Recovery of Metallic Lead of Cupel Wastes from Gold Analysis by Alkaline Fusion in the Presence of Sulfur

2022 ◽  
Author(s):  
Cristiane Isaac Cerceau ◽  
Cornélio de Freitas Carvalho ◽  
Eduardo Vinícius Vieira Varejão ◽  
Cláudio Gouvea dos Santos ◽  
Víctor de Andrade Alvarenga Oliveira
Keyword(s):  
Metallic Lead ◽  
Alkaline Fusion

scholarly journals Synthesis of Valeric Acid by Selective Electrocatalytic Hydrogenation of Biomass-Derived Levulinic Acid

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 692
Author(s):  
Yan Du ◽  
Xiao Chen ◽  
Ji Qi ◽  
Pan Wang ◽  
Changhai Liang
Keyword(s):  
Levulinic Acid ◽  
Active Sites ◽  
Valeric Acid ◽  
Future Research ◽  
Adsorbed Hydrogen ◽  
Electrocatalytic Hydrogenation ◽  
Ambient Conditions ◽  
Metallic Lead ◽  
Faradaic Efficiency ◽  
Lead Electrode

The electrocatalytic hydrogenation (ECH) of biomass-derived levulinic acid (LA) is a promising strategy to synthetize fine chemicals under ambient conditions by replacing the thermocatalytic hydrogenation at high temperature and high pressure. Herein, various metallic electrodes were investigated in the ECH of LA in a H-type divided cell. The effects of potential, electrolyte concentration, reactant concentration, and temperature on catalytic performance and Faradaic efficiency were systematically explored. The high conversion of LA (93%) and excellent “apparent” selectivity to valeric acid (VA) (94%) with a Faradaic efficiency of 46% can be achieved over a metallic lead electrode in 0.5 M H2SO4 electrolyte containing 0.2 M LA at an applied voltage of −1.8 V (vs. Ag/AgCl) for 4 h. The combination of adsorbed LA and adsorbed hydrogen (Hads) on the surface of the metallic lead electrode is key to the formation of VA. Interestingly, the reaction performance did not change significantly after eight cycles, while the surface of the metallic lead cathode became rough, which may expose more active sites for the ECH of LA to VA. However, there was some degree of corrosion for the metallic lead cathode in this strong acid environment. Therefore, it is necessary to improve the leaching-resistance of the cathode for the ECH of LA in future research.

The upscaling of the alkaline fusion process

2019 ◽  
Author(s):  
Ahmad K. B. Zahari ◽  
Nuraqilah Sapiee ◽  
Khaironie Mohamed Takip ◽  
Roshasnorlyza Hazan
Keyword(s):  
Fusion Process ◽  
Alkaline Fusion

Complete recovery of Eu from BaMgAl10O17:Eu2+ by alkaline fusion and its mechanism

RSC Advances ◽  
2015 ◽  
Vol 5 (2) ◽  
pp. 1113-1119 ◽  
Author(s):  
Shengen Zhang ◽  
Hu Liu ◽  
De'an Pan ◽  
Jianjun Tian ◽  
Yifan Liu ◽  
...  
Keyword(s):  
Environmentally Friendly ◽  
Complete Recovery ◽  
Efficient Process ◽  
Alkaline Fusion

An environmentally friendly and efficient process for recycling waste phosphors has been developed.

scholarly journals Post mortem analysis of burned magnesia-chromite brick used in short rotary furnace of secondary lead smelting

Cerâmica ◽  
2009 ◽  
Vol 55 (333) ◽  
pp. 61-66 ◽  
Author(s):  
E. Prestes ◽  
A. S. A. Chinelatto ◽  
W. S. Resende
Keyword(s):  
Reduction Process ◽  
Rotary Furnace ◽  
Furnace Lining ◽  
X Ray Diffraction ◽  
Good Resistance ◽  
Metallic Lead ◽  
Parallel Cracks ◽  
Standard Product ◽  
Short Service Life ◽  
Powder Analysis

Burned magnesia-chromite bricks are the standard product for the lining of furnaces in lead industry, where the short service life is a great problem. Used sintered magnesia-chromite brick sample from short rotary furnace lining, sent by a secondary lead manufacturer, showed parallel cracks to the hot face due to structural spalling damage. The refractory infiltrated region and slag interface were analyzed using a scanning electron microscope with an energy dispersive spectroscopy analyzer, and X-ray diffraction powder analysis. Crucible corrosion test was performed to evaluate the influence of slag attack. The results showed that the structural spalling was due to strong Pb-infiltration of the refractory microstructure by bath components of the furnace (metallic lead and lead sulphite) during the reduction process and that the slag infiltration had little contribution due to the good resistance of the magnesia-chromite bricks to FeO rich slag attack.

scholarly journals Investigation of quantum transport and local density of states in a graphene strip connected to a square lattice

2021 ◽  
Author(s):  
Elnaz Rostampour
Keyword(s):  
Quantum Transport ◽  
Dirac Point ◽  
Local Density ◽  
Square Lattice ◽  
Density Of State ◽  
Metallic Lead ◽  
Resonant Tunnelling ◽  
Quantum Billiard ◽  
Plasmon Polaritons ◽  
Theoretical Results

Abstract We theoretically express quantum transport at Dirac points via graphene quantum billiard as a non-magnetic material to connect metallic leads. Our results indicate that the quantum billiard of graphene is similar to a resonant tunnelling device. The centerpiece size and the Fermi energy of the graphene quantum billiard play an important role in the resonant tunnelling. In graphene, change of carrier density can affect plasmon polaritons. At the Dirac point, the conductivity of graphene depends on the geometry, so that the conduction of the evanescent modes is close to the theoretical value of 4e2/πh (where Planck's constant and the electron charge are denoted by h and e, respectively.). This transport property can be used to justify chaotic quantum systems and ballistic transistors. Our theoretical results demonstrate that the local density of state of the graphene sheet for EL = ER = 0 is larger than EL = ER = t (where EL (ER) is onsite energy of the left (right) metallic lead) unlike the current obtained from the calculations.

In Metallic Lead

2007 ◽  
pp. 96-97
Author(s):  
M. Dräger ◽  
N. Kleiner
Keyword(s):  
Metallic Lead
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