Kinetics and mechanism of oxidation for nickel-containing pyrrhotite tailings
Alexander M. Klyushnikov , Rosa I. Gulyaeva , Evgeniy N. Selivanov , Sergey M. Pikalov
International Journal of Minerals, Metallurgy, and Materials ›› 2021, Vol. 28 ›› Issue (9) : 1469 -1477.
Kinetics and mechanism of oxidation for nickel-containing pyrrhotite tailings
X-ray powder diffraction, scanning electron microscopy, energy dispersive spectroscopy, thermogravimetry, differential scanning calorimetry, and mass spectrometry have been used to study the products of nickel-containing pyrrhotite tailings oxidation by oxygen in the air. The kinetic triplets of oxidation, namely, activation energy (E a), pre-exponential factor (A), and reaction model (f(α)) being a function of the conversion degree (α), were adjusted by regression analysis. In case of a two-stage process representation, the first step proceeds under autocatalysis control and ends at α = 0.42. The kinetic triplet in the first step is E a = 262.2 kJ/mol, lg A = 14.53 s−1, and f(α) = (1 − α)4.11(1 + 1.51 × 10−4 α). For the second step, the process is controlled by the two-dimensional diffusion of the reactants in the layer of oxidation products. The kinetic triplet in the second step is E a = 215.0 kJ/mol, lg A = 10.28 s−1, and f(α) = (−ln(1 − α))−1. The obtained empirical formulae for the rate of pyrrhotite tailings oxidation reliably describe the macro-mechanism of the process and can be used to design automatization systems for roasting these materials.
pyrrhotite tailings / oxidation / thermogravimetry / kinetics / mechanism
| [1] |
|
| [2] |
|
| [3] |
|
| [4] |
|
| [5] |
|
| [6] |
|
| [7] |
|
| [8] |
|
| [9] |
|
| [10] |
|
| [11] |
|
| [12] |
|
| [13] |
|
| [14] |
|
| [15] |
|
| [16] |
|
| [17] |
|
| [18] |
|
| [19] |
|
| [20] |
|
| [21] |
Metso Outotec, HSC Chemistry, Metso Outotec, Helsinki [2006-06-12]. https://www.outotec.com/HSC |
| [22] |
ICDD, Powder Diffraction File™ (PDF®) Search, JCPDS International Centre for Diffraction Data, Pennsylvania [2019-09-05]. https://www.icdd.com/index.php/pdfsearch |
| [23] |
ASTM International. ASTM Standard E112–13. Standard Test Methods for Determining Average Grain Size, 2013, West Conshohocken, ASTM International |
| [24] |
|
| [25] |
|
| [26] |
The NETZSCH Group, NETZSCH Advanced Software version 2006.08, The NETZSCH Group, Selb [2019-09-05]. https://www.therm-soft.com |
| [27] |
|
| [28] |
|
| [29] |
|
| [30] |
|
| [31] |
|
/
| 〈 |
|
〉 |