Kinetics of pyrite dissolution by hydrogen peroxide in perchloric acid

Redox potential (Eh) and anion effects of pyrite (FeS2) leaching at pH 1

“…Previous studies of aqueous oxidation of pyrite by H 2 O 2 in different leach media found oxidation rates to vary according to HClO 4 < HCl < H 2 SO 4 (Dimitrijevic et al, 1996(Dimitrijevic et al, , 1999Antonijevic et al, 1997Antonijevic et al, , 2005. The same trend is observed for leaches conducted at 700 mV in this study; however, at 900 mV HClO 4 < HCl.…”

“…It was suggested that Cl À and SO 2À 4 adsorb onto the pyrite surface and inhibit the access of oxidants to the pyrite surfaces. Increasing HClO 4 concentration or the addition of ClO À 4 had no effect on the oxidation rates, while addition of SO 2À 4 into HClO 4 leach solutions resulted in decreased oxidation rates (Dimitrijevic et al, 1996). This behaviour may have also been explained by reduced Fe 3+ activity on increasing SO 2À 4 and Cl À concentration.…”

Dissolution kinetics of sphalerite with hydrogen peroxide in sulphuric acid medium

“…However, hydrogen peroxide can also act as a reducing agent in accordance with the following equation: leaching agent for various mineral raw materials, such as uranium ores [23,24], and its use has been studied with a zinc-lead bulk sulphide concentrate [25] and silver ore [26,27] and with a concentrate of pyrite [28][29][30][31][32] and sphalerite [33].…”

The Effect of Ultrasound on the Dissolution of Pyrite Ores in Acidic and Fe2(SO4)3 Solutions

“…It was found that by non-linear regression analysis, a modified Avrami type equation fitted to the kinetic data gave the activation energy of 30 kJ/mol in both cases, and the ultrasound increased the pre-exponential factor in the Arhenius equation. Pyrite is one of the most abundant sulfide minerals, and occurs in the form of concentrates and often with other metals [9].Dimitrijevic et al investigated the kinetics of pyrite dissolution by hydrogen peroxide in perchloric acid [10]. The activation energy was calculated to be 57 kJ/mol, indicating that the dissolution of pyrite is chemically controlled.…”