Study on Pressure-Cyanide Dissolution of Metal Palladium Powder

2012 ◽  
Vol 554-556 ◽  
pp. 695-699
Author(s):  
L. Yan ◽  
J.S. Zhao
Keyword(s):  
Oxygen Pressure ◽  
Room Temperature ◽  
Research Study ◽  
Elevated Temperatures ◽  
Rotation Speed ◽  
Sodium Cyanide ◽  
Platinum Group Metals ◽  
Maximum Value ◽  
Palladium Powder ◽  
Increasing Temperature

A research study has been undertaken to develop the fundamentals of a method for the direct dissolution of Metal Palladium. At room temperature and pressures, the reaction between sodium cyanide and platinum group metals (PGMs) does not occur because of poor kinetics. However, at elevated temperatures between 100°C and 180°C, PGMs can be dissolved by sodium cyanide like the reaction of gold. In this work, the dissolution of Palladium was measured in pressure clear cyanide solution. The data at different cyanide concentrations, different temperature and different oxygen pressure are obtained. With increasing cyanide concentration and oxygen pressure, the dissolution first increased to a maximum value and then decreased. With increasing temperature the dissolution is increased. The dissolution was found to have a relation of the cyanide and oxygen level. The dissolution were independent of rotation speed for oxygen-saturated solutions and cyanide concentrations above 5 mol.m-3 and were well below chemical reaction-limited for cyanide and oxygen.

Study on Pressure-Cyanide Dissolution of Metal Platinum Powder

2012 ◽  
Vol 554-556 ◽  
pp. 541-545
Author(s):  
L. Yan ◽  
J.S. Zhao
Keyword(s):  
Oxygen Pressure ◽  
Room Temperature ◽  
Research Study ◽  
Elevated Temperatures ◽  
Rotation Speed ◽  
Sodium Cyanide ◽  
Cyanide Solution ◽  
Platinum Group Metals ◽  
Maximum Value ◽  
Increasing Temperature

A research study has been undertaken to develop the fundamentals of a method for the direct dissolution of Metal Platinum. At room temperature and pressures, the reaction between sodium cyanide and platinum group metals (PGMs) does not occur because of poor kinetics. However, at elevated temperatures between 20°C and 180°C, PGMs can be dissolved by sodium cyanide like the reaction of gold. In this work, the dissolution of Platinum was measured in pressure clear cyanide solution. The data at different cyanide concentrations, different temperature and different oxygen pressure are obtained. With increasing cyanide concentration and oxygen pressure, the dissolution first increased to a maximum value and then decreased. With increasing temperature the dissolution is increased. The dissolution was found to have a relation of the cyanide and oxygen level. The dissolution was independent of rotation speed for oxygen-saturated solutions and cyanide concentrations above 5 mol.m-3 and was well below chemical reaction-limited for cyanide and oxygen.

Kinetics and Mechanism of Platinum Pressure-Cyanide Dissolution

2014 ◽  
Vol 522-524 ◽  
pp. 424-428
Author(s):  
J.S. Zhao ◽  
J.H. Dai
Keyword(s):  
Oxygen Pressure ◽  
Room Temperature ◽  
Research Study ◽  
Elevated Temperatures ◽  
Sodium Cyanide ◽  
Cyanide Solution ◽  
Platinum Group Metals ◽  
Maximum Value ◽  
Direct Dissolution ◽  
Increasing Temperature

A research study has been undertaken to develop the fundamentals of a method for the direct dissolution of metal platinum. At room temperature and pressures, the reaction between sodium cyanide and platinum group metals (PGMs) does not occur because of poor kinetics. However, at elevated temperatures, PGMs can be dissolved by sodium cyanide like the reaction of gold. In this work, the dissolution of Platinum was measured in pressure clear cyanide solution. The data at different cyanide concentrations, temperature and oxygen pressure are obtained. With increasing cyanide concentration and oxygen pressure, the dissolution first increased to a maximum value and then decreased. With increasing temperature the dissolution is increased.

Pressure-Cyanide Dissolution of Palladium by Rotating Disk Method

2011 ◽  
Vol 347-353 ◽  
pp. 1744-1748
Author(s):  
Ji Shou Zhao ◽  
Li Yan ◽  
Kun Huang ◽  
Jing Chen
Keyword(s):  
Room Temperature ◽  
Elevated Temperatures ◽  
Rotation Speed ◽  
Rotating Disk ◽  
Sodium Cyanide ◽  
Cyanide Solution ◽  
Platinum Group Metals ◽  
Maximum Value ◽  
Increasing Temperature ◽  
Disk Method

At room temperature and pressures, the reaction between sodium cyanide and platinum group metals (PGMs) does not occur because of poor kinetics. However, at elevated temperatures between 100°C and 180°C, PGMs can be dissolved by sodium cyanide like the reaction of gold. In this work, the dissolution of Palladium was measured in pressure clear cyanide solution using a Palladium rotating disk. The data at different rotation speed, different cyanide concentrations, different temperature and different oxygen pressure are obtained. With increasing cyanide concentration and oxygen pressuer, the dissolution first increased to a maximum value and then decreased. With increasing temperature the dissolution is increased.The dissolution was found to have a relation of the cyanide and oxygen level. The dissolution were independent of rotation speed for oxygen-saturated solutions and cyanide concentrations above 5 mol.m-3 and were well below chemical reaction-limited for cyanide and oxygen.

