Thermal behaviour of chrome shavings and of sludges recovered after digestion of tanned solid wastes with calcium hydroxide

Journal Article · Sun Jul 01 00:00:00 EDT 2007 · Waste Management

DOI:https://doi.org/10.1016/j.wasman.2005.12.012· OSTI ID:20877606

Tahiri, S ^[1]; Albizane, A ^[2]; Messaoudi, A ^[2]; Azzi, M ^[3]; Bennazha, J ^[2]; Younssi, S Alami ^[2]; Bouhria, M ^[2]

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1. Faculte des Sciences d'El Jadida, Universite Chouaib Doukkali, Departement de Chimie, B.P.20, El Jadida (Morocco)
2. Faculte des Sciences et Techniques, Universite Hassan II-Mohammedia, B.P.146, Avenue Hassan II, C.P.20650, Mohammedia (Morocco)
3. Faculte des Sciences Ain Chock, Universite Hassan II, Km.8, Route El Jadida, B.P.5366, Maarif, Casablanca (Morocco)

The thermal behaviour of chrome shavings and of sludges recovered after digestion of tanned wastes with Ca(OH){sub 2} was studied. Ashes obtained after incineration of wastes at various temperatures were analysed by X-ray diffraction and EDX method. The main crystallized phases present in the ash obtained at 600 deg. C are Cr{sub 2}O{sub 3} and NaCl. The diffractograms revealed an increase in the intensities of the chromium oxide peaks and a very notable decrease of the amount of sodium chloride at 1100 deg. C. EDX analysis revealed a total disappearance of the chlorine peak at this temperature. Scanning electron micrographs show that the waste lost its fibrous aspect when the temperature increases. Formation of aggregates was noted after 550 deg. C. Combustion of organic matters and decarbonation phenomenon are the main stages observed on GTA and DTA curves of sludges. These phenomena are, respectively, exothermic and endothermic. The diffractogram of sludges recorded at 550 deg. C, in the presence of a constant oxygen surplus, revealed the presence of CaCrO{sub 4} and CaCO{sub 3}.

• OSTI ID: 20877606
• Journal Information: Waste Management, Vol. 27, Issue 1; Other Information: DOI: 10.1016/j.wasman.2005.12.012; PII: S0956-053X(06)00009-2; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0956-053X
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ASHES
CALCIUM CARBONATES
CALCIUM HYDROXIDES
CHLORINE
CHROMATES
CHROMIUM OXIDES
COMBUSTION
DIFFERENTIAL THERMAL ANALYSIS
ELECTRON SCANNING
ORGANIC MATTER
SLUDGES
SODIUM CHLORIDES
SOLID WASTES
X-RAY DIFFRACTION