scholarly journals Mechanism, Thermodynamics and Kinetics of Rutile Leaching Process by Sulfuric Acid Reactions

Processes ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 640 ◽  
Author(s):  
Anastasiia V. Dubenko ◽  
Mykola V. Nikolenko ◽  
Eugene V. Aksenenko ◽  
Andrii Kostyniuk ◽  
Blaž Likozar
Keyword(s):  
Sulfuric Acid ◽  
Raw Materials ◽  
Bifunctional Catalyst ◽  
Chemical Transformations ◽  
Phase Component ◽  
Fluoride Ions ◽  
Thermodynamics And Kinetics ◽  
Lattice Geometry ◽  
Kinetics Of Dissolution ◽  
Kinetics Of

Rutile decomposition by sulfuric acid, including the formation of two salts, Ti(SO4)2/TiOSO4, is thermodynamically modelled. It is shown that TiO2 can spontaneously dissolve in H2SO4 solutions. However, titania is considered as an inert (ballast) phase component of titanium-containing raw materials due to the decelerated separate nature of such chemical transformations. It is concluded that the hampered related kinetics of dissolution can be attributed to the lability of Ti(IV) cations/the specific engineered features of the hierarchical crystalline structure. It is suggested that the breaking of Ti–O–Ti bonds without additional mechanical strains in crystal lattice geometry becomes more advantageous when smaller negative anions/fluoride ions can be used. The analysis of sulfate-fluoride extraction leaching of titanium confirmed that a decrease in the Gibbs energy in the presence of F occurs. It is indicated by kinetic research studies that the addition of corrosive sodium reagent (NaF) reduces the activation by 45 kJ/mol, which results in intensification. A mechanism is proposed for the interactions involving the Ti–O–Ti cleavage on the surface/the H2SO4-induced Ti dioxide degradation on the sites of defects. Moreover, F acts as a homogeneous/heterogeneous bifunctional catalyst.

Kinetics of Dissolution of Limestone Slurries in Sulfuric Acid

1985 ◽  
Vol 57 (10) ◽  
pp. 882-883
Author(s):  
Mario Díaz ◽  
Laureano Fonseca ◽  
José Coca
Keyword(s):  
Sulfuric Acid ◽  
Kinetics Of Dissolution ◽  
Kinetics Of

scholarly journals Kinetics of Dissolution of Copper-Zinc Alloy in Nitric-Sulfuric Acid Solutions

2019 ◽  
pp. 214-221
Author(s):  
Natalya М. Vostrikova ◽  
Elena D. Kravtsova
Keyword(s):  
Sulfuric Acid ◽  
Noble Metals ◽  
Chemical Processes ◽  
Zinc Alloy ◽  
Acid Solutions ◽  
Copper Zinc ◽  
Kinetics Of Dissolution ◽  
Sulfuric Acid Solutions ◽  
Kinetics Of ◽  
Base Substrate

Studies were carried out on the dissolution of a copper-zinc alloy imitating a base substrate of an electron scrap containing noble metals in nitric-sulfuric acid solutions. A mathematical model is obtained that allows calculating the rate of copper and zinc transition to nitric-sulfuric solutions by varying the concentration of H+ ions from 1 to 4 g-ion / dm3 and NO3 – ions from 0,5 to 1,0 g-ion / dm3. In the range of concentrations of H+ and NO3 – ions studied, the maximum rate of copper transition into the solution is 6,5·10–5, and zinc is 4,5·10–5 kg / m2s. The equation of regression allowing to carry out a choice of conditions for proceeding with necessary speed of the chemical processes taking place in metallurgical practice is presented

scholarly journals Technological Processes of Receiving Metals in The Conditions of Moderate Temperatures

2019 ◽  
Vol 8 (12) ◽  
pp. 1826-1828 ◽  
Keyword(s):  
Melting Point ◽  
Great Influence ◽  
Chemical Transformations ◽  
Moisture Evaporation ◽  
Thermodynamics And Kinetics ◽  
Recovery Processes ◽  
Metallurgical Furnaces ◽  
Physical And Chemical ◽  
Kinetics Of

In article questions of physical and chemical transformations of starting materials at their heating in metallurgical furnaces are considered. It first of all moisture evaporation, dissociation of the difficult connections, oxidizing and recovery processes, formation of fusible eutectics. An attention to interaction of oxides and sulfides with formation of the new connections having smaller melting point than initial components. It is shown that these connections are the beginning of formation of melts and actually define thermodynamics and kinetics of all process. Transition of firm components of fusion mixture to flux has a great influence on technological indicators of smelting of metal. Considering it, the research on establishment was conducted began courses of these of reaction and a possibility of determination of this criterion without direct the made experiments

Thermodynamics and kinetics of thorium extraction from sulfuric acid medium by HEH(EHP)

2014 ◽  
Vol 150 ◽  
pp. 167-172 ◽  
Author(s):  
Liangshi Wang ◽  
Ying Yu ◽  
Xiaowei Huang ◽  
Feng Hu ◽  
Jinshi Dong ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Acid Medium ◽  
Thermodynamics And Kinetics ◽  
Sulfuric Acid Medium ◽  
Kinetics Of

scholarly journals Modeling the thermodynamics and kinetics of sulfuric acid-dimethylamine-water nanoparticle growth in the CLOUD chamber

2016 ◽  
Vol 50 (10) ◽  
pp. 1017-1032 ◽  
Author(s):  
L. Ahlm ◽  
T. Yli-Juuti ◽  
S. Schobesberger ◽  
A. P. Praplan ◽  
J. Kim ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Cloud Chamber ◽  
Nanoparticle Growth ◽  
Thermodynamics And Kinetics ◽  
Kinetics Of

Thermodynamics and kinetics of indole oligomerization in 0.5 mol L−1 aqueous sulfuric acid: evaluation of some temperature-dependant parameters

2014 ◽  
Vol 27 (8) ◽  
pp. 680-689 ◽  
Author(s):  
Giuseppe Quartarone ◽  
Andrea Pietropolli Charmet ◽  
Lucio Ronchin ◽  
Claudio Tortato ◽  
Andrea Vavasori
Keyword(s):  
Sulfuric Acid ◽  
Thermodynamics And Kinetics ◽  
Aqueous Sulfuric Acid ◽  
Temperature Dependant ◽  
Kinetics Of

Irradiation behavior of pyrolytic silicon carbide

1983 ◽  
Vol 41 ◽  
pp. 72-73
Author(s):  
R. J. Lauf
Keyword(s):  
Silicon Carbide ◽  
Fission Products ◽  
Thermodynamics And Kinetics ◽  
Neutron Fluences ◽  
Fuel Particles ◽  
Sic Coatings ◽  
Irradiation Behavior ◽  
Kinetics Of ◽  
Htgr Fuel

Fuel particles for the High-Temperature Gas-Cooled Reactor (HTGR) contain a layer of pyrolytic silicon carbide to act as a miniature pressure vessel and primary fission product barrier. Optimization of the SiC with respect to fuel performance involves four areas of study: (a) characterization of as-deposited SiC coatings; (b) thermodynamics and kinetics of chemical reactions between SiC and fission products; (c) irradiation behavior of SiC in the absence of fission products; and (d) combined effects of irradiation and fission products. This paper reports the behavior of SiC deposited on inert microspheres and irradiated to fast neutron fluences typical of HTGR fuel at end-of-life.

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