Особенности состава и свойств золошлаковых отходов Апатитской ТЭЦ (Мурманская область)

The aim of this study is to assess the rare earth element (REE) content in hair samples of children living in Lovozero village, near an REE mining site, and the possible effects of REEs on the prevalence of nervous system diseases in Lovozersky District (Murmansk region, Kola Peninsula). Fifty-three school-age children were recruited for the analysis of REE content in hair samples. REE (Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) content was estimated by means of inductively coupled plasma mass spectrometry (ICP-MS). The analysis of REE content in the hair of children living in Russia, Kazakhstan, and China indicated REE intake from the environment. The possible contribution of REEs to nervous system disorders is supported by the link between the REE content in hair samples of children living near REE mining areas (China) and the manifestation of cognitive disorders in these children. It is also found that the prevalence of nervous system diseases in children aged 15-17 years is higher in Lovozersky District compared to the other districts of the Murmansk region. In this paper, the possible contribution of REEs to the prevalence of episodic paroxysmal disorders (G40-G47), cerebral palsy (G80-G83), and epilepsy and status epilepticus (G40-G41) is discussed.

The impact of rare earth elements on the soil environment is not only related to its total amount, but also more closely related to its chemical form. The green and environmentally friendly acid digestion and morphological continuous extraction methods were used to extract and analyze the total amount of rare earth elements and the forms of rare earth elements in the soil samples. Inductively coupled plasma mass spectrometry was used to determine the content of rare earth elements and the content of rare earth elements in the soil samples. Form content. The results show that the content of rare earth elements in the collected soil samples is 200-1418mg/kg, and the content of light rare earth elements is much higher than that of heavy rare earth elements; the recovery rate of the sum of the combined forms of rare earth elements relative to the total amount is 88.2% to 110%, indicating that the continuous extraction method is suitable for the analysis of rare earth elements in soil samples. The rare earth elements in soil samples mainly exist in the residue state, which is 33%-80%; the co-precipitation state of crystalline iron and manganese hydroxide is 10%-31%; the adsorption state of humus and amorphous oxide is 5.0%-18%; The exchange state and the carbonate combined state are 4.0% to 23%; the amorphous iron-manganese oxide co-precipitation state is less than 3%. The influence of the location of the sampling point and the nature of rare earth elements on the content of rare earth elements was analysed, and the influence of soil properties on the distribution of morphology was discussed.

Introduction. This extended study is the first to analyze the chemical composition of the surface waters and bottom sediments of the lakes affected to various extents by Lovozersky Mining and Processing Plant (Revda urban settlement, Murmansk Region) performing mining and processing of rare metal ores. Methods. During the study, we used data obtained in the course of research in 1995–2005 and 2019–2020. Water and bottom sediment samples were analyzed using various methods. The total contents of elements in the bottom sediments were compared with the background values or, in their absence, with the clarke contents of elements in the Earth’s crust. To assess the level of pollution in the Sergevan River receiving wastewater from the plant, the maximum pollution index was calculated. Results. Over the past 35 years, the chemical composition of the surface waters of nearby water bodies underwent minor changes. No significant excess of maximum permissible concentrations for fishery water bodies was found. The comparison of the contents of heavy metals in the bottom sediments collected from Lakes Ilma and Krivoye with the background values revealed contamination of the Lake Ilma with strontium, zinc and manganese. Besides, a multiple excess of the content of rare earth elements (La, Ce, Pr, Nd), Nb and Ta was established in the bottom sediments of Lake Ilma in comparison with that in Lake Krivoye. The analysis of the river water samples taken at different distances upstream and downstream the site of wastewater discharge confirmed the assumption about the pollution of the Sergevan River by wastewater from the plant. Conclusion. The pollution of the water bodies is mainly caused by wastewater discharged from the plant, however, the increased content of rare earth elements in the bottom sediments of Lake Ilma may be due to air transport of particles of loparite ore concentration tailings, drainage from tailing dams, or degradation of underlying rocks.

