Abstract
A series of nCaO·Al2O3·2SiO2 samples (n = 1-4) were prepared by solid-state reaction of mechanochemically treated mixtures of kaolinite and calcite fired at 600-1000°C for 24 h. All the samples were X-ray amorphous after firing at 600-800°C but had crystallized by 900°C. The main crystalline phases were anorthite (n = 1), gehlenite (n = 2 and 3) and larnite (n = 4). The uptake of Ni2+ by nCaO·Al2O3·2SiO2 samples fired at 800 and 900°C was investigated at room temperature using solutions with initial Ni2+ concentrations of 0.1-50 mmol/l. Amorphous samples (fired at 800°C) showed a higher Ni2+ uptake capacity than crystalline samples (fired at 900°C). Ni2+ uptake was found to increase with increasing of CaO content. Amorphous 4CaO·Al 2O3·2SiO2 showed the highest Ni 2+ uptake capacity (about 9 mmol/g). The Ni2+ uptake abilities of the present samples are higher than those of other materials reported in the literature. Since the sorbed Ni2+/released Ca 2+ ratios of these samples are close to unity, ion replacement of Ni2+ for Ca2+ is thought to be the principal mechanism of Ni2+ uptake by the present samples.
Original language | English |
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Pages (from-to) | 281-287 |
Number of pages | 7 |
Journal | Journal of Hazardous Materials |
Volume | 123 |
Issue number | 1-3 |
DOIs | |
Publication status | Published - Aug 31 2005 |
Externally published | Yes |
Keywords
- CaO-AlO-SiO system
- Calcite
- Kaolinite
- Mechanochemical treatment
- Ni uptake
ASJC Scopus subject areas
- Environmental Engineering
- Environmental Chemistry
- Waste Management and Disposal
- Pollution
- Health, Toxicology and Mutagenesis