TY - JOUR 
A1 - Jeldres, Matías
AU - Piceros Fuentes, Eder Cristóball
AU - Robles Vásquez, Pedro Adrián
AU - Toro Villarroel, Norman Rodrigo
AU - Jeldres Valenzuela, Ricardo Iván
T1 - Viscoelasticity of Quartz and Kaolin Slurries in Seawater: Importance of Magnesium Precipitates
Y1 - 2019
SN - 2075-4701
UR - http://hdl.handle.net/10317/9398
AB - In this study, the viscoelastic properties of quartz and kaolin suspensions in seawater were analysed considering two distinct conditions: pH 8 and 10.7. Creep and oscillatory sweep tests provided the rheological parameters. An Anton Paar MCR 102 rheometer (ANAMIN Group, Santiago, Chile) was used with a vane-in-cup configuration, and the data were processed with RheoCompass (TM) Light software (ANAMIN Group, Santiago, Chile). The outcomes were associated with the formation of solid species principally composed of magnesium precipitates. The magnesium in solution reduced in the presence of quartz (68 wt %), from 1380 to 1280 mg/L. Since the difference was not large regarding the solid-free seawater, the disposition of solid complexes at pH 10.7 was expected to be similar. The jump in pH caused both yield stress and viscoelastic moduli to drop, suggesting that the solid precipitates diminished the strength of the particle networks that made up the suspension. For the kaolin slurries (37 wt %), the yield stress raised when the pH increased, but unlike quartz, there was significant adsorption of magnesium cations. In fact, the concentration of magnesium in solution fell from 1380 to 658 mg/L. Dynamic oscillatory assays revealed structural changes in both pulps; in particular, the phase angle was greater at pH 8 than at pH 10.7, which indicates that at more alkaline conditions, the suspension exhibits a more solid-like character.
KW - Química-Física
KW - Tecnologías del Medio Ambiente
KW - Viscoelasticity
KW - Quartz
KW - Kaolin
KW - Seawater
KW - Magnesium precipitates
KW - 251090-1 Geología Marina. Dinámica Sedimentaria
KW - 2210 Química Física
LA - eng
PB - MDPI
ER -