Kinetics of Aqueous Pyrite Oxidation by Potassium Dichromate - An Experimental Study

Paul CHIRITA

Makale detayları

Kinetics of Aqueous Pyrite Oxidation by Potassium Dichromate - An Experimental Study

Yazarlar:

Paul CHIRITA

Yayıncı:

TUBITAK

Dergi:

Turkish Journal of Chemistry 2003 Vol.27 Issue 1, pp.111-118

Belge Tipi:

Makale

Yayın Tarihi:

12/2002

Belge Dili:

Türkçe

Document ID (Org No.):

2000729691

Sıklık:

İki Aylık

eISSN:

1303-6130

pISSN:

1300-0527

Özet:

 

The kinetics of pyrite oxidation in perchloric acid  solutions were investigated at temperatures ranging from 30°C to 40°C,  potassium dichromate concentration from 0.001 to 0.05 mol L - 1,  particle size fractions from 50 to 150 m m and pH values down to  2.83.  The rate of the oxidation reaction is described by the  following expression:    r = bkS0.51[K2Cr2O7]0.64[H+ ]0.22    where S is the surface area of reacting solid, r represents the amount  of Fe release in solution per unit surface area per unit time, b is a  stoichiometric factor, k is the rate constant, and [K2Cr2O7]  and [H+ ] are the potassium dichromate and hydrogen ion  concentrations respectively.  The magnitude of the activation energy  (74.83 kJ mol-1) and the direct relationship between the rate  constant and initial pyrite specific surface area are in agreement  with a mechanism controlled by a chemical reaction.  Trace element  content had no statistically significant effect on the oxidation rate.

 

The kinetics of pyrite oxidation in perchloric acid  solutions were investigated at temperatures ranging from 30°C to 40°C,  potassium dichromate concentration from 0.001 to 0.05 mol L - 1,  particle size fractions from 50 to 150 m m and pH values down to  2.83.  The rate of the oxidation reaction is described by the  following expression:    r = bkS0.51[K2Cr2O7]0.64[H+ ]0.22    where S is the surface area of reacting solid, r represents the amount  of Fe release in solution per unit surface area per unit time, b is a  stoichiometric factor, k is the rate constant, and [K2Cr2O7]  and [H+ ] are the potassium dichromate and hydrogen ion  concentrations respectively.  The magnitude of the activation energy  (74.83 kJ mol-1) and the direct relationship between the rate  constant and initial pyrite specific surface area are in agreement  with a mechanism controlled by a chemical reaction.  Trace element  content had no statistically significant effect on the oxidation rate.

Makale detayları

Kinetics of Aqueous Pyrite Oxidation by Potassium Dichromate - An Experimental Study

Yazarlar: Paul CHIRITA

Yayıncı: TUBITAK

Dergi: Turkish Journal of Chemistry 2003 Vol.27 Issue 1, pp.111-118

Belge Tipi: Makale

Yayın Tarihi: 12/2002

Belge Dili: Türkçe

Document ID (Org No.): 2000729691

Sıklık: İki Aylık

eISSN: 1303-6130

pISSN: 1300-0527

Sayı

Yazarlar:

Paul CHIRITA

Yayıncı:

TUBITAK

Dergi:

Turkish Journal of Chemistry 2003 Vol.27 Issue 1, pp.111-118

Belge Tipi:

Makale

Yayın Tarihi:

12/2002

Belge Dili:

Türkçe

Document ID (Org No.):

2000729691

Sıklık:

İki Aylık

eISSN:

1303-6130

pISSN:

1300-0527