Crystallization of inorganic salts from aqueous solutions in a microwave field

The crystallization of some inorganic salts (KH2PO4, NaCl, Sr(NO3)(2), KNO2, Ca(OH)(2)) by the thermal-gradient (with decreasing temperature) and solvent-evaporation methods using, microwave heating of solutions is investigated. It is established that the growth rates of single crystals in a microwave field are an order of magnitude higher than obtained in other known techniques at comparable crystallization temperatures and supersaturations. For example, the growth rate of prismatic faces {100} of KH2PO4 crystals is as high as 11 mm/day at supersaturations of similar to 1.2%. The results obtained are discussed in the context of the effect of microwave radiation on the adsorption surface layers of crystals. Fine-grained phases of the salts under study are obtained by evaporation of the solvent.