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  • 1.
    Ahmadi, R.
    et al.
    Iran Mineral Processing Research Centre (IMPRC), Karaj.
    Hashemzadehfini, M.
    Iran Mineral Processing Research Centre (IMPRC), Karaj.
    Parian, Mehdi Amiri
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Rapid determination of Bond rod-mill work index by modeling the grinding kinetics2013Inngår i: Advanced Powder Technology, ISSN 0921-8831, E-ISSN 1568-5527, Vol. 24, nr 1, s. 441-445Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Generally, Bond work index is a common method for selecting comminution equipment as well as estimation of grinding efficiency and calculating required power. In the current research, a simple, fast and accurate procedure is introduced to find the rod-mill work index based on the conventional Bond work index. The grinding experiments were carried out on four typical samples of iron, copper, manganese and lead–zinc ore with three test-sieves in specified time periods and aimed to shortening the procedure. Furthermore, the grinding kinetics and mass balance equations were applied to model the standard Bond rod-mill work index. For comparing the standard Bond rod-mill work index and the new modeled method, work index (Wi) and produced fine particles in a cycle (Gi) for the four samples determined. The performed paired Student’s t-test results indicated that the Standard Deviation for Gi and Wi obtained by the shortened method are respectively 0.50 and 0.58 in respect of traditional Bond method.

  • 2.
    Chelgani, Saeed Chehreh
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Parian, Mehdi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Semsari, Parisa
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Ghorbani, Yousef
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Rosenkranz, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    A comparative study on the effects of dry and wet grinding on mineral flotation separation: a review2019Inngår i: Journal of Materials Research and Technology, ISSN 2238-7854, Vol. 8, nr 5, s. 5004-5011Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Water scarcity dictates to limit the use of water in ore processing plants particularly in arid regions. Since wet grinding is the most common method for particle size reduction and mineral liberation, there is a lack of understanding about the effects of dry grinding on downstream separation processes such as flotation. This manuscript compiles various effects of dry grinding on flotation and compares them with wet grinding. Dry grinding consumes higher energy and produces wider particle size distributions compared with wet grinding. It significantly decreases the rate of media consumption and liner wear; thus, the contamination of pulp for flotation separation is lower after dry grinding. Surface roughness, particle agglomeration, and surface oxidation are higher in dry grinding than wet grinding, which all these effects on the flotation process. Moreover, dry ground samples in the pulp phase correlate with higher Eh and dissolved oxygen concentration. Therefore, dry grinding can alter the floatability of minerals. This review thoroughly assesses various approaches for flotation separation of different minerals, which have been drily ground, and provides perspectives for further future investigations.

  • 3.
    Guntoro, Pratama Istiadi
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Ghorbani, Yousef
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Parian, Mehdi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Butcher, Alan R.
    Geological Survey of Finland GTK, PO Box 96, 02151 Espoo, Finland.
    Kuva, Jukka
    Geological Survey of Finland GTK, PO Box 96, 02151 Espoo, Finland.
    Rosenkranz, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Development and experimental validation of a texture-based 3D liberation model2021Inngår i: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 164, artikkel-id 106828Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Prediction of mineral liberation is one of the key steps in establishing a link between ore texture and its processing behavior. With the rapid development of X-ray Microcomputed Tomography (µCT), the extension of liberation modeling into 3D realms becomes possible. Liberation modeling allows for the generation of particle population from 3D texture data in a completely non-destructive manner. This study presents a novel texture-based 3D liberation model that is capable of predicting liberation from 3D drill core image acquired by µCT. The model takes preferential, phase-boundary, and random breakage into account with differing relative contributions to the liberation depending on the ore texture itself. The model was calibrated using experimental liberation data measured in 3D µCT. After calibration, the liberation model was found to be capable of explaining on average of around 84% of the variance in the experimental liberation data. The generated particle population can be used for particle-based process simulation to evaluate the process responses of various ore textures subjected to various modes of breakage.

    Fulltekst (pdf)
    fulltext
  • 4.
    Isaksson, Jenny
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Andersson, Anton
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Vikström, Tommy
    Boliden Rönnskär, Skelleftehamn, 932 81, Skellefteå, Sweden.
    Lennartsson, Andreas
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Parian, Mehdi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Samuelsson, Caisa
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Improved Settling Properties of Iron Silicate Slag by CaO Modifications2023Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    One of the most significant sources of copper losses from pyrometallurgical copper extraction is attributed to dissolved and entrained copper in the discarded slag. The entrained copper can be recovered via pyrometallurgical slag cleaning in a settling furnace. Reduced copper losses mean increased smelter profits by improved raw material efficiency, and, in addition, the slag will become a more environmentally safe by-product. One way to increase the copper recovery during the settling process is to modify the slag to improve the properties that decrease copper solubility and slag viscosity. In this study, iron silicate slag was modified using CaCO3 on an industrial scale to evaluate its effect on the settling process. More specifically, the changes in settling were related to the modifications and measurements of slag viscosity and copper droplet size distributions in the slag. The trial was evaluated by comparing the copper content in different batches, the size distribution of copper-containing droplets using automated scanning electron microscopy, and performing rheological studies using a high-temperature rheometer. The results showed that increasing the CaO content of the slag by modification with CaCO3 has a positive effect on the settling process and is thus a possible method to improve the industrial settling process of valuable metals in slag.

