Positive results obtained from nitrate removal process

A European EIT Raw Materials project, ‘NITREM‘, has achieved positive results from a pilot scale implementation at LKAB’s Kiruna mine and is planned to be scaled up to full-scale. Nitrate concentrations of around 70 mg/litre in the leachate from waste rock piles was reduced to less than 10 mg/litre (an efficiency of 77%) after passing through a bioreactor. Nitrate is formed from the residual of ammonium nitrate-based explosives used in mining, and causes unwanted growth of algae leading to autrophication of waterways.

The bioreactor is a passive design, requiring little intervention. An oblong pit is constructed, the walls sealed with a geomembrane, and filled with wood chips and a dose of activated sewage sludge containing nitrogen-reducing bacteria. The bioreactor is covered an operates under anaerobic (oxygen-free) conditions. The bacteria utilise carbon from the wood chips to transform the nitrate to nitrogen gas, while the leachate flows through the reactor.A trial during 2019 recorded an average nitrate removal efficency of 77% with input nitrate contents of 61 – 87 mg/litre. During the operating period the average temperature was 3 °C, confirming that the microbial process is suited for use in cold climate conditions.

The process is proposed to be scaled up and implemented at further mining sites to reduce the impact on the environment. Further details are available at the NITREM project webpage. The project consortium consists of Uppsala University, WSP Sverige AB, Cedervall Arkitekter, Agencia Estatal Consejo Superior de Investigaciones Centificas, Boliden Mineral, LKAB, LTU Business and the Swedish University of Agricultural Sciences.

Schematic diagram of the NITREM nitrate biorector system
NITREM nitrate removal process, from https://nitrem.eu

Passive wastewater treatment systems have been widely reported for the reduction of heavy metals, a review is given here. These results that the technology is also suitable for reduction of anions such as nitrate in the wastewater.

Call for papers

A Call for Papers has been issued for a Special Issue of the Journal of Water & Climate Change, with the topic of “Integrated assessment and adaptation to climate change impacts in cold regions”. The Special Issue is related to the 6th IAHR (International Association for Hydro-Environment Engineering and Research) EUROPE Congress – at which Hanna Virpiranta is scheduled to present results from the Kolarctic CBC SEESIMA project. Tiina Leiviskä is one of the Guest Editors of the Special Issue. The submission deadline is 31 March 2021, with expected publication in October 2021.

This Special Issue will cover the following topics:

  • Data sources and acquisitions (e.g. observations, reconstructed, reanalysis, models, remote sensing data).
  • Data calibration, verification and sensitivity analysis.
  • Use of state-of-the-art research methods (e.g. machine learning, hydrological model, climate model simulations).
  • Natural hazards and risk assessment (e.g. urban flooding, snow avalanches, rockfall, landslides, debris flows).
  • Future climatic and hydrological simulations and projections.
  • Changes in the hydrological cycle and heat and energy transfer.
  • Water pollution control and quality management.
  • Innovative wastewater treatment processes, waste management and resource reuse.
  • Impacts of climate change on the total environment.
  • Mitigation and adaptation options (e.g. blue-green solutions, nature-based solutions, and performance assessment, social-economic value and multi-benefits, etc). 
  • Rehabilitation and repairing technologies of structural defects and the use of new materials and new construction methods.
  • Other aspects of hydro-environmental research and innovation topics.

The link to the call for papers is here.

Nussir eyeing a possible start in 2020

The planned mine at Repparfjord in Finnmark is edging closer to a start, after a decade of negotiations. The mining licence was received in February 2019 from the Norwegian Ministry for Trade, Industry and Fisheries. Despite some uncertainty created by the corona-virus it is still hoped to start operations in 2020.

The planned Nussir copper mine involves two deposits – at Ulveryggen/Gumppenjunni and Steinfjellet/Nussir. (Picture from Nussir, via High North News)

Planning and financing for the start of operations was underway, but faces some uncertainty regarding the recovery of the financial markets after the corona virus. The Managing Director still hopes to see the mine operations to start in 2020, according to a recent article in High North News.

Nussir plans to extract copper, silver and gold, and also will look into the development of technologies to recover platinum, palladium and tellurium. The delays from the permitting process have allowed the adoption of new technologies, such as the electrification of the mining operations. The demand for copper has also continued to grow, such as for electric vehicles, wind turbines and other forms for renewable energy.

Conference in Minerals Engineering in Luleå

On the 4th-5th February Luleå Technical University is arranging the Minerals Engineering Conference in the Luleå City Hall. The conference includes the following sessions:

  • Introduction
  • Session 1: New Development Projects
  • Session 2: Surface chemistry and wet processing
  • Session 3: Metal intelligence – future efficient minerals analysis, processing and training
  • Session 4: Physical separation
  • Session 5: SEESIMA: Results from a Kolarctic Cross-Border Collaboration

The detailed programme can be downloaded here:

International Plaksin Readings

On September 21-26 September 2020 The International Plaksin Readings will be hosted by The Federal Kola Research Center of the Russian Academy of Sciences, in Apatity, North-West Russia.

The International Plaksin Readings is one of the most significant conferences in the field of mineral processing, hydrometallurgy, and geoenvironmental engineering. Igor Plaksin is the founder of the Soviet research school in the field of mineral processing and hydrometallurgy of rare, non-ferrous, and noble metals, and a two-time winner of the USSR State Prize.

