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Rosenkranz, Jan
Publications (10 of 83) Show all publications
Chelgani, S. C., Parian, M., Semsari, P., Ghorbani, Y. & Rosenkranz, J. (2019). A comparative study on the effects of dry and wet grinding on mineral flotation separation: a review. Journal of Materials Research and Technology, 8(5), 5004-5011
Open this publication in new window or tab >>A comparative study on the effects of dry and wet grinding on mineral flotation separation: a review
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2019 (English)In: Journal of Materials Research and Technology, ISSN 2238-7854, Vol. 8, no 5, p. 5004-5011Article, review/survey (Refereed) Published
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.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Flotation, Energy consumption, Grinding media type, HPGR, Dry grinding, Wet grinding
National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-75591 (URN)10.1016/j.jmrt.2019.07.053 (DOI)000486630400124 ()
Note

Validerad;2019;Nivå 2;2019-10-28 (johcin)

Available from: 2019-08-20 Created: 2019-08-20 Last updated: 2019-10-28Bibliographically approved
Guntoro, P. I., Tiu, G., Ghorbani, Y., Lund, C. & Rosenkranz, J. (2019). Application of machine learning techniques in mineral phase segmentation for X-ray microcomputed tomography (µCT) data. Minerals Engineering, 142, Article ID 105882.
Open this publication in new window or tab >>Application of machine learning techniques in mineral phase segmentation for X-ray microcomputed tomography (µCT) data
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2019 (English)In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 142, article id 105882Article in journal (Refereed) Published
Abstract [en]

X-ray microcomputed tomography (µCT) offers a non-destructive three-dimensional analysis of ores but its application in mineralogical analysis and mineral segmentation is relatively limited. In this study, the application of machine learning techniques for segmenting mineral phases in a µCT dataset is presented. Various techniques were implemented, including unsupervised classification as well as grayscale-based and feature-based supervised classification. A feature matching method was used to register the back-scattered electron (BSE) mineral map to its corresponding µCT slice, allowing automatic annotation of minerals in the µCT slice to create training data for the classifiers. Unsupervised classification produced satisfactory results in terms of segmenting between amphibole, plagioclase, and sulfide phases. However, the technique was not able to differentiate between sulfide phases in the case of chalcopyrite and pyrite. Using supervised classification, around 50–60% of the chalcopyrite and 97–99% of pyrite were correctly identified. Feature based classification was found to have a poorer sensitivity to chalcopyrite, but produced a better result in segmenting between the mineral grains, as it operates based on voxel regions instead of individual voxels. The mineralogical results from the 3D µCT data showed considerable difference compared to the BSE mineral map, indicating stereological error exhibited in the latter analysis. The main limitation of this approach lies in the dataset itself, in which there was a significant overlap in grayscale values between chalcopyrite and pyrite, therefore highly limiting the classifier accuracy.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
X-ray micro-tomography (µCT), Machine learning, Mineral segmentation, Feature-based classification, Feature matching
National Category
Metallurgy and Metallic Materials Geology
Research subject
Mineral Processing; Ore Geology
Identifiers
urn:nbn:se:ltu:diva-75703 (URN)10.1016/j.mineng.2019.105882 (DOI)000488141400014 ()2-s2.0-85070948239 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-08-27 (svasva)

Available from: 2019-08-27 Created: 2019-08-27 Last updated: 2019-10-30Bibliographically approved
Koch, P.-H., Lund, C. & Rosenkranz, J. (2019). Automated drill core mineralogical characterization method for texture classification and modal mineralogy estimation for geometallurgy. Minerals Engineering, 136, 99-109
Open this publication in new window or tab >>Automated drill core mineralogical characterization method for texture classification and modal mineralogy estimation for geometallurgy
2019 (English)In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 136, p. 99-109Article in journal (Refereed) Published
Abstract [en]

In geometallurgy, a process model operating at the mineral liberation level needs quantitative textural information about the ore. The utilization of this information within process modeling and simulation will increase the quality of the predictions.

In this study, descriptors derived from color images and machine learning algorithms are used to group drill core intervals into textural classes and estimate mineral maps by automatic pixel classification. Different descriptors and classifiers are compared, based on their accuracy and capacity to be automated. Integration of the classifier approach with mineral processing simulation is also demonstrated. The quantification of textural information for mineral processing simulation introduced new tools towards an integrated information flow from the drill cores to a geometallurgical model.

