Thermochemical stability of delafossite and other relevant ternary phases in the Cu–Fe–S–O–H system

Aquino, Andrea; Lezzerini, Marco; Giaccherini, Andrea; Montegrossi, Giordano; Benedetto, Francesco Di

doi:10.1016/j.apgeochem.2020.104795

Cited by 2 publications

(1 citation statement)

References 49 publications

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“…The amount of Cu 2+ measured in the leachate solutions ranged from 0.23 to 0.65% for the materials of the Cu:GP pH series and increased slightly with increasing initial Cu:GP pH ratio (Figure 5c), which suggests that a partial dissolution of CuO and Cu(OH) 2 phases accounted for the Cu 2+ release. This assertion is supported by the lower stability of these minerals under acidic conditions and their higher solubility in pure water (K tenorite = 10 −8.6 ; K spertiniite = 10 −11.3 ; 25 • C) compared to gerhardtite [58,[62][63][64]. No visible microstructural modifications were recognized for the leached Cu-GPs of the Cu:GP pH series (Figure 5d).…”

Section: Implications For Water Treatment and Environmental Remediationmentioning

confidence: 80%

Substantial Copper (Cu2+) Uptake by Metakaolin-Based Geopolymer and Its Resistance to Acid Leaching and Ion Exchange

et al. 2023

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Geopolymers are inorganic, chemically resistant aluminosilicate-based binding agents, which remove hazardous metal ions from exposed aqueous media. However, the removal efficiency of a given metal ion and the potential ion remobilization have to be assessed for individual geopolymers. Therefore, copper ions (Cu2+) were removed by a granulated, metakaolin-based geopolymer (GP) in water matrices. Subsequent ion exchange and leaching tests were used to determine the mineralogical and chemical properties as well as the resistance of the Cu2+-bearing GPs to corrosive aquatic environments. Experimental results indicate the pH of the reacted solutions to have a significant impact on the Cu2+ uptake systematics: the removal efficiency ranged from 34–91% at pH 4.1–5.7 up to ~100% at pH 11.1–12.4. This is equivalent to Cu2+ uptake capacities of up to 193 mg/g and 560 mg/g in acidic versus alkaline media. The uptake mechanism was governed by Cu2+-substitution for alkalis in exchangeable GP sites and by co-precipitation of gerhardtite (Cu2(NO3)(OH)3) or tenorite (CuO) and spertiniite (Cu(OH)2). All Cu-GPs showed excellent resistance to ion exchange (Cu2+ release: 0–2.4%) and acid leaching (Cu2+ release: 0.2–0.7%), suggesting that tailored GPs have a high potential to immobilize Cu2+ ions from aquatic media.

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Section: Implications For Water Treatment and Environmental Remediationmentioning

confidence: 80%

Substantial Copper (Cu2+) Uptake by Metakaolin-Based Geopolymer and Its Resistance to Acid Leaching and Ion Exchange

et al. 2023

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Thermodynamic Calculations of Direct Reduction Smelting Technology of Copper Oxide Ores Based on Smelting Slag from the Yubeidi Site, Yunnan Province

Zhu

et al. 2023

Metals

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The current research on metallurgical remains from scientific excavations in northeast Yunnan from the Bronze Age period is insufficient. In order to study the smelting technology of the Bronze Age in north-eastern Yunnan, samples of slag and mineral excavated from the Yubei Di site in Dongchuan were examined. Based on the outcome of the characterization analysis, a simulation was executed utilizing the software Factsage 7.1 in order to generate a phase diagram that accurately portrays the melting procedure. This simulation aimed to produce the most credible representation of the phase transition by employing computational methods. Characterisation methods included Metallographic Microscopy, Scanning Electron Microscopy Energy Dispersive Spectromicropy (SEM-EDS), X-ray diffraction (XRD), and Radiocarbon Date (14C dating). The results showed that there was much copper ore left in the slag of the site. Most of these copper ores were in the form of copper ferrite or cuprous oxide. The copper ore was copper oxide ore, and metal copper particles appeared in a small amount of the slag. Most of the slags unearthed from the site of the Yubeidi site were products of sulfur-containing oxide reduction and smelting into copper. Based on the outcomes of the simulations, it was established that the slag excavated from the Yubeidi site was mainly from the reduction and smelting process of sulphur-containing copper oxide minerals into copper, without consciously adding fluxes, not having mastered the slag-making techniques for different types of copper ores, and with primitive techniques. The carbon 14 dating results show that the age of the slag was during the Spring and Autumn Period and the Warring States Period.

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Thermochemical stability of delafossite and other relevant ternary phases in the Cu–Fe–S–O–H system

Cited by 2 publications

References 49 publications

Substantial Copper (Cu2+) Uptake by Metakaolin-Based Geopolymer and Its Resistance to Acid Leaching and Ion Exchange

Substantial Copper (Cu2+) Uptake by Metakaolin-Based Geopolymer and Its Resistance to Acid Leaching and Ion Exchange

Thermodynamic Calculations of Direct Reduction Smelting Technology of Copper Oxide Ores Based on Smelting Slag from the Yubeidi Site, Yunnan Province

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