Geomicrobiology of sulfide mineral oxidation
The same process is also very important in the weathering and enrichment of sulfide ore deposits (Lindgren 1928). Biohydrometallurgists ... (tvlurr et al. 1978, Lawrence et al, 1986, Barrett et al. 1993). Hence, the geomicrobiology of sulfide mineral oxidation has important ramifications from the global cycling Of elements to the industrial ...
Sulfide Mineral Oxidation
Sulfide-mineral oxidation is a complex hydrobiogeochemical process involving the oxidation of metal-sulfide minerals, catalyzed by numerous bacterial and archaeal microbial species, and …
(PDF) Sulfide Mineral Oxidation
Oxidation of sulfide particles, process iron and dissolved ions in process water affect the behaviour of sulfides. The effects of some essential factors on flotation of Ni-Cu ores are...
Oxidative Dissolution of Sulfide Minerals in Porous Media …
The oxidative dissolution of sulfide minerals in subsurface environments exerts a significant control on pore water quality and on the dynamics of biogeochemical processes. …
A New Insight Into Oxidation Mechanisms of Sulphide …
oxidation of sulphide minerals. Oxidation of sulphide minerals takes place during the grinding process when the particle size is reduced for flotation. Recently it was shown that formation of H2O2 take place in the pulp liquid during wet grinding of complex sulphide ore …
(Electro)catalytic oxidation of sulfide and recovery of …
Mn x O y coated over TiO 2 nanotube array substrate was doped with Mo and polyaniline (PANI) and applied for electrochemical desulfurization of concentrated sulfide (HS −) solutions at basic pH, typical of biogas scrubbing solutions and industrial wastewater.Mo and PANI co-dopants significantly enhanced the anode activity towards sulfide oxidation and …
Sulfide Mineral
The exposure of sulfide minerals contained in mine wastes to atmospheric oxygen results in the oxidation of these minerals. The oxidation reactions are accelerated by the catalytic effects of …
Acid leaching and dissolution of major sulphide ore minerals: processes …
The kinetics and mechanisms of dissolution of the major base metal sulphide minerals, pyrite, chalcopyrite, galena and sphalerite in acidic (chloride) media have been investigated. Minerals were ground in air, then dissolved in air-equilibrated solutions at pH 2.5, while monitoring the redox potential.
Kinetic Studies of Sulfide Mineral Oxidation and …
Kinetic Studies of Sulfide Mineral Oxidation and Xanthate Adsorption Neeraj K. Mendiratta Chair: Dr. R.-H. Yoon Materials Engineering and Science ABSTRACT Sulfide minerals are a major source of metals; however, certain sulfide minerals, such as pyrite and pyrrhotite, are less desirable. Froth flotation is a commonly used separation
Sulfide Mineral
Sulfide minerals are the main form of metal resources in nature and play an important role in human production and life. In ancient China, people began to use and process sulfide minerals. For example, from the Shang Dynasty relics unearthed from the Yin Ruins, weapons made from arsenopyrite (FeAsS) and galena (PbS) were discovered (Wen, 1980 ...
Thermodynamics and kinetics of sulfide oxidation by …
Figure 1A describes the thermodynamics of sulfide oxidation in one-electron transfers of oxygen in four steps from O 2 to to H 2 O 2 to OH• to produce H 2 O. Only OH• can lead to formation of HS•. Even the oxidation of sulfide by O 3 and 1 O 2 are unfavorable. However, the two-electron transfer reactions (e.g., Eq.
Recent challenges in biological cyanidation and oxidation of …
Gold is found in sulfide mineral phases such as pyrite, pyrrhotite, arsenopyrite, and chalcopyrite in refractory concentrates and these structures reduce the efficiency of the gold …
Application of natural mineral materials in advanced oxidation
Owing to the cycle of metal redox pairs mediated by S species, the iron sulfide minerals present more superior catalytic activity than iron oxide minerals towards H 2 O 2, ... To improve the efficiency of Fenton or Fenton-like oxidation process, photo-Fenton oxidation process introducing ultraviolet or visible light into the reaction system is ...
Thermoanalytical study on the oxidation of sulfide …
The oxidation of sulfide minerals at high temperatures is of interest in both flash smelting of copper concentrates (Jorgensen and Koh, 2001) and flash converting of solid copper mattes (Hanni ala, 1998). Copper concentrate particles consist of copper and iron sulfide minerals that are oxidized at high temperatures in an oxygen-enriched
High Temperature Pressure Oxidation of a Low-Grade Nickel Sulfide
The hydrometallurgical processing of nickel sulfide concentrates per se is not commonly practiced commercially though several processes for these feeds have been developed and tested at pilot scale [1,2].Many nickel refineries (e.g., Nihama, Harjavalta, Kwinana) process nickel mattes [], whereas only a few operations, such as those at Fort Saskatchewan, Kokkola …
Sulfide oxidation affects the preservation of sulfur isotope …
Processes affecting δ 34 S (left panel) and Δ 33 S values (right panel) for sulfate (blue) and pyrite (gray). Colored areas represent range of values, and vertical black lines represent average ...
