The basic aim of mine planning is to design mine layouts and schedules
that achieve optimisation of operations, minimum cost and maximum
resource recovery. Successful accomplishment of this aim is facilitated
by timely and comprehensive rehabilitation planning commencing at the
pre-feasibility stage and continuing until the end of mining. Incorporation
of a final landfomt design for waste rock dumps in a mine plan requires a
prediction of surface stability, which may be achieved through erosion
modelling. Erosion prediction models can be placed in two broad
categories: soil loss prediction models eg USLE and CREAMS, and
geomorphic models such as SIBERIA. A waste rock dump landform design based on selected slope form and
grade and drainage systems should be developed as part of planning. A
digital terrain model (DTM) of the landfonn should then be produced
which can be modelled for long-term erosional stability using
pre-determined parameter values. If acceptable standards of stability are
not achieved, the landform should be redesigned and remodelled until the
desired result is obtained. The planning process incorporating models requires knowledge of
spoil or waste rock properties and model parameter values. This
information is site specific and can be obtained from drill cores or
costeans at the pre-mining stage and from spoil or waste rock during the
mining stage. Realistic model parameter values are critical in
post-mining landfonn design and can be obtained by several methods,
including rainfall simulation, monitoring, geochemical analyses and grain
size analysis.