Occurrence Of Cu Research Articles

Effect of Reaction Period on Stoichiometry, Phase Purity, and Morphology of Hydrothermally Synthesized Cu2NiSnS4 Nanopowder

The effect of reaction period on the phase purity, morphology, and stoichiometry of Cu2NiSnS4 (CNTS) nanopowder prepared by hydrothermal method has been investigated. Polyvinylpyrrolidone (PVP) and thioglycolic acid were used as capping agent and sulfur source, respectively. The presence of cubic stannite crystal structure and its phase purity were confirmed by powder x-ray diffraction analysis and Raman spectroscopy. Furthermore, the morphological, crystallographic, and optical features of the prepared CNTS nanopowder were characterized by field-emission scanning electron microscopy, transmission electron microscopy, and ultraviolet–visible (UV–Vis) spectrophotometry. The elemental ratios of Cu/(Ni + Sn) and Ni/Sn showed that the stoichiometry of CNTS was maintained for the compounds synthesized at 230°C with reaction period of 24 h. The occurrence of Cu+, Ni2+, Sn4+, and S2− was evaluated by x-ray photoelectron spectroscopy. The prepared material was used as counter electrode in a dye-sensitized solar cell (DSSC) as an alternative to platinum (Pt), resulting in conversion efficiency of 0.92%. These results indicate that CNTS is a prospective material to replace conventional Pt-based counter electrodes in DSSCs.

Multiplexed analysis combining distinctly-sized CdTe-MPA quantum dots and chemometrics for multiple mutually interfering analyte determination

Semiconductor quantum dots (QDs) have demonstrated a great potential as fluorescent probes for heavy metals monitoring. However, their great reactivity, whose tunability could be difficult to attain, could impair selectivity yielding analytical results with poor accuracy. In this work, the combination in the same analysis of multiple QDs, each with a particular ability to interact with the analyte, assured a multi-point detection that was not only exploited for a more precise analyte discrimination but also for the simultaneous discrimination of multiple mutually interfering species, in the same sample. Three different MPA-CdTe QDs (2.5, 3.0 and 3.8nm) with a good size distribution, confirmed by the FWHM values of 48.6, 55.4 and 80.8nm, respectively, were used. Principal component analysis (PCA) and partial least squares regression (PLS) were used for fluorescence data analysis. Mixtures of two MPA-CdTe QDs, emitting at different wavelength namely 549/566, 549/634 and 566/634nm were assayed. The 549/634nm emitting QDs mixture provided the best results for the discrimination of distinct ions on binary and ternary mixtures. The obtained RMSECV and R2CV values for the binary mixture were good, namely, from 0.01 to 0.08mgL−1 and from 0.74 to 0.89, respectively. Regarding the ternary mixture the RMSECV and R2CV values were good for Hg(II) (0.06 and 0.73mgL−1, respectively) and Pb(II) (0.08 and 0.87mg L−1, respectively) and acceptable for Cu(II) (0.02 and 0.51mgL−1, respectively). In conclusion, the obtained results showed that the developed approach is capable of resolve binary and ternary mixtures of Pb (II), Hg (II) and Cu (II), providing accurate information about lead (II) and mercury (II) concentration and signaling the occurrence of Cu (II).

Influence of Cu fractions on soil microbial activities and risk assessment along Cu contamination gradient

