SUSTAINABILITY TOPIC: waste and RESOURCE USAGE

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. Some 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 perspective.

The secondary raw materials for Boliden smelters, such as 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.

During 2020, an additional amount of 624,000 metric tons of non-hazardous process waste was treated externally due to the closing of the Kylylahti mine. This involved old machines being recycled.

Boliden processes a number of different metals and substances that are both toxic and environmentally harmful. 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 and Ireland. 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.

Tailings result from underground mining operations, such as 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.

Waste rock from underground mines that is directly used for backfilling is not considered to be 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.

In the beginning of 2021, the construction of the 750 m SEK investment in a new leaching plant at the Rönnskär site will be completed. The plant will enable waste material that has been stored at the site since 1975 to be reprocessed. The 460,000 metric tons of waste material currently held will decrease to 220,000 metric tons. The remaining 220,000 metric tons will be stored in a deep underground repository, located under the Rönnskär smelter plant. The deposition of waste material in the repository commenced in 2021. 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.

Safe and responsible Tailings management

The International Council on Mining and Metals (ICMM), the United Nations Environment Programme (UNEP) and the Principles for Responsible Investment (PRI) conducted a review and launched a global industry standard on tailings management in August 2020.

Boliden’s position regarding the implementation of the Global Industry Standard on Tailings Management is that all Boliden’s facilities with ‘Extreme’ or ‘Very high’ potential consequences will be in conformance with The Global Industry standard on Tailings Management within three years of today, and all other facilities within five years. A Gap analysis has been caried out during 2020 to define where Boliden needs to improve and to define action to reach its commitment. During 2020, large investment projects related to tailings management commenced and continued – both to enhance our operations and minimize risk. For example, our mine sites have increased their tailings storage capacity with planned dam uplifts and liquefaction assessments have been performed in accordance with current standards to minimize risks.

More information available in the Annual and Sustainability Report on page 23.

A total of 33 (37) moderate (more than 150 liters) oil and/or diesel spills, were reported from Aitik, Boliden Area, ­Kevitsa and Tara. All spills occurred within the site area, 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 implement measures that avoid similar instances from happening in the future.

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 2020, 9,200 (9,200) metric tons were sent for external use, treatment, recovery or disposal.