METHODS OF BENEFICIATING SILICEOUS PHOSPHATES

摘要

A method of beneficiating siliceous phosphate, designated as "reverse Crago", which includes subjecting a siliceous phosphate-containing flotation feed to amine flotation so as to form a prefloat concentrate and subjecting the prefloat concentrate to fatty acid flotation. A further improved reverse crago process for beneficiating siliceous phosphate includes the steps of subjecting a siliceous phosphate or material to amine flotation so as to obtain a prefloat concentrate, and screening the prefloat concentrate so as to separate it into 1) a fine predominantly phosphate fraction without substantial amounts of silica, and 2) a coarse fatty acid flotation feed fraction containing phosphate and substantial silica. The coarse fraction is subjected to fatty acid flotation so as to recover phosphate as a fatty acid flotation concentrate.