Hydrometallurgical Processing of a Nigerian Galena Ore in Nitric Acid: Characterization and Dissolution Kinetics

Nnanwube, Ikechukwu A.; Onukwuli, Okechukwu Dominic

doi:10.4236/jmmce.2018.63020

Cited by 9 publications

(6 citation statements)

References 24 publications

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“…Herein, all the peaks observed in the orange curve were attributed to the barite sample in agreement with previous reports. , Similarly, the results for celestite (shown in green) are supported by previous literature reports. , With regard to sulfide scales, XRD confirmed that the sample used herein is pure PbS. All the peaks, shown in purple at 2 theta of 26, 30, 43.5, 51, 63, 69, and 71° are for PbS. − Pyrite sample results are given elsewhere, whereas the four peaks at 30, 34.5, 44, and 53.5° (in red color) are for pyrrhotite. − Finally, carbonate scales are studied using the CaCO 3 sample with the XRD peaks illustrated in black and are in agreement with the published literature. , All samples were pure minerals as confirmed by the XRD results.…”

Section: Resultssupporting

confidence: 91%

Dissolution Kinetics of Different Inorganic Oilfield Scales in Green Formulations

et al. 2020

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Scale mineral deposition is a critical problem that hinders the daily production of oil and gas fields. Chemical removal of these scales, based on the scale type, is common. In this paper, borax and diethylene tremaine penta acetic (DTPA) acid-based formulations are used for the removal of sulfides, carbonates, and sulfate scales. In particular, the dissolution rates of sulfide (pyrite, pyrrhotite, and galena), sulfate (celestite and barite), and carbonate (calcite) scales were investigated in a rotating disc apparatus at typical well conditions. Scanning electron microscopy–energy-dispersive X-ray and X-ray diffraction analyses were performed for characterizing scale composition and type. The effect of temperature, scale type, and formulation on the dissolution rate is studied. Even though borax formulation has been developed for the sulfide scale removal, it showed a high dissolution rate for the carbonate scale (7.23 × 10–7 mol·L–1·s–1·cm–2). For the sulfide scale, the highest dissolution in borax formulation was obtained with galena (lead sulfide, PbS), followed by pyrrhotite, and the lowest dissolution was reported for pyrite (1.55 × 10–8 mol·L–1·s–1·cm–2). Borax formulation was found to be inefficient in the removal of sulfate scales with a dissolution rate lower than carbonate and sulfide scales by 3 and 2 orders of magnitude, respectively. Similarly, DTPA-based formulation has yielded the highest dissolution for the carbonate scale (7.98 × 10–6 mol·L–1·s–1·cm–2). However, for sulfate, DTPA-based formulation showed better performance than borax. The increase in temperature leads to an increase in the dissolution rate for almost all types of scales; however, DTPA-based formulation showed improved performance with temperature. Both formulations are efficient in removing sulfate- and sulfide-rich scales. The experimental results of DTPA have been validated by density functional theory calculations of binding energies between DTPA and metal ions present in the mixed scale.

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Section: Resultssupporting

confidence: 91%

Dissolution Kinetics of Different Inorganic Oilfield Scales in Green Formulations

et al. 2020

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“…The formation of galena is often linked to the hydrothermal alteration of leadbearing minerals in the presence of sulfur-rich fluids. Additional compounds like lead carbonate and lead sulfate can also be present in galena, depending on the location of the ore mining site [1][2][3][4][5][6]. PbS, with a lead-to-sulfur ratio of 86:13 mass percent, is found in the Japanese and American galena ores [1].…”

Section: Introductionmentioning

confidence: 99%

“…Additional compounds like lead carbonate and lead sulfate can also be present in galena, depending on the location of the ore mining site [1][2][3][4][5][6]. PbS, with a lead-to-sulfur ratio of 86:13 mass percent, is found in the Japanese and American galena ores [1]. This compound is commonly used in various practical applications, including solar energy and infrared sensors, due to its low energy gap of bulk pieces (~0.4 eV), optoelectronics, semiconductors, thermoelectric materials, and biconical uses [7][8][9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Study of Galena Ore Powder Sintering and Its Microstructure

