Smithsonite Flotation from Zinc Oxide Ore using Alkyl Amine Acetate Collectors

Flotation of smithsonite from tailing coming from a cerussite flotation circuit was investigated using Armac C and Armac T as alkyl amine acetate collectors. The results showed that the dosage of Na2S, collector type and dosage, collector's mixture ratio, and desliming are the main affecting parameters on the Zn grade and recovery of smithsonite flotation concentrate. The contact angle measurement on smithsonite and calcite minerals indicated that Armac T acts more selectively than Armac C and enhances the Zn grade of the concentrate. At the mixture ratio of Armac C:Armac T, 1:6, the collectors' consumption are decreased significantly and an optimal concentrate with 94.4% recovery and 42.3% Zn grade is obtained without any gangue depressant reagents. Nevertheless, using NaOH as a pH regulator, the dosage of Na2S is decreased significantly but the flotation results are affected negatively. The recovery of Zn in the concentrate is more sensitive to the slime than Zn grade. The Zn minerals lost in the tailing are mostly in the form of very fine disseminated particles. About 11% of smithsonite with particle sizes finer than 10 mu m is lost in the slime. Overall Zn flotation recovery is estimated to be about 84%.