Unique challenges of clay binders in a pelletised chromite pre-reduction process.
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Date
2012Author
Kleynhans, E.L.J.
Beukes, J.P.
Van Zyl, P.G.
Kestens, P.H.I.
Langa, J.M.
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Ferrochrome producers strive towards lower overall energy consumption due to increases in costs, efficiency
and environmental pressures. In South Africa, in particular, higher electricity prices have placed
pressure on ferrochrome producers. Pelletised chromite pre-reduction is most likely the ferrochrome production
process option with the lowest specific electricity consumption currently applied. In this paper,
the unique process considerations of clay binders in this process are highlighted and demonstrated utilising
two case study clays. It is demonstrated that the clay binder has to impart high compressive and
abrasion resistance strengths to the cured pellets in both oxidising and reducing environments (corresponding
to the oxidised outer layer and pre-reduced core of industrially produced pellets), while ensuring
adequate hot strength of pellets during the curing process. The possible effects of the clay binder
selection and the amount of binder addition on the degree of chromite pre-reduction achieved were also
investigated, since it could have substantial efficiency and economic implications. The case study results
presented in this paper indicated that it is unlikely that the performance of a specific clay binder in this
relatively complex process can be predicted, based only on the chemical, surface-chemical and mineralogical
characterisation of the clay.
URI
http://hdl.handle.net/10394/14809https://doi.org/10.1016/j.mineng.2012.03.021
https://www.sciencedirect.com/science/article/pii/S0892687512001124