avenue, Bromsgrove, Worcestershire, B60 2AH, England. Hardcover, 27.6 3 21.8 cm, 432 pages; £40 (+£35 shipping to the U.S.; £10 and £20 to the UK and Europe; £40 to Australia and New Zealand). Order from www.BritishMineralogy.com.