Effect of redox potential on chalcopyrite dissolution imposed by addition
                        of ferrous ions

Santos, Ana Laura; Arena, Fabiana Antonia; Benedetti, Assis Vicente; Bevilaqua, Denise

doi:10.26850/1678-4618eqj.v42.1.2017.p40-50

Cited by 16 publications

(5 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Santos et al also observed an increase from 300-400 mV to 570-600 mV (Ag/AgCl/KCl) in leaching solution Eh during the seven first days of chalcopyrite bioleaching by A. ferrooxidans, under different ferrous ions concentrations [35]. Redox potential of leaching solution is recognized as one of the most important issues on chalcopyrite bioleaching and it is mainly controlled by the [Fe 3+ ]/[Fe 2+ ] ratio dynamics along the process [35]. One of the proposed mechanisms is that Eh must allow the initial reduction of chalcopyrite to chalcocite (Cu 2 S) and its subsequent oxidation and releasing the soluble copper which is achieved under 400-450 mV (Ag/AgCl/KCl) [10].…”

Section: Ph and Eh Monitoringmentioning

confidence: 86%

“…An increase to 600 mV was observed after the 6th day until the 21th day in the reactor 2 amended with the weathered ore probably due to the accumulation of Fe 3+ in the absence of reduced mineral sulfides, reaching a final value of 586 mV at the 50th day ( Figure 7B). Santos et al also observed an increase from 300-400 mV to 570-600 mV (Ag/AgCl/KCl) in leaching solution Eh during the seven first days of chalcopyrite bioleaching by A. ferrooxidans, under different ferrous ions concentrations [35]. Redox potential of leaching solution is recognized as one of the most important issues on chalcopyrite bioleaching and it is mainly controlled by the [Fe 3+ ]/[Fe 2+ ] ratio dynamics along the process [35].…”

Section: Ph and Eh Monitoringmentioning

confidence: 98%

See 1 more Smart Citation

Bioleaching for Copper Extraction of Marginal Ores from the Brazilian Amazon Region

Nascimento

Lucheta

Palmieri

et al. 2019

Metals

View full text Add to dashboard Cite

The use of biotechnology to explore low-grade ore deposits and mining tailings is one of the most promising alternatives to reduce environmental impacts and costs of copper extraction. However, such technology still depends on improvements to be fully applied in Brazil under industrial scale. In this way, the bioleaching, by Acidithiobacillus ferrooxidans, in columns and stirred reactors were evaluated regarding to copper extraction of a mineral sulfide and a weathered ore from the Brazilian Amazon region. Samples (granulometry of 2.0/4.75 mm) were characterized by X-ray diffraction (XRD), energy dispersive X-ray fluorescence (EDXRF) spectrometry and scanning electrons microscopy (SEM). The pH and Oxidation-reduction potential (Eh) were daily monitored and leachate samples were collected for copper extraction determination by EDXRF. After 47 days, the columns bioleaching efficiency was 1% (1298 mg Cu·L−1) and 0.95% (985 mg Cu·L−1) for 2.00/4.75 mm sulfide ore, respectively, whereas the stirred reactors bioleaching resulted in 4% (348 mg Cu·L−1) for the mineral sulfide and 47% (295.5 mg Cu·L−1) for the weathered ore.

show abstract

Section: Ph and Eh Monitoringmentioning

confidence: 86%

Section: Ph and Eh Monitoringmentioning

confidence: 98%

Bioleaching for Copper Extraction of Marginal Ores from the Brazilian Amazon Region

Nascimento

Lucheta

Palmieri

et al. 2019

Metals

View full text Add to dashboard Cite

show abstract

“…The obtained results support the earlier study suggesting that the dissolution of chalcopyrite appears to be an acidic consuming reaction [27] B. Leaching solid residue XRD characterization Figure 3, Tables 3 and 4 show the mineral content of the various solid residues collected according to the red dots as shown on the Cu dissolution curve. The progressive chalcopyrite dissolution was observed; a decrease in its major peak intensity was noticed suggesting an effective mineral dissolution [28]. In addition to that, the Cu dissolution appeared to be accompanied with new mineral phases formation.…”

Section: A Leachate Characterizationmentioning

confidence: 90%

Mineralogical Observation Made During the Kinetic Dissolution Study of Chalcopyrite Mineral in Sulphate Media under Free pH at Room Temperature

Nyembwe¹,

Fosso‐Kankeu²,

Waanders³

et al. 2018

ASETH-18,ACABES-18 &Amp; EBHSSS-18 Nov. 19-20 2018 Cape Town (South Africa)

