Dispersants & Water Reducers
Cut your water-to-stucco ratio and pay the kiln less per square metre.
Every kilogram of free water you carry into the kiln is roughly 2,260 kJ of evaporation cost. Modern polycarboxylate ether (PCE) and naphthalene sulfonate dispersants make a 25–35% water reduction possible without losing slurry workability — the single largest energy lever on a board plant.
PCE dispersants use a comb-polymer architecture: an anionic carboxylate backbone that adsorbs onto positively-charged hemihydrate sites, with non-ionic polyethylene oxide side chains that produce steric repulsion. Side-chain length, grafting density and backbone charge density are tunable for early or sustained flow. Naphthalene sulfonate (BNS) and lignosulfonate dispersants rely on electrostatic repulsion alone — cheaper, but more sensitive to stucco chemistry and temperature.
The right dispersant lets the mixer break agglomerates and wet every hemihydrate crystal at lower water demand. Result: lower slurry density variability, faster setting, and a measurable drop in kiln gas consumption. Side effect to manage: PCE can extend the induction period; pair with NG-A 310 to keep the knife window intact.