Goc = nuclei growth rate (eq 2) (m/s) i = relative kinetic order j = exponent of magma density (eq 1) KR = nucleation rate constant, no./L s (g/L)I (m/s)' MT = magma density, g/L N = agitator speed, rpm s = supersaturation, g of crystallizing substance/g of water YA, yc = constants in size-dependent growth equations (eq E = specific power input, W/kg T = residence time, s 0 = temperature, "C An electrochemical technique was used for global measurement of overall solid-liquid mass transfer coefficients in upward cocurrent gas-liquid flow through a packed bed under bubble flow and surging flow conditipns. The feasibility of the technique was ascertained and the coefficients were compared with those obtained by other techniques. An energetic correlation has been proposed for both single and gas-liquid flow which extends the range of application of previous works.