Arsenic behavior during the treatment of refractory gold ores via POX: Characterization of Fe-AsO4-SO4 precipitates

Strauss, Jakolien A.; Bazhko, V.; Ventruti, Gennaro; Liguo, Xuan; Goméz, Mario A.

doi:10.1016/j.hydromet.2021.105616

Cited by 9 publications

(1 citation statement)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Both STRB and POX play important roles in processing gold-bearing sulfide concentrates containing arsenopyrite. Leaching reduces the formation of toxic gaseous emissions with arsenic oxides, while dissolved arsenic can be removed from pregnant solutions via inert scorodite (FeAsO 4 •2H 2 O) formation after neutralization [1][2][3][4]7,[16][17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Combined Bacterial and Pressure Oxidation for Processing High-Sulfur Refractory Gold Concentrate

Boduen,

Zalesov,

Melamud

et al. 2023

Processes

View full text Add to dashboard Cite

Microbially assisted bio-oxidation of sulfide concentrates in stirred-tank reactors (stirred-tank reactor bio-oxidation (STRB)) and acid pressure oxidation (POX) are widely used to pretreat refractory sulfide concentrates and increase gold extraction via cyanidation. Continuous STRB requires a comparatively long residence time; however, in some cases, it cannot effectively oxidize some sulfide minerals. POX enables oxidation in a short residence time. At the same time, if a processed concentrate contains a large amount of sulfur, it decreases the ratio of the solid mineral phase to liquid (pulp density) during POX and limits its economic attractiveness. In the present work, experiments were performed to investigate the problems associated with both processing methods for refractory sulfide concentrates. The experiments combined both treatments (STRB and POX) based on the example of a pyrite–arsenopyrite gold-bearing concentrate. The gold recovery from the untreated concentrate via cyanidation reached 58%. Continuous STRB for 2, 4, and 6 days oxidized 43, 74, and 79% of the sulfide sulfur (Ss), respectively. The gold recovery rates from the bio-oxidation residues were 68, 82, and 88%, respectively. The pressure oxidation of both the concentrate and STRB residues increased Ss oxidation by 97–99% and gold recovery by 96–97%. For 2 days, STRB decreased the Ss content and increased the possible liquid-to-solid ratio for POX. The combined processes result in a new promising direction because the POX stage allows high gold recovery, whereas combining STRB and POX provides products for further POX in terms of Ss content and increases POX productivity.

show abstract