scholarly journals Investigations of regularities in the accumulation of hydrogen-reduced slags in circulation circuits with lead-containing coolants

2021 ◽  
Vol 7 (3) ◽  
pp. 245-252
Author(s):  
Vladimir V. Ulyanov ◽  
Mikhail M. Koshelev ◽  
Vladlena S. Kremlyova ◽  
Sergey E. Kharchuk
Keyword(s):  
Lead Oxide ◽  
Computational Analysis ◽  
Slag Formation ◽  
Oxide Formation ◽  
Timely Manner ◽  
Argon Flow ◽  
Out Of The Loop ◽  
Lead Oxides ◽  
Oxygen Gas ◽  
Bismuth Alloy

The paper presents a computational analysis of regularities in the accumulation of slags during the interaction of lead and lead-bismuth coolants with oxygen gas. Oxidation of lead-containing coolants will cause the formation of lead oxide, while the formation of bismuth oxide is unlikely. Dosed supply of oxidizing gas to lead-containing coolants makes it possible to oxidize, selectively, chromium and nickel to their oxides without the slag formation from solid lead oxide. Regularities were studied which are involved in the lead oxide formation during the interaction of lead-containing coolants with oxygen gas. It has been found that, in the process of interacting with oxygen gas, a lead-bismuth alloy is oxidized 1.7 times as intensively as lead, this being explained by the presence of bismuth in the alloy. Bismuth is oxidized more intensively than both lead and the lead-bismuth alloy. The inert gas overpressure during depressurization does not prevent air oxygen from entering the circuit, and the dependence of the nitrogen and oxygen flow into the circuit on the argon flow out of the loop is close to linear regardless of the circuit state (cold, without coolant; heated, without coolant; heated, with circulating coolant). Oxygen is a chemically active impurity and is absorbed by the circuit; it is therefore important to control nitrogen in the gas spaces of the reactor and research plant circuits with lead-containing coolants. This will make it possible to signal, in a timely manner, the ingress of oxygen into the circuit and to take measures required to avoid or reduce the scale of the slag formation from lead oxides.

Preliminary study of a Georgia O'Keeffe pastel drawing using XRF and μXRD

2009 ◽  
Vol 24 (2) ◽  
pp. 116-123 ◽  
Author(s):  
Lynn B. Brostoff ◽  
Catherine I. Maynor ◽  
Robert J. Speakman
Keyword(s):  
Lead Oxide ◽  
X Ray Diffraction ◽  
Pigment Layer ◽  
X Ray ◽  
Georgia O'keeffe ◽  
Red Lead ◽  
Lead Oxides ◽  
Preliminary Study ◽  
Yellow Pigments ◽  
Xrf Analyses

X-ray fluorescence spectrometry (XRF) and micro-X-ray diffraction (μXRD) were used to analyze the composition of pigments on a pastel drawing, Special No. 32, by Georgia O’Keeffe. XRF analyses showed that, among other pigments present in the drawing, the red, orange, and yellow pigments may possibly be identified with lead- and chromium-based pigments: lead chromates, red and yellow lead oxides, and/or lead carbonates, plus calcium-based pastel fillers, such as whiting or gypsum. XRD examination of a sample removed from a dark mottled area of coral red pastel confirmed that this pigment layer, which is associated with a darkened appearance and high Pb:Cr ratios, matches the red lead oxide, minium (2PbO⋅PbO2).

Elucidating the Cathodic Electrodeposition Mechanism of Lead/Lead Oxide Formation in Nitrate Solutions

2017 ◽  
Vol 121 (12) ◽  
pp. 6835-6843 ◽  
Author(s):  
Lingcong Meng ◽  
Jon Ustarroz ◽  
Mark E. Newton ◽  
Julie V. Macpherson
Keyword(s):  
Lead Oxide ◽  
Oxide Formation ◽  
Cathodic Electrodeposition ◽  
Nitrate Solutions

Reduction of lead dioxide with oxalic acid to prepare lead oxide as the positive electrode material for lead acid batteries

RSC Advances ◽  
2016 ◽  
Vol 6 (110) ◽  
pp. 108513-108522 ◽  
Author(s):  
Wei Liu ◽  
Beibei Ma ◽  
Fajun Li ◽  
Yan Fu ◽  
Jian Tai ◽  
...  
Keyword(s):  
Oxalic Acid ◽  
Electrode Material ◽  
Lead Oxide ◽  
Lead Dioxide ◽  
Positive Electrode ◽  
Lead Acid Batteries ◽  
Positive Electrode Material ◽  
Lead Oxides ◽  
Lead Acid

Sponge-like lead oxides prepared from PbO2can discharge a capacity of 115.2 mA h g−1after 50 cycles at 100 mA g−1.

