Behov for kompetanse

Behov for hydromatallurgikompetanse

(fra NFR søknaden, skrevet på engelsk)

Nettstedansavarlig: Jon Petter Omtvedt (UiO)

For two decades the industrialised world has relied on China and Chinese resources for satisfying their needs for metals and raw materials used in production of state-of-the-art technological items. An example here is the rare earth elements. The Western world closed down mines, production facilities and even the universities stopped or reduced their education in recovery methods for these and related compounds. In 2009 China shocked the same industrialized world by declaring that they will reduce production and export of rare earth elements. This has led to a new understanding in industrial management on security of supply of raw materials and the cost of such security, but also an understanding at government-level of the importance of surveying and exploring domestic resources. Thus, in Norway there is an on-going major survey initiated by the Norwegian Government on mineral deposits in Northern Norway. In addition, the Ministry of Trade and Industry has presented a Strategy for the Mineral Industry in Norway (2013).

The Canadian Mining industry has in 2012 pinpointed the following topics as essential: Discovering new mineral resources; Extending life of existing ore bodies; Lowering production costs; Improving productivity; Increasing value added; Reducing environmental footprint; Improving health and safety. Except for the first two topics, hydrometallurgy will play a significant role in solving these challenges.

Norway is a high cost society with an economy strongly influenced by the petroleum industry. Nevertheless, there are strong Norwegian industries based on minerals and refined raw materials, domestic as well as imported. Some types of minerals are scarce and the exploitation of less rich deposits or deposits with high content of impurities is to be expected in the future. This means that even less than world class deposits in Norway may be considered as resources, and possibly exploited. It is however required, that the processes must be adjusted so that the gangue materials and impurities are removed, and here hydrometallurgy will offer solutions. As one example in the fertilizer industry the removal of cadmium from dissolved phosphate feed-stocks has been worked on for several decades, but still economical viable solutions are lacking.

The Norwegian mineral and refining industry is among the most environmentally friendly in the world, but still there are possible improvements to be made. For the mining industry, recovery of metals from waste steams will reduce waste, reduce the solids to deposit, and reduce the amount of caustic needed for sliming. It is important to be able to exploit the available resources in the best possible way to improve competitiveness. For example, to just produce the mineral and export it as a crushed rock material is not the optimum way of doing business from the society’s point of view. Instead, to extract as much of the high value elements as possible is beneficial in several ways:

  • Increased income
  • The local and international industry is supplied with high quality raw materials from a near-by source
  • The supply comes from stable sources and a stable society
  • The Norwegian society gets economic benefits
  • The Norwegian knowledge base is maintained and increased, making it possible to have spin-offs, e.g. in nanotechnology, semiconductors, and electronics.
  • Reduced footprint with respect to transport

To maintain and even improve existing technology it is imperative that there exists educational- and research-environments in the field of hydrometallurgy. Traditionally, the key topics of hydrometallurgy are: leaching, solid-liquid separation, liquid-liquid (solvent) extraction, ion-exchange, precipitation-, cementation-, and filtration technologies, membrane separations, electrolysis for recovery and refining, etc. In addition, beneficiation of minerals is often regarded as a part of hydrometallurgy, comprising magnetic separation of minerals, gravitational separation and floatation. Figure 1 is a diagram showing the different parts in the process from mining of ore containing the mineral of interest to a high value product. Too often Norwegian mining enterprises sell their minerals as concentrates, i.e. stops at the upper circle, whereas the lower, large circle indicates the high value product which may be used in production of high technology items.

University of Oslo (UiO), Norwegian University of Technology (NTNU), Institute of Energy Technology (IFE), and SINTEF together cover many of the above-mentioned topics, but only in parts. For example, UiO has for many years employed solvent extraction in research for super-heavy elements, but this is only of limited interest to the industrial user. Similarly, NTNU has no longer any research in solvent extraction, but has good facilities for leaching. A research group within precipitation, crystallization and filtration has been developed at NTNU during the last 10 years.

The industry is in a similar situation. From mines and mineral processing plants the methods for recovery of valuables from the outgoing streams are traditional and low cost. To meet future environmental legislation and standards, it is important that new enterprises have access to optimum technological means. Today, the industry is in great need for  hydrometallurgical skills and knowhow. For example:

  • Nordic Mining is developing a process for recovery of rutile from the Naustdal deposit. With approximately 5% rutile, TiO2, the remaining 95% of the ore material must be removed and deposited.
  • Yara is establishing a pilot plant for enabling tests of new raw materials, and also to recover valuable elements and to remove unwanted constituents.
  • Norsk Separation Technology in co-operation with UiO is testing new technology for purification of lanthanides by chromatographic means.
  • Glencore Nikkelverk has for the last decades been toll refining nickel matte from various sources. The nickel market is, however, in a state of change and the traditional nickel sulphide resources are depleted and oxidic ores (laterites) are taking over. To produce high purity nickel from laterites require new hydrometallurgical methods as these ores also contain a variety of metallic and non-metallic impurities.
  • Boliden Odda wants to implement new technology for removal of halogenides. This will open up the market for use of secondary Zn resources and waste as raw material. With improved knowledge in hydrometallurgy and liquid-liquid extraction in particular, Boliden Odda will be able to extract Pb and Ag from the present waste streams.
  • The mineral and refining industry expect tougher demands regarding removal of As for the waste water in the coming years. Since the present technology is inadequate there is a need for new research and development.
  • New copper- and gold mines are under development in Northern Norway. Sulphide containing gangue material deposits may represent a serious threat to environment due to effluents.

The Norwegian hydrometallurgical industry is in a situation of revival and substitution of the old generation of engineers and technological expertise. Yara, for example, has been seeking new employees with hydrometallurgical skills, but could not find qualified applicants in Norway.