Silicate Covering Layer on Pyrite Surface in the Presence of Silicon–Catechol Complex for Acid Mine Drainage Prevention

Abstract

In this paper, prevention of pyrite oxidation by carrier microencapsulation (CME) was investigated. A possible layer structure was suggested following analysis with electrochemical and surface analysis techniques. Electrochemical study of treated pyrite samples showed that treatment with siliconcatechol (Si-Cat) for 6 h at an initial pH of 9.5 gave the best barrier properties and suppression of the samples. Scanning electron microscopy with energy-dispersive X-ray, and Fourier transform infrared (FTIR) analyses confirmed the presence of a silicate layer on the surface of treated pyrite. X-ray photoelectron spectroscopy indicated that the coating layers on the treated pyrite samples consisted of a network of Fe-O-Si and Si-O-Si units bonded to the surface of pyrite. The Si-O-C asymmetric stretching mode was also observed in FTIR spectra. Detailed spectroscopic analyses confirmed the formation of a silicate polymer on a silicaquinone layer, which resulted in the effective suppression effect shown by Si-Cat-treated pyrite at increasing pH.

Synthesis and characterization of coal fly ash and palm oil fuel ash modified artisanal and small-scale gold mine (ASGM) tailings based geopolymer using sugar mill lime sludge as Ca-based activator

“…The MT sample also exhibited a clear peak at 430 cm −1 assigned to S–S vibration in pyrite ( Tabelin et al., 2017c ). Meanwhile, the absorption bands at 955, 532 and 462 cm −1 are assigned to Fe–O stretching of the Fe-oxyhydroxides/oxides ( Tabelin et al., 2019 ; Yuniati et al., 2015 ), the presence of which could be explained by the oxidation of pyrite once exposed to the air ( Park et al., 2019 ; Tabelin et al., 2018 ).…”

Synergistic effects of boron-doped silicone resin and a layered double hydroxide modified with sodium dodecyl benzenesulfonate for enhancing the flame retardancy of polycarbonate

“…The absorption bands at 2965–2870 cm −1 are ascribed to the stretching vibrations of C–H units (including –CH 3 or –CH 2 CH 3 ). The characteristic peaks at 1110 cm −1 and 827 cm −1 are due to the stretching modes and bending vibrations of Si–O–Si, 32 respectively. The absorption by O–C bonds occurs at 1050 cm −1 .…”

Synthetic ferripyrophyllite: preparation, characterization and catalytic application

“…The existence of Fe-O-Si units in the material was evidenced by ATR-IR spectroscopy. [38][39][40][41][42][43] While physical mixtures of Fe 2 O 3 and SBA-15 showed only the additive signals of the two components (Fig. S21 †), distinct differences are evident for the new material (Fig.…”