Research On Beneficiation Of Fine Tailing Of Florida Phosphate

Phosphorite, as a kind of important chemical raw material mineral, is mainly used to produce the phosphorus,chemical material and animal feed, which is distinguished in its unrenewable nature and non-recyclable nature, Many countries has regarded the phosphorite as strategic resources,so its exportion is prohibited. It must be viewed that fine particles processing is the inexorable trend of the new age of industrialization mainly due to two reasons. One is that there is massive tailing produced in the mineral processing of scrubbing-desliming, which contains large amount of slimes and high phosphorus pentoxide grade, also has the characteristic of fine particle. The other reason is that ore must be grinded finely for valuable minerals'monomer dissociation to process the lean,fine and impurity inclusion phosphate,because there are less an less easily processing and rich phosphate.Mineralogical characteristics and processing experiment were studied in this paper aiming at recovering the phosphrous contained in the finely tailing of Florida phosphate. The tailing typically include hydroxyapatite, which is the valuable mineral account for 26%,and gangue minerals including quartz,hematite,dolomite, and may be some aluminosilicate minerals, the major gangue mineral is quartz. Additionally, the size of particls vary from 0.669μm to 39.234μm, with the d5o 5.867μm and d95 13.377μm. So, it is hard to process this kind of tailing through gravity separation,magnetic coating,photoelectric sorting method and chemical beneficiation. In this experiment, direct flotation is used to remove the silicate materials firstly, and then reverse flotation is used to remove the carbonate materials to decrease the content of magnesium Oxide. The result of flotation experiment show that the rough concentrate with 10.86% grade and 80.55% recovery was obtained under the conditions of oxidized paraffin soap dosage of 10.3kg/t, sodium silicate dosage of 6kg/t, pH value 9.5, temperature 38℃, pulp density 7% and flotation cell rotating speed 2800r/min. By adopting the flowsheet of once roughing, twice scavenging and three times concentrating, the batch flotation experiment obtained concentrate with 18.94% grade and 16.43% recovery under the condition of pH value 9.5, temperature 38℃, pulp density 3.5% and flotation cell rotating speed 2800r/min. The suitable consumption of oxidized paraffin soap dosage and sodium silicate dosage is 15.5kg/t and 6kg/t respectively to the roughing,3.1kg/t and zero to the scavenging(Ⅰ),0.6kg/t and zero to the scavenging (Ⅱ); 5.1kg/t and 2kg/t to the concentrating(Ⅰ),2.55kg/t ang 1kg/t to the concentrating (Ⅱ),1.275kg/t and 0.5kg/t to the concentrating (Ⅲ).The function mechanism between the reagents and minerals had been researched through the way of IR and academic calculation of solution chemistry, which pointed out the adsorption of fatty acids on the surface of phosphorite belonged to physical and chemical types, but the chemical one was in the highest flight. The leading components of sodium silicate were HSiO3- and particle of silica, which depress quartz and disperse the pulp.