Stone coal is a special resource, because it is associated with a variety of rare metal elements. The elemental geochemical characteristics of stone coal can provide useful information for the study of its formation and evolution history. The content of rare earth elements in stone coal has been the focus of attention. Stone coal is widely distributed in southern Shaanxi province of China. In order to study the content and distribution of rare earth elements in stone coal, and provide a plan for the comprehensive development and utilization of stone coal, this study tested the rare earth elements content of stone coal, parting and coal ash samples, respectively, compared the content of rare earth elements in stone coal, parting, coal ash with the mean value of China coal, the mean value of world coal and the abundance value of upper crust, and discussed the features of rare earth elements content in different types of samples in southern Shaanxi province of China. The average contents of rare earth elements in the samples of stone coal, parting and coal ash were calculated, and the enrichment coefficients of the samples with the mean value of China coal, the mean value of world coal and the abundance value of upper crust were listed. The distribution rules and characteristics of the contents of rare earth elements in different types of samples in southern Shaanxi province of China were summarized.

Volcanogenic massive sulfide (VHMS) deposits in the Abitibi subprovince are preferentially associated with volcanic successions containing >150 m thicknesses of felsic volcanic rocks ( approximately 50% by area of volcanic terranes) and are found within volcanic sequences of at least three distinct affinities. Group I, which is host to greater than half of the volcanogenic massive sulfide deposits by tonnage and which comprises only approximately 10 percent by area of volcanic terranes, is composed of bimodal, tholeiitic basalt-basaltic andesite, and high silica rhyolite. The basaltic andesites and high silica rhyolites are characterized by high high field strength element and heavy rare earth element (REE) contents, low light to heavy REE ratios (most with La N /Yb N = 0.8-3), and strong negative Eu anomalies. The Kamiskotia, Matagami, and Chibougamau (Lower cycle) volcanogenic massive sulfide areas, all of which are also underlain by large, synvolcanic gabbroic complexes, are associated with group I volcanic sequences. The Kidd Creek, Potter, Normetal, and Horne deposits are also included in this category. Group II, which is host to one-third of the volcanogenic massive sulfide deposits by tonnage and which is also approximately 10 percent by area of volcanic terranes, is composed of bimodal, transitional tholeiitic to calc-alkalic andesitc and rhyolite, characterized by intermediate high field strength element contents and slightly higher REE ratios (La N /Yb N = 1-4: Noranda camp (excluding the Horne deposit) and Val d'Or camp). Group III is host to only one known deposit, the Selbaie mine, which is unusual in that much of its mineralization cuts stratigraphy. The Selbaie mine sequence contains calc-alkalic andesite-rhyolite with relatively low high field strength element and REE contents, and higher REE ratios (La N /Yb N = 3-9). The vast majority of volcanogenic massive sulfide-bearing mafic and felsic volcanic rocks in the Abitibi subprovince have La N /Yb N < 5.Barren volcanic sequences are group IV--calc-alkalic basaltic andesite to rhyodacite, with low high field strength element and relatively high REE ratios (La N /Yb N = 8-20), represented by the upper Skead Group, the Quebec Hunter Mine Group, and the Upper cycle Chibougamau rocks; and group V, mafic to felsic alkalic volcanic rocks, with high REE ratios (La N /Yb N = 12-62), represented by the Timiskaming, Opemisca, and Ridout series rocks.Group I is most similar to thickened oceanic rift suites (e.g., Galapagos spreading center, Iceland East rift), group II is similar to suites in rifled island arcs (e.g., Hokuroku district, Japan), and group III is comparable to continental arc suites (e.g., Southern Volcanic zone, central Chile). Groups IV and V are comparable to arc-related suites derived from metasomatized mantle, with variable amounts of crustal contamination (e.g., Setouchi area, Japan; Roman province, Italy).Known Ni-Cu deposits in volcanic sequences are hosted exclusively in komatiitic flows and hypabyssal sills, represented by chill compositions with high MgO contents (20-35 wt %, anhydrous), very low incompatible element contents, and depleted signatures (La N /Sm N = 0.5-0.8; Zr/Y < 2.5; Alexo, Marbridge, and Shaw Dome deposits), in comparison to most barren komatiites in the Abitibi subprovince. Their depleted trace element signatures indicate minimal crustal assimilation, which would appear contrary to the widely held view that crustal contamination (e.g., addition of silica, sulfur, oxygen) of a mantle-derived melt is necessary for sulfur saturation and magmatic sulfide segregation. This problem may be reconciled by considering the dynamics of komatiite flows (Lesher and Arndt, 1990) where contaminated* Present address: 23 Euclid Avenue, Ottawa, Ontario, Canada KiS 2W2. komatiite liquid segregated and deposited sulfide and was subsequently swept downstream and replenished by uncontaminated magma over the deposit as the flow ebbed and cooled. When considered together with geologic features such as evidence for thermal erosion in the footwall (Langmuir deposits) and the presence of sulfidic footwall rocks (Shaw Dome deposits), the distinctive, depleted geochemical signature of mineralized komatiites is useful in exploration for Ni-Cu deposits.