  • 5.
    Lamberg, Pertti
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Parian, Mehdi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Lund, Cecilia
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Using Mineral rather than Elemental Grades in Mineral Resource Estimate: Motivation and Techniques2015Inngår i: Mineral Resources in a Sustainable World / [ed] A.S. Andre-Mayer; M. Cathelineau; P. Muchez; E. Pirard; S. Sindern, 2015, s. 1423-1425Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Mineral resource estimates of metallic ores use traditionally elemental grades when describing the quality of the deposit. This information is very defective as it does not take into account how much of metal is recoverable. When considering the processing properties of an ore, i.e. geometallurgy, more comprehensive picture could be received if the resource model would report mineral grades rather than elemental grades. This is because minerals define the value and possible processing options of the deposit. Techniques commonly used for an analysis of mineral composition, i.e. modal analysis, are either tedious or poor in quality. This paper shows with few examples how reliable modal analysis can be done by combining diagnostic analysis methods with element to mineral conversion.

  • 6.
    Lamberg, Pertti
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Parian, Mehdi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Mwanga, Abdul
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Rosenkranz, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Mineralogical Mass Balancing of Industrial Circuits by Combining XRF and XRD Analyses2013Inngår i: Proceedings Conference in Minerals Engineering 2013 / [ed] Jan Rosenkranz; Tommy Karlkvist, Luleå: Luleå tekniska universitet, 2013, s. 105-116Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Mineralogical information forms a vital basis for designing, diagnosing and optimizing mineral processing circuits. Often modal mineralogical mass balance (i.e. mass balance on mineral grades) is adequate; i.e. liberation data is not required. In analysing mineral grades in process samples automated mineralogy (SEM based image analysis) is mostly used. As this method is tedious, slow, and costly, and has some limitation, an alternative technique was developed by combining quantitative X-ray diffraction (XRD) and chemical assays by X-ray fluorescence (XRF). A case study on magnetic separation test is presented. Method has potential for an automatized off-line technique for providing mineralogical mass balance in majority of mineral processing plants.

  • 7.
    Lamberg, Pertti
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Rosenkranz, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Wanhainen, Christina
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Lund, Cecilia
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Minz, Friederike
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Mwanga, Abdul
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Parian, Mehdi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Building a Geometallurgical Model in Iron Ores using a Mineralogical Approach with Liberation Data2013Inngår i: Geomet13: The Second AusIMM International Geometallurgy Conference 2013 / [ed] Simon Dominy, Parkville, Victoria: The Australasian Institute of Mining and Metallurgy, 2013, s. 317-324Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A geometallurgical model is currently built in two different ways. The first and the most common way relies on geometallurgical testing, where a large number of samples are analysed for metallurgical response using small-scale laboratory tests, eg Davis tube testing. The second, mineralogical approach focuses on collecting mineralogical information over the orebody and building the metallurgical model based on mineralogy. At Luleå University of Technology,Sweden, the latter method has been adopted and taken further in four ongoing PhD studies. The geological model gives modal composition by the help of element-to-mineral conversion and Rietveld X-ray diffraction. Texturally, the orebody is divided into different archetypes, and liberation measurements for each of them are carried out in processing fineness using IncaMineral, a SEM-based technique. The grindability and liberation spectrum of any given geological unit (sample, ore block, domain) are extrapolated from the archetypes. The process model is taken into a liberation level by mass balancing selected metallurgical tests using the particle tracking technique. The approach is general and can be applied to any type of ores. Examples of ongoing studies on iron and massive sulfide ores are given.

  • 8.
    Larsson, Simon
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Pålsson, Bertil
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Parian, Mehdi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Jonsén, Pär
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    A novel approach for modelling of physical interactions between slurry, grinding media and mill structure in wet stirred media mills2020Inngår i: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 148, artikkel-id 106180Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Wet comminution is an important process in the mineral processing industry. Modelling of wet comminution in stirred media mills requires the simultaneous modelling of grinding media, a moving internal stirrer, and slurry. In the present study, a novel approach for modelling the physical interactions between slurry, grinding media and mill structure in a stirred media mill is presented. The slurry is modelled with the particle finite element method (PFEM). The grinding media is modelled using the discrete element method (DEM) and the mill structure is modelled using the finite element method (FEM). The interactions between slurry, grinding media and mill structure are modelled by two-way couplings between the PFEM, the DEM and the FEM models. The coupled model of the present study is used to predict the motion of slurry and grinding media, and to calculate the power draw during wet comminution in a pilot scale horizontal stirred media mill. Furthermore, the model is used to compare a Newtonian and a non-Newtonian model of the slurry, where the non-Newtonian model is used to capture experimentally observed shear-thinning. The coupled PFEM-DEM-FEM model preserves the robustness and efficiency of each of the methods and it gives the possibility to use large time increments for the fluid, greatly reducing the computational expense. The coupled model of the present work provide information on the complex dynamics of slurry and grinding media. The numerical model is shown to be a useful tool for increasing the knowledge and understanding of wet comminution in stirred media mills.

    Fulltekst (pdf)
    fulltext
  • 9.
    Larsson, Simon
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Pålsson, Bertil
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Parian, Mehdi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Jonsén, Pär
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Particle Methods for Modelling Stirred Media Mills2019Konferansepaper (Fagfellevurdert)
    Fulltekst (pdf)
    fulltext
  • 10.
    Larsson, Simon
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Pålsson, Bertil
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Parian, Mehdi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Jonsén, Pär
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Preliminary validation of a stirred media mill model2019Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Wet fine grinding is an important process in the minerals industry. Modelling of wet grinding in stirred media mills is challenging since it requires the simultaneous modelling of grinding media consisting of a huge number of small grinding bodies, moving internal stirrer, and the pulp fluid. All of them in interaction with each other. In the present study, wet grinding in a stirred media mill is studied using coupled incompressible computational fluid dynamics (ICFD) and discrete element method (DEM) and finite element method (FEM) simulations. The DEM is used to model the grinding media, and the pulp fluid flow is modelled using the ICFD. Moreover, the FEM is used to model the structure of the mill body and is in combination with DEM used to estimate the wear rate in the system. The present implementation of the coupled ICFD-DEM-FEM preserves the robustness and efficiency of both methods, and it gives the possibility to use large time steps for the fluid with very low computation times.