The International Plaksin Readings has been held annually since 1977 at various venues across the USSR and Russia (Apatity, Novosibirsk, Tosk, Petrozavodsk, Krasnoyarsk, Irkutsk, Khabarovsk, Moscow, St Petersburg, Vladivostok, etc) as well as abroad (Almaty in Kazakhstan, Tbilisi in Georgia, etc).

The 2020 International Platsin Readings is organised by Academician V.A. Chanturia, Chief Researcher at the Melnikov Institute for Integrated Development of the Mineral Resources at the Russian Academy of Sciences, Chair of the RAS Research Board for Mineral Processing.

Invitation flyer for the International Plaksin Readings 2020

Contact persons:

  • Galina Mitrofanova gera@goi.kolasc.net.ru
  • Anastasia Yenutina anyen@yandex.ru
  • Anton Svetlov a.svetlov@ksc.ru

More details are available in this 1st Informational letter, and at the webpage for the event.

LKAB proceeding with evaluation of mine waste valorisation

The valorisation of mine waste is part of LKAB’s sustainability strategy. A recent press release from LKAB announced that they are proceeding with the development of processes to recover Rare Earth Minerals and phosphorus from the mining waste from the mining operations in Malmberget and Kiruna.

LKAB has had collaboration with a Ragn-Sells subsidiary, Easymining, since 2018, with the establishment of a 45 MSEK pilot plant, as posted earlier. The developments are now proceeding to the next phase, involving further partners, and leading to an investment decision for full-scale implementation for mine waste valorisation.

The process is described as involving production of a apatite concentrate by flotation of the mine waste. The concentrate is then to be processed with acid dissolution, producing phosphorus, rare earth minerals and gypsum.

Mining waste, from www.lkab.com

CAMM² seminar in Luleå 21-22 April 2020

Luleå Technical University is arranging a seminar on Exploration, Mining, Mineral Processing, Metallurgy and Environment. This arrangement is part of the Centre for Advanced Mining and Metallurgy (CAMM) which was established at LTU in 2010 as a strategic research area. More details about the CAMM² Centre can be found here.

Announcement for the CAMM² seminar in Luleå 21-22 April

Resources for schools about mining

To encourage school children to consider careers in the mining industry the Swedish Association of Mines, Mineral and Metal producers has produced a magazine entitled “Stabilt” (meaning “stable”, as in long term reliability). This is available from their web page, or a copy can be downloaded here.

The Stabilt magazine includes profiles of young persons working in the mining industry, what they do and what education path they took to get there. The magazine stresses the variety of types of work – with over 250 different types of work.

Mine locations in Sweden
Illustration of the location of mines in Sweden, from the Svemin “STABILT” magazine

Sustainability and biomining in focus

The increasing focus on sustainability and environmental impact of mining activity is the basis for two Mineral Engineering conferences to be held in Falmouth, Cornwall in June 2020. These conferences, on biomining and sustainable minerals, have relevance to activities within the SEESIMA project, such as within WP4 and WP5.

Biomining ’20

The first is the Biomining ’20 conference, to be held 8-9 June 2020 in Falmouth. This is the 10th time that this conference has been arranged (after a name change from the earlier title of ‘Biohydrometallurgy’). The conference focuses on the development, optimisation and implementation of integrated biomining processing of mineral ores. This is an alternative processing route whereby the microbes are used to cause or catalyse the release of metals from the ore. This includes the microbiology of heap or tank leaching, bioflotation. This approach can be used on low grade or complex ores, or on novel resources such as mine and electronic waste, or the rehabilitation of environments damaged by mining. As such, biomining is a contributor to the sustainability of mining activity.

Biomining has achieved increased attention in recent years, and a flagship implementation is represented by the Terrafame mine in Finland. The following cartoon, taken from here) illustrates one of the main bacteria (Thiobacillus ferroxidans) used in releasing copper metal from copper ore.

biomining - a sustainable mining activity.
one view of the new workforce in biomining, (by downtoearth.org.in)

Sustainable Minerals ’20

The second conference is the Sustainable Minerals ’20 conference, to be held from 10-11 June 2020, also in Falmouth, Cornwall. This is being held for the 6th time, and focuses on sustainability aspects of mining. Modern society’s extensive use of metals and mineral-based materials creates a strain on sustainable use of natural resources. Hence, mining needs a focus on sustainability.

The topics of Sustainability ’20 include:

  • Acid Mine drainage
  • Wastewater treatment
  • Energy recovery and reduction
  • Industrial applications
  • Processing of Industrial Wastes
  • Recycling of post-consumer materials
  • Development of geopolymers as cement alternatives.

The Eden Project – nearby in Cornwall

A further attraction in the Cornwall area is the possibility to visit the Eden Project, nearby. This was formerly an open pit mine, extracting china clay. After the mine was closed it was transformed into one of the largest tourist attractions in the United Kingdom. The two pictures below show the ‘before’ and ‘after’ views of the site. This is a great answer as to what to do with the hole in the ground after mining has finished. A different approach to sustainability and biomining!.

Transformation of a china clay pit mine into the Eden Project tourist attraction - a good example of sustainable mining activity.
‘Before’ and ‘After’ views of the transformation of the china clay pit mine into the Eden Project.