This experimental work investigates the geochemical occurrence of Cu in soil polluted with mining activities and its impact on soil microflora activities. Samples of soil and tailing were collected from four Cu mines according to distance from Cu smelters. The Cu fractionation was carried out following the modified Tessier scheme resulted in six fractions: water extractable (F1), exchangeable (F2), carbonate bound (F3), FeMn oxide bound (F4), organic bound (F5) and residual forms (F6). Cu from anthropogenic sources existed mainly in active forms (28–37%), followed by oxide bound (22–30%), organic bound (17–25%) and residual forms (15–21%). On the other side, geogenic forms of copper were present in residual forms (33–48%), followed by organic bound (21–29%), oxide bound (12–25%) and active forms (6–12%). Relative percentage fractions of Cu in uncontaminated samples were: F6~F5>F4>F3>F2>F1. However, fractions of Cu in contaminated samples were: F3>F4>F5>F6>F2>F1. Microbial biomass carbon (Cmic) and soil enzyme activities along a Cu contamination gradient were also determined. Significant negative correlations were observed between Cmic, enzyme activities, water extractable and exchangeable form of Cu. This paper demonstrates the relationship between bioavailability and toxicity of Cu to soil microflora along a contamination gradient. The risk assessment code (RAC) was also applied to the current study and demonstrated that samples closer to mining sites (50–600m) have high mobility factor (>30%), presenting high risk category and can effortlessly get into the food chain. However, samples from 600 to 1000m have mobility factor of 6–12%, which presents low to medium risk categories, with the possibility of entry into the food chain.

Highly conductive grain boundaries in copper oxide thin films

High conductivity in the off-state and low field-effect mobility compared to bulk properties is widely observed in the p-type thin-film transistors of Cu2O, especially when processed at moderate temperature. This work presents results from in situ conductance measurements at thicknesses from sub-nm to around 250 nm with parallel X-ray photoelectron spectroscopy. An enhanced conductivity at low thickness is explained by the occurrence of Cu(II), which is segregated in the grain boundary and locally causes a conductivity similar to CuO, although the surface of the thick film has Cu2O stoichiometry. Since grains grow with an increasing film thickness, the effect of an apparent oxygen excess is most pronounced in vicinity to the substrate interface. Electrical properties of Cu2O grains are at least partially short-circuited by this effect. The study focuses on properties inherent to copper oxide, although interface effects cannot be ruled out. This non-destructive, bottom-up analysis reveals phenomena which are commonly not observable after device fabrication, but clearly dominate electrical properties of polycrystalline thin films.

Yeast diversity on grapes in two German wine growing regions

The yeast diversity on wine grapes in Germany, one of the most northern wine growing regions of the world, was investigated by means of a culture dependent approach. All yeast isolates were identified by sequence analysis of the D1/D2 domain of the 26S rDNA and the ITS region. Besides Hanseniaspora uvarum and Metschnikowia pulcherrima, which are well known to be abundant on grapes, Metschnikowia viticola, Rhodosporidium babjevae, and Curvibasidium pallidicorallinum, as well as two potentially new species related to Sporidiobolus pararoseus and Filobasidium floriforme, turned out to be typical members of the grape yeast community. We found M. viticola in about half of the grape samples in high abundance. Our data strongly suggest that M. viticola is one of the most important fermenting yeast species on grapes in the temperate climate of Germany. The frequent occurrence of Cu. pallidicorallinum and strains related to F. floriforme is a new finding. The current investigation provides information on the distribution of recently described yeast species, some of which are known from a very few strains up to now. Interestingly yeasts known for their role in the wine making process, such as Saccharomyces cerevisiae, Saccharomyces bayanus ssp. uvarum, Torulaspora delbrueckii, and Zygosaccharomyces bailii, were not found in the grape samples.

Towards controlling PCDD/F production in a multi-fuel fired BFB boiler using two sulfur addition strategies. Part II: Thermodynamic analysis

A staged equilibrium process model was developed for a bubbling fluidized bed boiler firing SRF, bark and sludge. The model was used to study the influence of sulfur addition strategies (S-pellet additive and peat co-firing) on the behavior of copper, bromine, and alkalis. Aerosol samples collected from the backpass of the boiler were used to validate the chemistry predicted by the model. The model revealed that Cu existed as Cu2S(s3) in the reducing zone, and CuCl(g) (for all test cases) and CuO(s) (during peat co-firing) in the oxidation zones. CuBr3(g) was also present after the introduction of tertiary air. However the model failed to predict the formation of CuSO4, an important passive species of Cu necessary for PCDD/F abatement. The modes of occurrence of Cu were classified as either active or passive with respect to de novo synthesis and an active/passive species molar ratio (APR) was introduced. APR showed high correlation with the PCDD/F production levels. Sensitivity analysis revealed that excessive Cu in the fuel mixture decreased the volatility of the element due to the formation of CuO(s). Simulation for peat co-firing with low Cu content showed that PCDD/F concentration is decreased and is comparable to that of S-pellet addition. Sensitivity analysis revealed that increasing the energy share of sludge can likewise lower PCDD/F production.

