Pretreatment of a refractory arsenopyritic gold ore using hydroxyl ion

Espitia, Sandra Liliana Mesa; Lapidus, G.T.

doi:10.1016/j.hydromet.2015.02.013

Cited by 45 publications

(13 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…For this experiment, the authors carried out a pretreatment with pyrite as a reducing agent, achieving an increase in silver extraction of 43.92%. Another study by Mesa and Lapidus [28] proposed a pretreatment with sodium hydroxide at room temperature for the extraction of gold from refractory arsenopyrite. The authors varied the use of a sodium hydroxide concentration, the concentration of solids, and treatment time, obtaining a gold extraction of 29% without performing a pretreatment (thiosulphate leaching) process.…”

Section: Introductionmentioning

confidence: 99%

Pretreatment of Copper Sulphide Ores Prior to Heap Leaching: A Review

Neira

Pizarro

Quezada

et al. 2021

Metals

View full text Add to dashboard Cite

Although the main cause of hydrometallurgical plant closures is the depletion of oxidized copper minerals reserves, the lack of new hydrometallurgy projects also contributes to these closures. One solution is to be able to process copper sulphide ores hydrometallurgically. However, it is widely known that sulphide copper ores—and chalcopyrite in particular—have very slow dissolution kinetics in traditional leaching systems. An alternative to improve the extraction of copper from sulphide ores is the use of a pretreatment process. Several investigations were developed evaluating the effects of pretreatment, mainly in the extraction of copper from chalcopyrite in chloride media. This study presents a review of various pretreatment methods prior to heap leaching to aid in the dissolution of copper from sulphide ores. Different variables of pretreatment that affect the extraction of copper were identified, including the type of salts used in agglomeration, curing time, and curing temperatures. Successful cases such as the implementation of the CuproChlor® process (use of calcium chloride), and various pilot studies using sodium chloride and temperature, show that pretreatment is an alternative that aids in the dissolution of copper from sulphide ores.

show abstract

Section: Introductionmentioning

confidence: 99%

Pretreatment of Copper Sulphide Ores Prior to Heap Leaching: A Review

Neira

Pizarro

Quezada

et al. 2021

Metals

View full text Add to dashboard Cite

show abstract

“…Oxidative roasting, pressure oxidation, chemical oxidation and biological oxidation are currently the four commonly adopted pre-treatment methods [2,3]. Although the first three methods can improve the extraction of gold from the refractory ores efficiently, they also suffer from having high energy consumptions, requiring a variety and large amount of chemical reagents, and yielding high levels of environmental pollutions [4,5]. Biological oxidation pre-treatment, in contrast, is a green, low-cost, and simple technology for leaching valuable metals from a range of minerals, ores/concentrates and waste materials.…”

Section: Introductionmentioning

confidence: 99%

Formation Process of the Passivating Products from Arsenopyrite Bioleaching by Acidithiobacillus ferrooxidans in 9K Culture Medium

Liu¹,

Li²,

Zhang³

et al. 2019

Metals

View full text Add to dashboard Cite

Arsenopyrite is a common sulphide mineral occurring in deposits of gold ore that makes the extraction of gold difficult and, thus, pre-treatment is necessary prior to gold leaching. Bioleaching pre-treatment of arsenopyrite has drawn significant attention owing to its environmental friendliness, low cost and simple operation. A critical impedance of bioleaching to its large-scale industrial application is the slow leaching kinetics. Various passivating products on the surface of arsenopyrite have been found to limit the bioleaching process. This paper reports results from an in-depth investigation into the formation process of passivating products from arsenopyrite bioleaching by Acidithiobacillus ferrooxidans in 9K culture medium including bioleaching experiments and physicochemical analyses of the materials as well as thermodynamic analyses of the leaching system. The results of phase transformation and morphological change of the solid products suggest that the passivation occurring in the bioleaching of arsenopyrite is largely attributed to an initially formed passivating film consisting mainly of realgar (As2S2), orpiment (As2S3) and elemental sulphur (S0) on the arsenopyrite surface. Based on the results, the paper also proposes possible passivation mechanisms to allow for a better understanding on the passivation behaviour of the bioleaching of arsenopyrite.

show abstract

“…In the cyanide leaching process, lime addition can avoid the formation of toxic cyanide species by reaching a pH of ≈ 10. In refractory gold ores, an oxidation step aimed at oxidizing the sulfide minerals enclosing the gold is usually performed prior to the cyanide leaching process (Mesa Espitia and Lapidus 2015 ). The goal of this step is to increase the availability of cyanide for dissolving the gold.…”

Section: Introductionmentioning

confidence: 99%

The formation of unsaturated zones within cemented paste backfill mixtures—effects on the release of copper, nickel, and zinc

Hamberg

Maurice

Alakangas

2018

Environ Sci Pollut Res

View full text Add to dashboard Cite

Flooding of cemented paste backfill (CPB) filled mine workings is, commonly, a slow process and could lead to the formation of unsaturated zones within the CPB fillings. This facilitates the oxidation of sulfide minerals and thereby increases the risk of trace metal leaching. Pyrrhotitic tailings from a gold mine (cyanidation tailing (CT)), containing elevated concentrations of nickel (Ni), copper (Cu), and zinc (Zn), were mixed with cement and/or fly ash (1–3 wt%) to form CT-CPB mixtures. Pyrrhotite oxidation progressed more extensively during unsaturated conditions, where acidity resulted in dissolution of the Ni, Cu, and Zn associated with amorphous Fe precipitates and/or cementitious phases. The establishment of acidic, unsaturated conditions in CT-CBP:s with low fractions (1 wt%) of binders increased the Cu release (to be higher than that from CT), owing to the dissolution of Cu-associated amorphous Fe precipitates. In CT-CPB:s with relatively high proportions of binder, acidity from pyrrhotite oxidation was buffered to a greater extent. At this stage, Zn leaching increased due the occurrence of fly ash-specific Zn species soluble in alkaline conditions. Irrespective of binder proportion and water saturation level, the Ni and Zn release were lower, compared to that in CT. Fractions of Ni, Zn, and Cu associated with acid-soluble phases or amorphous Fe precipitates, susceptible to remobilization under acidic conditions, increased in tandem with binder fractions. Pyrrhotite oxidation occurred irrespective of the water saturation level in the CPB mixtures. That, in turn, poses an environmental risk, whereas a substantial proportion of Ni, Cu, and Zn was associated with acid-soluble phases.

show abstract

Pretreatment of a refractory arsenopyritic gold ore using hydroxyl ion

Cited by 45 publications

References 36 publications

Pretreatment of Copper Sulphide Ores Prior to Heap Leaching: A Review

Pretreatment of Copper Sulphide Ores Prior to Heap Leaching: A Review

Formation Process of the Passivating Products from Arsenopyrite Bioleaching by Acidithiobacillus ferrooxidans in 9K Culture Medium

The formation of unsaturated zones within cemented paste backfill mixtures—effects on the release of copper, nickel, and zinc

Contact Info

Product

Resources

About