Work Packages
WP1: Exploration
- WP leader: Thorkild Maack Rasmussen
Innovative exploration technologies
CAMM is providing research on the mineralization potential within Sweden and is contributing to the development of more efficient exploration methods. Proper information on the mineral resource potential is in addition to the significance in the search for mineral deposits also valuable information with respect to decisions related to the establishment of mining activities in specific areas on both a short and long-term time perspective.
Development of efficient mineral exploration strategies is in general characterized by involvement of a cross-disciplinary approach. The research is performed with the aim of providing new and improved solutions for securing the supply of raw materials necessary for the development of the society. Sweden hosts several “world class” mineral deposits and mineral districts and has a very good potential for exploitation of critical metals. The geology and mineral resources of northern Sweden are in focus for the CAMM work package on exploration. In our work we focus on the development of innovative exploration technologies by integrating regional-scale 3D geological and geophysical modelling of mineral belts with ore genetic studies and micro-analytical resource characterization.
One tool to trigger a higher degree of investment in exploration is to enhance our three-dimensional geometrical understanding of the Earth’s crust and its development over time. Within WP1 Exploration in CAMM we generate and integrate four-dimensional geological models from regional to deposit scale. Continuous integration and outward communication of our modelling and visualization expertise supports better targeting of new mineral resources at depth, which leads to a reduction of environmental impacts and costs by enhancing the efficiency of exploration workflows. Specific information about the interior of the Earth comes from three sources – drilling, mining and geophysical data. The latter are used to infer rock types and geological structures at depth and models derived from the geophysical data are often used to plan and guide drilling campaigns. Within CAMM, we specifically investigate how regional scale geophysical data combined with geological observations from northern Sweden can be utilized to provide information on geological environments favourable for hosting mineralisation.
Another way to secure the domestic supply of both main commodities and critical raw materials is to characterize ores, waste rock, and production waste material in a detailed and efficient way. Ore characterization research contributes to the development of analytical methodologies for exploration and mineral processing, through an improved understanding of the rock mass (mineralogy, mineral chemistry, textures etc.). Within the exploration research group in CAMM, methodologies arise from a novel combination of state-of-the-art micro-chemical techniques, e.g. trace element mapping by Laser Ablation ICP-MS and 3D-visulalisation by high-resolution X-ray computed tomography. The LTU micro-analytical laboratory is successfully analysing ore-related minerals. The research encompasses detailed mineralogical studies of different ore types, with the aim to understand the formation of ore deposits, increase mining efficiency and utilize the ores fully.
WP2: Mining and Rock Engineering
- WP leader: Daniel Johansson
Some of the challenges for the mining industry are deeper mines, safety, reduction of production disturbances, improving the ore recovery and reduce the dilution. Therefore, the scientific understanding of the constituting elements and the whole mining system has to be improved.
Examples of activities within the respective areas are:
Digital Mining and Autonomous Mining Equipment
The aim is to reach the vision of fully autonomous mining with no human exposure at the production face by overcoming obstacles for automation and replace information based on human senses by automated systems. The work focuses on identifying and overcoming obstacles for automation and to improve resource knowledge and productivity limitations by smart use of automated data from underground equipment.
Short-and medium term mine planning
The work aims to simplify and improve the continued underground mine scheduling, and enable a lean mining operation thus optimising the use of mining resources. Discrete event simulation models are developed and used as a digital twin of the mine, enabling further development of a scheduler and optimised use of resources.
Development of Data driven Mine Capacity Assurance Framework and Program
The main purpose of the project is to develop a framework to identify equipment related factors/issues introducing uncertainties in achieving planned volume in the mine production system with special focus on the deployed equipment and installed infrastructure considering both the back end and front end processes.
Ventilation and air conditioning
The main goal of the project is to formulate strategies to combat ventilation and air conditioning issues in deep underground mines in Sweden by assessing the feasibility of combining Ventilation on Demand (VOD) and Controlled Partial Recirculation (CPR), and review strategies used to combat the same issues in deep underground mines in Canada.