Coal waste is a potential source of rare-earth elements (REEs) and some economically critical elements recovery. The present study reports the abundance and enrichment of REEs and critical elements in the Hancheng Permo-Carboniferous (Weibei coalfield) and Binxian Jurassic coals (Huanglong coalfield) of Shaanxi, China. The Binxian coal is distinctly enriched in all REEs. The Hancheng coal is enriched in Y, Ce, Sc, La, Yb, Nd, Pr, Gd, Er, Sm and Dy and depleted in Lu, Eu, Ho, Tb and Tm, compared with that of the average earth’s crust abundance (ECA), world coal and the US coal. In the Binxian raw coal, the REEs contents, namely Sc 13.8, Y 13.1, La 27.8, Ce 48.49, Sm 4.1, Nd 22, Eu 0.8, Gd 3.8, Pr 5.43, Dy 2.5, Er 1.4 and Yb 1.3 in mg kg−1. The contents (mg kg−1) of REEs in the Hancheng raw coal were Sc 8.8, Y 18.6, La 34.8, Ce 60.2, Nd 26, Yb 1.8, Eu 01, Pr 6.71, Sm 5.3, Dy 3.4, Tb 0.66, Er 1.9 and Gd 5.16. The contents (mg kg−1) of critical elements in the Binxian raw coal were Cr 30.8, Pb 41.5, Ni 49.7, Cu 35.7, Ba 257.9, V 51.7, Zn 63.1, Li 135, Ga 20.6, U 2.9, Th 10.2 As 12.7, Al 98,887, Fe 23,916 and Ti 4289. The contents (mg kg−1) of critical elements in the Hancheng coal were Cr 384, Pb 56.1, Ni 93.9, Cu 49.5, Ba 371, V 90.7, Zn 7653, Li 183, Ga 35.9, U 4.9, Th 17.7, As 10.1, Al 108,344, Fe 20,433 and Ti 2873. The contents of REEs in the Binxian and Hancheng coals were not in a promising range, whereas some of the critical elements were highly abundant. The Al2O3/TiO2 ratio indicated that the Ordos Basin sediment was derived from intermediate-felsic rocks with a slight variation (r = 0.98). The Eu and Gd show positive anomalies with negative Ce anomalies almost in all the samples. The positive anomalies of Gd represent the intrusion of hydrothermal fluid with possibly Ba interference in the Binxian coal. The high volatile matter in the Binxian coal reflects bituminous to anthracite coal, whereas the low volatility of the Hancheng coal reflects peat to lignite coal. The recovery of the REEs and critical elements as a by-product from these coals may not only increase the revenue but will also lead to an improvement in the environmental quality.

Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was used to determine rare earth element (REE) content of 76 fossil bones collected from the Upper Cretaceous (Campanian) Two Medicine (TMF) and Judith River (JRF) Formations of Montana. REE content is distinctive at the formation scale, with TMF samples exhibiting generally higher overall REE content and greater variability in REE enrichment than JRF samples. Moreover, JRF bones exhibit relative enrichment in heavy REE, whereas TMF bones span heavy and light enrichment fields in roughly equal proportions. TMF bones are also characterized by more negative Ce anomalies and greater U enrichment than JRF bones, which is consistent with more oxidizing diagenetic conditions in the TMF. Bonebeds in both formations show general consistency in REE content, with no indication of spatial or temporal mixing within sites. Previous studies, however, suggest that the bonebeds in question are attritional assemblages that accumulated over considerable time spans. The absence of geochemical evidence for mixing is consistent with diagenesis transpiring in settings that remained chemically and hydrologically stable during recrystallization. Lithology-related patterns in REE content were also compared, and TMF bones recovered from fluvial sandstones show relative enrichment in heavy REE when compared with bones recovered from fine-grained floodplain deposits. In contrast, JRF bones, regardless of lithologic context (sandstone versus mudstone), exhibit similar patterns of REE uptake. This result is consistent with previous reconstructions that suggest that channel-hosted microfossil bonebeds of the JRF developed via the reworking of preexisting concentrations embedded in the interfluve. Geochemical data further indicate that reworked elements were potentially delivered to channels in a recrystallized condition, which is consistent with rapid adsorption of REE postmortem.