Oxidation of Sulfide Minerals in Benefication Processes
1. Properties of Sulfide Minerals Methods of Investigation of Sulfide Mineral Oxidation Processes 2. Electrode Kinetics and Oxidation Mechanism 3. Mutual Influence of Sulfide Minerals on Their Oxidation 4. Estimates of the Thermodynamic Stability of Sulfide Minerals Under Oxidizing Conditions 5. Oxidations of Sulfide Minerals in the Presence of …
Mineralogy-dependent sulfide oxidation via polysulfide and …
For acid insoluble sulfide (i.e., pyrite), pyrite oxidation by Fe 3+ can generate acid, dissolved S 2 O 32− and Fe 2+ following Eqn. 1 (Fig. 1). Dissolved S 2 O 32− may be directly …
XPS study of sulfide minerals surface oxidation under high …
Differences in the modification process, it was found that the chemical transformations of sulfur in the surface layer of pyrite, arsenopyrite, chalcopyrite include accumulation/formation of S 0 (S n 2−) at the first transformation stage (up to N ~ 10 3 pulses) followed by its removal. In the case of sphalerite and galena, the surface sulfur transformation …
Recent challenges in biological cyanidation and oxidation of sulfide
Jarosite formation in bioleaching is a complex chemical reaction that occurs because of the oxidative dissolution of sulfide minerals, particularly iron sulfides. It typically involves the oxidation of ferrous (Fe 2+) to ferric (Fe 3+), which can then react with sulfate ions (SO 4 2−) and water to form jarosite according to the following ...
OneMine | Minerals Beneficiation
The oxidation of copper sulfide minerals and subsequent leaching of the soluble copper has long been a profitable operation. The chief oxidizing agent is oxygen from the air. This reaction is …
The effect of iron complexes−nitrilotriacetate in the bio−oxidation …
The mineralogical and geochemical composition of sulfide mine wastes greatly affects the bio−oxidation of stibnite and Sb release (de Carvalho, et al. 2019; Muravyov 2019).Arsenopyrite (FeAsS) is commonly associated with Sb 2 S 3 in gold and antimony ores (Guo, et al. 2017; Zhang, et al. 2019).It acts as a mediator in various environmental processes …
Synergistic marriage of CO 2 reduction and sulfide oxidation …
Current CO 2 electrolyzers suffer from low economic feasibility due to the huge energy demand of water oxidation and the recovery of low-value oxygen. Herein, an energy-efficient co-valorization electrolysis is reported by coupling CO 2 reduction with sulfide oxidation, utilizing a dual doped cobalt hydroxide anode and an electrochemical-reduced Bi cathode in a …
Recovery of gold from sulfide refractory gold ore: Oxidation …
In the air oxidation roasting process, the major components (FeAsS, FeS 2) of the sulfide refractory gold ore would convert into iron oxides, arsenic oxides, sulfur oxides, sulfate and arsenate (Mikhail and Turcotte, 1992). Especially, arsenic is easily oxidized to As 2 O 3 or As 2 O 5, when heats in air, and As 2 O 3 is easy to volatilize.
Oxidation of sulfide mineral and metal extraction analysis in …
Pretreatment using microwave-assisted roasting with NaClO 3 as an additive to the oxidizing agent is a new method of processing refractory gold ore. Oxidation was studied …
A Simple Metal Free Oxidation of Sulfide Compounds
Abstract This work reports simple, efficient, selective protocol for the oxidation of sulfide compounds. Various sulfides were selectively and completely converted into their corresponding sulfoxides and sulfones using H2O2 as an oxidant in presence of catalytic amount of caprylic acid. The reaction proceeds at room temperature to give sulfoxide and by increasing …
Optimization of microwave-assisted roasting: Box-behnken …
The oxidation of sulfide minerals releasing SO 2 (g) to the atmosphere during roasting, is shown in Eqs. (11)–(15). ... Previous studies have shown a linear relationship between sulfide oxidation and the gold recovery in the leaching process [49]. Oxidation of 80 % sulfide minerals resulted in >90 % gold recovery [50]. 4.
Oxidation and Catalytic Oxidation of Dissolved Sulfide …
important role at the initial stage of the oxidation of sulfide in soil solutions. As a group of the strongest inorganic oxidizers in the environment, manganese oxide minerals participate in the oxidation processes of dissolved sulfide and metal sulfides (Aller and Rude, 1988; Yao and Millero, 1993; Schippers and Jørgensen, 2001; Liuet al ...
[PDF] Roasting of Sulfide Minerals | Semantic Scholar
In addition to common metals like copper, lead, zinc, and nickel a number of other metals such as antimony, bismuth, cadmium, cobalt, mercury, and molybdenum occur as sulfide minerals. Sulfides are not reduced with the most widely used reducing agents, carbon and hydrogen, because the free energy change for the reactions 2MS + C = 2M + CS2 and MS + H2 = M + …
Oxidative Hydrometallurgy of Sulphide Minerals
In this Chapter, we will treated the use of ozone and advanced oxidation process, including microwave system, as methods to improve or to help the leaching of different sulphide minerals.