Otimização da recuperação de esfalerita na usina de Morro Agudo através do estudo da distribuição granuloquímica da flotação

Abstract

Sphalerite flotation at the Morro Agudo mine owned by Nexa Resources is very old and consolidated process. The major challenge currently encountered is the gradual drop in the zinc feed content, making it difficult to capture profits from the smallest amount of avaible metal. From this challenge, it is important to optimize the process for maximum recovery of the ore, increasing the generation of gains making viable mineral bodies that were not used until then. For this, granulochemical tests, bench flotation tests and conduction of mettalurgical balance were carried out so that it was possible to propose an optimization of the flotation circuit. The evaluation showed that in general the circuit has low efficiency for zinc recovery >106 µm, with a value of 71,7%, well below the total circuit recovery of 87,4%. The reason for this low efficiency is related to the low recovery of flotation columns used in the circuit. The joint evaluation of all tests showed an opportunity to change the circuit, with adding a new claening stage, expected increase in zinc recovery flotation of around 2,71% justificated for the recovery optimization on the fraction above 106 µm of 12,58% when compared with the process circuit.