A review on electrochemical behavior of pyrite in the froth flotation process

• Published in: Journal of industrial and engineering chemistry (Seoul, Korea) 2017, 47(0), , pp.1-18
• Main Authors: Moslemi, Hossein, Gharabaghi, Mahdi
• Format: Article
• Language: English
• Subjects: Electrochemical potential; Flotation; Mineral processing; Pyrite; Surface chemistry; 화학공학
• ISSN: 1226-086X; 1876-794X
• DOI: 10.1016/j.jiec.2016.12.012

[Display omitted] •Pyrite mineral is floated in various pH conditions with xanthate as collector.•Electrochemical phenomena significantly influence pyrite flotation and depression.•Grinding condition has significant effects on the pyrite oxidation and flotation.•Water impurities and precipitated material on the pyrite surface, affect pyrite electrochemical behavior and its flotation. Metal sulfides are usually semiconductor and cause electrochemical reactions. This phenomenon plays an important role in sulfide flotation. Pyrite as the most abundant sulfide mineral is often associated with valuable sulfide minerals, coal and gold. It is very important to study its electrochemical behavior in the flotation process. This review focuses on researches carried out over the past several decades that have studied electrochemical processes associated with pyrite occurring during flotation. The mechanism of processes such as oxidation, activation, depression, and interactions of activated and non-activated surfaces with collectors as well as factors affecting them are described. Moreover, the effect of electrochemical conditions during grinding on the flotation process is also discussed. It has been found that moderately oxidizing conditions are favorable for collector-less flotation of pyrite while strongly reducing or oxidizing potentials lead to its depression. Increasing the electrochemical potential not only has a deleterious effect on the activation of pyrite by copper, but also facilitates its depression by depressants. In the case of the adsorption of xanthate whether on activated or non-activated surfaces, a great increase or decrease in the potential has adverse effects and it is necessary to optimize the electrochemical conditions. Various factors such as pH, solid percentage, particle size distribution, flotation time, type and concentration of reagents and oxygen content as well as grinding conditions can affect the intensity of these electrochemical interactions. It is proposed that further researches using advanced chemical analysis techniques are needed to understand the electrochemical processes involved in flotation systems.