  • 11.
    Mwanga, Abdul
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Parian, Mehdi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Lamberg, Pertti
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Rosenkranz, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Comminution modeling using mineralogical properties of iron ores2017Inngår i: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 111, s. 182-197Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Comminution modeling aims to predict the size and liberation distribution of mineral particles and the required comminution energy. The current state-of-the-art comminution models provide a calculation of neither particle size distribution, grinding energy and throughput dependency with neither a broad understanding of how the mineral grade varies by size nor the liberation distribution of the product. The underlying breakage mechanisms affect the liberation of mineral grains and are dependent on modal mineralogy and mineral texture (micro structure). It has also been a challenge to model comminution systems to predict the optimal energy and size for better mineral liberation because of the variability of the mineral particle properties i.e. grains arrangement and composition. A detailed mineralogical study was carried out in order to broaden the understanding of the nature and distribution of comminuted particles in a ball mill product. Focusing on iron ore samples the study showed how the particle breakage rate decreases when the particles reach the grain size of the main mineral component. Below that size, comminution does not increase mineral liberation and therefore in most of the cases passing over that boundary is only a waste of energy. The study involving iron ores from Malmberget and Kiruna, Northern Sweden, showed that certain shortcuts can be applied to empirically model the mineral liberation distribution of the particles in a ball mill based on the mineral grade-by-size pattern from a geometallurgical program. In Malmberget and Kiruna the mineral grade-by-size pattern is depending on the mineral distribution and grain size of gangue as well as magnetite or hematite minerals. A significant difference between mineral breakage of the same grade and gangue minerals can be observed due to texture differences.

  • 12.
    Månbro, Carolina
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Kolodziejczyk, Joanna
    Process and Product Development, LKAB, Malmberget and Kiruna, Sweden.
    Krolop, Patrick
    Process and Product Development, LKAB, Malmberget and Kiruna, Sweden.
    Öberg, Eva
    Process and Product Development, LKAB, Malmberget and Kiruna, Sweden.
    Parian, Mehdi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Characterisation of apatite-bearing magnetite ore indrillcores using µ-XRF2023Inngår i: 17th Biennial SGA Meeting: Proceedings Volume 3, The Society for Geology Applied to Mineral Deposits (SGA) , 2023, Vol. 3, s. 279-283Konferansepaper (Fagfellevurdert)
  • 13.
    Månbro, Carolina
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Parian, Mehdi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Chemical and Mineralogical Characterisation of Iron Ore Drillcore using µ-XRF2023Inngår i: Proceedings Digital Conference i Minerals Engineering, 7-8 February, 2023, Luleå, Sweden / [ed] Jan Rosenkranz; Tommy Karlkvist, Bertil Pålsson; Mehdi Parian, Luleå University of Technology, 2023, s. 159-174Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Traditionally, geochemical assays have been used in geometallurgical programs to determine grade and recovery of the ore. The efficiency of this approach is questionable, since assays i) provide bulk geochemistry without providing host mineralogy for the element(s) of interest, and ii) are performed on small samples. Thus, ore mineral grade might be lower than the assays imply, due to the inclusion of elements of interest in the gangue mineralogy. Also, the samples analysed might not be representative on a deposit size scale due to their small volume. In μ-XRF, areas analysed are on a dm scale, providing a larger, and therefore more representable, analysis than e.g. a scanning electron microscope (SEM), yet providing a resolution comparable to SEM analyses. Another advantage of the μ-XRF is the possibility to detect elements as light as sodium, while simultaneously detecting heavy elements, e.g. REEs.Here, cut drillcore samples were scanned by μ-XRF at varying resolutions. The μ-XRF data was utilised for i) comparison with chemical assays, ii) identification of sample mineralogy, iii) comparison with mineralogy from X-ray diffraction (XRD), and iv) analysis of ore texture. The results show that regardless of the resolution used, the μ-XRF analyses correlate well with the results from geochemical assays, whereas for textural features a finer resolution yielded a more detailed picture, as was expected. The drillcore mineralogy compares well with the phases identified by XRD. However, mineral identification from μ-XRF is based on elemental spectrums. Therefore, polymorphs cannot be successfully discriminated and an insight into the deposit mineralogy, is needed for a correct mineral classification in these cases.

    Fulltekst (pdf)
    fulltext
  • 14.
    Parian, Mehdi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Development of a geometallurgical framework for iron ores - A mineralogical approach to particle-based modeling2017Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The demands for efficient utilization of ore bodies and proper risk management in the mining industry have resulted in a new cross-disciplinary subject called geometallurgy. Geometallurgy connects geological, mineral processing and subsequent downstream processing information together to provide a comprehensive model to be used in production planning and management. A geometallurgical program is an industrial application of geometallurgy. Various approaches that are employed in geometallurgical programs include the traditional way, which uses chemical elements, the proxy method, which applies small-scale tests, and the mineralogical approach using mineralogy or the combination of those. The mineralogical approach provides the most comprehensive and versatile way to treat geometallurgical data. Therefore it was selected as a basis for this study.

