PROCESSO PARA ENRIQUECIMENTO POR FLOTACAO DE MINERIOS FOSFATADOS SEDIMENTARES QUE COMPORTAM UMA GANGA DO TIPO CARBONATO

The present invention relates to an enrichment process, by flotation, of sedimentary ores containing phosphate, and comprising a gangue of the carbonated type and in some cases a gangue of the siliceous type, wherein an amphoteric product of formula is at least used as collecting agent, in which formula: R is of form R1 or R1O-, R1 being a saturated or unsaturated alkyl radical, either linear or branched, and comprising between 5 and 19 carbon atoms. R' and R'' are H or -Aq-Z, bearing in mind that for R'', when n is greater than 1, there can be in the molecule simultaneously radicals H and radicals -Aq-Z. Ap and Aq are polymethylene chains containing between 1 and 4 carbon atoms, n is a number equal to O or an integer between 1 and 5, Z is a radical selected from the carboxylic, the sulphonic and the phosphonic radicals, and in obtaining the flotation of the carbonated gangue by a reverse flotation in "basic medium .