Material Topic: Discharges to water and Waste

306–2  Waste by type and disposal method

Boliden handles considerable amounts of waste materials. These waste materials mainly comprise various types of dust and slag, tailings, rock, and other mineral formations. Boliden has developed processes to extract as much value as possible from the material streams at mines and smelters. Hazardous waste is sent for disposal or stabilization, in some cases to landfill and deep repository. The increasing amounts of waste rock in 2018 are attributable to the expansion of the Kevitsa mine in Finland.

Waste by type and disposal method (tonnes)





Hazardous waste, total




Whereof to external use, treatment, or recovery




Whereof to external disposal




Non-hazardous waste, total




Whereof to external use, treatment, or recovery




Whereof to external disposal




Waste rock, total




Waste rock for internal construction




Storage of waste rock for future use




Sold waste rock




Tailings total




Tailings for internal construction




MM3  Waste types and disposal methods including overburden, rock, tailings and sludge, and their associated risks

Boliden processes a number of different metals and substances that are both toxic and environmentally harmful. The mining and smelting operations generate residual waste consisting of waste rock, tailings, slag, sludge, and dust. EU waste legislation currently has a strategic approach that views waste as a resource and deposition as the last option (Waste Framework Directive, 2008/98/EC). There is considerable awareness of the importance of waste issues within the Boliden Group: e.g. waste sorting, significant recycling of process residues and scrap, good reporting procedures and ongoing waste projects. The majority of Boliden’s process and mining wastes are sent to landfills in accordance with the EU Landfill of Waste Directive (1999/31/EC) and the Mining Waste Directive (2006/21/EC). The remainder is used as construction material or as filler material. Waste rock dumps are covered continuously, wherever possible, in order to prevent weathering or leaching. Boliden’s mine waste is handled in accordance with applicable environmental permits that specify how and where it may be stored and how it shall be covered and reclaimed.

Extensive monitoring programs are in place to ensure a high level of dam safety and several measures to increase dam safety have been finalized or are in progress. Boliden is responsible for around 40 dam facilities in Sweden, Norway, Finland, Ireland, and Canada. They are used or have been used to deposit tailings sand or other waste and for water management. This figure includes both operational and decommissioned facilities. Dam facilities in Sweden are managed according to GruvRIDAS (mining industry guidelines for dam safety).

Correctly processed waste can be turned into valuable products. Approximately 45% of the process residues generated are sent to another Boliden site for metals recovery or final deposition. What is considered waste for one operation can often constitute a raw material for another. Appropriately handled, the trade in waste and by-products can be of benefit to society by increasing overall resource efficiency. Boliden works continuously to identify internal and external recycling or landfill solutions for any process wastes generated. Boliden receives significant amounts of waste from external parties for recycling, construction purposes or safe deposition in landfills.

The export of waste to landfill or for recycling is extensively regulated. Boliden has also developed procedures for monitoring and following up on the receiving party’s processing operations to ensure that their waste processing is acceptable from a health and environmental viewpoint.

The secondary raw materials for Boliden smelters, i.e. electronic scrap and waste batteries, contain plastics that are incinerated in the process. The incineration of the plastics serves as a reducing agent in order to produce the metal. The excess heat from the process is used for district heating.

Waste rock tonnage is based on calculations of volume and density. Tailings are based on calculations of tonnage of ore minus tonnage of concentrate output.

There are no statistics available for overburden as it is seldom that any overburden exists. Sludge that is not reused in the process accounts for an insignificant percentage of either hazardous waste or non-hazardous waste, depending on its properties.

Tailings are from underground mining operations, i. e. from the concentrator and, are, to a certain extent, used as back-fill, both as reinforcement and to reduce the amount of tailings above ground. Some waste is sent for final storage in underground facilities. Odda stores jarosite and slag in mountain caverns. In 2018, the Board approved an SEK 750 m investment in a new leaching plant at the Rönnskär site, with construction starting in 2019. This will enable waste material that has been stored at the site since 1975 to be reprocessed. The 460 ktonnes of waste material currently held will decrease to 220 ktonnes. The remaining 220 ktonnes will be stored in a deep underground repository, located under the Rönnskär smelter plant. The first phase of construction work on the underground repository was finished in 2018, and deposition of waste material in the repository will commence in 2020. This is a globally unique solution. This is the only place in the world where a deep underground repository shares a site with a smelter. Boliden has no organic waste material that is suitable for composting, other than small amounts from canteens, which are sent for municipal treatment.

Boliden does not practice deep well injection or waste ­incineration.

306–3 Significant spills

A total of 36 (23) larger (more than 150 liters) oil and/or diesel spills, were reported from Aitik, Boliden Area, Kevitsa, Odda and Rönnskär. All spills occurred within the site area. All spills were immediately sanitized and any contaminated soil was excavated. These events have not entailed any significant environmental impact or caused lasting harm to the surroundings. Investigations have been conducted in conjunction with all of the incidents in order to ascertain the causes of the spills and, wherever possible, to institute measures that will prevent any repeats.

306–4 Transport of hazardous waste

Processing of intermediate and waste products is a natural part of Boliden’s value chain in order to maximize metal recovery levels. In some cases, however, hazardous waste is sent for disposal or stabilization, and/or to external landfill and deep repository. During 2018 7,300 (7,400) tonnes were sent for external use, treatment, or recovery and 1,850 (400) tonnes were sent for external disposal.