Flotation is a theme in the December issue of International Mining magazine. Two recent examples from Australia have seen benefits to flotation circuits from using Borregaard’s Pionera F-100. At Newcrest’s Telfer mine, clay gangue minerals have been shown to pose a deleterious effect on flotation. Laboratory tests, full scale plant trials and production use, show that Pionera F-100 may mitigate the negative effect of clay minerals resulting in the improved copper and gold flotation.

Preferential adsorption of Pionera F-100 onto the clay minerals suggests a scenario where the added dispersants prevent coating of the secondary copper sulphide chalcocite. Elimination of the slime coating increases the efficacy of the flotation reagent suite. Pionera F-100 can effectively disperse clay to improve copper and gold recovery in the Telfer flotation circuits.

And at MMG’s Century mine, the use of this biopolymer flotation depressant improves the recovery of zinc. It is a combined lead and zinc flotation process with graphite and silica as the main gangue material. Declining grades required optimising the suite of flotation chemicals.

Pionera F-100 was evaluated as an alternative to dextrin as a depressant. Lab test work and several plant trials showed graphite depression and improved zinc grades as well as lower silica content in the concentrate were all achieved using Pionera F-100.

It was established that replacing dextrin with Pionera F-100 in the zinc circuit improves silica depression and increases zinc recovery at the Century concentrator. Economic analysis reveals that the use of Pionera F-100 delivers a significant return on investment provided the ore being processed continues to have a high zinc grade. Permanent implementation of Pionera F-100 there commenced in June 2014.