Utilisation of mine waste

Teemu Karlsson and Päivi Kauppila, Geological Survey of Finland, P.O. BOX 1237, FI-70211 Kuopio, FINLAND, e-mail: teemu.karlsson(at)gtk.fi


Mining generates variable amounts of waste, mainly waste rock and tailings. Waste rock can be defined as rock material, with or without low grades of ore, which cannot be processed profitably, but which must be removed to exploit the ore. Waste rock is usually assigned to stockpiles in close proximity to the mine. Tailings are a waste product from enrichment of ore in concentration plants, and consist primarily of gangue minerals, and are usually transported as slurry to an impoundment known as tailings area. The size of mine waste facilities varies according to ore to gangue ratio, scale of operations and amount of backfilled material, typically ranging from several to hundreds of hectares in extent, having a significant impact on the surrounding landscape and environment. (Heikkinen et al. 2008)
Waste rock can commonly be used in different kinds of earthworks on site during active mining operations, or may be sold outside for use as aggregate. It is generally more difficult to utilize tailings, partly due to its finer grain size. Nevertheless, tailings can also be selectively used. The use of mine waste at the mine site may require permit from the environmental authorities and preparation of a plan detailing specific activities, prior to commencement of mining. Likewise, environmental permits will be required for transport and use of mine waste beyond the limits of the mining concession area. (Heikkinen et al. 2008)
A condition for mine waste utilization is that the material satisfies both geotechnical criteria and is environmentally benign; mine waste must not, for example, be a source of potential contamination. Therefore thorough characterisation of the mine waste material is essential. The value and utilisation potential of mine waste can be enhanced if it is first sorted on the basis of environmental constraints and geotechnical properties, prior to transfer to separate waste piles. (Heikkinen et al. 2008)
According to Mitchell et al. (2004) benefits for mine waste utilisation include:
  • Efficient use of mineral resources
  • Reduced environmental impacts
  • Increased profitability through increased income and reduced disposal costs
  • Improved sustainability for local communities
Ideally, if mine waste can be exploited, it is best to commence utilisation as early as possible during the mining process, for this reduces the volume of material that needs to be dealt with at mine closure, and hence may also accrue financial benefit in terms of reduced closure expenditure (Heikkinen et al. 2008).
Commonly however, such large volumes of waste rock and tailings are generated during mining operation that it is difficult to find sufficient economically viable applications in reasonable proximity to the mine, even if the waste is suitable from a technical or environmental viewpoint (Heikkinen et al. 2008). Also the periodic stagnations in construction industry may diminish the need for large volumes of construction materials, making a utilisation plan impractical (ITRC 2010).

Possible uses for mine waste

Suitable possibilities to utilise waste rock include:
  • Road constructions
  • Construction material for building industry
  • Material for landfill
  • Material for embankments designed for mitigating traffic noise
  • Material to stabilize pit walls or tunnels and to backfill stopes and galleries
  • Material for landscaping and stabilization during mine closure
  • Material in the neutralization of acidic groundwater generated in the mine pit
  • Tailings dams
Suitable possibilities to utilise tailings and other types of mine waste include:
  • Road constructions and other earthworks
  • As fertilizer or supplement to enhance soil quality
  • Material for backfilling the mine workings
  • Raising of tailings dams

Figure 1. Inert waste rock from a nearby mine has been used to construct a stone wall. Photo: Teemu Karlsson, GTK.

Enhancing the mine waste utilisation

In Finland the construction industry consumes over 100 million tonnes of rock materials annually, of which about 40 % is used for road construction. The consumption of natural rock material totals on average 70–80 million tonnes annually, which is the same amount that the recovered materials (e.g. fly ashes, slags, tailings and waste rocks, overburden soils, etc.), possibly suitable for construction purposes, are produced. (Inkeröinen & Alasaarela 2010)
Enhancing the use of recovered materials, such as mine waste, is an efficient way of improving material efficiency and promoting the Green Mining ideology, leading to a significant decrease in the use of untouched natural resources and energy consumption required in their transport.
Examples of projects to promote the use of secondary materials in Finland include:
  • UUMA2
    • “The goal of the UUMA2 programme is to promote the use of recovered materials in groundworks and thus decrease the use of untouched natural resources and the environmental effects of groundworks. The UUMA2 programme especially focuses on promoting eco-efficient project-specific material solutions and the commercialisation of groundworks with recovered materials. The main focus of the programme is on product development, in the development of planning and acquisitions carried out by clients and the related demonstration projects.” (Motiva 2013)
  • Utilization of mining waste rock for infrastructure construction in North Savo
    • “The purpose of the project is to integrate waste rocks and stone-based extractive waste of the mines and quarries into a part of regional construction aggregates accounting, land-use planning and stone raw materials trading.” (Savonia 2013)
  • ProMine
    • The four-year (2010-2013) ProMine project has carried out 4D modelling for the mining industry, created new nano products from waste and by-product minerals of the mining industry, surveyed European raw material resources, including secondary resources, and recorded them in a minerals database. (GTK 2013)


GTK 2013. The ProMine Project. http://promine.gtk.fi/

Heikkinen, P.M., Noras, P. & Salminen, R. (eds.) 2008. Mine Closure Handbook – Environmental Techniques for the Extractive Industries. Geological Survey of Finland (GTK), Technical Research Center of Finland (VTT), Outokumpu Oyj, Finnish Road Enterprise, and Soil and Water Ltd. ISBN 978-952-217-042-2. 169p. http://en.gtk.fi/informationservices/publications/publications/latest/publication/EJ74.html

Inkeröinen, J. & Alasaarela, E. (eds.) 2010. Uusiomateriaalien käyttö maarakentamisessa – Tuloksia UUMA-ohjelmasta 2006–2010 (in Finnish). Ympäristöministeriön raportteja 13/2010. 94p. http://www.motiva.fi/files/7913/YM_13-2010_Uusiomateriaalien_kaytto_maarakentamisessa_Tuloksia_UUMA-ohjelmasta_2006-2010.pdf

ITRC (Interstate Technology & Regulatory Council) 2010. Re-use and reprocess (R2) Technologies. Technology overview. Washington, D.C.: Interstate Technology & Regulatory Council, Mining Waste Team. http://www.itrcweb.org/miningwaste-guidance/to_reuse.htm

Mitchell, C., Harrison, D.J., Robinson, H.L. & Ghazireh, N. 2004. Minerals from waste : recent BGS and Tarmac experience in finding uses for mine and quarry waste. Minerals Engineering, 17 (2). 279-284. 10.1016/j.mineng.2003.07.020

Motiva 2013. UUMA 2 Programme Briefly in English. http://www.uuma2.fi/briefly-english

Outokumpu Oy 2013. Material safety data sheet – OKTO-Murske (OKTO-Aggregate). 6.8.2013. http://www.morenia.fi/media/tiedostot/okto-aggregate-06_08_2013.pdf

Savonia 2013. Utilization of mining waste rock for infrastructure construction in North Savo. http://codez.savonia.fi/cdio3_2013_gtk/gtk/en/index.html