Besides arsenopyrite, pyrite (Fe +2 S 2 −1) and pyrrhotite (Fe 1−x 2 S 2x−2) are two common sulphide matrix of refractory gold ores and often coexist with arsenopyrite (Vaughan and Craig, 1997). At ambient pressure, it is found that the presence of pyrite may retard the dissolution of arsenopyrite (Yang et al., 2017). However, so far ...

Arsenopyrite (FeAsS), the most common arsenic-bearing mineral, is usually found associated with pyrite (FeS 2) in gold mining tailings.This work examined the galvanic effect of FeS 2 on As release from FeAsS oxidation in circumneutral media under oxygen-depleted and oxygen-saturated conditions. The oxidation experiments were …

Nesbitt HW, Muir IJ (1994) X-ray photoelectron spectroscopic study of a pristine pyrite surface reacted with water vapour and air. Geochim Cosmochim Acta 58: 4667–4679. …

The As content of arsenopyrite and phase relationships of arsenian pyrite and arsenopyrite indicate that the formation temperature of euhedral arsenopyrite was …

Raman spectra of arsenopyrite samples, like their pyrite counterparts, reveal clearly resolved elemental sulfur peaks; however, the signal from arsenopyrite itself is not as easily distinguished. The phonon bands of bulk arsenopyrite appear as a series of broad features between 130 and 400 cm −1 [13] .

Bou Beker, Touissit-Bou Beker District, Jerada Province, Oriental Region, Morocco

Quantitative molecular orbital (MO) calculations and qualitative perturbational MO arguments are used to interpret the spectra and structure of transition metal …

Initial prospecting discovered subangular boulders (glacial float) with pyrite, arsenopyrite and rare fine specks of visible gold in quartz-rich metasediments. Assays are pending. The Company has ...

In our previous study [32], it was found that the pyrite-catalyzed arsenopyrite oxidation in sulfuric acid was due to the galvanic effect and the control of pH and redox potential, which hindered the formation of well-crystallized ferric arsenate (scorodite).While leaching in iron-free 9 K medium, the catalytic effect was only associated with the …

Other mineral constituents of arsenopyrite are copper and silver (Dos Santos et al., 2017). In addition, natural arsenopyrite samples are always associated with pyrite and are generally found with large domains of pyrite randomly inlaid in its structure (Fleet and Mumin, 1997; Dos Santos et al., 2017).

The early quartz–pyrite stage contains coarse euhedral-subhedral pyrite grains with a corona around the cubic pyrite, associated with silicification (Fig. 5 k). The middle quartz–polymetallic sulfide stage is characterized by enrichment in polymetallic sulfides of subhedral-anhedral pyrite, arsenopyrite, with minor galena, sphalerite, and ...

The more frequent ore minerals are pyrite, arsenopyrite, acanthite, grey ores of the freibergite–tetrahedrite series, stephanite, polybasite, low-fineness native gold (fineness varies in the range 249–532‰), and titanite. The amount of ore minerals in veins does not commonly exceed 0.5%, reaching 3% in some rare cases. ...

The selective action mechanism of sodium butyl xanthate (BX), ammonium salt (NH 4 +), and sodium m-nitrobenzoate (m-NBO) on pyrite and arsenopyrite was examined by experiments and quantum chemistry.The experiments show that under alkaline conditions, ammonium salt (NH 4 +) and m-NBO can have a strong inhibitory …

A SUPERB, incredibly sharp cluster of lustrous blades of Wolframite from old mining here back in the 1990s. The blades range up to 5.5 cm long and 2 cm wide, and the edges, seemingly beveled in appearance, are super-sharp. Associated with the Wolframite are crystals of Arsenopyrite up to 5 mm, Pyrite up to several mm, and small, subhedral ...

Gold occurs mostly as electrum in equilibrium with base metals sulfides filling fractures of pyrite and arsenopyrite. A novel combination of secondary ion mass spectrometry, laser ablation inductively coupled plasma mass spectrometry, and electron probe microanalysis is used to track the compositional evolution of ore fluid(s) and to ...

