Oxidation of Copper Sulfides in Aqueous Ammonia. I. Formation of Sulfur

1979 ◽  
Vol 32 (5) ◽  
pp. 961 ◽  
Author(s):  
AO Filmer ◽  
AJ Parker ◽  
LGB Wadley
Keyword(s):  
Ammonium Sulfate ◽  
Aqueous Ammonia ◽  
Copper Ions ◽  
Sulfide Oxidation ◽  
Metal Sulfide ◽  
Metal Sulfides ◽  
Copper Sulfides ◽  
Consecutive Reactions ◽  
Partial Pressures ◽  
Sulfur Containing

Elemental sulfur, rather than sulfate or thiosulfate ions, is the major sulfur-containing product when CuS or Cu2S are oxidized at temperatures below 40� with oxygen in a large excess of aqueous ammonia containing ammonium sulfate at pH 10-10.5. At temperatures above 60�, or in solutions containing low proportions of ammonia or ammonium sulfate, very little sulfur is formed. Higher partial pressures of oxygen lead to higher proportions of sulfur. These observations are explained in terms of concurrent and consecutive reactions involving copper polysulfides. The high proportion of ammonia to soluble copper ions which is required imposes some practical limitations on any potential leaching process aimed at producing sulfur. Proportions of sulfur from metal sulfide oxidation in aqueous ammonia decrease in the series of metal sulfides, Cu2S > CuS > NiS > FeS > ZnS > CoS. Some aspects of the chemistry of sulfur in aqueous ammonia are discussed.

Oxidation of Copper Sulfides in Aqueous Ammonia. III. Kinetic Characteristics

1979 ◽  
Vol 32 (12) ◽  
pp. 2597 ◽  
Author(s):  
AO Filmer ◽  
AJ Parker ◽  
BW Clare ◽  
LGB Wadley
Keyword(s):  
Aqueous Ammonia ◽  
Sulfide Oxidation ◽  
Metal Sulfide ◽  
Diffusion Control ◽  
Sulfate Ions ◽  
Kinetics Of Oxidation ◽  
Copper Sulfides ◽  
Shrinking Core ◽  
Kinetics Of ◽  
And Diffusion

The kinetics of oxidation with oxygen of chalcocite, Cu2S, to CuS in buffered aqueous ammonia at pH 10.5 at 30� can be modeled approximately by a shrinking core of Cu2S within a thickening shell of CuxS (x ≥ 1). The Cu2S core offers partial cathodic protection to the CuxS and diffusion of Cu+ through CuxS controls the rate of reaction. The kinetics of oxidation of covellite, CuS, to Cu2+, sulfur and sulfate ions in the same solvent can be modeled by a shrinking core of CuS surrounded by a shrinking sphere of CuyS (y < 1) which is much less effectively protected cathodically by the CuS core. Oxidation of CuS is subject to mixed chemical and diffusion control. Rates of oxidation of NiS and of CuS, in the presence and absence of tetrachloroethene and ammonium sulfate, show that, whether sulfur is a major oxidation product or not, the presence of sulfur has very little, if any, influence on the rate or mechanism of oxidation. This is contrary to current ideas on metal sulfide oxidation.

FISH Analysis of Bacterial Attachment to Copper Sulfides in Bioleaching Processes

2009 ◽  
Vol 71-73 ◽  
pp. 329-332
Author(s):  
J. Huergo ◽  
C. Bernardelli ◽  
M. Viera ◽  
Wolfgang Sand ◽  
Edgardo R. Donati
Keyword(s):  
Cell Attachment ◽  
Sulfide Oxidation ◽  
Metal Sulfide ◽  
Bacterial Attachment ◽  
Water Soluble ◽  
Soluble Form ◽  
Metal Sulfides ◽  
Fish Analysis ◽  
Acidithiobacillus Thiooxidans ◽  
Copper Sulfides

Bioleaching is the biological conversion of an insoluble metal compound into a water soluble form. In this process metal sulfides are oxidized to metal ions and sulfate by acidophilic microorganisms capable of oxidizing Fe2+ and/or sulfur-compounds. The metal solubilization from sulfide minerals is a chemical process which requires Fe3+ reduction. It is an environmentally friendly technique and an economical method for recovering metals that requires low investment and operation costs. In this work we studied the bioleaching of two kinds of acid-soluble copper sulfides, one easily leached by mesophilic bacteria (covellite), and the other one refractory to their activity (chalcopyrite), in acidic media with or without Fe2+ ions. We studied attached and planktonic populations of autotrophic bacteria, such as Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Leptospirillum ferrooxidans in pure or mixed cultures. The influence of a heterotrophic microorganism, Acidiphilium cryptum, was also studied. Attachment was evaluated with fluorescence staining and FISH using four specific probes. L. ferrooxidans showed highest initial attachment in all cases. The presence of Ap. cryptum increased the cell attachment compared with the autotrophic pure cultures. It was possible to correlate experimental data with a mechanism of bacterial-metal sulfide oxidation, the polysulfide pathway for acid- soluble metal sulfides.

