Rota de processo para o underflow da deslamagem de minério de ferro do concentrador da Samarco Mineração

Abstract

The iron ore reverse cationic flotation process, using etheramine as a collector/frothing and corn starch as a depressor, is very important in all major Brazilian pellet-feed concentration plants. One of the major challenges found by these plants is the metallic recovery increase, whose main factor is the reduction of iron minerals loss on the frothor true flotation. The main purposes of this study were the characterization of the two products proceeding from the desliming circuit (cleaner hydrocyclones underflow and desliming hydrocyclones underflow) that constitute the reverse cationic flotation process of ironore feed on Samarco concentration plant and study alternative routes and process changes. Laboratory flotation tests on mechanical cells were performed with the target of comparing the performance of these two products separately regarding the common reagents used on concentration plants and also alternative ones. Different behaviorswere evidenced for each of the products studied. Laboratory flotation tests on mechanical cells were also performed to check the influence of different conditioning times. It was observed the necessity of thedetermination of the best conditioning time for the cleaner hydrocyclones underflow flotation. It was evidenced that bigger conditioning time on the desliming hydrocyclones underflow flotation leads to lower silica grade on the concentrate without metallic recovery changes. Better metallic recovery values without damage on the quality of the concentrate wereobserved on pilot column flotation tests if compared with the laboratory mechanical cells flotation tests for both products. The metallic recovery increase was more expressive on the desliming hydrocyclones underflow flotation