THE INFLUENCE OF CRYSTAL-CHEMISTRY PROPERTIES ON THE FLOATABILITY OF APATITES WITH SODIUM OLEATE

Several apatites from Brazilian deposits of different origins (igneous , metamorphic and sedimentary) had their crystal chemistry properties determined. The main goal was to establish correlations with their fro th flotation behavior. X-ray diffraction studies were carried out, wit h computer support and a high degree of analytical detail, to determin e precisely the a underbar and c underbar crystal lattice parameters, and the crystallinity level of the apatite Samples. A thorough chemica l analysis of these minerals was also conducted. Microflotation tests were carried out, using sodium oleate as collector. Metamorphic and se dimentary apatites were the most chemically heterogeneous, mainly for the substitution of phosphate ions by carbonate. Parameter a underbar showed a broader variation than c underbar. Crystallinity level values ranked from 10.0 to 4.4. A marked correlation was observed between th is crystallinity sequence and floatability; the latter dropped drastic ally for crystallinity values lower than 8.0.