Thermodynamic Analysis of the Reduction of WO3 by Al Powder

2012 ◽  
Vol 581-582 ◽  
pp. 616-619
Author(s):  
Lian Ping Chen ◽  
Yuan Hong Gao ◽  
Bai Tao Su
Keyword(s):  
Gibbs Energy ◽  
Ball Milling ◽  
Thermodynamic Analysis ◽  
Room Temperature ◽  
Tungsten Powder ◽  
Tungsten Oxides ◽  
Al Powder

Hydrogen is widely used to prepare tungsten from tungsten oxides. Such a gas is combustible and strict measures must be taken. However, assisted by Mg or Li3N, tungsten can be prepared through the ball milling at room temperature. The reduction of WO3by Al powder is investigated thermodynamically. Simulations on the loss of Gibbs energy of these hypothetic reactions reveal that the reduction of WO3and WO2(OH)2(or H2WO4) is feasible when Al powder is used; and it is more difficult to generate the intermediate tungsten oxides such as WO2, WO2.72and WO2.9. In addition, it is better to prepare tungsten powder in vacuum containers in view of economy.

Thermodynamic Analysis of the Reduction of Na2WO4 through the Mechanochemical Reaction

2011 ◽  
Vol 399-401 ◽  
pp. 85-89 ◽  
Author(s):  
Yuan Hong Gao ◽  
Jian Gao Yang ◽  
Bai Tao Su ◽  
Lian Ping Chen
Keyword(s):  
Gibbs Energy ◽  
Ball Milling ◽  
Thermodynamic Analysis ◽  
Room Temperature ◽  
Mechanochemical Reaction ◽  
Tungsten Oxides ◽  
Al Powder

Hydrogen is widely used to prepare tungsten from tungsten oxides. Such a gas is combustible and strict measures must be taken. However, assisted by Mg or Li3N, tungsten can be prepared through the ball milling at room temperature. Al powder is supposed to be one of the proper reducers. Simulations on the loss of Gibbs energy of these reactions have been investigated. Studies reveal that the reduction of Na2WO4 is feasible when reducers such as Al, Mg and Li3N are used; and the intermediate tungsten oxides such as WO2, WO2.72 and WO2.9 can be seldom generated. In addition, the calculation favors that NH3 does not react with Na2WO4 or WO3 theoretically.

Influence of ball milling duration on the morphology, features of the structural-phase state and microhardness of 3Ni-Al powder mixture

2021 ◽  
Author(s):  
Ivan A. Ditenberg ◽  
Denis A. Osipov ◽  
Michail A. Korchagin ◽  
Ivan V. Smirnov ◽  
Konstantin V. Grinyaev ◽  
...  
Keyword(s):  
Ball Milling ◽  
Powder Mixture ◽  
Phase State ◽  
Structural Phase ◽  
Structural Phase State ◽  
Milling Duration ◽  
Al Powder

The ball to powder ratio (BPR) dependent morphology and microstructure of tungsten powder refined by ball milling

2018 ◽  
Vol 339 ◽  
pp. 256-263 ◽  
Author(s):  
Z.M. Wu ◽  
Y.X. Liang ◽  
Y. Fan ◽  
P.P. Wang ◽  
J.L. Du ◽  
...  
Keyword(s):  
Ball Milling ◽  
Tungsten Powder

Solid-state mechanical alloying of plastic crystals

1997 ◽  
Vol 12 (12) ◽  
pp. 3254-3259 ◽  
Author(s):  
J. Font ◽  
J. Muntasell ◽  
E. Cesari ◽  
J. Pons
Keyword(s):  
Solid State ◽  
Binary System ◽  
Mechanical Alloying ◽  
Ball Milling ◽  
Room Temperature ◽  
Binary Systems ◽  
Solid Phase ◽  
Stable State ◽  
Plastic Crystals ◽  
Dsc Measurements

Ball milling has been used as a solid-state mechanical alloying technique in two binary systems of plastic crystals: neopentylglycol/pentaglycerin (NPG/PG), showing a partial solubility in the ordered phase, and 2-amino-2-methyl-1,3-propanediol/tris(hydroxymethyl) (AMP/TRIS) whose immiscibility in this ordered solid phase is almost total. For the AMP/TRIS system the stable state at room temperature was reached by milling. Contrarily, for NPG/PG, DSC measurements reveal that an annealing period is required after milling. These results have been compared with those of the pentaglycerin/pentaerythritol (PG/PE) binary system, previously studied, whose miscibility is total at room temperature.

