scholarly journals Use of the System S2o3 (2-) -O2 for the Leaching of Precious Metals Contained in a Mineral From Molango in the State of Hidalgo, Mexico

2018 ◽  
Vol 14 (3) ◽  
pp. 48 ◽  
Author(s):  
Edmundo Roldán-Contreras ◽  
Juan Hernández-Ávila ◽  
Eduardo Cerecedo-Sáenz ◽  
Ma. Isabel Reyes-Valderrama ◽  
Eleazar Salinas-Rodríguez
Keyword(s):  
Electron Microscopy ◽  
Inductively Coupled Plasma ◽  
Energy Dispersive Spectrometry ◽  
Precious Metals ◽  
X Rays ◽  
X Ray ◽  
Plasma Spectrometry ◽  
Inductively Coupled ◽  
Inductively Coupled Plasma Spectrometry ◽  
Scanning Electron

The newer tendencies of research, related with the leaching of precious metals, involves the use of non toxic reagents that allows the leaching of a mineral of sedimentary origin using the system S2 - O3 2- - O2. Prior to thisprocess, the mineral was characterized by Scanning Electron Microscopy (SEM) in conjunction with Energy Dispersive Spectrometry of X – rays (EDS), X- ray mapping. Finally, the chemical composition was executed by Inductively Coupled Plasma Spectrometry (ICP). According to the results obtained, it was possible to determine that the mineral studied has adequate contents of gold, palladium, silver, and platinum. And after the leaching process, it could be possible to leach the gold and palladium that it contains, getting recoveries of 90% and 85 %, respectively. In the case of silver, a redissolution or precipitation could occur during the first minutes of reaction.

scholarly journals Efflorescent Sulfate Crystallization on Fractured and Polished Colloform Pyrite Surfaces: A Migration Pathway of Trace Elements

Minerals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 12
Author(s):  
Dimitrina Dimitrova ◽  
Vassilka Mladenova ◽  
Lutz Hecht
Keyword(s):  
Electron Microscopy ◽  
Trace Elements ◽  
Inductively Coupled Plasma ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
X Ray ◽  
Inductively Coupled ◽  
Migration Pathway ◽  
Plasma Mass Spectrometry ◽  
Scanning Electron

The colloform pyrite variety incorporates many trace elements that are released in the environment during rapid oxidation. Colloform pyrite from the Chiprovtsi silver–lead deposit in Bulgaria and its oxidation efflorescent products were studied using X-ray diffractometry, scanning electron microscopy, electron microprobe analysis, and laser ablation inductively coupled plasma mass spectrometry. Pyrite is enriched with (in ppm): Co (0.1–964), Ni (1.8–3858), Cu (2.9–3188), Zn (3.1–77), Ag (1.2–1771), As (8179–52,787), Se (2.7–21.7), Sb (48–17792), Hg (4–2854), Tl (1.7–2336), Pb (13–7072), and Au (0.07–2.77). Gypsum, anhydrite, szomolnokite, halotrichite, römerite, copiapite, aluminocopiapite, magnesiocopiapite, coquimbite, aluminocoquimbite, voltaite, and ammoniomagnesiovoltaite were identified in the efflorescent sulfate assemblage. Sulfate minerals contain not only inherited elements from pyrite (Cr, Fe, Co, Ni, Cu, Zn, Ag, In, As, Sb, Hg, Tl, and Pb), but also newly introduced elements (Na, Mg, Al, Si, P, K, Ca, Sc, Ti, V, Mn, Ga, Rb, Sr, Y, Zr, Sn, Cs, Ba, REE, U, and Th). Voltaite group minerals, copiapite, magnesiocopiapite, and römerite incorporate most of the trace elements, especially the most hazardous As, Sb, Hg, and Tl. Colloform pyrite occurrence in the Chiprovtsi deposit is limited. Its association with marbles would further restrict the oxidation and release of hazardous elements into the environment.

scholarly journals Acetalization of Glycerol with Citral over Heteropolyacids Immobilized on KIT-6

Catalysts ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 81
Author(s):  
José Castanheiro
Keyword(s):  
Electron Microscopy ◽  
Inductively Coupled Plasma ◽  
Fixed Time ◽  
Tungstophosphoric Acid ◽  
X Ray Diffraction ◽  
Glycerol Conversion ◽  
X Ray ◽  
Inductively Coupled ◽  
Catalytic Stability ◽  
Scanning Electron

