The distribution of Na(I), K(I), Ag(I), Mg(II), Ca(II), Sr(II), As(V) and Mo(VI) traces was investigated during the crystallization
of NH4H2PO4 (ADHP). A tracer technique using22Na,42K,76As,90Sr/90Y,99Mo and110mAg was applied for studying the crystallization process of ADHP.
Mg(II) and Ca(II) was determined by atomic absorption spectoscopy. The optimum conditions for obtaining NH4H2PO4 of high purity have been established. The elaborated method of crystallization was used for the production of semiconductor