Estudo comparativo entre o oleato de sódio e os óleos de mamona e algodão na hidrofobicidade da apatita e hidrofilicidade da dolomita.

Abstract

This work developed the studies about hydrophobicity of apatite and hydrophilicity of dolomite utilizing castor oil and cotton oil as collectors, and were compared to sodium oleate. This last one is used in large scale in the flotation of phosfatie rocks and corn starch. It is extremely necessary to have the presence of depressor agents in the anionic flotation of phosphates, through fatty acids. This is due to the low efficiency showed for the process of flotation when these depressors are absent. At first some tests were performed to determine the point of zero charge of apatite and dolomite and through this we could verify that for apatite there were two zero charge points of charge at pH 7 and pH 12. For dolomite two zero points of charge at pH 9 and pH 12, were also observed. Among the concentration levels tested during this work the one which showed the best recovery was the sodium oleate, about 100%. The cotton oil was the one, which showed good selectivity, nearly 90%, among other regional oils. The results of cotton oil showed us that its use as collector is possible because the cotton oil is able to hydrophobize the apatite and this way it reaches recoveries approximating to that of the sodium oleate.