Recovery of phosphate from Florida beneficiation slimes I. Re-identifying the problem

摘要: Abstract Thirty phosphatic clay (slime) samples were collected from four operating plants in Florida. These thoroughly characterized order to identify feasible techniques for recovering the phosphate values. It was found that three major characterisrics of slimes cause extreme difficuflty recobvering economically: high content (30–50%) minerals, ultra-fine particle size (35–50% below 1 micron), and nearly even distribution among different fractions. Preliminary tests excluded magnetic separation an electrical method as potential solutions. However, sizing using a six-inch hydrocyclone showed some encouraging results, generating underflow product approximately plus ten microns with 18% P 2 O 5 , 0.5% MgO, 3.3.% Al 3 . Based on detailed physicochemical analyses preliminary tests, most viable approaches seem be selective flocculation, followed by flotation, perhaps bioleaching.