PROCESS MINERALOGY STUDIES FOR OPTIMIZING THE FLOTATION PERFORMANCE OF 2 REFRACTORY PHOSPHATE ORES

This paper is a result of research work carried out with three differe nt phosphate ore types (SCO - standard calcitc ore, PCO - phlogopite c arbonatic ore, and OCO - olivine carbonatic ore), all of them present on Morro da Mina carbonatic phosphate deposit, exploited by Serrana S. A. de Mineracao, Jacupiranga, Sao Paulo, Brazil. The PCO and OCO types show a refractory behaviour whith respect to flotation. Characterizat ion studies on this three ores were performed, firstly, to understand the reasons for poor flotation performance observed for the two refrac tory ores. From the characterization programme it was possible to prop ose and test alternate reagent schemes to treat each of the refractory ores. The major parameters investigated during the characterization p rogramme included surface heterogeneity, collector response and solubi lity determination. Batch scale flotation tests were performed to inve stigate the new reagent schemes. These new process routes encompassed the use of different modifier agents for the PCO type and the applicat ion of an ancillary non-ionic collector to treat the OCO ore type.