An Introduction to Mining and Metallurgy - Thanatia: The Destiny of the Earth's Mineral Resources - page 169

Additionally, there is a huge potential in minimising gangue and other refuse
material resulting from the washing, concentration, or treatment of ground ore,
i.e. tailings, via recycling and re-use. There are for instance, immense amounts
of low calorific residual coal in existing or abandoned coal mines across the globe
that could be recovered in the future with new clean and e cient carbon-capture
and storage technologies. Energy e ciency solutions are also needed, since they
contribute to cost reductions whilst minimising greenhouse gas emissions. Likewise,
good logistical planning in order to shorten transport distances, optimisation of
blasting techniques to reduce the need for grinding; and gearless drive solutions for
low-speed applications, may also help to make important savings.
Should the above research and development needs be achieved, an improvement
in energy, water and chemical consumption in the mining industry should certainly
occur.
7.4 Reclamation, rehabilitation and post-closure
Reclamation of a mine once it is exhausted is a universally accepted norm, with the
exact details of which dependent on the legal framework: national regulations or
voluntary international standards such as ISO or even company policy the mine or
mining company operates under.
Each environmental externality must be converted into current production costs
regardless of how costly they are. Backfilling the hole left by open-pit mining with
waste rock and previously removed overburden 2 , re-contouring the land, replacing
the topsoil and re-vegetating the mined site, restoring and improving the water-
sheds, avoiding drainage and other rehabilitating actions are all responsibilities of
the mining company. In addition, financial guarantee in order to ensure that recla-
mation measures are stable with time and no long term effect has been left in the
abandoned mine must be provided. This is especially important in the control of
tailings dams, waste dumps and contaminated soils. Unfortunately very few mining
plans take into account all these frequently hidden costs.
Many environmentally conscious people would not react negatively towards min-
ing if its activities would follow the sustainable development recommendations writ-
ten by internationally recognised entities such as the Global Reporting Initiative 3
(GRI) who promote amongst other practices, transparent annual reporting.
7.5 Smelting and refining
Ferrous and non-ferrous metallic minerals undergo treatment, smelting and refining
processes. These processes are, in general, very energy intensive. In fact, their
2 The rehabilitation and reclamation of the land once the mine closes depends heavily on the
tonnage of waste rock removed.
3 https://www.globalreporting.org/Pages/default.aspx. Accessed December 2013.