Apparatus for producing compact polycrystalline InP and GaP ingots

An apparatus for use in producing compact polycrystalline InP, GaP and GaAs ingots of defined geometric form comprising an elongated reaction boat having a plurality of melting pots, each of the shape of a single crystal melting crucible in which said ingots are to be further processed, formed therein, said plurality of melting pots arranged in a line and, a canal between each two adjacent melting pots extending over essentially the full height thereof, whereby said melting pots can be filled with indium or gallium, the reaction boat disposed in zone melting apparatus, heated in a narrow zone in an atmosphere staurated with phosphorous or arsenic and the zone moved from one end to the other to form ingots in succession with free indium or gallium migrating to the other end and available for reuse.