The Millennium Inorganic Chemicals do Brasil S/A company produces at Guaju mine several types of zircon concentrated, which are derived of a product denominated Zircon Pre-Concentrated (PCZ). This product is derived from ilmenite's concentration processes. The ilmenite and other heavy minerals of PCZ are disseminated in dunes, in the Paraíba state, from northeast of Brazil. PCZ contains high zircon concentration and a reduced mass of minerals considered pollutants. It is treated by both electrostatic and magnetic processes that remove the pollutants and it concentrates the mineral zircon. An amount of polluting mineral is involved by an iron-clay coating that interferes in its removal during the processes. The result is the contamination of the zircon final product, that is classified according both core of ZrO 2 and another substances, which are related to the mass of polluting minerals. PCZ was treated with attrition process to eliminate the problem of the clay and to increase the effectiveness of the electric and magnetic processes in the removal of the pollutants. It was chosen an semi-industrial equipment to verify the technical viability of the process. The operational parameters were: the amount of solids in pulp, the concentration of NaOH in pulp and the time of agitation of the pulp. The combinations of values indicated more than one viable alternative for the process. It was chosen the rehearsal with 70% of solids in pulp, with 600 g NaOH/t pulp and with the time of 20 minutes of agitation. The company suggested the accomplishment of a rehearsal without NaOH, for environment reasons. Two samples were attritioned with the same operation parameters, being one without the chemical reagent. Then they were treated in both electrostatic and magnetic separators. The analytic results showed that the final product (non-magnetic) of the sample attritioned with NaOH had 50% less TiO2 than other sample. Therefore, the attrition process was more effective with the use of the caustic soda. The TiO2 it is one of the polluting substances of the zircon concentrate.
attrition; scrubbing; zircon; mineral treatment