    For the mineralogical approach, quantitative mineralogical information is needed both for the deposit and the process. The geological model must describe the minerals present, give their chemical composition, report their mass proportions (modal composition) in the ore body and describe the ore texture. The process model must be capable of using mineralogical information provided by the geological model to forecast the metallurgical performance of different geological volumes and periods. A literature survey showed that areas, where more development is needed for using the mineralogical approach, are: 1) quick and inexpensive techniques for reliable modal analysis of the ore samples; 2) ore textural characterization of the ore to forecast the liberation distribution of the ore when crushed and ground; 3) unit operation models based on particle properties (at mineral liberation level) and 4) a system capable of handling all this information and transferring it to production model. This study focuses on developing tools in these areas.

    A number of methods for obtaining mineral grades were evaluated with a focus on geometallurgical applicability, precision, and trueness. A new technique developed called combined method uses both quantitative X-ray powder diffraction with Rietveld refinement and the Element-to-Mineral Conversion method. The method not only delivers the required turnover for geometallurgy but also overcomes the shortcomings if X-ray powder diffraction or Element-to-Mineral Conversion were used alone.

    Characterization of ore texture before and after breakage provides valuable insights about the fracture pattern in comminution, the population of particles for specific ore texture and their relation to parent ore texture. In the context of the mineralogical approach to geometallurgy, predicting the particle population from ore texture is a critical step to establish an interface between geology and mineral processing. A new method called Association Indicator Matrix developed to assess breakage pattern of ore texture and analyze mineral association. The results of ore texture and particle analysis were used to generate particle population from ore texture by applying particle size distribution and breakage frequencies. The outcome matches well with experimental data specifically for magnetite ore texture.

    In geometallurgy, process models can be classified based on in which level the ore, i.e. the feed stream to the processing plant and each unit operation, is defined and what information subsequent streams carry. The most comprehensive level of mineral processing models is the particle-based one which includes practically all necessary information on streams for modeling unit operations. Within this study, a particle-based unit operation model was built for wet low-intensity magnetic separation, and existing size classification and grinding models were evaluated to be used in particle level. A property-based model of magnetic beneficiation plant was created based on one of the LKAB operating plants in mineral and particle level and the results were compared. Two different feeds to the plant were used. The results revealed that in the particle level, the process model is more sensitive to changes in feed property than any other levels. Particle level is more capable for process optimization for different geometallurgical domains.

    Fulltekst (pdf)
    fulltext
  • 15.
    Parian, Mehdi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Development of the mineralogical path for geometallurgical modeling of iron ores2015Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The demands for more effective utilization of ore bodies and proper risk management in the mining industry have resulted in a new cross discipline called geometallurgy. Geometallurgy connects geological, mineral processing and subsequent downstream processing information together to provide a comprehensive model to be used in production planning and management. A geometallurgical program is the industrial application of geometallurgy. It provides a way to map the variation in the ore body, to handling the data and giving metallurgical forecast on spatial level.Three different approaches are used in geometallurgical programs. These include the traditional way, which uses chemical elements, the proxy method, which applies geometallurgical tests, and the mineralogical approach using mineralogy. The mineralogical approach provides the most comprehensive and versatile way to treat geometallurgical data. Therefore it was selected as a basis for this study. For the mineralogical method, quantitative mineralogical information is needed both on deposit and for the process. The geological model must describe the minerals present, give their chemical composition, report their mass proportions (modal composition) in the ore body and describe the texture. The process model must be capable of using mineralogical information provided by the geological model to forecast the metallurgical performance of different geological volumes (samples, ore blocks, geometallurgical domains or blends prepared for the plant) and periods (from minutes via hourly and daily scale to week, monthly and annual production). A literature survey showed that areas, where more development is needed for using the mineralogical approach, are: 1) quick and inexpensive techniques for reliable modal analysis of the ore samples; 2) textural classification of the ore capable to forecast the liberation distribution of the ore when crushed and ground; 3) unit operation models based on particle properties (at mineral liberation level) and 4) a system capable to handle all this information and transfer it to production model. This study focuses on solving the first and the third problem. A number of methods for obtaining mineral grades were evaluated with a focus on geometallurgical applicability, precision and trueness. The method survey included scanning electron microscopy based automated mineralogy, quantitative X-ray powder diffraction with Rietveld refinement, and element-to-mineral conversion. A new technique called combined method uses both quantitative X-ray diffraction with Rietveld refinement and the element-to-mineral conversion method. The method not only delivers the required turnover for geometallurgy, but also overcomes the shortcomings if X-ray powder diffraction or element-to-mineral conversion when used alone. Furthermore, various methods of obtaining modal mineralogy were compared and a model for evaluating precision and closeness of the methods was developed.Different levels of processing models can be classified in geometallurgy based on in which level the ore, i.e. the feed stream to the processing plant, is defined and what information subsequent streams carry. For mineral processing models the following five levels can be distinguished: particle size only level, elemental level, element by particle size level, mineral level, mineral by particle size level and mineral liberation (particle) level. The most comprehensive level of mineral processing models is the particle-based one which includes all necessary information for modeling unit operations. Within this study, as the first step, a unit operation model is built on particle level for wet low-intensity magnetic separation. The experimental data was gathered through a survey of the KA3 iron ore concentrator plant of Luossavaara-Kiirunavaara AB (LKAB) in Kiruna. The first wet magnetic separator of the process was used as the basis for the model development since the degree of liberation is important at this stage. Corresponding feed, concentrate and tailings streams were mass balanced on a mineral by size and liberation level. The mass balanced data showed that the behavior of individual particles in the magnetic separation is depending on their size and composition. The model, which has a size dependent by-pass parameter and a separation parameter dependent of the magnetic volume of the particle, is capable of forecasting the behavior of particles in magnetic separation. Modeling and simulation show the benefits that particle-based simulation provides compared to lower level process models which take into account only elemental or mineral grades.

