scholarly journals Spectral Response (VNIR-SWIR) Associated with the Octahedral Sheet of Smectites

2021 ◽  
Vol 6 (1) ◽  
pp. 23
Author(s):  
Adrián Lorenzo ◽  
Andrea García-Vicente ◽  
Juan Morales ◽  
Emilia García-Romero ◽  
Mercedes Suárez
Keyword(s):  
Chemical Analysis ◽  
Inductively Coupled Plasma ◽  
Near Infrared ◽  
Spectral Response ◽  
Short Wave ◽  
Absorption Feature ◽  
X Ray Diffraction ◽  
Octahedral Sheet ◽  
Mineralogical Characterization ◽  
Inductively Coupled

A mineralogical characterization of a group of bentonite samples was done by X-ray diffraction (XRD), chemical analysis by inductively coupled plasma mass spectroscopy (ICP-MS), and visible-near infrared and short-wave infrared spectroscopy (VNIR-SWIR). As tested by XRD, all samples are very pure, composed mainly of smectites with very small amounts of impurities, such as quartz and feldspar. The results of the chemical analysis show high contents of Al2O3 in all the samples except for COU(V), which has high contents of Fe2O3 and R4, which is a trioctahedral smectite. Within VNIR-SWIR spectra, absorption feature characteristics of the smectites due to the presence of Fe are observed at lowest wavenumber while, at the SWIR region, the absorptions are related to the M-OH bonds and there are differences among the samples according to their octahedral content.

scholarly journals Mineralogical Characterization and Acid Pretreatment of a Gold Calcine Leach Residue

Minerals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 10
Author(s):  
Godfrey Tinashe Bare ◽  
Jean Jacques Kalombo Mbayo ◽  
Sehliselo Ndlovu ◽  
Alan Shemi ◽  
Liberty Chipise
Keyword(s):  
Inductively Coupled Plasma ◽  
Acid Leaching ◽  
Leach Residue ◽  
X Ray Diffraction ◽  
Acid Pretreatment ◽  
Mineralogical Characterization ◽  
Inductively Coupled ◽  
Left Behind ◽  
Process Route ◽  
Ultrafine Milling

Miners around Zimbabwe used to supply gold concentrates from sulphide flotation to the Kwekwe Roasting Plant (Zimbabwe) for toll treatment. The concentrates were roasted in Edward’s roasters and the calcine product was leached by cyanidation. Due to inefficient roasting, overall gold recoveries of 75–80% left behind a rich calcine leach residue at the Kwekwe Roasting Plant. The characterization performed to establish a potential process route involved several techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), fire assaying and inductively coupled plasma (ICP). Assays conducted on samples from the 350,000 tons tailings dam residue, created over the operational years, gave an average Au grade of 8.58 g/t and 12.54 g/t for Ag. The base metals assayed—0.11% Cu, 0.10% Pb, 0.17% Zn and 26.05% Fe. SiO2 (36.1%), Fe2O3 (36.9%), Mg3Si4O10 (OH)2 (8.9%), NaAlSi3O8 (6.9%), and Fe3O4 (6.4%)—were the major mineral phases in the cyanide leach residue. SEM gold scans on 24 polished sections showed only 2 discrete gold particles of less than 5 µm, with one partially liberated and associated with quartz, while the other was fully liberated. Therefore, the particulate gold in the calcine leach residue was negligible. It was deduced from the analysis after ultrafine milling (P80 < 5 µm) followed by cyanidation that 68.53% of the gold was sub-microscopic. Direct cyanidation using bottle roll resulted in only 2.33% of the total gold being leachable, indicating that the calcine leach residue was highly refractory. Diagnostic leaching by sequential use of acids in order of their strength resulted in HCl leachable phases (CaCO3, CaMg(CO3)2, PbS, Fe1-XS, and Fe2O3) freeing 4.2% of the total Au during subsequent cyanidation leach. H2SO4 leachable phases (Cu–Zn sulphides, labile FeS2) released an additional 26.57% during cyanidation, whereas HNO3 leachable phases (FeS2, FeAsS) released a further 20.98% of Au. After acid treatment and subsequent cyanidation, hot caustic leach of the residue followed by carbon in pulp resulted 4.43% of the total gold being eluted. Therefore, 4.43% of the total gold was surface bound. From the analysis after diagnostic acid leaching, it was deduced that a total of 54.08% of the gold was in the acid-leachable phase. Due to cost and environmental considerations, H2SO4 was selected for the evaluation of acid digestion as a pretreatment stage followed by cyanidation. Increasing the H2SO4 strength for the pretreatment of the calcine leach residue increased gold recoveries during cyanidation.