A Schiff base and its copper(II) complex as a highly selective chemodosimeter for mercury(II) involving preferential hydrolysis of aldimine over an ester group.

The syntheses of a new Schiff base, diethyl-5-(2-hydroxybenzylidene)aminoisophthalate (HL), and a copper complex, [Cu(L2)] (1), imparting L(-), have been described. Both the ligand HL and complex 1 have been thoroughly characterized by elemental analyses, electrospray ionization mass spectrometry, FT-IR, NMR ((1)H and (13)C), electronic absorption, and emission spectral studies and their structures determined by X-ray single-crystal analyses. Distinctive chemodosimetric behavior of HL and 1 toward Hg(2+) has been established by UV/vis, emission, and mass spectral studies. Comparative studies further revealed that the chemodosimetric response solely originates from selective hydrolysis of the aldimine moiety over the ester group and 1 exhibited greater selectivity toward Hg(2+) relative to HL while the sensitivity order is reversed. Further, these followed different hydrolytic pathways but ended up with the same product analyzed for diethyl-5-aminoisophthalate (DEA). Hg(2+)-induced displacement of Cu(2+) and subsequent hydrolysis of the -HC═N- moiety in 1 affirmed the identity of the actual species undergoing hydrolysis as HL. The occurrence of Cu(2+) displacement and Hg(2+) detection via hydrolytic transformation has been supported by various physicochemical studies.

Occurrence of Cu and Cr in the sedimentary humic substances and pore water from a typical sugar cane cultivation area in São Paulo, Brazil

Purpose The purpose of this paper is to study the interactions of sedimentary humic substances (SHS) from a sugarcane cultivation area with Cu(II) and Cr(III) and to evaluate the occurrence of these metals in the pore water and SHS.

Erythemal dose rate under noon overcast skies

The incidence of ultraviolet radiation (UVR) under noon overcast skies was investigated in an urban, tropical site. Overcast skies stimulate people to be outdoors more freely and carelessly than under a cloudless scenario, thereby representing a situation with UVR. 153 occurrences of noon overcast skies were reported for erythemal dose rates (EDR) of up to 0.395 W m(-2) (Extreme UV-Index) and average of 0.121 W m(-2) (Moderate UVI). Erythemal doses varied from 0.4 to 21.6 Standard Erythema Dose (SED) units and averaged 7.7 SED. 34% of the occurrences of Extreme UVI were events of radiation enhancement up to 19% above the summer peak value of 0.332 W m(-2). The elapsed time for such events ranged from 2 to 7 minutes and averaged 4.5 minutes. Cloud genera referring to EDR were predominantly Cu followed by As in summer, and Cu plus Sc and As in the other seasons. For events of radiation enhancement, cloud genera featured a reduction in the occurrence of Cu and an increase in the occurrence of As and Ac.

One-Pot Synthesis of Cu(II) Complex with Partially Oxidized TTF Moieties

The one-pot synthesis of a Cu(II) complex with partially oxidized tetrathiafulvalene (TTF) moieties in its capping MT-Hsae-TTF ligands, [CuII(MT-sae-TTF)2] [CuICl2] was realized by the simultaneous occurrence of Cu(II) complexation and CuIICl2 mediated oxidation of TTF moieties. The crystal structure was composed of one-dimensional columns formed by partially oxidized TTF moieties and thus the cation radical salt showed relatively high electrical conductivity. Tight binding band structure calculations indicated the existence of a Peierls gap due to the tetramerization of the TTF moieties in the one-dimensional stacking column at room temperature, which is consistent with the semiconducting behavior of this salt.