    Fulltekst (pdf)
    FULLTEXT01
  • 16.
    Parian, Mehdi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Particle-based Process Models in Mineral Processing2016Konferansepaper (Annet vitenskapelig)
  • 17.
    Parian, Mehdi
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Lamberg, Pertti
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Combining chemical analysis (XRF) and quantitative X-ray diffraction (Rietveld) in modal analysis of iron ores for geometallurgical purposes in Northern Sweden2013Inngår i: Mineral deposit research for a high-tech world: Proceedings of the 12th Biennial SGA Meeting, 12-15 August 2013, Uppsala, Sweden / [ed] Erik Jonsson, Uppsala: Sveriges Geologiska Undersökning , 2013Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Mineralogical information forms an essential basis in geometallurgy. Minimum information required in a mineralogical approach of a geometallurgical program is: modal mineralogy (mineral quantities) and mineral textures. Based on this information it is possible to link geological model with production model. Modal analysis is currently mostly done with Scanning Electron Microscopy (SEM) based image analysis, often called as automated mineralogy. As this method is tedious, slow, and costly, and has some limitation, an alternative technique was developed by combining quantitative X-ray diffraction (XRD) and chemical assays by X-ray fluorescence (XRF). In iron ores in Northern Sweden combined method gives a quantity of about ten minerals with adequate accuracy.

  • 18.
    Parian, Mehdi
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Lamberg, Pertti
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Reconciling modal mineralogy and chemical compositions of a sample2016Inngår i: Bulletin of The Geological Society of Finland: Special Volume, 2016, s. 181-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Knowledge of the grade of valuable elements and its variation is not sufficient for geometallurgy. Minerals define not only the value of the deposit, but also the method of extraction and concentration. However, mineralogy is quite rarely used as the key information in geometallurgy and it is even more exceptional in mineral resource estimation.One of the reasons is the lack of fast, low-cost but still reliable modal analysis. The other is that the results from various methods of modal mineralogy such as automated mineralogy and quantitative XRD are not consistent with chemical assay. In other words, the chemical composition back calculated from modal analysis does not match with the true chemical assay. Element-to-mineral conversion is the known method to get modal mineralogy that matches with the chemical composition of samples. However, in complicated mineralogy or the lack of enough chemical components assayed, it fails to provide accurate results. Reconciling the results of a modal analysis with chemical assays can improve the agreement between chemical assays and back-calculated chemical composition. This is achievable by doing minor adjustments to modal mineralogy. The method used here is called combined method and it principally uses Levenberg-Marquardt algorithm to minimize differences (residuals) between chemical assays and back-calculated chemical composition of a sample. The advantage of the method over other combined methods is that it does not use weighting factors. Additionally, the adjustments are minor unlike other methods that can cause mineral grades to drift away significantly. These features make it possible to apply the method for a large number of samples unsupervised.

    Fulltekst (pdf)
    FULLTEXT01
  • 19.
    Parian, Mehdi
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Lamberg, Pertti
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Möckel, Robert
    Helmholtz-Zentrum Dresden – Rossendorf, Helmholtz Institute Freiberg for Resource Technology, Halsbruecker Straße 34, 09599 Freiberg.
    Rosenkranz, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Analysis of mineral grades for geometallurgy: Combined element-to-mineral conversion and quantitative X-ray diffraction2015Inngår i: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 82, s. 25-35Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Knowledge of the grade of valuable elements and its variation is not sufficient for geometallurgy. Minerals define not only the value of the deposit, but also the method of extraction and concentration. A number of methods for obtaining mineral grades were evaluated with a focus on geometallurgical applicability, precision and trueness. For a geometallurgical program, the number of samples to be analyzed is large, therefore a method for obtaining mineral grades needs to be cost-efficient, relatively fast, and reliable. Automated mineralogy based on scanning electron microscopy is generally regarded as the most reliable method for analyzing mineral grades. However, the method is time demanding and expensive. Quantitative X-ray diffraction has a relatively high detection limit, 0.5%, while the method is not suitable for some base and precious metal ores, it still provides significant details on gangue mineral grades. The application of the element-to-mineral conversion has been limited to the simple mineralogy because the number of elements analyzed limits the number of calculable mineral grades. This study investigates a new method for the estimation of mineral grades applicable for geometallurgy by combining both the element-to-mineral conversion method and quantitative X-ray diffraction with Rietveld refinement. The proposed method not only delivers the required turnover for geometallurgy, but also overcomes the shortcomings if quantitative X-ray diffraction or element-to-mineral is used alone

