Cubic and tetragonal ferrite crystal structures for copper ion immobilization in an iron-rich ceramic matrix

Abstract

This study proposes a “waste-to-resource” strategy by reusing the incineration ash of municipal wastewater sludge as a ceramic material to immobilize copper.

Spinel copper ferrite nanoparticles: Preparation, characterization and catalytic activity

“…XRD patterns was obtained to specify the crystal structure of the prepared CuFe 2 O 4 nanoparticles. As shown in Figure a, the strong and sharp reflection peaks in XRD patterns of nanoparticles are corresponded to the cubic phase of CuFe 2 O 4 with a good crystallinity (JCPDS file No:04–005‐7637) . According to the EDX analysis, the distribution of the elements in the produced CuFe 2 O 4 nanoparticles was Cu = 15.66%, Fe = 32.17% and O = 50.98%, that the its corresponding iron\copper ratio 2.05 is almost agreement to the atomic ratio in the formula CuFe 2 O 4 (Figure b).…”

Dual role of coal fly ash in copper ion adsorption followed by thermal stabilization in a spinel solid solution

“…Reactions between copper and iron ions have also been reported previously in a solid CuO-Fe 2 O 3 system followed by the formation of CuFe 2 O 4 with a spinel structure. 37 The copper leachability from the spinel was found to decrease by over two orders in magnitude in comparison with that from copper oxides in acetic acid solutions, 37 which conrmed the effective immobilization of copper ions in copper-adsorbed y ash aer sintering. With a further increase in the sintering temperature, the CuFe 2 O 4 peaks eventually grew while the CuO signals reduced accordingly.…”

“…Previous studies have also reported a lower sintering temperature for a ferrite spinel when compared to that of an aluminate spinel. 36,37 The tendency for peaks to shi with an increase in temperature was further analyzed and the results are shown in Fig. 4c.…”

“…It has been reported that hazardous metal-containing wastes can be used to fabricate ceramic products, 34,35 with the hazardous metals being effectively stabilized in matrices rich in aluminum (Al), silicon (Si), and iron (Fe) via encapsulation into a variety of crystal structures. 36,37 Aluminum, silicon, and iron have also been reported as predominant components in coal y ash, 38,39 which provides a possible matrix for heavy metal stabilization aer its exhaustion as a heavy metal adsorbent. Therefore, in this work, coal y ash is used as an adsorbent for copper removal from aqueous solutions, and its dual role in the immobilization of heavy metals is further studied.…”

“…In copper-containing systems either rich in aluminum or iron, crystalline phases with a spinel structure can be generated with the chemical formulae CuAl 2 O 4 and CuFe 2 O 4 , respectively. 36,37 However, in y ash containing both aluminum and iron as the major components, a different mechanism is anticipated due to the competition for copper between aluminum and iron during thermal processes. This study will rst investigate the adsorption of copper ions on coal y ash, and then propose a ceramic sintering scheme for the disposal of the copper-adsorbed y ash.…”