Depressant behavior of tragacanth gum and its role in the flotation separation of chalcopyrite from talc

Guar gum is an effective depressant of talc, but it also has some depression effect on sulfide minerals. To find new selective depressants, the depression effects and mechanisms of tragacanth gum to talc were studied and its role in the flotation separation of chalcopyrite from talc was investigated by flotation test, adsorption and zeta potential tests as well as XPS analysis. The individual mineral flotation test results showed that the natural flotability of talc is good which make it easy to be reported into the concentrate. The guar gum and tragacanth gum can effectively depress the flotation of talc, and their depression effect is not affected by pH. The mixed minerals flotation tests indicated that the tragacanth gum can effectively separate chalcopyrite from talc, both the copper concentrate grade and recovery are high, besides, tragacanth gum exhibits less depression effects for chalcopyrite compared with guar gum. According to the Zeta potential and XPS measurements, it can be concluded that tragacanth gum adsorbed on talc surface mainly through physical interactions, and hydrophobic interaction was considered as the main driving force and hydrogen bond may also play a role. (C) 2018 Brazilian Metallurgical, Materials and Mining Association. Published by Elsevier Editora Ltda.