ZnO nanorods decorated with metal sulfides as stable and efficient counter-electrode materials for high-efficiency quantum dot-sensitized solar cells

2016 ◽  
Vol 4 (21) ◽  
pp. 8161-8171 ◽  
Author(s):  
Chandu V. V. M. Gopi ◽  
Mallineni Venkata-Haritha ◽  
Young-Seok Lee ◽  
Hee-Je Kim
Keyword(s):  
Solar Cells ◽  
Quantum Dot ◽  
Counter Electrode ◽  
Electrode Materials ◽  
High Efficiency ◽  
Zno Nanorods ◽  
Metal Sulfide ◽  
Metal Sulfides ◽  
Sensitized Solar Cells

Metal sulfide decorated with ZnO NRs (ZnO/CoS, ZnO/NiS, ZnO/CuS and ZnO/PbS) were fabricated and used as efficient CEs for QDSSCs.

Recent Advances and the Design Criteria of Metal Sulfide Photocathode and Photoanode for Photoelectrocatalysis

2021 ◽  
Author(s):  
Cui Ying Toe ◽  
Shujie Zhou ◽  
Michael Gunawan ◽  
Xinxin Lu ◽  
Yun Hau Ng ◽  
...  
Keyword(s):  
Optical Properties ◽  
Light Absorption ◽  
Rapid Development ◽  
Metal Sulfide ◽  
Metal Sulfides ◽  
Design Criteria ◽  
Structural And Optical Properties ◽  
Recent Advances ◽  
Favorable Light

Metal sulfides have emerged as promising materials for photoelectrochemical (PEC) applications due to their favorable light absorption ability, tunable structural and optical properties. With the rapid development of PEC systems,...

Synthesis and Tribological Behavior of Metal Sulfide Nanoparticles Produced by Thermosolvolysis of Sulfur-Containing Precursors

2019 ◽  
Vol 59 (9) ◽  
pp. 1028-1036
Author(s):  
E. Yu. Oganesova ◽  
E. G. Bordubanova ◽  
A. S. Lyadov ◽  
O. P. Parenago
Keyword(s):  
Tribological Behavior ◽  
Metal Sulfide ◽  
Sulfur Containing

Design, synthesis, and application of metal sulfides for Li–S batteries: progress and prospects

2020 ◽  
Vol 8 (35) ◽  
pp. 17848-17882 ◽  
Author(s):  
Bo Yan ◽  
Xifei Li ◽  
Wei Xiao ◽  
Junhua Hu ◽  
Lulu Zhang ◽  
...  
Keyword(s):  
High Performance ◽  
Recent Progress ◽  
Review Paper ◽  
Metal Sulfide ◽  
Design Principles ◽  
Metal Sulfides ◽  
Comprehensive Overview ◽  
Design Synthesis

This review paper presents a comprehensive overview of recent progress in the use of metal sulfide for high-performance Li–S batteries with a particular focus on the modified approaches, design principles, synthetic strategies, and representative applications.

scholarly journals Reactivity of Small Oxoacids of Sulfur

Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2768 ◽  
Author(s):  
Sergei V. Makarov ◽  
Attila K. Horváth ◽  
Anna S. Makarova
Keyword(s):  
Atmospheric Chemistry ◽  
Sulfide Oxidation ◽  
Chemical Properties ◽  
Sulfenic Acid ◽  
Biochemical Processes ◽  
Sulfur Monoxide ◽  
Physical And Chemical ◽  
Sulfoxylic Acid ◽  
Sulfur Containing ◽  
Reducing Properties

Oxidation of sulfide to sulfate is known to consist of several steps. Key intermediates in this process are the so-called small oxoacids of sulfur (SOS)—sulfenic HSOH (hydrogen thioperoxide, oxadisulfane, or sulfur hydride hydroxide) and sulfoxylic S(OH)2 acids. Sulfur monoxide can be considered as a dehydrated form of sulfoxylic acid. Although all of these species play an important role in atmospheric chemistry and in organic synthesis, and are also invoked in biochemical processes, they are quite unstable compounds so much so that their physical and chemical properties are still subject to intense studies. It is well-established that sulfoxylic acid has very strong reducing properties, while sulfenic acid is capable of both oxidizing and reducing various substrates. Here, in this review, the mechanisms of sulfide oxidation as well as data on the structure and reactivity of small sulfur-containing oxoacids, sulfur monoxide, and its precursors are discussed.

Copper Recovery by Bioleaching of Chalcopyrite: A Microcalorimetric Approach for the Fast Determination of Bioleaching Activity

2013 ◽  
Vol 825 ◽  
pp. 322-325
Author(s):  
Beate Krok ◽  
Axel Schippers ◽  
Wolfgang Sand
Keyword(s):  
Enrichment Culture ◽  
Sulfide Oxidation ◽  
Exothermic Reaction ◽  
Metal Sulfide ◽  
Copper Recovery ◽  
Heat Output ◽  
Low Grade ◽  
Non Invasive ◽  
Pure Cultures ◽  
Invasive Method

Low grade copper ores containing chalcopyrite are increasingly used for copper recovery via biomining. Since metal sulfide oxidation is an exothememic process, bioleaching activity can be measured due to the heat output by microcalorimetry, which is a non-destructive and non-invasive method. The bioleaching activity of pure cultures ofSulfolobus metallicus,Metallosphaera hakonensisand a moderate thermophilic enrichment culture on high grade chalcopyrite was evaluated. Chalcopyrite leaching by microorganisms showed a higher copper recovery than sterile controls. Chemical chalcopyrite leaching by acid produced heat due to the exothermic reaction, the heat output was increased while metal sulfide oxidation by microorganisms.

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