FORMATION OF FERRIC HYDROXIDE-SILICA COATINGS ON PYRITE AND ITS OXIDATION BEHAVIOR

The approach used most commonly to prevent pyrite oxidation in the fie ld is the use of limestone. This approach, however, has a short span o f effectiveness because the pyrite particle surfaces remain exposed to the atmospheric O-2 after treatment, The objective of this study was to examine the feasibility of controlling pyrite oxidation in bench-sc ale studies by creating a ferric hydroxide-silica coating that would p revent either O-2 or Fe3+ from oxidizing pyrite further, Ferric hydrox ide-silica coating formation involved leaching pyrite at room temperat ure using a 10-mm-i.d, chromatographic column with a solution containi ng H2O2, Na-acetate (NaOAC), and soluble silicate at a flow rate of 0. 43 mL min(-1). The results of this bench-scale study show that formati on of a ferric hydroxide-silica coating was induced on the pyrite surf ace and that it inhibited pyrite oxidation under acid conditions.