Two-stage process of bacterial-chemical oxidation of refractory pyrite-arsenopyrite gold-bearing concentrate

Zaulochnyi, P. A.; Булаев, А. Г.; Savari, E. E.; Pivovarova, T. A.; Kondratieva, T. F.; Sedelnikova, G. V.

doi:10.1134/s0003683811090080

Cited by 8 publications

(2 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The study of semicontinuous cultivation in a two stage temperature regime (35-37°C in reactors 1 and 2 and 38-42°C in reactors 3 and 4) showed that thio bacilli were dominant in all reactors, whereas the numbers of sulfobacilli were much lower in both tem perature regimes [82]. At a temperature of 38-42°С, the abundance of thiobacilli slightly decreased, and the numbers of sulfobacilli, on the contrary, increased from 1.34-1.42 × 10 8 to 1.64-2.08 × 10 8 , indicating enhanced activity of moderate thermophiles at ele vated temperatures.…”

Section: Temperaturementioning

confidence: 99%

Diversity of the communities of acidophilic chemolithotrophic microorganisms in natural and technogenic ecosystems

Pivovarova

Цаплина

et al. 2012

Microbiology

Self Cite

View full text Add to dashboard Cite

The communities of acidophilic chem olithotrophic microorganisms (ACM) are formed in sulfide ore deposits, mine waters, pyrite coals, the wastes of ore mining and processing industry in differ ent geographical and climatic zones, as well as in the pulps of reactors for the technologies of bacterialchemical oxidation of sulfide ore concentrates, i.e., in the presence of sulfide minerals and their oxidation products, elemental sulfur, reduced sulfur com pounds, and ferrous iron. As a result of their activity, the medium is acidified, sometimes to pH 0.5 or less, and the concentrations of heavy metals and toxic ele ments (copper, zinc, nickel, cobalt, arsenic, etc.) increase. These microorganisms therefore belong to extreme chemolithotrophic acidophiles. They include representatives of bacteria (both gram negative and gram positive) and archaea.Tables 1-3 present the best studied and most fre quently occurring ACM, the substrates they oxidize, and the ranges and optimal values of pH and tempera ture for their growth . It can be seen that some microorganisms can oxidize all inorganic substrates mentioned above, e.g., gram negative bacteria of the genus Acidithiobacillus (At. ferrooxidans, At. fer rivorans), gram positive bacteria of the genus Sulfoba cillus (S. thermosulfidooxidans, S. thermotolerans, S. benefaciens), and the archaeon Acidianus (Ac.) bri erleyi. Ferrous iron, elemental sulfur and sulfide min erals are used as energy sources by Metallosphaera sedula and M. prunae. Other microorganisms can obtain energy by oxidizing only ferrous iron or pyrite: Leptospirillum ferrooxidans, L. ferriphilum, and Ferro plasma acidiphilum. Most of the microorganisms (At. thiooxidans, At. caldus, and archaea) use elemen tal sulfur and reduced sulfur compounds as an energy substrate. The pH optima for the growth of these microorganisms are different, but all of them are in the range of acidic values. ACM live in a broad tempera ture range of 4 to 90°С. They include mesophiles with the optimal temperature for growth and oxidation of the energy substrate in the range of 28-35°С, moder ate thermophiles with the temperature optimum at 40 to 55°С, and thermophiles with the temperature opti mum above 60°С. The latter include mainly archaea. For instance, Ac. infernus has a temperature optimum for growth at 90°С [20].Abstract-The main representatives of acidophilic chemolithotrophs oxidizing sulfide minerals, ferrous iron, elemental sulfur, and reduced sulfur compounds and forming microbial communities in the natural and technogenic ecosystems with low pH values and high concentrations of heavy metal ions are listed. The spe cies and strain diversity of the communities and environmental factors affecting their composition (temper ature, pH value, energy substrate, mineralogical composition of sulfide ore concentrates, the presence of organic substances, and level of aeration) are analyzed. Involvement of mobile genetic elements (IS elements and plasmids) in the structural changes of the chromosomal DNA in the course of switching m...

show abstract

Section: Temperaturementioning

confidence: 99%

Diversity of the communities of acidophilic chemolithotrophic microorganisms in natural and technogenic ecosystems