Nanostructure formation mechanism during in-situ consolidation of copper by room-temperature ball milling

2015 ◽  
Vol 65 ◽  
pp. 1083-1090 ◽  
Author(s):  
M. Samadi Khoshkhoo ◽  
S. Scudino ◽  
T. Gemming ◽  
J. Thomas ◽  
J. Freudenberger ◽  
...  
Keyword(s):  
Ball Milling ◽  
Formation Mechanism ◽  
Room Temperature ◽  
Nanostructure Formation

scholarly journals Forming pressure effect on microstructure and mechanical properties of nanocrystalline aluminum synthesized by inert gas condensation

2019 ◽  
Vol 79 ◽  
pp. 02002
Author(s):  
Shangshu Wu ◽  
Zhou Yu ◽  
Junjie Wang ◽  
Hanxin Zhang ◽  
Chaoqun Pei ◽  
...  
Keyword(s):  
Room Temperature ◽  
High Vacuum ◽  
Inert Gas ◽  
Helium Atmosphere ◽  
Gas Condensation ◽  
Inert Gas Condensation ◽  
In Situ Forming ◽  
Nanocrystalline Aluminum ◽  
Al Powder

The preparation of nanocrystalline aluminum (NC Al) was conducted in two steps. After the NC Al powder was synthesized by an Inert gas condensation (IGC) method in a helium atmosphere of 500 Pa, the NC Al powder was in-situ compacted into a pellet with a 10 mm diameter and 250 μm-300 μm thickness in a high vacuum (10-6 Pa-10-7 Pa) at room temperature. The NC Al samples were not exposed to air during the entire process. After the pressure reached 6 GPa, the relative density could reach 99.83%. The results showed that the grain size decreased with the increased of in-situ forming pressure. The NC Al samples present obvious ductile fracture, and the tensile properties were greatly changed with the increase of forming pressure.

Synthesis of Al2O3-Ni3Al Cermets by Room-Temperature Ball Milling of Al, Ni and Al2O3 Mixtures

2006 ◽  
pp. 123-128
Author(s):  
E. Rocha-Rangel ◽  
M.S. Moreno-Guerrero ◽  
A. Velásquez-Naranjo ◽  
E. Refugio-García
Keyword(s):  
Ball Milling ◽  
Room Temperature

scholarly journals Quantum Chemical Calculation of Reactions Involving C20, C60, Graphene and H2O

2019 ◽  
Vol 18 (03n04) ◽  
pp. 1940008 ◽  
Author(s):  
N. A. Poklonski ◽  
S. V. Ratkevich ◽  
S. A. Vyrko ◽  
A. T. Vlassov ◽  
Nguyen Ngoc Hieu
Keyword(s):  
Gibbs Energy ◽  
Chemical Reactions ◽  
Atmospheric Pressure ◽  
Room Temperature ◽  
Hydrogen Release ◽  
Graphene Sheets ◽  
Water Molecules ◽  
Hydroxyl Groups ◽  
Chemical Calculation ◽  
Assisted Decomposition

Calculations of chemical reactions between C20, C60, hydrogen and water molecules are carried out using the PM3 method. Reactions with a hydrogen release at room temperature and atmospheric pressure are identified by the Gibbs energy change. The hydrogen release can be raised by increasing the number of water molecules in chlorine-assisted decomposition of fullerenes. Calculations of the Gibbs energy of chemical reactions involving water molecules between two parallel curved graphene sheets are carried out using DFT with the functional UB3LYP. During pumping between plates of an electric capacitor designed from curved graphene sheets, the water vapor with the assistance of external illumination is enriched by electrically neutral hydroxyl groups (OH)0.

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