Glycerol acetalization with citral was studied using a heteropolyacid (tungstophosphoric acid) supported on KIT-6, as a catalyst, at 100 °C. Different catalysts were synthesized. Catalysts were characterized by scanning electron microscopy (SEM), inductively coupled plasma (ICP), X-ray diffraction (XRD), attenuated total refletion-Fourier transform infrared spectroscopy (ATR-FTIR), and potentiometric titrations. At a fixed time, the glycerol conversion increased with the H3PW12O40 (PW) on KIT-6. PW4-KIT-6 material had a higher conversion than other catalysts. The optimization of glycerol’s acetalization with citral was studied under the PW4-KIT-6 catalyst. After 5 h, it was found that, at T = 100 °C, with m = 0.3 g of solid, molar glycerol:citral = 1:2.25, the conversion of glycerol was 89%. Moreover, the PW4-KTI-6 catalyst showed good catalytic stability.

Electron microscopical observations and chemical analyses supporting Mn uptake in white rot degraded Alstonia and pine wood stakes exposed in acid coniferous soil

1997 ◽  
Vol 43 (7) ◽  
pp. 663-671 ◽  
Author(s):  
Geoffrey Daniel ◽  
Thomas Nilsson ◽  
Jindrich Volc
Keyword(s):  
Electron Microscopy ◽  
Inductively Coupled Plasma ◽  
Acid Soil ◽  
Middle Lamella ◽  
White Rot ◽  
Pine Wood ◽  
Plasma Spectrometry ◽  
Inductively Coupled ◽  
Inductively Coupled Plasma Spectrometry ◽  
Electron Microscopical

Brownish-black spots and flecks several millimetres wide were frequently recognized on the surface and within nonpreservative-treated hardwood (Alstonia scholaris (R.Br.)) and softwood (Pinus sylvestris L.) test stakes placed in an acid forest soil. Energy-dispersive X-ray microanalysis in conjunction with transmission electron microscopy (TEM) and gross chemical analysis of wood using inductively coupled plasma spectrometry showed the flecks to be composed primarily of Mn, which was selectively removed from the surrounding soil. A similar uptake of Mn into wood stakes placed in presterilized acid soil was not noted, indicating the process resulted from biotic activity. Detailed TEM observations showed intrusion of Mn into the wood cell lumina and into areas of erosion, cavity formation, and decayed middle lamella in Alstonia and pine wood cells attacked by an unknown white rot decay fungus. Distinct zones of apparent delignification were also noted progressing across secondary cell walls and middle lamella regions of attacked cells, although it was unclear if the effect was caused by nonenzymatic attack by Mn, enzymatic attack by the fungus, or a combination of both. Mn is thought to play a major regulating role in both lignin depolymerization and mineralization in the presence of organic acids during white rot decay. Present observations also suggest that uptake of Mn into wood stakes during microbial degradation results from biotic activity and soil type and pH are of major significance.Key words: Mn, test stakes, electron microscopy, white rot decay, inductively coupled plasma spectrometry.

Appendix VI: Report on the Examination and Analysis of a Group of Copper Alloy Fragments and other Material from Sarn-Y-Bryn-Caled, Powys

1994 ◽  
Vol 60 (S1) ◽  
pp. 34-35
Author(s):  
Ornean Hook
Keyword(s):  
Trace Elements ◽  
Bronze Age ◽  
Copper Alloy ◽  
Inductively Coupled Plasma ◽  
Scientific Research ◽  
Major And Trace Elements ◽  
X Ray ◽  
Plasma Spectrometry ◽  
Inductively Coupled ◽  
Inductively Coupled Plasma Spectrometry

Ten amorphous copper alloy fragments from Sam-y-bryn-caled, Powys, were submitted to the Department of Scientific Research for analysis. They were analysed qualitatively using X-ray fluorescence (XRF) to identify the major and trace elements. Three of the larger fragments were alto analysed quantitatively using inductively-coupled plasma spectrometry (ICP), allowing their compositions to be compared with other analyses of bronze age mctalwork (e.g. Northover, 1980).In additionna number of clay/daub fragments ant i possible piece of slag from the upper levels of the central pit were analysed to try and determine whether they were connected with metalworking.

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