Mineralogical Characterization and Acid Pretreatment of a Gold Calcine Leach Residue

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.

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Dissolution of Black Copper Oxides from a Leaching Residue

Metals ◽

10.3390/met10081012 ◽

2020 ◽

Vol 10 (8) ◽

pp. 1012

Author(s):

Víctor Quezada ◽

Oscar Benavente ◽

Cristopher Beltrán ◽

Danny Díaz ◽

Evelyn Melo ◽

...

Keyword(s):

Inductively Coupled Plasma ◽

Acid Leaching ◽

Atomic Emission ◽

Copper Oxides ◽

Leach Residue ◽

Copper Extraction ◽

Original Sample ◽

Hydrogen Electrode ◽

Inductively Coupled ◽

Leaching Residue

This article presents the behavior of black copper minerals in reducing acid leaching using FeSO4 as reducing agent. The original sample, which was a blend of green and black copper minerals, was treated first by an oxidizing acid leach using O3 to dissolve the soluble phase (green copper oxides). The residue (mainly black copper) was evaluated by agitated leaching under three different solution potentials, with respect to the standard hydrogen electrode (SHE) (450, 500, and 600 mV (SHE)) at 25 °C. The original sample and the leach residue were characterized by scanning electron microscope (SEM) and inductively coupled plasma atomic emission spectroscopy (ICP-AES). The O3 leach residue was 1.43% copper, with 50% of the insoluble phase associated with copper pitch, copper limonites, and unreacted chrysocolla. The results of leaching using FeSO4 demonstrate that it is possible to obtain 90% copper extraction using a solution with a potential of 450 mV, while leaching at 600 mV resulted in 65% copper extraction. Acid consumption was 40 kg/t in the test at 450 mV, followed by 30 kg/t in the 500 mV test, and finally 25 kg/t in the 600 mV test, showing that reactivity decreases with increased solution potential. The results show that retreatment of a leaching residue is possible, considering the presence of copper pitch, copper limonites, and chrysocolla as the main copper contributing minerals. Modeling of copper extraction with nonlinear regression is proposed. The retreatment of residues resulting from conventional acid leaching can be an alternative to make use of the treatment capacity of hydrometallurgical plants.

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Experimental Research on Preparation Technics of High-Purity Quartz Material

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.748.17 ◽

2017 ◽

Vol 748 ◽

pp. 17-21

Author(s):

Qi Dong Zhang ◽

Xiao Li Li ◽

Yong Sheng Song ◽

Gui Ying Zhou

Keyword(s):

High Purity ◽

Inductively Coupled Plasma ◽

Acid Leaching ◽

Mineral Surfaces ◽

X Ray Diffraction ◽

Magnetic Minerals ◽

Natural Quartz ◽

Inductively Coupled ◽

Magnetic Concentration ◽

Quartz Sands

In order to make the natural quartz up to the standard of high purity quartz sands, quartz ores are processed to obtain high purity quartz sands by the purifying technologies which include grinding, high-intensity magnetic concentration, flotation and acid leaching, washed by deionized water. The phase, morphology and composition of the prepared quzrtz sands were determined by X-ray diffraction, scanning electron microscope and inductively coupled plasma spectrometers.The results show that impurity minerals adsorb onto the quartz mineral surfaces. Magnetic minerals were removed by magnetic concentration experiment, while other impurities were removed by flotation and acid leaching experiments and they show excellent cleaning effect. Finally a high purity quartz product which contains higher than 99.95% SiO2, less than 0.003% Fe2O3, and less than 0.01% Al2O3 was obtained.

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

Environmental Sciences Proceedings ◽

10.3390/iecms2021-09352 ◽

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.

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High-efficiency method for recycling lithium from spent LiFePO4 cathode

Nanotechnology Reviews ◽

10.1515/ntrev-2020-0119 ◽

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.

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

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.118.639 ◽

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.

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

E-Journal of Chemistry ◽

10.1155/2012/451801 ◽

2012 ◽

Vol 9 (4) ◽

pp. 1788-1795 ◽

Cited By ~ 13

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.

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

The European Physical Journal Applied Physics ◽

10.1051/epjap/2021210002 ◽

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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Preliminary Archaeopetrological Study of the Lithic Industry From the l’Hort de la Boquera Rock Shelter (Margalef de Montsant, Tarragona, Spain): Applying Mineralogical and Geochemical Techniques

Archaeologia Polona ◽

10.23858/apa56.2018.002 ◽

2018 ◽

Vol 56 ◽

pp. 23-33

Author(s):

Mar Rey-Solé ◽

Maria Pilar García-Argüelles ◽

Jordi Nadal ◽

Xavier Mangado ◽

Anders Scherstén ◽

...

