A turbidmetric method was used to investigate the kinetics of a gas-promoted process for agglomerating an aqueous suspension of coal particles using either heptane or hexadecane as an agglomerant. Suspensions of either Pittsburgh No. S seam coal or Upper Freeport seam coal were mixed with measured quantities of air and an agglomerant in a closed cylindrical tank fitted with baffles and a controllable speed agitator. Agglomeration was monitored by observing the change in turbidity of the suspension. Initial particle concentration, agglomerant dosage, amount of air, and agitator speed were varied among runs. The experimental data were correlated and analyzed by employing a semiempirical rate equation which gave consistent results. During any given run the agglomeration rate (#x2014; dN/dt) was proportional to the particle number concentration (N) raised to a power between l.O and 1.3. The rate increased with increasing amounts of either air or agglomerant and with increasing agitator speed. The rate was also greater for Upper Freeport coal than for Pittsburgh coal, apparently because of the greater hydrophobicity of the former.
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