Process Mineralogy of a Low Grade Cu-Ni-PGM Sulphide Ore and its Implications for Mineral Processing

Based on process mineralogical study of a low-grade Cu-Ni-platinum group metal(PGM) sulfide ore in SW China, the occurrence of Cu and Ni, the distribution of platinum group minerals (PGMs) and their relationships with other minerals are determined in detail, which provides scientific reference for forthcoming mineral processing and extractive metallurgy. The mineralogical results show that 18 individual PGMs containing all the 6 platinum group elements (PGEs) are investigated, and it can be concluded that the PGMs in the ores mainly occur as individual minerals. SEM images show that the PGMs are mainly disseminated in sulphides, most occur as inclusions or semi-inclusions, and part are inlayed along the other minerals to form coarse compound grains. Due to the the complex mineral composition and texture, processing the Cu-Ni-PGM ores by traditional flotation may be difficult to get a good processing performance.

Geostatistical Assessment of the Impact of World War I on the Spatial Occurrence of Soil Heavy Metals

Previous research showed a regional Cu enrichment of 6 mg kg(-1) in the top soil of the Ypres war zone (Belgium), caused by corrosion of WWI shell fragments. Further research was required since in addition to Cu, also As, Pb, and Zn were used during the manufacturing of ammunition. Therefore, an additional data collection was conducted in which the initial Cu data set was tripled to 731 data points and extended to eight heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) which permitted (1) to evaluate the environmental impact of the heavy metals at a regional scale and (2) to assess their regional spatial occurrence by performing an optimized geostatistical modeling. The results showed no pollution at a regional scale, but sometimes locally concentrations exceeded the soil sanitation threshold, especially for Cu, Pb, and Zn. The spatial patterns of Ni and Cr were related to variations in soil texture whereas the occurrences of Cu and Pb were clearly linked to WWI activities. This difference in spatial behavior was confirmed by an analysis of coregionalization.

Formation of the Vysoká–Zlatno Cu–Au skarn–porphyry deposit, Slovakia

The central zone of the Miocene Stiavnica stratovolcano hosts several occurrences of Cu–Au skarn–porphyry mineralisation, related to granodiorite/quartz–diorite porphyry dyke clusters and stocks. Vysoka–Zlatno is the largest deposit (13.4 Mt at 0.52% Cu), with mineralised Mg–Ca exo- and endoskarns, developed at the prevolcanic basement level. The alteration pattern includes an internal K- and Na–Ca silicate zone, surrounded by phyllic and argillic zones, laterally grading into a propylitic zone. Fluid inclusions in quartz veinlets in the internal zone contain mostly saline brines with 31–70 wt.% NaCl eq. and temperatures of liquid–vapour homogenization (Th) of 186–575°C, indicating fluid heterogenisation. Garnet contains inclusions of variable salinity with 1–31 wt.% NaCl eq. and Th of 320–360°C. Quartz–chalcopyrite veinlets host mostly low-salinity fluid inclusions with 0–3 wt.% NaCl eq. and Th of 323–364°C. Data from sphalerite from the margin of the system indicate mixing with dilute and cooler fluids. The isotopic composition of fluids in equilibrium with K-alteration and most skarn minerals (both prograde and retrograde) indicates predominantly a magmatic origin (δ18Ofluid 2.5–12.3‰) with a minor meteoric component. Corresponding low δDfluid values are probably related to isotopic fractionation during exsolution of the fluid from crystallising magma in an open system. The data suggest the general pattern of a distant source of magmatic fluids that ascended above a zone of hydraulic fracturing below the temperature of ductile–brittle transition. The magma chamber at ∼5–6 km depth exsolved single-phase fluids, whose properties were controlled by changing PT conditions along their fluid paths. During early stages, ascending fluids display liquid–vapour immiscibility, followed by physical separation of both phases. Low-salinity liquid associated with ore veinlets probably represents a single-phase magmatic fluid/magmatic vapour which contracted into liquid upon its ascent.

