scholarly journals Synchrotron Radiation XRD Investigation of the Fine Phase Transformation during Synthetic Chalcocite Acidic Ferric Sulfate Leaching

Minerals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 461
Author(s):  
Chaojun Fang ◽  
Shichao Yu ◽  
Xingxing Wang ◽  
Hongbo Zhao ◽  
Wenqing Qin ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Synchrotron Radiation ◽  
Sulfate Solution ◽  
Transformation Process ◽  
Ferric Sulfate ◽  
Dissolution Process ◽  
X Ray Diffraction ◽  
Leaching Process ◽  
Leaching Experiments ◽  
Two Stages

The fine phase transformation process of chalcocite (Cu2S) leaching in acidic ferric sulfate solution was studied by leaching experiments and synchrotron radiation X-ray diffraction (SRXRD) tests. The results showed that the dissolution process of chalcocite was divided into two stages. In the first stage, Cu2S was firstly transformed to Cu5FeS4 and Cu2−xS, then the galvanic effect between Cu5FeS4 and Cu2−xS accelerated the dissolution process of Cu1.8S → Cu1.6S → CuS, and finally Cu5FeS4 was also transformed to CuS. While in the second stage, CuS was transformed to elemental sulfur, which formed the passivation layer and inhibited the leaching of chalcocite. Specifically, Cu5FeS4 was detected during the chalcocite leaching process by SRXRD for the first time. This research is helpful for revealing the detailed leaching process of chalcocite.

scholarly journals Hydrogen-Induced Buckling of Pd Films Deposited on Various Substrates

2015 ◽  
Vol 365 ◽  
pp. 55-62 ◽  
Author(s):  
Marián Vlček ◽  
František Lukáč ◽  
Martin Vlach ◽  
Ivan Procházka ◽  
Stefan Wagner ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Phase Transitions ◽  
Synchrotron Radiation ◽  
Deposition Temperature ◽  
Model System ◽  
Lattice Expansion ◽  
X Ray Diffraction ◽  
Palladium Hydride ◽  
X Ray ◽  
Temperature Lattice

A Pd-H system is a model system suitable for studying interactions of hydrogen with metals. In the present work, we studied hydrogen-induced buckling of thin Pd films deposited on various substrates with different bonding strengths (sapphire, glimmer) and also the effect of deposition temperature. Lattice expansion and phase transitions were investigated by X-ray diffraction of synchrotron radiation. The influence of the substrate and microstructure of the film on the buckling process and phase transformation to palladium hydride are discussed.

The effect of TiO2 addition on the thermal behavior of sol-gel derived β-spodumene powders

1999 ◽  
Vol 14 (1) ◽  
pp. 97-102 ◽  
Author(s):  
Moo-Chin Wang
Keyword(s):  
Phase Transformation ◽  
Sol Gel ◽  
Transformation Process ◽  
X Ray Diffraction ◽  
Crystallization Sequence ◽  
X Ray ◽  
Transmission Electron ◽  
Tio2 Addition ◽  
A Minor ◽  
Increasing Temperature

The effect of TiO2 addition on the crystallization and phase transformation process in Li2O · Al2O3 · 4SiO2 gels with various TiO2 contents was investigated using differential thermal analysis, x-ray diffraction, and transmission electron microscopy. The activation energy increased from 98.2 to 184.6 kcal/mol as the TiO2 content rose from 2.0 to 8.0 wt. %. The crystallization sequence and phase transformation were similar in LAS gels with various wt.% of TiO2 additions, except in the case of a 2.0 wt.% TiO2 content. During calcination from 800 to 1200 °C, crystallization of the β-spodumene phase progressed with increasing temperature, and a minor crystalline phase, rutile, also appeared.

Thermal phase transformation of In2Se3 nanowires studied by in situ synchrotron radiation X-ray diffraction

2011 ◽  
Vol 21 (19) ◽  
pp. 6944 ◽  
Author(s):  
Yang Li ◽  
Jing Gao ◽  
Qinliang Li ◽  
Mingfa Peng ◽  
Xuhui Sun ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Synchrotron Radiation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermal Phase

scholarly journals Phase Transformation Kinetics of High Nb-TiAl Alloy during Continuous Heating

2021 ◽  
Vol 2133 (1) ◽  
pp. 012029
Author(s):  
Ying Li ◽  
Lian Zhou ◽  
Junpin Lin ◽  
Hui Chang ◽  
Jianglei Fan ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Tial Alloy ◽  
Transformation Process ◽  
Continuous Heating ◽  
Heating Process ◽  
Transformation Kinetics ◽  
Transformation Behavior ◽  
Α Phase ◽  
Two Stages ◽  
Kinetics Of

Abstract In this work, the phase transformation behavior of Ti-45Al-8.5Nb-(W, B, Y) alloy during continuous heating was investigated using dilatometer and optical microscopy. Results indicated that the phase transformation process of high Nb-TiAl alloy during continuous heating included two stages: ordered α2 → disorder α and tetragonal γ → hexagonal α. According to the microstructure analysis, the initial α2/γ lamellar structure transformed into the massive γ phase and α phase (retained as α2) during the heating process. The activation energy of α2 → α and γ → α was 989.65 kJ/mol and 995.30 kJ/mol, respectively. Moreover, the lower the heating rate was, the faster the phase transformation reached the equilibrium state.

Effect of Secondary Phases Formation in the Leaching of UO2 Under Simulated Radiolytic Products

1994 ◽  
Vol 353 ◽  
Author(s):  
P. Díaz-Arocas ◽  
J. Quinoñes ◽  
C. Maffiotte ◽  
J. Serrano ◽  
J. Garcia ◽  
...  
Keyword(s):  
Secondary Phase ◽  
Point Of View ◽  
Spent Fuel ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ph Values ◽  
Leaching Process ◽  
Leaching Experiments ◽  
Solid Phases

AbstractThe leaching of the spent fuel matrix (UO2) is function of the radiolytic products formation. The effect of each radioiytic product on the leaching process is not totally understood. In the literature, the influence of H2O2 on the dissolution process is described from the qualitative point of view, and most of the studies were performed for pH values from 8 to 12. In this paper we report on the effect of the H2O2 in the leaching process of UO2 by dissolution experiments at various H2O2 concentrations. Also, it was tested the influence of S/V ratio (surface area exposed to the leaching media) on the UO2 leaching and secondary phases formation. It was identified the formation of secondary phases on the UO2 surface. Solid phases characterization was carried out by x-ray Photoelectron Spectrometry (XPS), x-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) techniques. By XPS studies the secondary phase formed corresponded to a U(VI) phase. By XRD analyses the solid was identified as studtite, UO4 - 4H2O, (card n0 16–206, [I]). A comparison of the U(VI) phases formed in spent fuel and UO, leaching experiments in various media has been carried out.

Sign in / Sign up

Export Citation Format

Share Document