Influência do tempo de saponificação de óleos amazônicos na flotabilidade da apatita

Abstract

Some researches indicate be technically possible to use salts of fatty acids, obtained from alkaline hydrolysis (saponification) of vegetable oils, as collectors reagents in ore flotation. However, making it uneconomical for industrial use of these oils is the need to solubilize them in water through the saponification reaction, which is performed at high temperature and under high reaction time. For this reason, this work is being proposed in order to evaluate the influence of time of saponification of oils obtained from Brazil nuts (Bertholletia excelsa), Buriti pulp (Mauritia flexuosa) and Inajá seed (Attalea maripa) , in the flotability of the mineral apatite. The fatty acid composition of vegetable oils has been obtained by gas chromatography and alkaline hydrolysis reaction (saponification) was conducted using an alcoholic solution of sodium hydroxide at different times (minutes): 0; 7,5; 15; 30; 90. The efficiency of the collector reagent obtained (fatty acid salt) in each saponification time was evaluated from tests microflotation in Hallimond tube, using pure apatite, with the use of extensor of height to prevent excessive entrainment. The results of the apatite flotability obtained by vegetable oils saponified were compared with those obtained with sodium oleate. Concluding that there is no need for a saponification time greater than 7.5 minutes (at a temperature of 75°C) and collector concentration greater than 1mg/L to obtain a satisfactory recovery of apatite (near 100%).