Unraveling Atomic Positions in an Oxide Spinel with Two Jahn−Teller Ions: Local Structure Investigation of CuMn2O4

At first sight, the quenched tetragonal spinel CuMn(2)O(4) can be formulated with Cu(2+) and Mn(3+), implying that the tetrahedral site is Jahn-Teller (JT)-active Cu(2+) and the octahedral site is JT-active Mn(3+). High-resolution, high-momentum-transfer neutron scattering analysis suggests that the sample has approximately 30% inversion: Mn on the tetrahedral Cu site with compensating Cu on the octahedral site. Reverse Monte Carlo (RMC) analysis of the pair distribution function allows details of metal-oxygen connectivity to be probed in a manner that is significantly on the local rather than the average scale. Bond valence analysis of the RMC supercell reveals that both JT ions disproportionate to higher and lower valence states as a means of avoiding their JT tendency, particularly on the tetrahedral site. The occurrence of Cu(3+) in particular is suggested for the first time and is supported by X-ray photoelectron spectroscopy data. The bimodal distribution of O-Cu-O bond angles at the tetrahedral site (distinct from what is seen for O-Mn-O bond angles) further reveals a hidden distinction between sites previously considered to be equivalent. Application of total scattering techniques originally developed for highly disordered materials permits the examination of nanoscale crystalline structure with elemental specificity that is not available in traditional reciprocal-space analysis.

Mineralogy of the Precambrian southern Kostomuksha gold prospect in Karelia

The southern Kostomuksha gold-sulfide prospect with a grade of 0.2–30 g/t Au belongs to the gold-pyrrhotite-arsenopyrite mineral type and is localized in the metasomatically altered shear zone at the southern flank of the Kostomuksha iron deposit. The Au-bearing pyrite ore is commonly characterized by a low grade (0.02–1.0 g/t Au). The grade of Au-bearing mineralization composed of arsenopyrite, loellingite, and electrum (4.28–15.31 wt % Ag and up to 0.99–2.16 wt % Hg) is higher; pyrrhotite, chalcopyrite, galena, maldonite, aurostibite, and native bismuth are additional components of this mineral assemblage. The ore mineralization is hosted in the near-latitudinal shear zone close to the contact between the folded and metamorphosed banded iron formation (BIF) and halleflinta. The early stage of collision-related HP-HT metamorphism resulted in the formation of a garnet-amphibole-biotite assemblage (T = 680-750°C) and microcline. After an abrupt drop m pressure, metasomatic alteration and ore mineralization took place. The ore-forming process started at 510–440°C with deposition of arsenopyrite. Galena and electrum were formed at a lower temperature. The temperature continued to decline down to the stage of ore oxidation and deposition of colloform marcasite. Ore minerals precipitated from acid chloride aqueous solutions admixed with methane at the initial stage and from diluted aqueous solutions at the final stage. The character of wall-rock alteration and the gain of K, Rb, and B show that the ore-forming process postdated the emplacement of potassium granite. The occurrence of Cu, Zn, Pb, As, and Ni and other heterogeneous elements indicates a complex metamorphic-metasomatic source and an additional supply of Au, As, Bi, Sb, and Te under conditions of sulfur deficiency. The gold mineralization at the southern Kostomuksha prospect is classified as gold-sulfide (arsenopyrite) ore type related to shear zones in the BIF.