Pivovarova

Цаплина

et al. 2012

Microbiology

Self Cite

View full text Add to dashboard Cite

show abstract

“…Various options for pyro-and hydrometallurgical processing of refractory gold-bearing concentrates have been proposed: roasting at a relatively low temperature [1] and twostage fi ring in a fl uidized bed furnace [2,3], direct reduction smelting [4], pretreatment of concentrates using microwave pyrolysis [5,6], direct [7] and combined methods of leaching [8,9]. Some of them allow complex processing of mineral raw materials, but require multi-stage processing, expensive equipment and reagents.…”

Section: Introductionmentioning

confidence: 99%

Investigation of the process of sulfiding of gold-arsenic containing ores and concentrates

Mambetalieva¹,

Mamyrbayeva²,

Turysbekov³

et al. 2022

Nauk. visn. nat. hirn. univ.

View full text Add to dashboard Cite

Purpose. Research of the removal of arsenic by sulfiding from gold-arsenic containing concentrates of the Bakyrchik deposit. Methodology. To determine the composition of the samples, chemical and electron probe analysis were carried out; to determine the phase composition of materials, X-ray analysis was conducted. In order to predict the process of sulfidation of arsenic and its compounds in the range of 2982000 K, a thermodynamic analysis was performed. To establish the optimal conditions for the process of sulfiding arsenic and its compounds, studies were carried out to determine the effect of temperature and the consumption of elemental sulfur on the degree of sublimation of arsenic from gold-arsenic concentrate. The sulfiding roasting of the concentrate was carried out with elemental sulfur vapor coming from a new design evaporator with a mixture of gaseous nitrogen. Findings. The main minerals of the original concentrate are pyrite, marcasite, arsenopyrite, native gold and silver. Significant elements in the concentrate are, %: arsenic 2.93.1, iron 707.3, gold 40. It has been calculated by thermodynamic analysis that when the main minerals of gold-arsenic containing refractory ores and concentrates interact with sulfur in a neutral environment and in the range of 5001000 C, reactions of formation and removal of arsenic in the form of sulfides As2S3 and As4S4 occur. When a new design evaporator supplies elemental sulfur in a mixture with neutral gas and with an increase in firing temperature from 700 to 850 C at S : As = 0.35 : 1, the degree of sublimation of arsenic increases from 94.7 to 98.2%, with FeS2 : As = 1.3:1 from 94.0 to 99.5%. With an increase in the consumption of elemental sulfur vapor (with an increase in the S : As ratio from 0.35:1 to 0.6 : 1 and a temperature from 700 to 800 C), the degree of sublimation of arsenic from the gold-arsenic product reaches up to 99%. The condensed sublimes contained up to 98.599% As4S4 and As2S3, the dust caught in cyclones is close in its composition to the composition of cinder. Originality. A new technology for the removal of arsenic from gold-arsenic containing concentrates in an oxygen-free atmosphere in the temperature range of 700850 C with the removal and capture of arsenic sulfides up to 100% is proposed. The regularity of the degree of sulfidation of arsenic and its oxidized compounds by elemental sulfur vapors in a mixture with a neutral gas to As4S4 and As2S3 has been established. Practical value. The use of the new technology makes it possible to completely convert arsenic into sulfide forms which are environmentally friendly, convenient for storage, burial, or for use as antiseptics. The development can be used for processing arsenic-containing polymetallic ore materials.

show abstract

Two-step processing of refractory gold-containing sulfidic concentrate via biooxidation at two temperatures

Muravyov

2018

Chem. Pap.

View full text Add to dashboard Cite

Two-stage process of bacterial-chemical oxidation of refractory pyrite-arsenopyrite gold-bearing concentrate

Cited by 8 publications

References 4 publications

Diversity of the communities of acidophilic chemolithotrophic microorganisms in natural and technogenic ecosystems

Diversity of the communities of acidophilic chemolithotrophic microorganisms in natural and technogenic ecosystems

Investigation of the process of sulfiding of gold-arsenic containing ores and concentrates

Two-step processing of refractory gold-containing sulfidic concentrate via biooxidation at two temperatures

Contact Info

Product

Resources

About