Rare earth elements of the Altar Desert dune and coastal sands, Northwestern Mexico

Rare earth element content in the SPM of Daliao river system and its comparison with that in the sediments, loess and soils in China

The origin of amphibole in a sequence of gabbronoritic rocks recovered at Ocean Drilling Program Site 894 was evaluated on the basis of textural and geochemical criteria. Major element compositions indicate that all the amphibole is metamorphic whereas textural relations suggest that amphibole formed either by magmatic or metamorphic processes. The rare earth element (REE) content of amphibole, clinopyroxene, apatite, and zircon were determined by ion microprobe to assess these interpretations. Amphibole shows broad range in REE concentrations (up to 1,000 times chondritic values) with (La/Sm)N ratios from 0.1 to 1.4. There is no systematic relationship between REE content and textural type. The origin of amphibole with REE contents less than or equal to clinopyroxene cannot be distinguished by compositional criteria. By contrast, the REE content of all other amphibole can only be explained by magmatic processes. Calculated melts in equilibrium with igneous amphibole indicate that amphibole crystallized from melts with progressively higher REE contents; in some samples melts evolved without significant fractionation of the REEs whereas in other samples melts became light-REE-enriched. An increase in the total abundance of the REE melts is consistent with the crystallization of Plagioclase, clinopyroxene, and orthopyroxene from progressively more evolved melt. The light-REE-enriched melts may have been influenced by the crystallization of accessory phases or by interaction with exsolved magmatic fluids. These results indicate that there was a continuum between magmatic and hydrothermal processes and that groundmass amphibole records a complex history of crystallizati on from a melt and its exsolved magmatic fluids, followed by interaction with seawater-derived hydrothermal fluids.

Geochemical processes and indicative significance of rare earth elements in high arsenic geothermal fluids in Batang, western Sichuan, China

The article presents the results of the study, obtained original data on the content and distribution of rare earth elements in the soils of the south-eastern part of Sughd region. The concentrations of rare earth elements were determined by using a highly sensitive inductively coupled plasma mass spectrometry method. A total of 30 samples were collected and analyzed. Peculiarities of accumulation of rare earth elements depending on regional characteristics have been revealed. The average concentrations of the studied rare earth elements are within the clarke index and below. The use of variational-statistical methods for processing the obtained results made it possible at least to some extent, streamline the results of analytical studies of soils within the south-eastern part of the Sughd region. Concentrations of rare earth elements in the soils of the southeastern part of the Soghd region vary within narrow intervals. At the same time, the distribution of REE bears a regular character in the areas (2.44−9.72%) under study. Quantitative criteria degree of accumulation and enrichment of soils have been calculated: here refer factors of enrichment, concentration coefficient, concentration clarke and dispersion clarke. On the base of the obtained values of these indicators it is shown that the soils of the studied points are characterized by a moderate level of accumulation and enrichment. Based on the data obtained, a series was compiled for the average content of rare earth elements: &gt; &gt; &gt; &gt; &gt; &gt; &gt; &gt; &gt; &gt; , while the contents of La, Eu and Gd are very close to the clarkes of the earth’s crust, lower – Ce, Pr, Nd, Sm, Dy, Ho, Er, Tm. The highest concentrations are cerium, lanthanum and neodymium, the lowest concentrations are praseodymium, gadolinium, samarium, dysprosium, erbium, europium, terbium and holmium. The distribution of all studied rare earth elements is close in terms of asymmetry and kurtosis, and is observed for some elements. We have established a significant correlation between the content of Ce and La (r = 0,98), Pr and La (r = 0,97), Pr and Ce (r = 0,95), Nd and La (r = 0,94), Nd and Ce (r = 0,91), Nd and Pr (r = 0,99), Sm and Pr (r = 0,86), Sm and Nd (r = 0,86), Sm and Nd (r = 0,91), Gd and Pr (r = 0,81), Tb and Gd (r = 0,84), Er and Dy (r = 0,84), Er and Ho (r = 0,90), Tm and Er (r = 0,94),which indicates to their lithogenic origin.

