3442 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
Huffman and Davidson (1956) proposed that there is a
pathway that is linear in ferrous ions. Chmielewski and
Charewicz (1984) also made a similar proposal although
they did not incorporate this into their final rate equation.
Initial kinetic modelling performed by the authors
indicated that rate expressions of the type proposed by
Huffman and Davidson (1956) cannot describe the
deviation from second order kinetics found as the reaction
proceeds. If the second-order term is to describe the rate at
higher concentrations of ferrous ions, it continues to domi-
nate any first-order term at lower concentrations.
A possible explanation for the observed deviation from
second order kinetics is that it could be due to the onset
of equilibrium. This proposal was investigated by fitting a
Figure 10. A second-order plot of the concentration of ferrous ions in solution as a
function of the time spent in the batch reactor. Data reported by Chmielewski and
Clarewicz (1984)
Table 2. Test conditions for data given in Figure 9
Test
Temperature,
°C
Pressure,
bar g
Ferrous ion,
g/L
Acid,
g/L
Copper,
g/L
A 85 10.0 30.0 49.0 10
B 85 5.1 30.0 49.0 10
C 85 2.1 30.0 49.0 10
D 85 1.3 230.0 49.0 10
Table 3. Proposed kinetic models for the oxidation of ferrous ions in solution
ç
Authors Expression
Huffman and Davidson (1956) k k [Fe^II@p^O rate
1 2 2 2 =+h h 6Fe^IIh@2p^O
Keenan (1969) ]k rate
1 2 =+-0.35 h1.64[H 6Fe^IIh@2p^O
Mathews and Robins (1972) k ]rate
1 2 =+-0.25 h1.01[H 6Fe^IIh@1.84p^O
Chmielewski and Charewicz (1984) k rate
1 2 =h@2p^O h 6Fe^II
Iwai, Majima and Awakura (1982) k rate
2 1 2 4
2- =+^O h_k 6Fe^IIh@2p 7SO Ai
Verbaan and Crundwell (1986) k ]rate
1 2 =+-0.36 h[H 6Fe^IIh@2p^O
Huffman and Davidson (1956) proposed that there is a
pathway that is linear in ferrous ions. Chmielewski and
Charewicz (1984) also made a similar proposal although
they did not incorporate this into their final rate equation.
Initial kinetic modelling performed by the authors
indicated that rate expressions of the type proposed by
Huffman and Davidson (1956) cannot describe the
deviation from second order kinetics found as the reaction
proceeds. If the second-order term is to describe the rate at
higher concentrations of ferrous ions, it continues to domi-
nate any first-order term at lower concentrations.
A possible explanation for the observed deviation from
second order kinetics is that it could be due to the onset
of equilibrium. This proposal was investigated by fitting a
Figure 10. A second-order plot of the concentration of ferrous ions in solution as a
function of the time spent in the batch reactor. Data reported by Chmielewski and
Clarewicz (1984)
Table 2. Test conditions for data given in Figure 9
Test
Temperature,
°C
Pressure,
bar g
Ferrous ion,
g/L
Acid,
g/L
Copper,
g/L
A 85 10.0 30.0 49.0 10
B 85 5.1 30.0 49.0 10
C 85 2.1 30.0 49.0 10
D 85 1.3 230.0 49.0 10
Table 3. Proposed kinetic models for the oxidation of ferrous ions in solution
ç
Authors Expression
Huffman and Davidson (1956) k k [Fe^II@p^O rate
1 2 2 2 =+h h 6Fe^IIh@2p^O
Keenan (1969) ]k rate
1 2 =+-0.35 h1.64[H 6Fe^IIh@2p^O
Mathews and Robins (1972) k ]rate
1 2 =+-0.25 h1.01[H 6Fe^IIh@1.84p^O
Chmielewski and Charewicz (1984) k rate
1 2 =h@2p^O h 6Fe^II
Iwai, Majima and Awakura (1982) k rate
2 1 2 4
2- =+^O h_k 6Fe^IIh@2p 7SO Ai
Verbaan and Crundwell (1986) k ]rate
1 2 =+-0.36 h[H 6Fe^IIh@2p^O