scholarly journals High-efficiency method for recycling lithium from spent LiFePO4 cathode

2020 ◽  
Vol 9 (1) ◽  
pp. 1586-1593
Author(s):  
Tingting Yan ◽  
Shengwen Zhong ◽  
Miaomiao Zhou ◽  
Xiaoming Guo ◽  
Jingwei Hu ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
High Efficiency ◽  
Optical Emission ◽  
Extraction Process ◽  
Emission Spectrometry ◽  
X Ray Diffraction ◽  
Inductively Coupled ◽  
Moisture Analysis ◽  
Lifepo4 Cathode ◽  
Solid Liquid

Abstract The extraction of Li from the spent LiFePO4 cathode is enhanced by the selective removal using interactions between HCl and NaClO to dissolve the Li+ ion while Fe and P are retained in the structure. Several parameters, including the effects of dosage and drop acceleration of HCl and NaClO, reaction time, reaction temperature, and solid–liquid ratio on lithium leaching, were tested. The Total yields of lithium can achieve 97% after extraction process that lithium is extracted from the precipitated mother liquor, using an appropriate extraction agent that is a mixture of P507 and TBP and NF. The method also significantly reduced the use of acid and alkali, and the economic benefit of recycling is improved. Changes in composition, morphology, and structure of the material in the dissolution process are characterized by inductively coupled plasma optical emission spectrometry, scanning electron microscope, X-ray diffraction, particle size distribution instrument, and moisture analysis.

scholarly journals Chemistry of Tropical Eucheumatoids: Potential for Food and Feed Applications

Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 804
Author(s):  
Andrea Ariano ◽  
Nadia Musco ◽  
Lorella Severino ◽  
Anna De Maio ◽  
Annabella Tramice ◽  
...  
Keyword(s):  
Chemical Analysis ◽  
Inductively Coupled Plasma ◽  
Mineral Content ◽  
Kappaphycus Alvarezii ◽  
Optical Emission ◽  
Essential Elements ◽  
Feed Additive ◽  
Inductively Coupled ◽  
Food And Feed

The use of seaweeds as additives in animal nutrition may be a valid option to traditional feed as they represent a rich source of minerals, carbohydrates and antioxidants. The aim of this study was to analyze the chemical composition and in vitro antioxidant capacity of two tropical eucheumatoids, Kappaphycus alvarezii and Kappaphycus striatus, in Malaysian wild offshore waters. The chemical analysis was performed via inductively coupled plasma–optical emission spectroscopy for evaluating the concentration of toxic (Cd, Pb, Hg, As) and essential elements (Mn, Fe, Cu, Ni, Zn, Se); NMR spectroscopy was used for carrageenans investigation. Furthermore, the soluble and fat-soluble antioxidant capacities were determined by FRAP, DPPH and ABTS assays. The chemical analysis revealed a higher content of trace elements in K. alvarezii as compared to K. striatus, and both exhibited a high mineral content. No significant differences in metal concentrations were found between the two species. Both samples showed a mixture of prevailing κ- and t-carrageenans. Finally, the levels of soluble and fat-soluble antioxidants in K. alvarezii were significantly higher than in K. striatus. Our findings suggest that K. alvarezii could be used as a potential feed additive because of its favorable chemical and nutritional features.

