Closure technologies / Wastes and waste facilities

Päivi Kauppila1, Anna Tornivaara1, Teemu Karlsson1, Clayton Larkins1, Henna Punkkinen2 & Margareta Wahlström2, 1Geological Survey of Finland, P.O. BOX 1237, FI-70211 Kuopio, FINLAND, e-mail: paivi.kauppila(at)gtk.fi,2 VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044 VTT, FINLAND

Closure of wastes and waste facilities needs to be considered already in the planning and feasibility stage of the mine. Decisions made on e.g. basal and dam structures or disposal technique during this phase inevitably affect the closure technologies available in the mine closure phase. For example, the choice of the basal structures influences the methods that can be used in the closure phase to cover the waste facilities to meet the closure objectives and criteria set for the closure. However, one of the most important factors influencing on the selection of the closure technology for mine wastes is the characteristics of the waste and its potential to pose risks to environment and human health. Wastes classified as inert do not produce harmful effluents to the environment but they could be potential raw materials e.g. for earth construction. Their disposal does not require specific liner or cover structures to reduce environmental impacts. On the other hand, wastes classified as hazardous waste require impermeable liners and covers to prevent the onset of sulphide oxidation and AMD production or mobilization of radionuclides and to restrict groundwater and surface water pollution. In addition to the characteristics of the waste itself, the environmental conditions and requirements of the waste disposal site also affect on the choice of the closure technology. These include e.g. climatic conditions, local geological and hydrogeological conditions, as well as environmental tolerance of the water courses and species at the site.

In the following, a list of closure technologies is presented. Technologies have been divided into those used during operation and those used during mine closure phase. Evaluation of the various technologies is presented as separate articles of each technology.

During operation

During mine closure