Environmental Engineering Reference
In-Depth Information
Gove
Weipa
Northern
Territory
Western
Australia
Queensland
Boddington,
Willowdale
and Huntley
Figure 15.1.
Location of five operating bauxite mines in Australia.
a tacit acceptance that complete restoration on human time scales is not
achievable. Therefore the term 'rehabilitation' is often used to describe the
restoration processes and targets in the local literature.
Australia has developed some world leading practices in mine site restoration
after bauxite mining (Bell
2001
; Mulligan et al.
2006
). Restoration techniques are
underpinned by two key practices: (i) incremental rehabilitation, restoring land
progressively to forest after it has been mined out (Fourie & Tibbett
2006
; Koch
2007a
) and (ii) integratingmining with restoration, a practice that requires joint
planning by both ecological and mining engineers (Hinz
1992
; Koch
2007a
).
This is particularly evident in improvements in soil handling techniques in
bauxite mining, examples of which are outlined below.
Soils and bauxite ore
Australia has one of the most ancient landscapes in the world where the same
land surface has often been subject to weathering and pedogenesis for hun-
dreds of millions of years (McKenzie et al.
2004
). Bauxite ore bodies found in
Australia and elsewhere are formed through long-term pedogenic activity
where the eluviation of Fe and Al released from the chemical weathering of
secondary (clay) minerals in the upper soil horizons has illuviated in subsoil
horizons. Over millennia, subsoil concentration of Al can reach significant