Basic research on energy transmission from non-ideal detonations to rock
There is a need for a fundamental understanding of non-ideal detonations as in emulsion explosives, to develop improved models to describe the physics behind this phenomenon e.g., shock front curvatures, energy transmissions and chemical compositions. Improved and efficient explosives could then be developed which are designed both for individual rock types and varying conditions.
Development of algorithms for automatic waveform processing and source parameters
The investigations of mining induced seismicity usually require processing of large amount of data from thousands of seismic events. Manual processing is time consuming and expensive. Therefore, automatic processing is necessary. The aim of this project is to develop algorithms for different types of processing that can be adapted to mining seismicity.
Response of underground openings, the ground surface and the rock support to deep mining conditions
Deep mining ground control problems in Sweden are typically caused by mining-induced seismicity or failure of weak altered ore contact zones. The research aims at improving the understanding of the response of underground excavations, and its rock support, to seismic and static loading and to improve the design of ground control measures.
WP3: Mineral Processing
- WP leader: Jan Rosenkranz
Advanced mineral processing for better resource efficiency
Within mineral processing different unit operations for comminution and physical separation as well as flotation are combined to multi-stage beneficiation processes in order to provide an ore concentrate or to produce an industrial mineral product of defined application properties.
In recent decades, process technologies have matured but still need to be improved. Within mineral processing, innovative processing concepts and machinery as wells as optimization are the keys to improving resource efficiency while minimizing energy consumption, auxiliaries and waste. CAMM research on advanced mineral processing is conducted in the areas of (i) comminution, (ii) separation processes, and (iii) process systems engineering:
- Dynamic models of grinding mills and mill charge are developed using multi-phase computational physics in order to optimize tumbling mill and stirred media mill performance. This involves investigation of how energy is utilized and how wear of media and liners is affected by operational and design parameters as well as particle properties.
- Mineral liberation, being crucial for the efficiency of subsequent separation processes, can be enhanced by better adjusting target particle size and breakage mechanism to ore texture and mineral associations. In a more fundamental investigation different stress modes and rates are applied to various ore types in order to identify optimal liberation conditions and develop advanced process models.
- For fine-grained, complex ores and fine tailings the combination of mineral processing and hydrometallurgical processing is considered as a promising concept that requires further investigation. Raffinate milling will result in innovative processes, e.g. leaching while grinding, and novel grinding circuits for improved resource efficiency.
- The effect of low temperatures on the efficiency of flotation separation, particularly oxide and silicate flotation, is investigated in order to identify novel flotation reagents, suitable reagent regimes and hydrodynamic concepts adapted to mineral beneficiation and tailings treatment in cold climate.
- Using dry processes wherever possible will result in lower process water consumption and smaller ecological footprint. This refers to ore sorting, dry primary comminution, dry screening instead of wet classification, dry concentration, and also dry deposition techniques. Research on extending dry processes to the sub-millimeter range is particularly needed.
- New technologies available for mineralogical analysis, as hyperspectral imaging or computer tomography, are investigated with respect to their potential for process design and control. Challenges arise from linking mineralogy to processing properties in order to make property modelling more generic. Soft-sensors for advanced process control are developed that use such models.
- Improving resource efficiency requires processes that are flexible towards variations in an ore body. Geometallurgy as a holistic approach to optimizing process design and control provides methods and tools for linking ore properties and process behaviour. While ongoing research is on geometallurgical testing and modelling, a coherent methodology is developed here to integrate with sustainability and flexibility concepts.
WP4: Process Metallurgy
A collaboration within Process Metallurgy between Luleå university of technology and Swerim.
- WP leader: Fredrik Engström and Swerim
Resource efficient metal extraction
Metallurgical industry and not the least Swedish metallurgical industry are facing a number of large challenges; to be able to produce metals with minimum emissions of greenhouse gases, ores and scrap become increasingly complex and the metal content of scrap from consumer goods changes quickly over time.
