Argumentation for critical parameters and operating modes in the process of underwater mining of placersFarzad Fatehi, Yevhen Semenenko, Olha Medvedieva, Larysa Tatarko and Olexander HaminichE3S Web Conf., 168 (2020) 00043DOI: https://doi.org/10.1051/e3sconf/202016800043