Olivine dissolution from Indian dunite in saline water.
Environ Sci Pollut Res Int
; 23(22): 22331-22339, 2016 Nov.
Article
em En
| MEDLINE
| ID: mdl-27167373
ABSTRACT
The rate and mechanism of olivine dissolution was studied using naturally weathered dunite FO98.21(Mg1.884Fe0.391SiO4) from an Indian source, that also contains serpentine mineral lizardite. A series of batch dissolution experiments were carried out to check the influence of temperature (30-75 ∘C), initial dunite concentration (0.5 and 20 g/L), and salinity (0-35 g/L NaCl) under fixed head space CO2 pressure (P[Formula see text] = 1 barg) on dunite dissolution. Dissolved Mg, Si, and Fe concentrations were determined by inductive coupled plasma atomic emission spectroscopy. End-product solids were characterized by scanning electron microscopy and X-ray diffraction. Initially, rates of dissolution of Si and Mg were observed to be in stoichiometric proportion. After 8 h, the dissolution rate was observed to decline. At the end of the experiment (504 h), an amorphous silica-rich layer was observed over the dunite surface. This results in decay of the dissolution rate. The operating conditions (i.e., salinity, temperature, and mineral loading) affect the dissolution kinetics in a very complex manner because of which the observed experimental trends do not exhibit a direct trend.
Palavras-chave
Buscar no Google
Base de dados:
MEDLINE
Assunto principal:
Silicatos
/
Compostos de Magnésio
/
Compostos de Ferro
/
Salinidade
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Índia