Lesson 9 – Slurry Control, Chemistry & Suspension

What You Will Learn

• Measure concentration (e.g., Baumé via hydrometer) and mixing percentages
• Control pH; understand how chemistry influences agglomeration and finish
• Apply agitation and lubricity modifiers appropriately
• Use suspension additives to prevent settling and maintain distribution
• Explain electrostatic stabilization in colloidal slurries

Concentration & Chemistry

Track concentration using Baumé (hydrometer with graduated cylinder) or by initial mix ratios (e.g., 1:1 or 50%). Chemistry matters—verify acidic/basic conditions (e.g., via litmus) and keep within validated windows for your material and pad.

Agitation, Lubricity & Suspension

Maintain agitation to avoid settling and localized starvation. Additives may include lubricity modifiers (e.g., glycol) and suspension aids (e.g., Everflo, Suspendex). Colloidal slurries rely on electrostatic stabilization—particles mutually repel due to like charges; this behavior is strongly dependent on pH and not easily adjusted on the fly.

In‑Process Controls

Standardize renewal intervals, line filtration, and temperature control. Trend roughness, cosmetic counts, and removal rate against concentration/pH logs to keep the process centered.