During the condensation of the elements in the early solar system, volatility-controlled fractionations occurred. Such fractionations of refractory lithophile elements in individual chondrite components and between bulk chondrites, achondrites and planets are subject of this thesis. The contents of rare earth elements (REE) as well as Nb, Ta, Zr and Hf were analysed by means of laser ablation inductively coupled plasma mass spectrometry. Individual chondrite components were measured in-situ using the CV chondrite Leoville. Whole rock samples were prepared from bulk chondrites, achondrites and terrestrial samples by laser melting during aerodynamic levitation. The investigation of diverse components of the Leoville chondrite showed that refractory inclusions have volatility-controlled fractionated REE group-II-patterns and subchondritic Nb/Ta ratios. They hence formed from a residual gas from which an ultrarefractory component had been isolated before. Most chondrules have unfractionated REE patterns and unfractionated Zr/Hf and Nb/Ta ratios. However, some type-1-chondrules, the Al-rich chondrules and the chondrite matrix show fractionated REE patterns. This indicates an additive of refractory constituents with REE group-II-pattern. The analyses of bulk chondrites indicates that carbonaceous chondrites have characteristic volatility-controlled REE patterns (ultrarefractory or group-II) compared to the CI chondrite Orgueil. This could be explained by the occurrence of refractory components with fractionated rare earth elements. The majority of ordinary, enstatite and rumuruti chondrites has relatively unfractionated REE patterns. The results provide evidence that ordinary, enstatite and rumuruti chondrites as well as achondrites, Mars, Moon and Earth have small negative Tm anomalies compared to the CI chondrite Orgueil. On the basis of their relative contents of heavy rare earth elements (HREE), the inner solar system objects were divided into two groups: a carbonaceous and a non-carbonaceous chondrite reservoir which also includes the achondrites, Mars, Earth and Moon. It was assumed that the objects of the non-carbonaceous chondrite reservoir reflect solar system HREE ratios. In contrast, carbonaceous chondrites have variable Tm anomalies that are caused by the input of fractionated refractory components into the region where they formed. CI chondrites, that are generally regarded as the chemically most primitive chondrite group, would have a positive Tm anomaly of 4.8 ± 0.9 % and therefore do not agree with the solar system. A fraction of 0.2 wt% of a refractory component with group-II-pattern in CI chondrites could explain the observed Tm anomaly.

Petrographic and geochemical characterization of seep carbonate from Bush Hill (GC 185) gas vent and hydrate site of the Gulf of Mexico

The chemical composition of bottom sediments in the northern part of Lake Umbozero, located in close proximity to a closed rare metal mine in the Murmansk Region, was studied. This study is a continuation of our research into the impact of closed rare metal mines and tailings on the environment. Samples were collected using an open gravity sampler in two sections of the lake in three replicates. The content of rare earth elements was determined using inductively coupled plasma mass spectrometry. The total content of elements was determined both in the surface layers of bottom sediments and in the deep layers that were formed in the preindustrial period and, thus, characterize the geochemical background of the study area. The average ∑REE in the surface layers of bottom sediments of Lake Umbozero in the wastewater reception area (Site 1) reaches 774 mg/kg, while for the area located north of the discharge site (Site 2), ∑REE was 208 mg/kg. The enrichment factor (EF), the geoaccumulation index (Igeo), the coefficient of the index of potential ecological risk (Eir) and the index of potential ecological hazard (RI) were calculated. Assessing the total pollution of bottom sediments of Lake Umbozero with rare earth elements, the value of potential ecological risk reaches values corresponding to the level of low and moderate ecological risk of pollution (RISite 1 = 164; RISite 2 = 104). The conducted correlation analysis allowed us to establish the main phases containing rare earth elements in the bottom sediments of Lake Umbozero—oxyhydroxide complex compounds with iron and manganese.