The resource-saving technology to restore the accumulation ability of tailing ponds Olha Medvedieva, Yevhen Lapshyn, Natalia Koval, Abdikarim Zeynullin and Olena Gupalo E3S Web Conf., 168 (2020) 00054 Published online: 06 May 2020 DOI: 10.1051/e3sconf/202016800054