Evaluation of dissipation mechanisms by Lolium perenne L, and Raphanus sativus for pentachlorophenol (PCP) in copper co-contaminated soil

Though phytoremediation is widely studied in remediation of metal contaminated soils or organic contaminated soils, little information is available regarding the effectiveness and processes of phytoremediation of sites co-contaminated with organic and metal pollutants. Sites co-contaminated with organic and metal pollutants are common and considered to be a more complex problem as the two components often cause a synergistic effect on cytotoxicity as measured both by growth inhibition and colony-forming ability. In this paper, the dissipation mechanisms for pentachlorophenol (PCP) in copper co-contaminated soil by Lolium perenne L, and Raphanus sativus was investigated in a greenhouse experiment by monitoring the growth response of plants, evaluating the removal efficiency of extractable PCP, differentiating PCP residuals in strongly and loosely adhering rhizosphere soils, and analyzing the microbial activity in the rhizosphere. In copper co-contaminated soil with the initial PCP concentration of 50 mg/kg, plants grew better with the increment of soil Cu level (0, 150, 300 mg/kg), which implied that combinations of inorganic and organic pollutants sometimes exerted antagonistic effects on plant cytotoxicity. The observed higher PCP dissipation in soil spiked with 50 mg/kg PCP in the presence of Cu and the less difference of PCP residual between strongly and loosely adhering soils further suggests the occurrence of Cu–PCP interaction and the enhanced degradation and mass flow are two possible explanations. In copper co-contaminated soil with the initial PCP concentration of 100 mg/kg, however, both plant growth and microbial activity were inhibited with the increment of soil Cu level. The lowered degrading activity of microorganisms and the reduced mass flow were probably responsible for the significantly lower levels of PCP dissipation in copper co-contaminated soil. These results showed that remediation of sites co-contaminated with organic and metal pollutants is a complex problem and a more thorough understanding of the extent and mechanisms by which metals inhibit organic degradation is needed to develop phytoremediation of co-contaminated sites.

A multi-technique study of platinum group element systematic in some Ligurian ophiolitic peridotites, Italy

Fe–Ni–Cu sulfide mineralogy has been investigated along with bulk-rock and in-situ PGE analyses by ICP MS and LA-ICP-MS in eight lherzolites from the Internal (IL) and External Liguride (EL) ophiolites (Italy). The two EL lherzolites are fertile (2–4% partial melting) and slightly serpentinized while the six IL cpx-poor lherzolites have experienced 5–10% of partial melting, impregnation by instantaneous melt fractions [Geochim. Cosmochim. Acta 61 (1997) 4557] and have been highly serpentinized. The EL lherzolites show broadly chondritic PGE relative abundances with a slight to pronounced enhancement of the light PGE (Ru, Rh and Pd) relative to the heavy PGE (Os, Ir and Pt) (Ru N/Ir N=1.13; Rh N/Ir N=1.08–1.10; Pd N/Ir N=1.24–1.62; N=CI-chondrite normalized). Their magmatic sulfide modal abundances and S contents, similar to the orogenic peridotites values, are consistent with their very low degree of partial melting. The occurrence of Cu–Rh–Pd-rich pentlandite, however, demonstrates that, even for low degree of partial melting, a Cu–Ni-rich sulfide liquid can segregate, leaving the residual monosulfide solid solution (Mss) (now transformed into Cu-poor pentlandite) depleted in Rh and Pd (Rh N/Ir N and Pd N/Ir N<1). The IL cpx-poor lherzolites display a broadly flat PGE patterns from Os to Pt with a slight enhancement of Ru and Rh (Ru N/Ir N=1.05–1.38; Rh N/Ir N=1.01–1.31). Pd N/Ir N ratios range from chondritic to superchondritic (1.02–2.99) and cannot be interpreted in terms of partial melting models. Rh–Pd–Cu–Ni-rich pentlandite grains are associated with large corroded cpx crystals ascribed to exotic melt percolation by Rampone et al. [Geochim. Cosmochim. Acta 61 (1997) 4557]. It is concluded that precipitation of Cu–Ni–Rh–Pd-rich sulfides has significantly enhanced the Pd concentrations as well as the magmatic sulfide modal abundances. Such processes, previously documented in abyssal peridotites from slow-spreading mid-oceanic ridges, characterize residues from low to moderate melting degrees (5–10%) of the oceanic mantle as a whole, either from mature ocean or from short-lived oceanic basins.

