Formation of copper aluminate spinel and cuprous aluminate delafossite to thermally stabilize simulated copper-laden sludge

Ching Yao Hu, Kaimin Shih, James O. Leckie

Research output: Contribution to journalArticle

45 Citations (Scopus)

Abstract

The study reported herein indicated the stabilization mechanisms at work when copper-laden sludge is thermally treated with γ-alumina and kaolinite precursors, and evaluated the prolonged leachability of their product phases. Four copper-containing phases - copper oxide (CuO), cuprous oxide (Cu2O), copper aluminate spinel (CuAl2O4), and cuprous aluminate delafossite (CuAlO2) - were found in the thermal reactions of the investigated systems. These phases were independently synthesized for leaching by 0.1M HCl aqueous solution, and the relative leachabilities were found to be CuAl2O42≪≪Cu2O2O4 and CuAlO2 are extensively discussed here. With a 3h of short sintering, it was found that CuAl2O4 could be effectively formed between 850 and 950°C by the γ-alumina precursor. Although kaolinite had a lower incorporation capability than γ-alumina, it was found to transform a considerable amount of copper into CuAl2O4 between 950 and 1000°C. At higher temperatures, CuAlO2 was produced only in the γ-alumina system as the occurrence of Cu2O-cristobalite solution in the kaolinite system precluded the production of CuAlO2. The hypothesis that the spinel formation mechanism has two stages was supported by the results of the changing Cu/Al mole ratio in the system, and the rate-limiting step was identified as the diffusion process in the second stage.

Original languageEnglish
Pages (from-to)399-404
Number of pages6
JournalJournal of Hazardous Materials
Volume181
Issue number1-3
DOIs
Publication statusPublished - Sep 2010

Fingerprint

Aluminum Oxide
Sewage
Kaolin
spinel
Kaolinite
Copper
Alumina
aluminum oxide
sludge
copper
Copper oxides
kaolinite
oxide
cristobalite
Silicon Dioxide
Leaching
formation mechanism
Sintering
Stabilization
Hot Temperature

Keywords

  • Alumina
  • Copper
  • Kaolinite
  • Sludge
  • Spinel

ASJC Scopus subject areas

  • Health, Toxicology and Mutagenesis
  • Pollution
  • Waste Management and Disposal
  • Environmental Chemistry
  • Environmental Engineering
  • Medicine(all)

Cite this

Formation of copper aluminate spinel and cuprous aluminate delafossite to thermally stabilize simulated copper-laden sludge. / Hu, Ching Yao; Shih, Kaimin; Leckie, James O.

In: Journal of Hazardous Materials, Vol. 181, No. 1-3, 09.2010, p. 399-404.

Research output: Contribution to journalArticle

@article{f8554f374ec340b992b3fb644bd3c38d,
title = "Formation of copper aluminate spinel and cuprous aluminate delafossite to thermally stabilize simulated copper-laden sludge",
abstract = "The study reported herein indicated the stabilization mechanisms at work when copper-laden sludge is thermally treated with γ-alumina and kaolinite precursors, and evaluated the prolonged leachability of their product phases. Four copper-containing phases - copper oxide (CuO), cuprous oxide (Cu2O), copper aluminate spinel (CuAl2O4), and cuprous aluminate delafossite (CuAlO2) - were found in the thermal reactions of the investigated systems. These phases were independently synthesized for leaching by 0.1M HCl aqueous solution, and the relative leachabilities were found to be CuAl2O42≪≪Cu2O2O4 and CuAlO2 are extensively discussed here. With a 3h of short sintering, it was found that CuAl2O4 could be effectively formed between 850 and 950°C by the γ-alumina precursor. Although kaolinite had a lower incorporation capability than γ-alumina, it was found to transform a considerable amount of copper into CuAl2O4 between 950 and 1000°C. At higher temperatures, CuAlO2 was produced only in the γ-alumina system as the occurrence of Cu2O-cristobalite solution in the kaolinite system precluded the production of CuAlO2. The hypothesis that the spinel formation mechanism has two stages was supported by the results of the changing Cu/Al mole ratio in the system, and the rate-limiting step was identified as the diffusion process in the second stage.",
keywords = "Alumina, Copper, Kaolinite, Sludge, Spinel, Alumina, Copper, Kaolinite, Sludge, Spinel",
author = "Hu, {Ching Yao} and Kaimin Shih and Leckie, {James O.}",
year = "2010",
month = "9",
doi = "10.1016/j.jhazmat.2010.05.024",
language = "English",
volume = "181",
pages = "399--404",
journal = "Journal of Hazardous Materials",
issn = "0304-3894",
publisher = "Elsevier",
number = "1-3",

