| 摘要 |
<p>Beneficiation of phosphate ore comprises (a) flotation with an anionic reagent (I); (b) washing the single float prod. with acid to remove (I), then (c) floating with a cationic reagent (II) in two stages. In the first cationic stage (II) is added in starvation amts. and flotation retention is short so as to produce a float contg. most of the silica from the ore; this float is discarded. Then more (II) is added to the remaining phosphate ore and this floated for long enough to produce a float contg. most of the phosphate. Pref. retention time in the first stage is about one third that usual for cationic flotations. About two thirds of the phosphate values normally lost in the cationic tailings can now be covered, but the total amt. of (II) needed is not increased.</p> |
