Sustainability Topic: Sustainable resource usage and waste

306–2  Waste by type and disposal method

Boliden has developed processes to extract as much value as possible from the material streams at mines and smelters. Some hazardous waste is sent for disposal or stabilization, in some cases to landfill and deep repository.

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 the metal production. The excess heat from the process is used for district heating.

Waste by type
and ­disposal method
(metric tons)

2017

2018

2019

       

Hazardous waste, total

865,000

869,000

886,000

Landfill (storage)

     

Internal

839,000

843,000

861,000

External

400

1,800

2,600

Recycling

26,000

24,000

22,000

Non-hazardous waste, total

332,000

279,000

249,000

Landfill (storage)

     

Internal

278,000

222,000

175,000

External

1,600

2,200

2,200

Recycling

52,000

55,000

72,000


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. 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. Boliden’s wastes are managed in accordance with the EU Directive on the Landfill of Waste and the Mining Waste Directive. Waste rock dumps are covered continuously, in order to prevent weathering and 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 or for other water management. This figure includes both operational and decommissioned facilities. Dam facilities are managed according to mining industry guidelines for dam safety.

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.

Waste from extractive
industries (metric tons)

2017

2018

2019

       

Reuse (backfilling)

     

   Waste rock

5,417,000

8,892,000

8,887,000

   Tailings

2,729,000

3,182,000

3,174,000

Waste rock (dumps)

35,485,000

49,619,000

50,180,000

Sold waste rock

404,000

5,400

5,900

Tailings management ­facility

44,191,000

48,844,000

51,677,000


Waste rock from underground mines that goes directly to backfilling is not considered as waste and should not be reported as waste.

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.

In 2019, the constrcution project of the 750 m SEK investment in a new leaching plant at the Rönnskär site was started. This will enable waste material that has been stored at the site since 1975 to be reprocessed. The 460k metric tons of waste material currently held will decrease to 220k metric tons. The remaining 220k metric tons will be stored in a deep underground repository, located under the Rönnskär smelter plant. The deposition of waste material in the repository will commence in 2020. This is a globally unique solution. It is the only place in the world where a deep underground repository shares a site with a smelter. Boliden has no organic waste material 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 37 (36) moderate (more than 150 liters) oil and/or diesel spills, were reported from Aitik, Boliden Area, Garpenberg, Kevitsa 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.

During Q3 there was an increased discharge of metals to water at the Rönnskär smelter.

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 2019 6,500 (7,300) metric tons were sent for external use, treatment, or recovery and 2,600 (1,850 ) metric tons were sent for external disposal.