Kinetics and Mechanism of Palladium Pressure-Cyanide Dissolution

2013 ◽  
Vol 446-447 ◽  
pp. 164-167
Author(s):  
J.S. Zhao ◽  
L. Yan
Keyword(s):  
Dissolution Rate ◽  
Oxygen Pressure ◽  
Elevated Temperatures ◽  
Rotation Speed ◽  
Rotating Disk ◽  
Sodium Cyanide ◽  
Cyanide Solution ◽  
Platinum Group Metals ◽  
Maximum Value ◽  
Increasing Temperature

At room temperature and pressures, the reaction between sodium cyanide and platinum group metals (PGMs) does not occur because of poor kinetics. However, at elevated temperatures, PGMs can be leached by sodium cyanide like the reaction of gold. However, few rate expression which describe the leaching of Palladium in cyanide solution has been developed. In this paper, the rate of Palladium dissolution was measured in pressure clear cyanide solution using a Palladium rotating disk. The data at different rotation speed, cyanide concentrations, temperature and oxygen pressure are obtained. The dissolution rates were independent of rotation speed for oxygen-saturated solutions between 100-400rpm. With increasing temperature the dissolution rate is increased. With increasing cyanide concentration and oxygen pressure, the dissolution rate first increased to a maximum value and then decreased.

Study on Dissolution Different of Metal Palladium Powder and Place

2014 ◽  
Vol 1033-1034 ◽  
pp. 1283-1287
Author(s):  
Ji Shou Zhao ◽  
X.M. Zhang ◽  
J.H. Dai
Keyword(s):  
Room Temperature ◽  
Research Study ◽  
Elevated Temperatures ◽  
Sodium Cyanide ◽  
Cyanide Solution ◽  
Oxygen Level ◽  
Cyanide Leaching ◽  
Palladium Powder ◽  
Direct Dissolution ◽  
Leaching Reaction

The chemistry of the dissolution of Palladium in pressure-cyanide has not received considerable attention. At room temperature and pressures, the reaction between sodium cyanide and Palladium does not occur because of poor kinetics. However, at elevated temperatures between 100-160 °C, Palladium can be leached by sodium cyanide like the reaction of gold. A research study has been undertaken to develop the fundamentals of a method for the direct dissolution of Palladium In this work, the dissolution of Palladium powder and place were measured in pressure clear cyanide solution. The cyanide leaching reaction mechanism is also discussed. The data of Palladium powder and place at different cyanide concentrations, different temperature and different oxygen pressure are obtained. The dissolution rate of metal Palladium powder and place were found to be relate to the cyanide and oxygen level.

Study Pressure-Cyanide Dissolution Different of Metal Palladium and Platinum Powder

2013 ◽  
Vol 734-737 ◽  
pp. 2514-2518
Author(s):  
Li Yan ◽  
Ji Shou Zhao
Keyword(s):  
Room Temperature ◽  
Research Study ◽  
Elevated Temperatures ◽  
Sodium Cyanide ◽  
Cyanide Solution ◽  
Platinum Group Metals ◽  
Cyanide Leaching ◽  
Direct Dissolution ◽  
Platinum Group ◽  
Leaching Reaction

s: A research study has been undertaken to develop the fundamentals of a method for the direct dissolution of platinum group metals (PGMs). At room temperature and pressures, the reaction between sodium cyanide and platinum group metals (PGMs) does not occur because of poor kinetics. However, at elevated temperatures between 120-180 °C, PGMs can be leached by sodium cyanide like the reaction of gold. In this work, the dissolution of Palladium and Platinum powder were measured in pressure clear cyanide solution. The cyanide leaching reaction mechanism is also discussed.The data at different cyanide concentrations, different temperature and different oxygen pressure are obtained. The dissolution rate off metal Palladium and Platinum powder were found to be a function of the cyanide and oxygen level.