  • 20.
    Parian, Mehdi
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Lamberg, Pertti
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Rosenkranz, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Developing a particle-based process model for unit operations of mineral processing: WLIMS2016Inngår i: International Journal of Mineral Processing, ISSN 0301-7516, E-ISSN 1879-3525, Vol. 154, s. 53-65Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Process models in mineral processing can be classified based on the level of information required from the ore, i.e. the feed stream to the processing plant. Mineral processing models usually require information on total solid flow rate, mineralogical composition and particle size information. The most comprehensive level of mineral processing models is the particle-based one (liberation level), which gives particle-by-particle information on their mineralogical composition, size, density, shape i.e. all necessary information on the processed material for simulating unit operations. In flowsheet simulation, the major benefit of a particle-based model over other models is that it can be directly linked to any other particle-based unit models in the process simulation. This study aims to develop a unit operation model for a wet low intensity magnetic separator on particle property level. The experimental data was gathered in a plant survey of the KA3 iron ore concentrator of Luossavaara-Kiirunavaara AB in Kiruna. Corresponding feed, concentrate and tailings streams of the primary magnetic separator were sampled, assayed and mass balanced on mineral liberation level. The mass-balanced data showed that the behavior of individual particles in the magnetic separation is depending on their size and composition. The developed model involves a size and composition dependent entrapment parameter and a separation function that depends on the magnetic volume of the particle and the nature of gangue mineral. The model is capable of forecasting the behavior of particles in magnetic separation with the necessary accuracy. This study highlights the benefits that particle-based models in simulation offer whereas lower level process models fail to provide.

  • 21.
    Parian, Mehdi
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Lamberg, Pertti
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Rosenkranz, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Process simulations in mineralogy-based geometallurgy of iron ores2021Inngår i: Mineral Processing and Extractive Metallurgy: Transactions of the Institute of Mining and Metallurgy, ISSN 2572-6641, E-ISSN 2572-665X, Vol. 130, nr 1, s. 25-30Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Mineral processing simulation models can be classified based on the level that feed stream to the plant and unit models are described. The levels of modelling in this context are: bulk, mineral or element by size, and particle. Particle level modelling and simulation utilises liberation data in the feed stream and is more sensitive to the variations in ore quality, specifically ore texture. In this paper, simulations for two texturally different magnetite ores are demonstrated at different modelling levels. The model parameters were calibrated for current run-of-mine ore and then in the simulation applied directly to the other ore. For the second ore, the simulation results vary between the different levels. This is because, at the bulk level, the model assumes minerals do not change their behaviour if ore texture or grinding fineness are changed. At the mineral by size level, the assumption is that minerals behave identically in each size fraction even if the ore texture changes. At the particle level, the assumption is that similar particles behave in the same way. The particle level approach gives results that are more realistic and it can be used in optimisation, thus finding the most optimal processing way for different geometallurgical domains.

  • 22.
    Parian, Mehdi
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Lamberg, Pertti
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Rosenkranz, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Using modal composition instead of elemental grades in mineral resource estimate – high quality modal analysis by combining X-ray diffraction and X-ray fluorescence2014Konferansepaper (Annet vitenskapelig)
    Fulltekst (pdf)
    FULLTEXT01
  • 23.
    Parian, Mehdi
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Mwanga, Abdul
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Lamberg, Pertti
    Keliber Oy, Kaustinen.
    Rosenkranz, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Ore texture breakage characterization and fragmentation into multiphase particles2018Inngår i: Powder Technology, ISSN 0032-5910, E-ISSN 1873-328X, Vol. 327, s. 57-69Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The ore texture and the progeny particles after a breakage in the comminution have been a subject of interest in mineral liberation studies and are the missing link between geology and mineral processing in the concept of geometallurgy. A new method called Association Indicator Matrix (AIM) established based on co-occurrence matrix was introduced to quantify the mineral association of ore texture and its progeny particles. The Association Indicator Matrix can be used as a criterion for classifying ore texture as well as analyzing breakage behavior of ore texture. Within the study, the outcome of breakage analysis with Association Indicator Matrix was used to forecast particle population of iron ore texture after crushing. The particle size of forecasted particles was taken from experimental and frequency of breakage in phases was defined based on Association Indicator and liberation of minerals. Comparison of liberation distribution of iron oxide minerals from experimental and forecasted population shows a satisfactory agreement.

  • 24.
    Parian, Mehdi
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Pålsson, Bertil I.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Kuva, J.
    Geological survey of Finland, PO Box 96, 02151, Espoo, Finland.
    XCT investigation on the generation of fatigue in autogenous grinding pebbles and its contribution to pre-weakening before fracture2022Inngår i: IMPC Asia-Pacific 2022 Conference Proceedings, The Australian Institute of Mining and Metallurgy , 2022, s. 274-280Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Comminution is the process for the liberation and size reduction of ores prior to separationprocesses. Generally, in mineral processing, grinding is done using rod, ball, autogenous, or semiautogenous mills. The fully autogenous grinding (AG) is the most cost- and process-efficient grinding by benefiting from eliminating steel grinding media. It is also a superior choice for downstream processes such as flotation of some sulphide minerals that are sensitive to the reducing conditions caused by iron chipped away from the steel media.

    One of the main factors affecting the suitability of an ore for autogenous grinding is the ore competency, i.e., provide enough critical stones for the grinding process. Several experimental test routines exist and are used for assessing the viability of the ore for autogenous grinding. However, very little attention is given to the generation of fatigue in large stones experiencing repeated shocks in the mill. To investigate this, large pebbles sampled from industrial autogenous grinding mills for hard and soft ores which were categorized based on the grinding energy.

    From the pebbles, small drill core samples were prepared and went through a series of fatigue cycle tests. Both hard and soft ores showed similar average resistance to failure in compression tests, but the hard ore had a consistent resistance with lower variations. The cores were scanned before and in-between fatigue tests at the highest reachable resolution, 1.5 µm voxel size. The outcome showed that higher number of micro-cracks were visible in the soft ore compared to the hard ore. The frequency of micro-crack development in the soft ore may be the reason for its lower specific grinding energy compared to the hard ore.