Occurrence of ferromagnetic shape memory alloys (invited)

This article presents an overview of the necessary conditions for the formation of shape memory alloys (SMAs) and how these must overlap with the occurrence of ferromagnetism so that ferromagnetic shape memory alloys (MSMAs) may be formed. The electronic, elastic, and geometric conditions permit an understanding of the occurrence of Cu- and Fe-based SMAs as well as NiMnGa Heusler MSMAs except that the naively determined critical electron concentration for the latter, 7.3, disagrees with the values of 1.5 and 8.6 accepted for the Hume–Rothery phases and certain Fe-based systems.

Kinetics of reactions of chelates FeEDDHA and FeEDDHMA as affected by pH and competing ions

Iron chelates are widely used in fertigation because of their high stability and solubility. However, sudden changes of pH or concentrations of accompanying ions affect chelate stability and make kinetics as relevant as equilibrium data. The kinetics of FeEDDHA and FeEDDHMA reactions at acidic pH values in the presence and absence of calcium (Ca), magnesium (Mg), phosphorus (P), copper (Cu), nickel (Ni), and zinc (Zn) were studied. The FeEDDHA and FeEDDHMA decompound in few seconds at low pH values. The extension of the decomposition reaction is affected by the kind of chelate and concentration. Calcium, Mg, P, Cu, and Zn slightly slow down the reaction. The recovery of both chelates is observed when pH increases. The reaction is quick and practically complete in absence of competing ions, although the percentage of recompound chelate is affected by the chelating agent and pH. FeEDDHMA recompounds in a larger extension than FeEDDHA. The percentage of recompound chelate increases from pH 4 to 7. The rate of reaction and the quantity of recompound chelate are not modified by the presence of Ca or Mg ions. However, phosphate diminishes the percentages of recovery, and its effect is larger as higher is the relationship [P]/[chelate]. The occurrence of Cu, Ni, manganese (Mn), and Zn slows down the reaction at low chelate concentrations. They also decrease the percentage of recompound chelate. The negative effect of the microelements is higher on the recovery of FeEDDHMA than on FeEDDHA, but for both chelates, the influence of the competing ions diminishes as the chelate concentration increases. Copper has the greatest impact on the recomposition of the chelates FeEDDHA and FeEDDHMA, although Ni, a high concentrations, can end up impeding the recovery of FeEDDHMA.

Geochemical characteristics and Metallogenesis of volcanic rocks as exemplified by volcanic rocks in Ertix, Xinjiang

Volcanic rocks in Ertix, Xinjiang, occurring in the collision zone between the Siberia Plate and the Junggar Plate, are distributed along the Ertix River Valley in northern Xinjiang. The volcanic rocks were dated at Late Paleozoic and can be divided into the spilite-keratophyre series and the basalt-andesite series. The spilite-keratophyre series volcanic rocks occur in the Altay orogenic belt at the southwest margin of the Siberia Plate. In addition to sodic volcanic rocks, there are also associated potassic-sodic volcanic rocks and potassic volcanic rocks. The potassic-sodic volcanic rocks occur at the bottom of the eruption cycle and control the distribution of Pb and Zn deposits. The potassic volcanic rocks occur at the top of the eruption cycle and are associated with Au and Cu mineralizations. The sodic volcanic rocks occur in the middle stage of eruption cycle and control the occurrence of Cu(Zn) deposits. The basalt-andesite series volcanic rocks distributed in the North Junggar orogenic belt at the north margin of the Junggar-Kazakstan Plate belong to the potassicsodic volcanic rocks. The volcanic rocks distributed along the Ulungur fault are relatively rich in sodium and poor in potassium and are predominated by Cu mineralization and associated with Au mineralization. Those volcanic rocks distributed along the Ertix fault are relatively rich in K and poor in Na, with Au mineralization being dominant.