Surface Reconstruction and Oxide Nucleation Due to Oxygen Interaction with Cu(001) Observed by In Situ Ultra-High Vacuum Transmission Electron Microscopy

1998 ◽  
Vol 4 (3) ◽  
pp. 334-339 ◽  
Author(s):  
Judith C. Yang ◽  
Mark Yeadon ◽  
Borys Kolasa ◽  
J. Murray Gibson
Keyword(s):  
Surface Reconstruction ◽  
Dwell Time ◽  
High Vacuum ◽  
Copper Surface ◽  
Ultra High Vacuum ◽  
Oxide Formation ◽  
Transmission Electron ◽  
Oxygen Gas ◽  
Oxygen Interaction

Reconstruction of the Cu(001) surface due to oxygen gas impingement on a clean copper surface was directly observed by in situ UHV-TEM. Strain contrast between differently oriented surface reconstruction domains, assumed to be √2 × 2√2 R45, were clearly visible by this method. The reconstruction precedes the nucleation of Cu2O islands. When Cu2O islands were partially reduced and then re-oxidized, a dwell time before formation of Cu2O was noted, demonstrating that a reconstructed Cu-O surface monolayer is necessary before oxide formation.

Graphite Foil Waste to Graphene: New Carbon Precursors for Synthesis of Graphene and its Oxides

2021 ◽  
Vol 891 ◽  
pp. 68-74
Author(s):  
Lili Nadaraia ◽  
Tamar Dundua ◽  
Nino Gamkrelidze ◽  
Vladimer Tsitsishvili ◽  
Natia Barbakadze ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Temperature Treatment ◽  
Zinc Powder ◽  
High Temperature Treatment ◽  
Graphite Foil ◽  
Oxide Formation ◽  
Defective Structure ◽  
Argon Flow ◽  
Reduced Graphene ◽  
Methods Of Synthesis

In this paper, graphene oxide (GO) was obtained by oxidation of powdered graphite foil wastes (pGFW) at 0 - 40°C. Oxidizing reagents can easily penetrate the layers of graphite foil and thus, the intercalation or functionalization-oxidation processes may occur resulting in graphite oxide formation. The methods of synthesis of GO and its separation from the reaction mixture were partially corrected. GO was reduced, also, to the reduced graphene oxide (rGO) by using hydroiodic acid, ascorbic acid, zinc powder, hydrazine, and Alnus extract. Thermal treatment of GO powders and GO films, obtained from pGFW was implemented at 20-300° C in air and at 20-1000° C under argon flow and in a vacuum. At high-temperature treatment (1000°C) of GO graphene was obtained with a defective structure.

Flotation of a Copper-Lead Sulfide-Oxide Ore：Using a Combined Depressant for Galena and an Effective Activator D2 for Copper Oxide Minerals

2013 ◽  
Vol 634-638 ◽  
pp. 3368-3374
Author(s):  
Mei Hua Liu ◽  
Yi Qiang Liang ◽  
Sheng Jian ◽  
Xu Dong Zhang
Keyword(s):  
Copper Oxide ◽  
Lead Sulfide ◽  
Copper Sulfide ◽  
Lead Oxide ◽  
Sodium Sulfide ◽  
Sodium Thiosulfate ◽  
Oxidation Rates ◽  
Lead Oxides ◽  
Flotation Performance ◽  
Copper Lead

The properties of a Cu-Pb oxide ore are investigated by XRD and SEM. Results show that the ore is characterized by chalcocite, galena, azurite and cerusite. Copper and lead phases analysis show that the oxidation rates of copper and lead are up to 70% and 72%, respectively. In order to get a good flotation performance for the difficult-to-treat ore, an efficient flotation technology of bulk flotation of Cu-Pb sulfides，separation of Cu-Pb sulfides, copper and lead oxides flotation has been developed. By applying the combined depressants (sodium thiosulfate + peroxide), activator Disulhydroxybenzen Thiodiazole (developed by Kunming Metallurgy Research Institute) in copper oxide flotation and sodium sulfide in flotation of lead oxide, chalcocite and galena can be separated and the Cu-Pb oxides can be activated. Results in closed circuit test show that when the feed assays 0.59% Cu, 2.40% Pb and 39.87 g/t Ag, marketable copper sulfide and oxide concentrates, lead sulfide and oxide concentrates can be obtained. At the same time, silver got enriched in the concentrates too. This study is expected to give a technical support in utilizing this complex Cu-Pb oxide ores.

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