    It is obvious that for realistic conditions in an autogenous grinding mill, stones are pre-weakened by fatigue before they fracture. Therefore, shortcut methods focusing only on running tests on fresh and small samples may operate in unrealistic conditions by ignoring the fatigue phenomenon. This is even more important for ores that are in between the soft and hard ore boundary or on the borderline to be considered as a competent ore for autogenous milling.

  • 25.
    Pålsson, Bertil I.
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Parian, Mehdi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Larsson, Simon
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Hållfasthetslära.
    Jonsén, Pär
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Hållfasthetslära.
    An attempt to a full energy balance for a pilot-scale stirred media mill2022Inngår i: IMPC Asia-Pacific 2022 Conference Proceedings, The Australian Institute of Mining and Metallurgy , 2022, s. 266-273Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The question of effective energy utilisation in grinding mills is not new. There are several conflicting arguments about tumbling mills, whether the efficiency is around one per cent or maybe ten per cent, or even much lower. The energy not used is assumed to be lost as heating of the pulp, the grinding mill body, the charge, generation of shockwaves and vibrations, etc. Stirred media mills on the other hand are generally considered to have better energy utilisation, but their energy efficiency is still not that clear. To shed some light on this a pilot-scale, wet stirred media mill was investigated over a range of operating conditions. The wet stirred media mill is a Drais PMH 5 TEX pearl mill fitted with an electric motor at 11 kW. It has been investigated over a range of operating conditions to try to balance the dissemination of the input energy in forms of the net grinding energy, mechanical energy losses, and the heating transferred to the pulp, the mill, the charge, and the cooling water. It is found that approximately 20 – 40 per cent of the input energy accounts for the grinding process. Also, that the difference between gross and net input electrical energy is mainly disseminated as heating of the pulp and cooling water. Mechanical energy losses appear to be much smaller than the heating effects. The use of a dispersant seems to mainly influence the heating effect.

  • 26.
    Schmitt, Raoul
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Parian, Mehdi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Ghorbani, Yousef
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    McElroy, I.
    Division of Process Technology, Boliden AB, SE-936 81 Boliden, Sweden.
    Bolin, N.J.
    Division of Process Technology, Boliden AB, SE-936 81 Boliden, Sweden.
    A geometallurgical approach towards the correlation between rock type mineralogy and grindability: A case study in Aitik mine, Sweden2022Inngår i: IMPC Asia-Pacific 2022 Conference Proceedings, The Australian Institute of Mining and Metallurgy , 2022, s. 51-70Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Aitik is a large copper porphyry type deposit located in northern Sweden, currently exploited at an annual rate of approximately 45Mt. The ore’s exceptionally low head grade of 0.25 % Cu and varying degrees of hardness across the entire deposit pose challenges to the two fully autogenous grinding lines, each of which comprises a 25 MW primary autogenous mill in series with a pebble mill. The variability in ore grindability frequently leads to fluctuations in mill throughput. 

    Within the framework of a geometallurgical approach, the present study investigated the relationships between ore grindability and modal mineralogy. For this purpose, drill core samples from different lithologies were subjected to Boliden AB’s in-house grindability tests. This fully autogenous laboratory-scale test generates a grindability index mainly related to abrasion breakage, which is a significant breakage mechanism within autogenous mills. The test results suggested divergent degrees of grindability within and across the selected rock types.

    A combination of scanning electron microscopy, X-ray powder diffraction, and X-ray fluorescence analyses were performed for the grinding products and bulk mineral samples. The resulting mineralogical and elemental properties were subsequently correlated to the parameters from the grindability tests. It was shown that the main mineral phases, such as plagioclase, quartz, and micas, correlate well with the grindability indices. Similar correlations were found regarding the sample’s chemical composition, attributable to the main mineral phases. A further inverse correlation between the sample’s calculated average Mohs hardness and the grindability indices was established. Moreover, mineral liberation information provided by scanning electron microscopy was associated with the parameters mentioned earlier. The identified relationships between grindability, modal mineralogy, and element grades may help Boliden develop a predictive throughput model for Aitik based on the mine’s block model.

  • 27.
    Semsari Parapari, Parisa
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Parian, Mehdi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Forsberg, Fredrik
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Rosenkranz, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Characterization of ore texture crack formation and liberation by quantitative analyses of spatial deformation2020Inngår i: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 157, artikkel-id 106577Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In comminution, particle breakage starts with crack induction and propagation. The path of cracks defines the breakage mode, e.g. preferential in phase breakage or phase boundary breakage. For investigating crack formation behavior, the description by displacement fields can be applied. The displacement fields of the mineral phases can then be used to understand breakage mode and liberation. Ore texture and operational conditions such as loading mechanisms will affect the system. One of the ore texture aspects is the ore texture heterogeneity, which is a complex quantity comprising mineral heterogeneity, geometrical heterogeneity, weak grain boundaries, and micro-cracks. This study aims at investigating the effects of ore texture and loading displacement rate on minerals breakage mode. By knowing minerals breakage mode it is possible to identify the factors which affect minerals liberation and optimizing these factors in order to liberate minerals even in coarser size fractions. The approach is to describe the spatial displacement fields in different ore textures. In order to obtain these, in-situ compression loading tests with different displacement rates were conducted, followed by X-ray computed micro-tomography (XCT) and Digital Volume Correlation (DVC). In addition, the resulting cracks from ore breakage were analyzed and quantified in order to analyze the breakage mode. Moreover, XCT imaging was used for tracking the propagated cracks in the third dimension. For identifying mineral phases, automated scanning electron microscopy (SEM) complemented by energy dispersive spectroscopy was applied. The outcomes showed that both ore texture and loading mechanism should be considered for describing crack formation and consequently mineral liberation.

