Role of sodium hexametaphosphate in ultra-fine grinding of alumina-doped titanium dioxide

In wet stirred milling of Al-doped TiO2, sodium hexametaphosphate (SHMP) is used as a small molecule dispersant to improve milling performance. In both acidic and basic conditions, SHMP interacts strongly with Al-doped TiO2 and remains stable during milling. Considering the apparent and true particl...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Powder technology 2022-01, Vol.397, p.117022, Article 117022
Hauptverfasser: Austin, David, Hassanpour, Ali, Hunter, Timothy N., Robb, John, Edwards, John L., Sutcliffe, Stephen, Harbottle, David
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:In wet stirred milling of Al-doped TiO2, sodium hexametaphosphate (SHMP) is used as a small molecule dispersant to improve milling performance. In both acidic and basic conditions, SHMP interacts strongly with Al-doped TiO2 and remains stable during milling. Considering the apparent and true particle breakage performance, at pH 10.3, the optimal dosing concentration was 0.16 wt% (0.33θ, sub-monolayer coverage), which is consistent for both dilute (5 vol%) and concentrated (≥ 19.1 vol%) suspensions. At higher SHMP concentration (0.77θ), the increased solution conductivity compromised milling performance by weakly destabilizing the Al-doped TiO2 particles. At the optimal dose concentration of 0.33θ SHMP, particle dispersion is maintained through electrostatic and steric forces which contribute to moderating changes in suspension viscosity (~10% increase) as the particle size is reduced. [Display omitted] •SHMP adsorbs strongly on Al-doped TiO2 in both acidic and basic conditions.•At high solids content, milling performance greatly enhanced by SHMP addition.•Balance of electrostatic and steric forces means optimal dose is sub-monolayer.•SHMP moderates viscosity changes during milling.
ISSN:0032-5910
1873-328X
DOI:10.1016/j.powtec.2021.11.066