Given the above challenges for the metallurgical industry the research is organized into three different areas:
- Raw material efficiency
- Alternative reductants
- Recycling and residue utilisation
Raw material efficiency
Holistic modelling of combined scrap and ore processing. To optimize the extraction of minor components into suitable material streams, a holistic view on combined scrap and ore processing has to be developed based on fundamental thermodynamic and kinetic data included in models combining knowledge about all unit processes in the processing chain. As a first step impurity elimination in roasting operations are studied through laboratory experiments. A joint project between Ore Geology and Process Metallurgy.
Fundamental understanding of unit processes. To understand the impact of different raw materials on the unit processes a more fundamental knowledge about the behaviour of different elements in the unit processes is needed. The activity is for the moment focused on the alkali circulation in a Blast Furnace, part of an ongoing European research project.
Alternative reductants
Research within this area is mainly concerned with the use of biocoal in blast furnace ironmaking, the efficiency when introducing biocoal and the recycling of carbon containing residues and waste fractions. Several of the activities are also partly carried out within European and Swedish industry supported projects.
Flexibility in coke making. By developing methods for using e.g. biocoal, thermal coal, pet coke, etc. in the cokemaking the dependence on coking coals can be reduced. Fundamental studies are carried out in lab and pilot scale.
Improved coal combustion and efficiency of injected materials. Improved coal combustion efficiency under various BF conditions and with various new carbon containing materials is studied. The reaction kinetics are determined in lab scale, the kinetic data then used in CFD modelling giving input to modification of equipment.
Use of bio-coal for injection and in agglomerates. Large forest areas in Sweden gives possibilities to use forest residues or even stem wood to produce bio based reductants. Different types of bio coal, charcoal or torrefied, are tested in lab scale and in full scale plant trials.
The Use of waste plastic as reductant for reduction of metal oxides in slag in base metals production have been studied both in lab scale and in a full scale plant trial. A process concept on how to maximise the internal recycling of coal containing residues, e.g. blast furnace sludge, within iron- and steelmaking have been tested in full scale. Implementation is in both cases evaluated by the industry partners.
Recycling and residue utilisation
Slag utilization. Research projects are carried out to increase the utilization of both steelmaking slag and slag from base metals production. For both type of slags the research is based on the unique properties of the slags due to their mineralogical composition.
WP5: Environment
- WP leader: Lena Alakangas
Humans are today a significant geological factor that affects the Earth on a local, regional and global scale. Concerns about man's impact on the atmosphere, hydrosphere, lithosphere and potentially toxic effects on the biosphere have actualized the need for environmental geochemistry.
Mining produces visual and geochemical impact on the environment with the production of important amounts of mining waste, which need to be stored safely during and after production. Research activities focus on the characterizing, elimination, stabilization, and rehabilitation of mine waste in order to minimize the environmental impact and increase the sustainability and social acceptance of the extractive industry.
Platinum Group Elements (PGE) in Ni-laterites
PGE are critical for European industries and expected to become even more important in the future due to the Green Deal by the European Commission. The aim of this project is to gain basic knowledge about element mobility and precipitation mechanisms of PGE within the supergene environment. By applying the QanTmin flowsheet, Matías will study the PGE mineralogy within Ni-laterites to document transformation processes from primary to secondary environments. In a second step, microbiological studies in cooperation with Prof. Duran from the University of La Pau (France) will investigate the possibility of biologically-mediated platinum-group mineral (PGM) neoformation. During the second half of 2023, the analytical method as described in project 1a, will be applied on PGM from Ni-laterites to investigate the possibility to find an isotopic biomarker for in-situ PGM neoformation.
Uranium in rocks and mine waters
The focus is tracing source and transformations of uranium in mine areas. This project involves external cooperation with the mining company LKAB. The following activities are planned:
- Characterization of xx rock samples and analysis of the xx groundwater with focus on uranium and complexing ligands that mobilize uranium. Planned analysis are µXRF scans, Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS), Laser-Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS), sequential extraction and radioactive and stable isotopes.
