Kinetics of steel slag leaching: Batch tests and modeling
- CEREGE, UMR 6635 CNRS Aix-Marseille University, 13545 Aix-En-Provence (France)
Reusing steel slag as an aggregate for road construction requires to characterize the leaching kinetics and metal releases. In this study, basic oxygen furnace (BOF) steel slag were subjected to batch leaching tests at liquid to solid ratios (L/S) of 10 and 100 over 30 days; the leachate chemistry being regularly sampled in time. A geochemical model of the steel slag is developed and validated from experimental data, particularly the evolution with leaching of mineralogical composition of the slag and trace element speciation. Kinetics is necessary for modeling the primary phase leaching, whereas a simple thermodynamic equilibrium approach can be used for secondary phase precipitation. The proposed model simulates the kinetically-controlled dissolution (hydrolysis) of primary phases, the precipitation of secondary phases (C-S-H, hydroxide and spinel), the pH and redox conditions, and the progressive release of major elements as well as the metals Cr and V. Modeling indicates that the dilution effect of the L/S ratio is often coupled to solubility-controlled processes, which are sensitive to both the pH and the redox potential. A sensitivity analysis of kinetic uncertainties on the modeling of element releases is performed.
- OSTI ID:
- 21550337
- Journal Information:
- Waste Management, Vol. 31, Issue 2; Other Information: DOI: 10.1016/j.wasman.2010.05.018; PII: S0956-053X(10)00304-1; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0956-053X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
EXPERIMENTAL DATA
FURNACES
GEOCHEMISTRY
HYDROLYSIS
HYDROXIDES
LEACHING
OXYGEN
PH VALUE
PRECIPITATION
REACTION KINETICS
REDOX POTENTIAL
SENSITIVITY ANALYSIS
SIMULATION
SLAGS
SOLUBILITY
STEELS
THERMODYNAMICS
ALLOYS
CARBON ADDITIONS
CHEMICAL REACTIONS
CHEMISTRY
DATA
DECOMPOSITION
DISSOLUTION
ELEMENTS
HYDROGEN COMPOUNDS
INFORMATION
IRON ALLOYS
IRON BASE ALLOYS
KINETICS
LYSIS
NONMETALS
NUMERICAL DATA
OXYGEN COMPOUNDS
SEPARATION PROCESSES
SOLVOLYSIS
TRANSITION ELEMENT ALLOYS