The results of researches, implemented by “Irgiredmet” institute, evaluation of efficiency of gold extraction from sand at large-volume dredge with jigger technology via new generation jig washer “Trud-12” have been observed. This technology is recommended by the institute for reconstruction of concentrating component of a dredge. Advantage of this technology has been shown in comparison with flood-gate scheme previously used at a dredge and expedience of reconstruction of flood-gate drags and flushing fitting, processing sand, containing small particle of gold, to jigger technology, which correspond to word practice of alluvial gold minning.