The Characteristic Evaluation of Hydroxyapatite Powders Synthesized from CaCO3 Refined from Oyster Shell and H3PO4

2006 ◽  
Vol 118 ◽  
pp. 639-644
Author(s):  
Hye Sung Kim ◽  
Su Chak Ryu
Keyword(s):  
Bone Density ◽  
Inductively Coupled Plasma ◽  
Oyster Shell ◽  
Atomic Emission ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Inductively Coupled ◽  
Infra Red ◽  
Ft Ir

Hydroxyapatite (Ca10(PO4)6(OH)2, HAp) powders is synthesized using the mixed powders of CaCO3 refined from oyster shells and phosphoric acid (H3PO4-98%, Daejung) as starting materials. The characteristic evaluation and chemical analysis of the synthesized powders is performed by X-ray diffraction (XRD), Fourier-transformed infra-red spectroscopy (FT-IR), and inductively-coupled plasma atomic emission spectroscopy (ICPAES). XRD analysis of synthetic powder by heat treatment at 1300°C for 2hrs shows only HAp peaks corresponding to stoichiometric HAp. It is confirmed by ICP-AES test that impurities such as Zn, In, Ti, Ba, Cd, Pb, and Mn, is not detected at all, but small amounts of Ti and Be is observed (0.099ppm Ti and 0.002ppm Ba). Variation of bone density is measured by giving medication of HAp powder with drinking water into human body continuously for three month. After the medication, the bone density is higher than the medication before. This means that HAp powder made from this process can be used as improver of bone density.

scholarly journals Characterization of Fly Ash Generated from Matla Power Station in Mpumalanga, South Africa

2012 ◽  
Vol 9 (4) ◽  
pp. 1788-1795 ◽  
Author(s):  
Olushola S. Ayanda ◽  
Olalekan S. Fatoki ◽  
Folahan A. Adekola ◽  
Bhekumusa J. Ximba
Keyword(s):  
Fly Ash ◽  
Inductively Coupled Plasma ◽  
Coal Fly Ash ◽  
Harmful Effect ◽  
Point Of Zero Charge ◽  
X Ray Diffraction ◽  
Power Station ◽  
X Ray ◽  
Inductively Coupled ◽  
Plasma Mass Spectrometry

In this study, fly ash was obtained from Matla power station and the physicochemical properties investigated. The fly ash was characterized by x-ray fluorescence, x-ray diffraction, scanning electron microscopy, and inductively coupled plasma mass spectrometry. Surface area, particle size, ash and carbon contents, pH, and point of zero charge were also measured. The results showed that the fly ash is alkaline and consists mainly of mullite (Al6Si2O13) and quartz (SiO2). Highly toxic metals As, Sb, Cd, Cr, and Pb as well as metals that are essential to health in trace amounts were also present. The storage and disposal of coal fly ash can thus lead to the release of leached metals into soils, surface and ground waters, find way into the ecological systems and then cause harmful effect to man and its environments.

Fabrication and repair of GaN nanorods by plasma etching with self-assembled nickel nanomasks

2021 ◽  
Author(s):  
Shiying Zhang ◽  
Lei Zhang ◽  
Yueyao Zhong ◽  
Guodong Wang ◽  
Qingjun Xu
Keyword(s):  
Inductively Coupled Plasma ◽  
Average Diameter ◽  
Etching Time ◽  
X Ray Diffraction ◽  
Plasma Etch ◽  
Inductively Coupled ◽  
Icp Etching ◽  
Self Organized ◽  
Gan Film ◽  
Koh Etching

High crystal quality GaN nanorod arrays were fabricated by inductively coupled plasma (ICP) etching using self-organized nickel (Ni) nano-islands mask on GaN film and subsequent repaired process including annealing in ammonia and KOH etching. The Ni nano-islands have been formed by rapid thermal annealing, whose density, shape, and dimensions were regulated by annealing temperature and Ni layer thickness. The structural and optical properties of the nanorods obtained from GaN epitaxial layers were comparatively studied by high-resolution X-ray diffraction (HRXRD), Raman spectroscopy and photoluminescence (PL). The results indicate that damage induced by plasma can be successfully healed by annealing in NH3 at 900 °C. The average diameter of the as-etched nanorod was effectively reduced and the plasma etch damage was removed after a wet treatment process in a KOH solution. It was found that the diameter of the GaN nanorod was continuously reduced and the PL intensity first increased, then reduced and finally increased as the KOH etching time sequentially increased.

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