The approach has been verified by comparing traditional geological texture classification against the one obtained from automatic methods. The tested drill cores are sampled from a porphyry copper deposit located in Northern Sweden.

Place, publisher, year, edition, pages
Amsterdam: Elsevier, 2019
Keywords
Geometallurgy Drill core scanning Classification Texture Process mineralogy
National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-73323 (URN)10.1016/j.mineng.2019.03.008 (DOI)000470338700012 ()2-s2.0-85063084058 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-03-26 (inah)

Available from: 2019-03-26 Created: 2019-03-26 Last updated: 2019-06-20Bibliographically approved
Mulenshi, J., Khavari, P., Chelgani, S. C. & Rosenkranz, J. (2019). Characterization and beneficiation options for tungsten recovery from Yxsjöberg historical ore tailings. Processes, 7(12), Article ID 895.
Open this publication in new window or tab >>Characterization and beneficiation options for tungsten recovery from Yxsjöberg historical ore tailings
2019 (English)In: Processes, ISSN 2227-9717, Vol. 7, no 12, article id 895Article in journal (Refereed) Published
Abstract [en]

Repositories of historical tungsten mining tailings pose environmental risks, but are also potential resources for valuable metals. They still contain large tonnages of useful minerals and metals, reflecting the inefficient extraction methods and/or low metal prices at the time they were mined. The focus of this study is to evaluate the technical viability of reprocessing the tailings to recover some of the contained valuable minerals and metals, as well as reducing the negative environmental impact associated with the tailings. Geometallurgical studies were conducted on drill core samples taken from the Smaltjärnen tailings repository of the closed Yxsjöberg tungsten mine, Sweden. The collected samples were characterized physically, chemically, and mineralogically. Knelson concentrator dry low- and high-intensity magnetic separation methods were tested as potential beneficiation methods. The tailings are dominated by the −600 to +149 µm particles. The highest concentration of tungsten (W) was 0.22% WO3. Using a Knelson concentrator, scheelite (main W mineral) recovery was enhanced, with 75 wt.% tungsten recovered in the 34 wt.% heavy concentrate. Only 1.0 wt.% sulphur (S) reported to the non-magnetic fraction. Based on the findings, a methodology and a preliminary process flowsheet for reprocessing the tailings is proposed.

Place, publisher, year, edition, pages
Basel, Switzerland: MDPI, 2019
Keywords
Historical tailings, Tungsten, Scheelite, Geometallurgical approach, Characterization, Beneficiation, Reprocessing
National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing; Centre - Centre for Advanced Mining & Metallurgy (CAMM)
Identifiers
urn:nbn:se:ltu:diva-76419 (URN)10.3390/pr7120895 (DOI)
Projects
REMinE (Improve Resource Efficiency and Minimize Environmental Footprint)
Funder
Vinnova, 215 06 631
Note

Validerad;2019;Nivå 2;2019-12-02 (johcin)

Available from: 2019-10-18 Created: 2019-10-18 Last updated: 2019-12-02Bibliographically approved
Mulenshi, J., Khavari, P. & Rosenkranz, J. (2019). Characterization and feasible physical separation methods for Yxsjöberg historical tungsten ore tailings. In: : . Paper presented at Conference in Minerals Engineering, Luleå, Sweden, February 5-6, 2019 (pp. 99-114).
Open this publication in new window or tab >>Characterization and feasible physical separation methods for Yxsjöberg historical tungsten ore tailings
2019 (English)Conference paper, Oral presentation only (Other academic)
Abstract [en]

Relatively high minerals and metals content characterize historical tailings due to less efficient extraction methods and/or relatively low metal prices at the time. Repositories of such tailings pose environmental risks but could also become metals and minerals resources. An example of such tailings is the Yxsjöberg historical tungsten ore tailings in the Smaltjärnen tailings repository in Sweden.   