- Hydroseparation and sequential extraction of U minerals and complex ligands.
- Isotope analysis in groundwater and of concentrated U minerals.
One scientific paper will be published during 2023 describing the geochemical processes in mineral processing and a draft on uranium source and mobility of uranium at mine site.
Predictive model for pit lake water quality
The project will focus on the understanding of the water quality of open pits and/or pit lakes atmine sites. The aim is to develop a methodology, that can be used to obtain input data for predictive modelling of pit lake water quality, which is an important part of evaluating the environmental impact of mining. The total exposed surface area of pit walls will be estimated to be able to quantify the total element contributions from exposed mine walls. The estimation will be based on drone imagery and photogrammetry and coupled to data from previously conducted element leaching experiments at several mine sites. Together with data of other sources contributing to the element loads of the pit lakes, such as groundwater, the relative contributions of the individual sources can be estimated. Micro-XRF will be used to verify data previously collected with handheld XRF. In combination with data from Project 2 a thorough understanding of sources and mobility of elements at the studied mine sites can be obtained. The project will also focus on the remediation of pit lakes by studying wood ash as a potential alkaline fertilizer that can stimulate algal growth, lower element concentrations, and raise the pH of acidic pit lakes. Experiments have previously been conducted with good results in a pit lake with circumneutral pH and the aim is therefore to investigate if similar results can be achieved in pit lakes with low pH values.
Geochemistry of REE in tailings
Mining and usage of EU-critical raw materials will increase in the European Union to reach the European Green del by 2050 green technology. As the usage of these metals increase, there is a risk that the geochemical cycles of them will change. At present, background levels, guideline values and the geochemical knowledge regarding these EU-critical raw materials are missing. Without this knowledge, mine waste and water management might be insufficient, and reclamation to “pre-mining conditions” after mine closure will be hard to achieve. In this project, a new Ph.D. student will study the source mobility and fate of REE in historical tailings to increase the general knowledge about REE in the terrestrial environment (TRL-level 1). Drilled core samples from tailings will be analyzed with geochemistry, mineralogy and sequential extraction to determine REE-hosting minerals and weathering rate of the hosting minerals. Groundwater pipes will be installed and sampled monthly. Temperature measurements with drones will elucidate where groundwater draines to the surface water, and surface water will be sampled monthly as well.
Effekter av stress och åldrande på partikelns form i slagg
Beneath the chemical aspects of tailings, the mechanical behaviour and changes in the mechanical behaviour needs to be addressed. Tailings in tailing ponds are not a homogeneous material with constant mechanical properties. Variations in tailings might occur due to changes in the production line or due to variations in storage procedures. Further variations occur due to the fact that tailings are stored in deep deposits exposed to increased effective stresses. This increase in effective stresses can lead to changes in the particles due to crushing and abrasion, which has not been studied systematically yet but has an immediate effect on the mechanical behaviour. In addition, long term exposure to chemicals used in the extraction and storage phase might influence the mineralogical features and in return again influence the Geomechanics of tailing ponds and, having upstream build tailing dams, effects the stability and safety of those dams.
Here we are going to look at the interaction between composition and particle shape of tailings sampled from different depths (and thus changing storage time) by means of XRD and Laser analyses in combination with triaxial shear tests to establish the stress strain behaviour under equivalent stress states. Under the year 2022, the existing laboratory and field data were reviewed, as well as relevant field samples were obtained. Based on literature review and available laboratory and field data, the work on year 2023 will focus on changing of PSD and particle shape due to increased stress, i.e. study the change in mechanical behaviour due to increased stress. In particular the crushability and degradation of different tailings will be investigated. Determination of mineralogy and composition of the tested tailings will also be undertaken, in order to link changes in PSD and particle shapes to these parameters
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