O uso de óleos apolares na flotação catiônica reversa de um minério de ferro

Abstract

The main collectors utilized in the reverse cationic flotation of iron ores belong to the amines group, more specifically the etheramines. In addition, depressants (starches), dispersants, pH modulators, etc. are also employed. The cost of these reagents represents the major expense of the flotation process, the collector (amine) cost being the major item. Therefore, the search for less expensive collectors or collector combinations is a common practice of investigations. This thesis presents the studies performed aiming at defining, in bench scale, thetechnical and economical feasibility of replacing part of the amine by a fuel oil, keeping the quality of the concentrate and the flotation process performance. The work was developed, in a first stage, searching for the emulsifier, and its proportion with respect to the disperse phase (oil) more adequate to the process, followed by the selection of the non polar oil, and the proportion of substitution with respect to amine. Finally the influence of the emulsification method on the flotation tests results was assessed. The main responses that were considered in the flotation tests were: silica content in the concentrate, iron grade in the tailings, weight and metallurgical recoveries in the concentrate and Gaudins selectivity index. The proposed target was reached. A level of amine substitution by diesel oil of 20% possible, the mixture being mechanically emulsified in the presence of the emulsifier Tergitol TMN-10 (Dow Chemical), in a proportion of 5% of the disperse phase.