Kinetics and mechanism of oxidation for nickel-containing pyrrhotite tailings  

作　　者：Alexander M.Klyushnikov Rosa I.Gulyaeva Evgeniy N.Selivanov Sergey M.Pikalov 

机构地区：[1]Institute of Metallurgy of the Ural branch of the Russian Academy of Sciences,Yekaterinburg 620016,Russia

出　　处：《International Journal of Minerals,Metallurgy and Materials》2021年第9期1469-1477,共9页矿物冶金与材料学报（英文版）

摘　　要：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 atα=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 isЕa=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 roast-ing these materials.

关 键 词：pyrrhotite tailings OXIDATION THERMOGRAVIMETRY KINETICS mechanism 

分 类 号：TD926.4[矿业工程—选矿]