View full text Add to dashboard Cite

An attempt to determine the various phenomena at play and leaching mechanism of chalcopyrite dissolution, was conducted on a chalcopyrite concentrate. The study was performed at atmospheric conditions (room temperature) in a stirred Erlenmeyer flask with 10% solid at free pH in acidic sulphate system. It appears that, the mineral dissolution is to some extent dependent on the pH. The Cu dissolution curve was characterized at the early stage by a rapid withdrawal of both copper and solid residue. Leachate solid residue characterization results, obtained from the X-ray diffraction revealed the presence of intermediate minerals phases including bornite, covelite and chalcocite. Thermodynamic calculations predict that the dissolution of bornite and chalcocite would be spontaneous while covelite was found to be refractory. In addition to that, sulfur and gangue related mineral were identified as the dissolution reaction products.

show abstract

“…Os valores obtidos a partir da metade do experimento, próximos a 580mV, foram semelhantes aos obtidos por Mejía et al (2015) [23], que realizou biolixiviação da calcopirita em frascos agitados por 30 dias, empregando A. ferrooxidans. Santos e colaboradores [24] observaram valores de Eh variando entre 300 a 470mV em condições abióticas de oxidação da calcopirita, enquanto que na presença da bactéria A. ferrooxidans LR, os valores de Eh observados foram próximos a 600mV, semelhante aos observados no presente estudo.…”

Section: Monitoramento Do Ph E Ehunclassified

Biolixiviação Em Colunas Para Extração De Cobre a Partir De Minério Da Região Amazônica

Nascimento¹,

Lucheta²,

Palmieri³

et al. 2019

ABM Proceedings

View full text Add to dashboard Cite

Resumo A biolixiviação consiste na solubilização de componentes metálicos insolúveis presente nos minérios, em formas solúveis em água, por atividade direta ou indireta de micro-organismos, como o Acidithiobacillusferrooxidans. O objetivo deste trabalho foi avaliar a eficiência da biolixiviação em colunas, por A. ferrooxidans, de um sulfeto mineral proveniente de Carajás (PA), com granulometrias de 2,00 e 4,75 mm. Caracterizações mineralógica e química foram realizadas por DRX e FRX. O pH, potencial redox (Eh),extração do cobre, densidade e viabilidade bacteriana na solução lixiviadora foram medidos. A colonização bacteriana nas partículas foi determinada por MEV.Os minerais calcopirita, quartzo, magnetita e magnesiohornblenda ferrosaforam identificados, com o predomínio dos elementos S, Fe, Cu e Si na amostra mineral. Após 54 dias, foram extraídos 1,07% e 0,95% de cobre para as granulometrias de 2,00 e 4,75 mm, respectivamente. As bactérias permaneceram viáveis na forma planctônica e formaram biofilmes nas partículas. Os resultados indicam que a menor granulometria do minério favoreceu a extração, apesar da refração da calcopirita à biolixiviação. Mesmo pequena em escala laboratorial, esta diferença pode ser significativa em pilhas de processos industriais. Palavras-chave:Biolixiviação; Biomineração; Calcopirita;Copper. COLUMN BIOLEACHING FOR COPPER EXTRACTION FROM AN ORE OF THE AMAZON REGION Abstract The bioleaching consists in the solubilization of insoluble metals present in the ores to a water-soluble form, by the direct or indirect microorganism's action, like Acidithiobacillusferrooxidans. The goal of this work was to evaluate the column bioleaching, using A. ferrooxidans, of a sulfide mineral from Carajás (PA), with particle sizes of 2.00 and 4.75 mm. Mineralogical and chemical samplecharacterization were performed by XRD and EDXRF, respectively. The pH, redox potential (Eh), copper extraction, bacterial density and viability were monitored in the leaching solution. Bacterial colonization over the ore surface was checked by SEM.The minerals chalcopyrite, quartz, magnetite and iron-magnesium hornblende were identified, and the elements S, Fe, Cu e Si were the most abundant in the ore sample. After 54 days, were extracted 1.07% and 0.95% of copper for the 2.00 and 4.75 mm particles, respectively. Viable bacteria was observed in planktonic form and forming biofilms over the particles. The results indicated that lower granulometry favored the copper extraction, despite the chalcopyrite recalcitrance to bioleaching. Despite the small differences, it may be very significant considering a bioleaching heap scale.

show abstract

Effect of redox potential on chalcopyrite dissolution imposed by addition of ferrous ions

Cited by 16 publications

References 25 publications

Bioleaching for Copper Extraction of Marginal Ores from the Brazilian Amazon Region

Bioleaching for Copper Extraction of Marginal Ores from the Brazilian Amazon Region

Mineralogical Observation Made During the Kinetic Dissolution Study of Chalcopyrite Mineral in Sulphate Media under Free pH at Room Temperature

Biolixiviação Em Colunas Para Extração De Cobre a Partir De Minério Da Região Amazônica

Contact Info

Product

Resources

About