Al-Saqarat,

Al-Mobydeen,

Al-Dalahmeh

et al. 2024

Metals

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Galena is a natural mineral enriched with lead sulfide (PbS). It typically forms in hydrothermal veins associated with igneous rocks and can also occur as a gangue mineral in other ore deposits. PbS is of special importance for scientific research applications due to the possibility of tuning its semiconductor energy gap using nanotechnology in conjunction with powder metallurgy as an easy, controllable production route. In this paper, almost pure PbS was successfully produced starting from a high ratio of PbS phase galena ore. As-received galena lumps were roughly pulverized and milled to produce four particle size ranges of 38, 63, 125, and 250 µm prior to compaction and sintering in a vacuum (pre-flushed with argon gas). SEM coupled with the EDAX analysis unit was employed to investigate the microstructure and chemical composition of the as-received galena and the subsequent products after sintering. The chemical analysis confirmed the high ratio of PbS compound in the as-received galena and sintered products with approximately 85% Pb and 13% S mass ratio. The sintering process of the galena powder was carried out at different values of temperature, time, and compaction pressure. Additionally, the effect of length to diameter ratio of compacted and sintered samples was investigated. XRD analysis confirmed the existence of the PbS phase in the as-received and sintered samples at 700 °C with approximately 98 wt.%, as well as a new phase that is formed at 800 °C with a lower percentage. The micro-hardness of the as-received and sintered samples was measured and compared with the as-received galena ore. The results showed a significant reduction in the hardness of sintered galena powder compared with the bulk as-received galena by 52%. Furthermore, a relative sintered density of 99.3% for the as-received galena density signifies a novel result using powder metallurgy techniques.

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“…Galena mainly consists of lead sulfide (PbS) and other trace elements such as silver, zinc, silicon, iron, copper, and their oxides [ 1 , 2 ]. Depending on the mining site, many types of galena with different chemical composition have been reported [ 3 ], and it has been confirmed that the richest lead and sulfur galena ores were found in the USA and Japan. As long as galena mineral is the main source of lead, it will remain the main source of PbS compounds for many applications, such as thermoelectric parts, infrared detectors, solar selective surfaces, semiconductors, and solar cells [ 4 , 5 , 6 , 7 ].…”

Section: Introductionmentioning

confidence: 99%

Facile Production Method of PbS Nanoparticles via Mechanical Milling of Galena Ore

Al-Saqarat

Al-Mobydeen

Al-Masri³

et al. 2023

Micromachines

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In this research, some physical properties such as the density, specific heat capacity, and micro-hardness of galena ore lumps purchased from the public market were determined. The microscopic study, using the scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS), confirmed that the as-received galena ore was mostly lead sulfide (PbS). The XRD pattern of the galena powder also elucidated that all the peaks were assigned to PbS. In addition, the as-received galena was roughly crushed, and fine-milled using a high-vibration milling machine with tungsten carbide rings. Nanoscale particles of about 90 nm were produced in a very short milling time of around 15 min. The obtained nanoscale powder was well investigated in the SEM at low and high magnifications to assess the exact range of particle size. Meanwhile, the SEM was employed to investigate the microstructure of sintered samples, where a part of the milled galena powder was compacted and sintered at 700 °C for 2 h. Again, the result of this investigation proved the formation of PbS with even smaller grain size compared with the grain size of the starting galena ore. A high relative sinter density of approximately 97% for galena powder was achieved by sintering under vacuum.

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Hydrometallurgical Processing of a Nigerian Galena Ore in Nitric Acid: Characterization and Dissolution Kinetics

Cited by 9 publications

References 24 publications

Dissolution Kinetics of Different Inorganic Oilfield Scales in Green Formulations

Dissolution Kinetics of Different Inorganic Oilfield Scales in Green Formulations

Study of Galena Ore Powder Sintering and Its Microstructure

Facile Production Method of PbS Nanoparticles via Mechanical Milling of Galena Ore

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