scholarly journals Recovery of Copper and Magnetite from Copper Slag Using Concentrated Solar Power (CSP)

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1032
Author(s):  
Daniel Fernández-González ◽  
Janusz Prazuch ◽  
Íñigo Ruiz-Bustinza ◽  
Carmen González-Gasca ◽  
Cristian Gómez-Rodríguez ◽  
...  

On the one hand, copper slag is nowadays a waste in copper pyrometallurgy despite the significant quantities of iron (>40 wt. %) and copper (1 to 2 wt. %). On the other hand, solar energy, when properly concentrated, offers great potential in high-temperature processes. Therefore, concentrated solar power (CSP) could be used in the treatment of copper slag to transform fayalite into magnetite and copper sulfides and oxides into copper nodules. This is the objective of this paper. The results show that fayalite was partially decomposed into magnetite and silica. Moreover, copper nodules (65–85 wt. % Cu) were identified in the treated samples, while the initial slag, analyzed by X-ray diffraction, X-ray fluorescence, and SEM-EDX, did not show the presence of metallic copper. Finally, the treated copper slag was crushed and grinded down to 40 μm, and two fractions were obtained by magnetic separation. The magnetic fraction (85%) was mainly comprised of magnetite, while the non-magnetic fraction (15%) had 5–10 wt. % Cu. Considering the experimental results, 7.5–18 kg Cu/t slag might be recovered from the slag. A preliminary economic analysis, considering the current copper price, indicates that only the recovery of copper could represent a significant economic benefit (>30 €/t slag). Therefore, CSP might be a potential candidate for the treatment of copper slag to recover copper and iron.

2007 ◽  
Vol 336-338 ◽  
pp. 1914-1917
Author(s):  
Lei Yang ◽  
Zhen Yi Zhang ◽  
Xiao Shan Ning ◽  
Guang He Li

In this paper, a novel and highly efficient hydroxyapatite (HA) carrier for cultivating hydrocarbon degradation bacteria (HDB) is introduced. The HA particles synthesized through a sol-gel method and different heat treatments were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and BET method. The microbial amount and activities of HDB cultivated on HA carriers were quantitatively investigated in order to assess their enriching capabilities. The results showed that HA synthesized at 550°C and the one without calcination could enrich HDB 3 and 2 magnitude orders more than the activated carbon, respectively. Mechanisms of bacterial enrichment on HA and activated carbon were also studied, and it is believed that the high bioactivity and the surface morphology of HA were responsible for the efficient reproduction of HDB. It is concluded that HA is a potential candidate to replace the conventionally used activated carbon as a novel carrier applied in the filed of bioremediation for oil contaminated soil.


1981 ◽  
Vol 36 (8) ◽  
pp. 989-996 ◽  
Author(s):  
L. Horner ◽  
E. Pliefke

Abstract The analysis of the protective coating produced during the corrosion of copper in the presence of 2-aminopyrimidine (2-AP) is consistent with the composition [Cu1+-2-AP-Cl]n. The individual units form a three-dimensional macro-structure via chloride bridging and hydrogen bonding. The assignment of the structure was supported by NMR, IR, UV and magnetic susceptibüity measurements and an X-ray investigation using the Debye- Scherrer powder method. The thermal behaviour of the coating was studied by massspectral and DTA (differential thermal analysis) methods. Radiochemical experiments were carried out using active copper samples (i.e. containing 64Cu), or using added 64CuCl and 64CuCl2 in the corrosion of non-active copper both in the presence and absence of added 2-AP. The results elucidate the exchange reactions at the copper surface between dissolved and metallic components. The equilibrium between Cu2+ and metallic copper on the one hand and 2 Cu1+ ions on the other is central to the problem, as is also the dissociation of the [Cu1+-2-AP-Cl]n complex. The concepts here developed were confirmed by studies of the autoxidation of CuCl and CuO in the presence and absence of 2-AP.


Coatings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 510 ◽  
Author(s):  
Achenbach ◽  
Sahu ◽  
Völker ◽  
Hans ◽  
Primetzhofer ◽  
...  

MoAlB is a potential candidate for high-temperature application since a dense, adherent alumina scale is formed. While, based on X-ray diffraction investigations, the formation of phase pure orthorhombic MoAlB coatings is observed, energy dispersive X-ray spectroscopy carried out in a scanning transmission electron microscope reveals the presence of Al-rich and O-rich regions within the MoAlB matrix. The oxidation kinetics of coatings and bulk is similar to the scale thickness formed on the MoAlB coating after oxidation at 1200 °C for 30 min is similar to the one extrapolated for bulk MoAlB. Furthermore, the oxidation kinetics of MoAlB coatings is significantly lower than the one reported for bulk Ti2AlC. Finally, the elastic properties measured for the as-deposited coatings are consistent ab initio predictions.


2017 ◽  
Vol 8 (4) ◽  
pp. 1-19
Author(s):  
Oliveira Helio Marques de ◽  
◽  
Giacaglia Giorgio Eugenio Oscare ◽  

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 899
Author(s):  
Murendeni P. Ravele ◽  
Opeyemi A. Oyewo ◽  
Damian C. Onwudiwe

Pure-phase Cu2−xS (x = 1, 0.2) nanoparticles have been synthesized by the thermal decomposition of copper(II) dithiocarbamate as a single-source precursor in oleylamine as a capping agent. The compositions of the Cu2−xS nanocrystals varied from CuS (covellite) through the mixture of phases (CuS and Cu7.2S4) to Cu9S5 (digenite) by simply varying the temperature of synthesis. The crystallinity and morphology of the copper sulfides were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), which showed pure phases at low (120 °C) and high (220 °C) temperatures and a mixture of phases at intermediate temperatures (150 and 180 °C). Covellite was of a spherical morphology, while digenite was rod shaped. The optical properties of these nanocrystals were characterized by UV−vis–NIR and photoluminescence spectroscopies. Both samples had very similar absorption spectra but distinguishable fluorescence properties and exhibited a blue shift in their band gap energies compared to bulk Cu2−xS. The pure phases were used as catalysts for the photocatalytic degradation of tetracycline (TC) under visible-light irradiation. The results demonstrated that the photocatalytic activity of the digenite phase exhibited higher catalytic degradation of 98.5% compared to the covellite phase, which showed 88% degradation within the 120 min reaction time using 80 mg of the catalysts. The higher degradation efficiency achieved with the digenite phase was attributed to its higher absorption of the visible light compared to covellite.


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