The Sunrise Dam gold mine (11.1 Moz Au) is the largest deposit in the Archaean Laverton Greenstone Belt (Eastern Goldfields Province, Yilgarn Craton, …

Comparative voltammetric studies were performed between high purity pyrite mineral (98.86%) and arsenopyrite mineral (content of 85.96% arsenopyrite, FeAsS; …

Pyrite and arsenopyrite are the most important mineral phases in sulphide refractory gold ores due to their associative property in hosting gold and concomitant …

What is Arsenopyrite? Arsenopyrite is an iron arsenic sulfide with a chemical composition of FeAsS. It is the most abundant arsenic-bearing mineral and the primary ore of arsenic metal.It is associated with other sulfide minerals in organic-rich sedimentary rocks, metamorphic rocks, and igneous rocks in many parts of the world.. In addition to being …

The X-ray photoelectronic spectroscopy data give the grounds for statement that the powerful nanosecond electromagnetic pulse pretreatment improves sorption activity of pyrite surface and lowers sorption of a collector at arsenopyrite surface. The research results are verified by test data on the powerful nanosecond electromagnetic pulse effect …

The ICP provided the amount of arsenopyrite and pyrite reporting to the concentrate from the arsenic percentage, while the LECO gave an initial indication of the sulphur content in the concentrate. The XRD was used to confirm that the sample has only iron–arsenic compounds present, and no other metal sulphides in significant quantities. ...

The above can be Batch bioleaching of a pyrite-arsenopyrite concentrate 1243 attributed to the primary oxidation of arsenopyrite to produce As(Ill), according to Eq. 4, and the subsequent oxidation of the As(Ill) to As(V), according to Eq. 5. These results suggest that the reactions described by Eqs 4 and 5 are competing reactions, and are ...

The formation of arsenic-bearing acid mine drainage (AMD) via the oxidation of arsenopyrite refuse ore has attracted significant attention. Pyrite, as main a concomitant mineral, is a crucial factor that affects the (bio)dissolution of arsenopyrite, but there are still some points on the detailed action mechanism under normal environmental conditions …

General Arsenopyrite Information : Chemical Formula: FeAsS : Composition: Molecular Weight = 162.83 gm Iron 34.30 % Fe Arsenic ... Arsenical pyrite : Bismuthian Arsenopyrite : Cobaltian Arsenopyrite : ICSD 62400 : Mispickel : …

The structural chemistry of gold in arsenian pyrite (FeS2) and arsenopyrite (FeAsS) is as yet unknown, despite the economic importance of this element and its potential recovery from low-grade ores and mine …

We suggest that invisible gold in arsenian pyrite and marcasite and arsenopyrite from sediment-hosted gold deposits represents Au removed from ore fluids by chemisorption at As-rich, Fe-deficient surface sites and incorporated into the …

Pyrite and arsenopyrite are the most common hosts for invisible gold, but pyrite and arsenic are refractory during conventional sulfide oxidation, which significantly challenges subsequent gold extraction. One option is high-temperature pretreatment of arsenical materials to sequester > 90% of the arsenic as a gas, then convert it to a stable ...

The ore fluids then became depleted in Au and As and formed As-poor pyrite overgrowth rims on gold-bearing arsenian pyrite. Arsenopyrite overgrowth aggregates on arsenian pyrite indicate a late ...

Three phases of sulfide growth can be identified from their zoned texture: (i) As-poor syndiagenetic pyrite/arsenopyrite corresponding to the core (Fig. 2 a and d); (ii) main ore-forming stage pyrite/arsenopyrite corresponding to the mantle (Fig. 2 a and d) or the whole grain (Fig. 2 b and c); (iii) hydrothermal overgrowth by pyrite ...

The open-circuit potential of pyrite or arsenopyrite is a corrosion potential. Presence of Au (super 3+) shifts the corrosion potential to a value that depends on the relative rates of the reduction of Au (super 3+) and the oxidation of the mineral. Open-circuit potential measurements indicate that the rate of deposition of gold on pyrite is ...