A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Apatite and Portland/apatite composite cements obtained using a hydrothermal method for retaining heavy metals
Apatite and Portland/apatite composite cements containing steelwork dusts have been prepared using a low temperature hydrothermal method (200 deg C, 48 h). The produced solids were characterised by means of XRD (X-ray diffraction), IR (infrared), and SEM-EDX (scanning electron microscopy- energy dispersive X-ray), and the remaining liquid was analysed by ICP (inductively coupled plasma). The results clearly the capability of these cements to inertise the heavy metals contained in steelwork dusts, that is Fe, Pb, Mo, Cr, Mn, Ni, and Zn. In the case of apatitic cements, Fe, Mg, Cr, Mn, and Pb coming from steel dust replaced Ca in the divalent cation position of the apatite structure, while Si and Mo replaced P in tetrahedral position. The average crystal size of the apatite-containing dust is smaller than in pure apatite synthesised using the same procedure, which is related to the magnesium content of the dust, since magnesium seems to inhibit the crystal growth. XRD diagrams of composite cements show only peaks corresponding to phases observed in the single cements, and in that no new phases are found. However, EDX analysis reveals the introduction of cations coming from Portland cement into the apatite structure. From the results of water analysis it could be concluded that the capability of retention is higher in composite matrices than in the pure apatite one. In conclusion, the obtained data allow stating that the proposed method, the hydrothermal synthesis of steelwork dust containing cement, is a reliable one for immobilisation of toxic residues containing heavy leachable cations.
Apatite and Portland/apatite composite cements obtained using a hydrothermal method for retaining heavy metals
Apatite and Portland/apatite composite cements containing steelwork dusts have been prepared using a low temperature hydrothermal method (200 deg C, 48 h). The produced solids were characterised by means of XRD (X-ray diffraction), IR (infrared), and SEM-EDX (scanning electron microscopy- energy dispersive X-ray), and the remaining liquid was analysed by ICP (inductively coupled plasma). The results clearly the capability of these cements to inertise the heavy metals contained in steelwork dusts, that is Fe, Pb, Mo, Cr, Mn, Ni, and Zn. In the case of apatitic cements, Fe, Mg, Cr, Mn, and Pb coming from steel dust replaced Ca in the divalent cation position of the apatite structure, while Si and Mo replaced P in tetrahedral position. The average crystal size of the apatite-containing dust is smaller than in pure apatite synthesised using the same procedure, which is related to the magnesium content of the dust, since magnesium seems to inhibit the crystal growth. XRD diagrams of composite cements show only peaks corresponding to phases observed in the single cements, and in that no new phases are found. However, EDX analysis reveals the introduction of cations coming from Portland cement into the apatite structure. From the results of water analysis it could be concluded that the capability of retention is higher in composite matrices than in the pure apatite one. In conclusion, the obtained data allow stating that the proposed method, the hydrothermal synthesis of steelwork dust containing cement, is a reliable one for immobilisation of toxic residues containing heavy leachable cations.
Apatite and Portland/apatite composite cements obtained using a hydrothermal method for retaining heavy metals
Dominguez, M.I. (author) / Carpena, J. (author) / Borschnek, D. (author) / Centeno, M.A. (author) / Odriozola, J.A. (author) / Rose, J. (author)
Journal of Hazardous Materials ; 150 ; 99-108
2008
10 Seiten, 10 Bilder, 6 Tabellen, 49 Quellen
Article (Journal)
English
Zement , Verbundwerkstoff , Portlandzement , Schwermetallentfernung , Stahlherstellung , Mühle , hydrothermales Verfahren , Entstaubung , Metallpulver , Schleifstaub , Eisenverbindung , Eisenion , Bleiverbindung , Bleiion , Molybdänverbindung , Molybdänion , Chromverbindung , Chromion , Manganion , Manganverbindung , Nickelverbindung , Nickelion , Zinkverbindung , Zinkion , Kationenaustausch , Abwasserreinigung , Lauge
Effect of Apatite Cements on Human Osteoblasts in Vitro
| British Library Online Contents | 2001
Effect of Apatite Cements on Human Osteoblasts in Vitro
| Trans Tech Publications | 2000
Porous Apatite Carrier Prepared by Hydrothermal Method
| British Library Online Contents | 2006
Mechanical properties and apatite-forming ability of PMMA bone cements
| British Library Online Contents | 2009
Apatite formation on calcined kaolin–white Portland cement geopolymer
| Tema Archive | 2015