Effect of K₃PO₄, K₂HPO₄, KH₂PO₄ and H₃PO₄ as Dispersing Agents on the Rheological Behaviour of Kaolin Suspensions

Abstract

Effects of phosphate addition on the rheological properties of kaolin suspensions were investigated. Various phosphate compounds were added, such as orthophosphoric acid (H₃PO₄), potassium dihydrogen phosphate (KH₂PO₄), potassium monohydrogen phosphate (K₂HPO₄) and potassium phosphate (K₃PO₄). The rheological properties of kaolin suspensions were studied in connection with the mass ratios of kaolin and dispersants. The obtained data showed that the viscosity decreased according to the order: H₃PO₄>KH₂PO₄>K₂HPO₄>K₃PO₄. Use of K₃PO₄ as a dispersant led to the reduction of viscosity of the kaolin suspension to 1/₆th of that of the original one even when it was used at a lower rate of about 0.05 wt%.

Keywords:

• Kaolin
• Rheology
• Phosphates
• Suspension
• Dispersant