}

TY - JOUR

T1 - Formation of copper aluminate spinel and cuprous aluminate delafossite to thermally stabilize simulated copper-laden sludge

AU - Hu, Ching Yao

AU - Shih, Kaimin

AU - Leckie, James O.

PY - 2010/9

Y1 - 2010/9

N2 - The study reported herein indicated the stabilization mechanisms at work when copper-laden sludge is thermally treated with γ-alumina and kaolinite precursors, and evaluated the prolonged leachability of their product phases. Four copper-containing phases - copper oxide (CuO), cuprous oxide (Cu2O), copper aluminate spinel (CuAl2O4), and cuprous aluminate delafossite (CuAlO2) - were found in the thermal reactions of the investigated systems. These phases were independently synthesized for leaching by 0.1M HCl aqueous solution, and the relative leachabilities were found to be CuAl2O42≪≪Cu2O2O4 and CuAlO2 are extensively discussed here. With a 3h of short sintering, it was found that CuAl2O4 could be effectively formed between 850 and 950°C by the γ-alumina precursor. Although kaolinite had a lower incorporation capability than γ-alumina, it was found to transform a considerable amount of copper into CuAl2O4 between 950 and 1000°C. At higher temperatures, CuAlO2 was produced only in the γ-alumina system as the occurrence of Cu2O-cristobalite solution in the kaolinite system precluded the production of CuAlO2. The hypothesis that the spinel formation mechanism has two stages was supported by the results of the changing Cu/Al mole ratio in the system, and the rate-limiting step was identified as the diffusion process in the second stage.

AB - The study reported herein indicated the stabilization mechanisms at work when copper-laden sludge is thermally treated with γ-alumina and kaolinite precursors, and evaluated the prolonged leachability of their product phases. Four copper-containing phases - copper oxide (CuO), cuprous oxide (Cu2O), copper aluminate spinel (CuAl2O4), and cuprous aluminate delafossite (CuAlO2) - were found in the thermal reactions of the investigated systems. These phases were independently synthesized for leaching by 0.1M HCl aqueous solution, and the relative leachabilities were found to be CuAl2O42≪≪Cu2O2O4 and CuAlO2 are extensively discussed here. With a 3h of short sintering, it was found that CuAl2O4 could be effectively formed between 850 and 950°C by the γ-alumina precursor. Although kaolinite had a lower incorporation capability than γ-alumina, it was found to transform a considerable amount of copper into CuAl2O4 between 950 and 1000°C. At higher temperatures, CuAlO2 was produced only in the γ-alumina system as the occurrence of Cu2O-cristobalite solution in the kaolinite system precluded the production of CuAlO2. The hypothesis that the spinel formation mechanism has two stages was supported by the results of the changing Cu/Al mole ratio in the system, and the rate-limiting step was identified as the diffusion process in the second stage.

KW - Alumina

KW - Copper

KW - Kaolinite

KW - Sludge

KW - Spinel

KW - Alumina

KW - Copper

KW - Kaolinite

KW - Sludge

KW - Spinel

UR - http://www.scopus.com/inward/record.url?scp=77954542829&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77954542829&partnerID=8YFLogxK

U2 - 10.1016/j.jhazmat.2010.05.024

DO - 10.1016/j.jhazmat.2010.05.024

M3 - Article

C2 - 20570043

AN - SCOPUS:77954542829

VL - 181

SP - 399

EP - 404

JO - Journal of Hazardous Materials

JF - Journal of Hazardous Materials

SN - 0304-3894

IS - 1-3

ER -