Silica Scale

Definition

Glassy amorphous deposits formed when dissolved silica exceeds its practical limit, favored by high cycles and low temperatures.

Silica usually exists as neutral dissolved silicic acid that contributes little to conductivity, so it can concentrate quietly while conductivity based control looks normal. Practical limits are often treated around 120 to 180 mg/L as silica depending on pH, temperature, magnesium, residence time, and inhibitor chemistry. Once exceeded, silica can polymerize into amorphous glassy deposits that are extraordinarily difficult to remove, and calcium carbonate indices do not account for it.

Related concepts

Conductivity · Scale Indices · Magnesium Silicate Scale

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Part of The Blueprint of Water · 🧪 chemistry