scholarly journals A Novel Technology for Recovery and Separation of Vanadium and Chromium from Vanadium-Chromium Reducing Residue

2019 ◽  
Vol 10 (1) ◽  
pp. 198 ◽  
Author(s):  
Hao Peng ◽  
Liu Yang ◽  
Ya Chen ◽  
Jing Guo
Keyword(s):  
Activation Energy ◽  
Apparent Activation Energy ◽  
Chemical Reaction ◽  
Selective Adsorption ◽  
Surface Chemical ◽  
Shrink Core Model ◽  
Surface Chemical Reaction ◽  
Novel Technology ◽  
Efficient Recovery ◽  
Almost All

This paper was to develop an efficient process for efficient recovery and separation of vanadium and chromium. The vanadium-chromium reducing residue was conducted by oxidation acidic leaching with MnO2, followed by selective adsorption of vanadium and precipitation of chromium, respectively. The results showed that 97.93% vanadium was leached out and then adsorbed by melamine at pH 1.8 at 90 °C for 60 min. Almost all chromium was leached out and efficiently recovered as Cr2O3. The leaching process was mainly controlled by surface chemical reaction, and its kinetic behaviors fitted well with the shrink core model. The apparent activation energy for vanadium and chromium leaching out wascalculated as 19.93 kJ·mol−1 and 21.26 kJ·mol−1, respectively.

scholarly journals Leaching Kinetics of Selenium, Tellurium and Silver from Copper Anode Slime by Sulfuric Acid Leaching in the Presence of Manganese(IV) Oxide and Graphite

2021 ◽  
Vol 3 (1) ◽  
pp. 16
Author(s):  
Kurniawan Kurniawan ◽  
Jae-chun Lee ◽  
Jonghyun Kim ◽  
Rina Kim ◽  
Sookyung Kim
Keyword(s):  
Activation Energy ◽  
Sulfuric Acid ◽  
Chemical Reaction ◽  
Acid Leaching ◽  
Anode Slime ◽  
Surface Chemical ◽  
Copper Anode ◽  
Surface Chemical Reaction ◽  
Sulfuric Acid Leaching ◽  
Copper Anode Slime

Sulfuric acid leaching of copper anode slime (CAS) in the presence of manganese(IV) oxide (MnO2) and graphite was investigated for Se, Te and Ag recovery. The study reveals that the leaching of Se, Te and Ag was facilitated by the galvanic interaction with MnO2, and graphite played the role of a catalyst. The leaching process could yield 81.9% Se, 90.8% Te, and 80.7% Ag leaching efficiency when the conditions were maintained as 500 rpm, 2.0 M H2SO4, 0.8/0.8/1 MnO2/graphite/CAS, and 90 °C temperature. The kinetic study showed that Se leaching followed the surface chemical reaction at all the tested temperature range (25–90 °C) with the activation energy of 27.7 kJ/mol. Te and Ag leaching at temperature 25–50 °C followed the mixed and surface chemical reaction models, respectively, and changed to fit the diffusion and mixed control models, respectively, in the temperature range 60–90 °C with the corresponding activation energy of 17.8 and 12.2 kJ/mol.

scholarly journals Fluoride Leaching of Titanium from Ti-Bearing Electric Furnace Slag in [NH4+]-[F−] Solution

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1176
Author(s):  
Fuqiang Zheng ◽  
Yufeng Guo ◽  
Feng Chen ◽  
Shuai Wang ◽  
Jinlai Zhang ◽  
...  
Keyword(s):  
Activation Energy ◽  
Electric Furnace ◽  
Kinetic Equations ◽  
Surface Chemical ◽  
Leaching Rate ◽  
Surface Chemical Reaction ◽  
Mechanism And Kinetics ◽  
Semi Empirical ◽  
Kinetics Of ◽  
Furnace Slag

The effects of F− concentration, leaching temperature, and time on the Ti leaching from Ti-bearing electric furnace slag (TEFS) by [NH4+]-[F−] solution leaching process was investigated to reveal the leaching mechanism and kinetics of titanium. The results indicated that the Ti leaching rate obviously increased with the increase of leaching temperature and F− concentration. The kinetic equation of Ti leaching was obtained, and the activation energy was 52.30 kJ/mol. The fitting results of kinetic equations and calculated values of activation energy both indicated that the leaching rate of TEFS was controlled by surface chemical reaction. The semi-empirical kinetics equation was consistent with the real experimental results, with a correlation coefficient (R2) of 0.996. The Ti leaching rate reached 92.83% after leaching at 90 °C for 20 min with F− concentration of 14 mol/L and [NH4+]/[F−] ratio of 0.4. The leaching rates of Si, Fe, V, Mn, and Cr were 94.03%, 7.24%, 5.36%, 4.54%, and 1.73%, respectively. The Ca, Mg, and Al elements were converted to (NH4)3AlF6 and CaMg2Al2F12 in the residue, which can transform into stable oxides and fluorides after pyro-hydrolyzing and calcinating.

scholarly journals Pattern formation in a surface chemical reaction with global delayed feedback

2001 ◽  
Vol 63 (6) ◽  
Author(s):  
M. Bertram ◽  
A. S. Mikhailov
Keyword(s):  
Pattern Formation ◽  
Chemical Reaction ◽  
Delayed Feedback ◽  
Surface Chemical ◽  
Surface Chemical Reaction

Surface chemical reaction of laser ablated aluminum sample for detonation initiation

2011 ◽  
Vol 109 (9) ◽  
pp. 093510 ◽  
Author(s):  
Chang-hwan Kim ◽  
Jack J. Yoh
Keyword(s):  
Chemical Reaction ◽  
Detonation Initiation ◽  
Surface Chemical ◽  
Surface Chemical Reaction ◽  
Aluminum Sample

Influence of the surface deformability on marangoni instability in a liquid layer with surface chemical reaction

1992 ◽  
Vol 148 (1) ◽  
pp. 42-55 ◽  
Author(s):  
Zhasmina Dimitrova Kozhoukharova ◽  
Slavcho Georgiev Slavchev
Keyword(s):  
Chemical Reaction ◽  
Liquid Layer ◽  
Surface Chemical ◽  
Surface Chemical Reaction ◽  
Marangoni Instability

Large Etch Rate Enhancement by NO-Induced Surface Chemical Reaction during Chemical Dry Etching of Silicon Oxide in F[sub 2] Remote Plasmas

2007 ◽  
Vol 154 (4) ◽  
pp. D267 ◽  
Author(s):  
Y. B. Yun ◽  
D. J. Kim ◽  
S. M. Park ◽  
N.-E. Lee ◽  
K. S. Kim ◽  
...  
Keyword(s):  
Chemical Reaction ◽  
Etch Rate ◽  
Silicon Oxide ◽  
Dry Etching ◽  
Surface Chemical ◽  
Surface Chemical Reaction ◽  
Rate Enhancement
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