Effect of Stress Relaxation on Springback of Steel Sheet in Warm Forming

2016 ◽  
Vol 725 ◽  
pp. 671-676 ◽  
Author(s):  
Naoko Saito ◽  
Mitsugi Fukahori ◽  
Daisuke Hisano ◽  
Hiroshi Hamasaki ◽  
Fusahito Yoshida
Keyword(s):  
Stress Relaxation ◽  
High Strength Steel ◽  
Room Temperature ◽  
Steel Sheet ◽  
Elevated Temperatures ◽  
High Strength ◽  
Warm Forming ◽  
Sheet Metals ◽  
Stress Relaxation Behavior ◽  
Increasing Temperature

Springback of a high strength steel (HSS) sheet of 980 MPa grade was investigated at elevated temperatures ranging from room temperature to 973 K. From U-and V-bending experiments it was found that springback was decreased with increasing temperature at temperatures of above 573 K. Furthermore, springback was decreased with punch-holding time because of stress relaxation. In this work, the stress relaxation behavior of the steel was experimentally measured. By using an elasto-vicoplasticity model, the stress relaxation was described, and its effect on the springback of sheet metals in warm forming was discussed theoretically.

The Room Temperature and Elevated Temperature Fracture Toughness Response of Alloy A-286

1978 ◽  
Vol 100 (2) ◽  
pp. 195-199 ◽  
Author(s):  
W. J. Mills
Keyword(s):  
Fracture Toughness ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Second Phase ◽  
Surface Micromorphology ◽  
Second Phase Particles ◽  
The Matrix ◽  
Temperature Fracture ◽  
Increasing Temperature ◽  
Base Superalloy

The elastic-plastic fracture toughness (JIc) response of precipitation strengthened Alloy A-286 has been evaluated by the multi-specimen R-curve technique at room temperature, 700 K (800°F) and 811 K (1000°F). The fracture toughness of this iron-base superalloy was found to decrease with increasing temperature. This phenomenon was attributed to a reduction in the materials’s strength and ductility at elevated temperatures. Electron fractographic examination revealed that the overall fracture surface micromorphology, a duplex dimple structure coupled with stringer troughs, was independent of test temperature. In addition, the fracture resistance of Alloy A-286 was found to be weakened by the presence of a nonuniform distribution of second phase particles throughout the matrix.

The Mechanical Properties of Fe-36.5Al and its Cr or ti Containing Alloys at Elevated Temperature

1994 ◽  
Vol 364 ◽  
Author(s):  
Dingqiang Li ◽  
Yi Liu ◽  
Aidang Shan ◽  
Dongliang Lin
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Tensile Tests ◽  
Ternary Alloys ◽  
Transgranular Cleavage ◽  
Feal Alloy ◽  
Fracture Surfaces ◽  
Increasing Temperature

AbstractThe mechanical properties of B2 structural FeAl alloys, prepared by hot rolling, at elevated temperatures have been measured by tensile tests. The alloys of Fe-36.5at.%A1, Fe-36.5at.%A1-5at.%Cr and Fe-36.5at.%Al-2at.%Ti were taken for tensile tests at a temperature range from room temperature to 1000°C. The fracture surfaces of these alloys were observed by SEM. The results showed that elongations of these alloys increased with increasing temperature when the testing temperatures were above 600°C. All the maximum elongations of these alloys appeared at 1000°C and those of Fe-36.5A1, Fe-36.5Al-5Cr, and Fe-36.5Al-2Ti alloys were 120%, 183% and 208% respectively. Fracture surfaces showed that failure of these alloys was by a combination of intergranular fracture and transgranular cleavage below 700°C. but showed a ductile fracture above 700°C. The ductility and strength of ternary alloys were higher than that of binary FeAl alloy at elevated temperatures, especially at high temperature. The <111> dislocations and helices have been observed in Fe-36.5A1 alloy by TEM. The large elongation of FeAl alloy at high temperature resulted from <111> dislocations slipping and <111> helices climbing.

scholarly journals Misfit in Inconel-Type Superalloy

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Pavel Strunz ◽  
Martin Petrenec ◽  
Vadim Davydov ◽  
Jaroslav Polák ◽  
Přemysl Beran
Keyword(s):  
Room Temperature ◽  
Elevated Temperatures ◽  
Relative Difference ◽  
Lattice Parameters ◽  
Neutron Diffractometer ◽  
High Temperature Furnace ◽  
Nickel Base ◽  
Increasing Temperature

An important parameter for the characterization of microstructural changes in nickel base superalloys is the misfit - the relative difference between lattice parameters ofγmatrix andγ′precipitates. The misfit in IN738LC superalloy was examined at POLDI time-of-flight (TOF) neutron diffractometer both at room temperature and in situ at elevated temperatures using a high-temperature furnace. A careful out-of-furnace measurement yielded the lattice parameters of bothγandγ′phase at room temperature (aγ=3.58611(10) Å,aγ′=3.58857(17) Å) as well as the misfit (equal to6.9(6)×10-4). The in situ measurement at elevated temperatures provided the temperature dependence of the lattice parameters ofγ(up to 1120°C) andγ′(up to 1000°C). Using these data, the evolution of the misfit with temperature was calculated. The misfit decreases with increasing temperature until it reaches zero value at a temperature around 800°C. Above 800°C, it becomes negative.

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