Preliminary study on collectorless flotation of chalcocite, bornite and copper-bearing shale in the presence of selected frothersJan Drzymala, Alicja Swebodzinska, Magdalena Duchnowska, Alicja Bakalarz, Andrzej Luszczkiewicz and Przemyslaw B. KowalczukE3S Web Conf., 8 (2016) 01031DOI: https://doi.org/10.1051/e3sconf/20160801031