Keyword(s):

Inductively Coupled Plasma ◽

Raw Materials ◽

Raw Material ◽

Stone Tool ◽

Petrographic Analysis ◽

X Ray Diffraction ◽

Inductively Coupled ◽

Study Results ◽

Lithic Industry ◽

Plasma Mass Spectrometry

The l’Hort de la Boquera site is located in the northeastern part of Iberia and its stone tool assemblage includes up to 25,000 flint artefacts. This is the first approach to the analysis of the raw material through an archaeopetrological study. Results were obtained by use of mineralogi¬cal techniques: macroscopic and petrographic analysis, Scanning Electronic Microscopy (SEM), Micro-Raman and X-Ray diffraction (XRD); additionally, Laser Ablation Inductively Coupled Plasma Mass Spectrometry was applied. It has been possible to discriminate at least four flint categories, the ‘Evaporitic flint type’ (with two local subvarieties – ‘Common evaporitic’ and ‘Garnet’ varieties) that comes from local outcrops of the Ulldemolins Complex, and two flint types that had their origin further afield: the ‘Charophyta flint type’ (coming from the Torrente de Cinca Unit) and the ‘Dark flint type’ (from the La Serra Llarga Formation).These results make this study the most comprehensive analysis of raw materials that has been carried out in the area so far

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A study concerning the pretreatment of CNTs and its influence on the performance of NIB/CNTs amorphous catalyst

Journal of the Serbian Chemical Society ◽

10.2298/jsc0611153h ◽

2006 ◽

Vol 71 (11) ◽

pp. 1153-1160 ◽

Cited By ~ 6

Author(s):

Chang Hu-Yuan ◽

Feng Li ◽

Li. Hua ◽

Bin Zhang

Keyword(s):

Selective Hydrogenation ◽

Inductively Coupled Plasma ◽

Acid Treatment ◽

Chemical Reduction ◽

X Ray Diffraction ◽

Chemical Reduction Method ◽

X Ray ◽

Inductively Coupled ◽

Selective Hydrogenation Of Acetylene ◽

Transmission Electron

As prepared carbon nanotubes were pretreated with nitric acid (CNTs-HNO3) or ammonia (CNTs-NH3). Fourier transform infrared spectroscopy (FTIR) measurements showed that the surface of the nanotubes was functionalized with carboxylic and hydroxyl functional groups after the acid treatment and that basic groups containing nitrogen, such as N-H and C-N, were introduced to the surface of the nanotubes after the ammonia treatment. X-Ray diffraction analysis implied that the nickel residue in the CNTs was effectively removed by acid treatment. However, the nickel residue was only partially eliminated by ammonia pretreatment. NiB amorphous catalysts supported on CNTs-HNO3 and CNTs-NH3 were prepared by the impregnation-chemical reduction method and characterized by transmission electron microscopy (TEM), as well as inductively coupled plasma (ICP) spectroscopy and studied in the selective hydrogenation of acetylene. TEM measurements showed that a high density NiB particles of about 9 nm were homogeneously dispersed on the CNTs-NH3. However, NiB particles (13-23 nm)with amean size of 16 nm were scattered on the CNTs-HNO3.As a result, the activity and selectivity of NiB/CNTs-NH3 were higher than those of NiB/CNTs-HNO3 in the selective hydrogenation of acetylene.

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Comparing the Physico-Chemical Characteristics of Formulated and Marketed Yashada Bhasma

Research Journal of Pharmacy and Technology ◽

10.52711/0974-360x.2021.01105 ◽

2021 ◽

pp. 6392-6398

Author(s):

Nitu Bhatnagar ◽

Avani Pareek

Keyword(s):

Inductively Coupled Plasma ◽

Thermo Gravimetric Analysis ◽

Human Consumption ◽

Chemical Characteristics ◽

Gravimetric Analysis ◽

X Ray Diffraction ◽

X Ray ◽

Inductively Coupled ◽

Physico Chemical ◽

The Difference

The present study is aimed to observe the difference in the Physico-Chemical characteristics of the marketed and formulated bhasma samples through X-Ray Diffraction analysis (XRD), Dynamic Light Scattering (DLS), Zeta potential, Thermo-Gravimetric analysis (TGA), Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray analysis (EDAX), apart from organoleptic methods. Inductively Coupled Plasma Mass Spectroscopy (ICPMS) analysis was also done to observe the presence of trace and heavy metals so that the safety of all these samples could be ensured. XRD shows variation in oxide nature of zinc as well crystallite size in all bhasma samples. DLS and SEM results show difference in particle size of marketed bhasma samples as compared to formulated Yashada bhasma. EDAX and ICPMS also confirm the alteration in elemental composition of all these bhasma samples. Thus, it can be concluded that these ayurvedic medicines should be prepared strictly using the formulation methods as mentioned in the Ayurvedic texts. This will help the prepared products to adopt the inherent quality of the ancient system of medicine, which shall be useful and devoid of any side effects for human consumption.

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