  • 28.
    Semsari Parapari, Parisa
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Parian, Mehdi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Forsberg, Fredrik
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Rosenkranz, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Spatial deformation of ore texture by quantitative characterization2020Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    In comminution, particle breakage starts with crack initiation and propagation. For investigating crack formation behavior, the description by displacement fields can be applied. Ore texture and operational conditions such as loading mechanisms will affect the crack formation. This study aims at investigating the effects of ore texture and loading displacement rate on particle deformation. The objective is to describe the spatial displacement fields in the ore textures. In order to obtain these, in-situ compression loading with different displacement rates were conducted, followed by X-ray computed micro-tomography and Digital Volume Correlation (DVC). The outcomes showed that DVC has the potential to predict crack formation for describing mineral liberation.

  • 29.
    Semsari Parapari, Parisa
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Parian, Mehdi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Pålsson, Bertil I.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Rosenkranz, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Quantitative analysis of ore texture breakage characteristics affected by loading mechanism: Multivariate data analysis of particle texture parameters2022Inngår i: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 181, artikkel-id 107531Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Understanding and optimizing the comminution process in terms of mineral liberation, fragmentation, and fracture energy are aligned with sustainable approaches and overall international goals of green solutions. This study investigates the combined effect of material properties (ore textural features) and process factors (displacement rate) on mineral liberation, fracture energy, and fragmentation. For achieving this aim, multivariate data analysis tools are used to examine the fragmentation by compression of multiple layers of iron oxide minerals in a particle bed. The results indicate that ore textural features distinctively influence particle fragmentation, mineral liberation, and fracture energy and the ore textural effects are more pronounced compared to displacement rate.

  • 30.
    Semsari Parapari, Parisa
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Parian, Mehdi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Rosenkranz, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Breakage process of mineral processing comminution machines – An approach to liberation2020Inngår i: Advanced Powder Technology, ISSN 0921-8831, E-ISSN 1568-5527, Vol. 31, nr 9, s. 3669-3685Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Mineral liberation and size reduction are the most critical steps before mineral separation. Several investigations showed that mineral liberation degree could be affected by ore texture and/or loading mechanisms. However, varied definitions have been used for the breakage fundamentals as the leading cause of mineral liberation. This review identifies the breakage fundamentals and analyzes them in terms of process and ore breakage behavior. It is highlighted that the breakage fundamentals are essential for optimizing of comminution environments and designing the comminution machines. Three main areas of breakage processes in regard to fundamentals of breakage are classified and addressed as “Loading mechanism”, “Breakage mechanism”, and “Breakage mode”. Despite the fact that many advances have been made in the design of the comminution machines; still, the combined effect of breakage fundamentals and ore properties such as ore texture in a quantitative manner is not fully understood. In this regard, this study identifies and discusses the material and process factors influencing the breakage phenomenon. This potentially paves the way for improving the comminution environment concerning a particular ore type.

  • 31.
    Semsari Parapari, Parisa
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Parian, Mehdi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Rosenkranz, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Quantitative analysis of ore texture breakage characteristics affected by loading mechanism: Fragmentation and mineral liberation2022Inngår i: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 182, artikkel-id 107561Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Mineral liberation as the main purpose of comminution in ore beneficiation is not applied in the design of comminution machines or even often neglected in designing comminution circuits. In addition, other factors critical for comminution efficiency such as fracture energy, and particle fragmentation are rarely considered. The current study investigates the combined effects of particle textural properties and process operational conditions on the fragmentation of bed particle. In particular, the influence of ore texture and loading displacement rate (as the material and machine properties) on particle specific fracture energy, breakage mode, liberation, and fragmentation was studied. The results indicate that ore textures with coarsest grain sizes and lower quantities of cleavage minerals have the least amount of fracture energy. In terms of fragmentation, a lower displacement rates results in higher quantities of the fragmented particles compared to the higher displacement rate. Among studied ore textures, two types of hematite ore textures which had the coarsest grain sizes had lower liberation in finer size fractions. Overall, the outcomes show that the displacement rate and ore texture can affect the specific fracture energy, particle fragmentation, mineral liberation, and breakage mode at different degrees.

  • 32.
    Shahbazi, B.
    et al.
    Department of Mining Engineering, Tarbiat Modares University, Tehran, Iran.
    Jafari, M.
    School of Mining, College of Engineering, University of Tehran, Tehran 16846-13114, Iran.
    Parian, Mehdi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Rosenkranz, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Chelgani, Saeed Chehreh
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Study on the impacts of media shapes on the performance of tumbling mills – A review2020Inngår i: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 157, artikkel-id 106490Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Grinding typically is the most cost-intensive stage of mineral beneficiation plants. Besides other design and operational parameters, grinding media have a crucial effect on the energy consumption of tumbling mills and generally on their operating costs. Steel balls are the most typical grinding media. However, in recent years, various media shapes with different properties have gained interest in the market, and their efficiencies were compared with balls. This study presents a comprehensive review of the impact of various media geometries on grinding factors (load behavior, power draw, toe, shoulder, contact mechanism, kinetic energy) and the product particle size in tumbling mills.

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