Abstract
Monodisperse spindle-shaped particles of barium sulfate were formed by means of the decomposion of barium-EDTA complex with hydrogen peroxide in the presence of sulfate. The logarithm of the size of the particle produced was linear with the logarithm of the concentration of reagents. The particles grew at the same rate of liberation of barium ion from the complex. The number of particles per unit volume of the reaction mixture was kept constant during the growth process of particles.