Insight into the effect of galvanic interactions between sulfide minerals on the floatability and surface characteristics of pyrite

Abstract

Complex sulfide ores are usually found as a mixture of various sulfide and gangue minerals, and froth flotation is the predominant method for the selective separation of sulfide minerals. Adherence and contact between sulfide minerals are inevitable during froth flotation, and galvanic interactions between sulfide minerals will occur because of differences in rest potentials. However, the effect of these galvanic interactions on the selective flotation of sulfide minerals have been rarely studied. In this work, the effect of the galvanic interaction between pyrite and sphalerite on the flotation behavior and surface characteristics of pyrite was investigated by micro-flotation tests, collector adsorption tests, electrochemical techniques and XPS (X-ray photoelectron spectroscopy) surface analysis. The micro-flotation tests indicated that the floatability of pyrite decreased in the pH range of 4.0 to 9.5 and increased under strongly alkaline pH conditions (pH > 10) due to the galvanic interaction. The collector adsorption results demonstrated that the adsorption capacity of the collector on the pyrite surface was significantly reduced because of the galvanic interaction between pyrite and sphalerite. The electrochemical measurements revealed that the decrease in the oxidation current of xanthates to dixanthogen was responsible for the decreasing adsorption capacity of the collector on the pyrite surface. The XPS results indicated that the formation of the S " O $ "% oxidation product on the pyrite surface decreased at a strongly alkaline pH due to the galvanic interaction. Therefore, pyrite floatability improved at an alkaline pH. These results consistently showed that the galvanic interaction between pyrite and sphalerite had an important influence on the floatability and surface characteristics of pyrite.

Dual Role of Fe2+ in the Galena Flotation and Influence on Selective Separation

“…Materials. The highly mineralized galena samples from Yunnan Province of China were treated with the method described as the previous work [2]. The galena samples with the three particle size of the coarse (+0.074 mm), the intermediate (-0.074 mm to +0.038 mm), and the fine (-0.038 mm) were prepared.…”

“…Galena (PbS), an essential raw material for producing lead metal, is commonly intergrown with chalcopyrite, sphalerite, and pyrite, making its direct utilization challenging [1]. The prebeneficiation of galena is commonly essential before the metallurgical process, and the flotation was considered as the most economical and efficient method for the prebeneficiation of galena [2, 3]. In froth flotation, galena is selectively floated from other minerals based on differences in surface hydrophilicity or hydrophobicity [4, 5].…”

Influence of Terpenic Oil on Flotation Behavior of Sphalerite and Implication for the Selective Separation

“…After crushing the samples with a hammer and manually removing gangue minerals, the samples were dry-ground in a porcelain ball mill and dry-screened using nylon sieves to obtain the desired particle size. The samples were then sealed in a polyethylene bag and stored in a refrigerator at a temperature of -5.0°C to prevent surface oxidation [7]. The chemical composition and X-ray diffraction analysis of the sphalerite samples are given in Table 1 and Figure 3, respectively.…”

“…In froth flotation, the hydrophobic mineral particles can adhere to air bubbles dispersed in the pulp and transfer from the pulp region to the froth layer, while the hydrophilic mineral particles remain in the pulp and are collected in the tailings. These air bubbles dispersed in the pulp region play an important role in froth flotation [3–7]. Generally, the finer the air bubbles are, the higher the flotation separation efficiency is.…”