The Smaltjärnen tailings repository was sampled by collecting drill core samples from different locations. The collected drill core samples were characterized physically (colour, texture, moisture content and particle size distribution) and chemically (elemental composition and distribution, and mineralogical composition). Feasible physical separation methods (magnetic and gravity separation) were pre-selected based on the tailings characteristics and the knowledge of processes from which the Yxsjöberg historical tailings were produced.

In this paper, results from three drill cores each representing a different location on the tailings repository are presented. The tailings mass distribution was high in the coarser particle size fractions of +300 µm and +149 µm.  Tungsten (W) and Copper (Cu) were the metals of interest with one location having higher concentrations than the other two at 0.20 %WO3 and 0.14 %Cu. Sulphur (S) was recovered in the magnetic fractions of the LIMS and HIMS. Using the Knelson concentrator, W recovery was enhanced. These results are fundamental in the development of methods for separation of minerals and extraction of metals of interest from the historical tailings in order to leave behind an inert and environmentally safe residue.

National Category
Engineering and Technology Metallurgy and Metallic Materials
Research subject
Mineral Processing; Centre - Centre for Advanced Mining & Metallurgy (CAMM)
Identifiers
urn:nbn:se:ltu:diva-76412 (URN)
Conference
Conference in Minerals Engineering, Luleå, Sweden, February 5-6, 2019
Projects
REMinE (Improve Resource Efficiency and Minimize Environmental Footprint)
Funder
Vinnova, 215 06 631
Available from: 2019-10-16 Created: 2019-10-16 Last updated: 2019-10-18Bibliographically approved
Malm, L., Sand, A., Bolin, N.-J., Rosenkranz, J. & Ymén, I. (2019). Dynamic vapor sorption measurement and identification of mineral species in industrial-scale flotation cell samples. Powder Technology, 356, 1016-1023
Open this publication in new window or tab >>Dynamic vapor sorption measurement and identification of mineral species in industrial-scale flotation cell samples
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2019 (English)In: Powder Technology, ISSN 0032-5910, E-ISSN 1873-328X, Vol. 356, p. 1016-1023Article in journal (Refereed) Published
Abstract [en]

In order to understand flotation performance in industrial-scale, it is of relevance to understand the surface properties and mineral species of materials contained in the various parts of the cell. In this work XRPD X-Ray Powder Diffraction) and DVS (Dynamic Vapor Sorption) were used to characterise the different minerals and the wettability of the sample collected at different depths in an industrial scale flotation cell.

DVS is a novel technique for wettability measurement in mineral processing, of higher robustness and reproducibility compared to the Washburn technique.

In the turbulent zone of the cell, the wettability properties are relatively similar, and decreases in the froth and concentrate. Differences in radial position were only found near the froth phase close to the shaft of the agitator.

The main finding was that wettability information obtained by DVS could be correlated with mineral composition and particle size distribution.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Froth flotation, Dynamic vapor sorption, Industrial scale, Wettability, Mineral processing
National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-75765 (URN)10.1016/j.powtec.2019.08.063 (DOI)2-s2.0-85073103391 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-10-21 (johcin)

Available from: 2019-08-29 Created: 2019-08-29 Last updated: 2019-10-21Bibliographically approved
Mulenshi, J., Khavari, P., Chelgani, S. C. & Rosenkranz, J. (2019). Feasibility of gravity and magnetic separation for Yxsjöberg historical tungsten ore tailings. In: : . Paper presented at Minerals Engineering International (MEI) Conference_Physical Separation ’19, Falmouth, UK, June 13-14, 2019.
Open this publication in new window or tab >>Feasibility of gravity and magnetic separation for Yxsjöberg historical tungsten ore tailings
2019 (English)Conference paper, Oral presentation only (Refereed)
Abstract [en]

Repositories of historical tailings (HT) pose environmental risks but could also become new resources for valuable metals. This is because relatively high minerals and metals content characterize them due to less efficient extraction methods and/or relatively low metal prices at the time. In this investigation, geometallurgical studies were conducted by collecting drill core samples (DCS) from the Smaltjärnen tailings repository in Yxsjöberg, Sweden. The collected DCS were from the main layers of the longest drill core, and were characterized physically (color, texture, moisture content and particle size distribution) and chemically (elemental composition and distribution, and mineralogical composition). The characterization of DCS indicated that the tailings mass distribution was high in the coarser particle size fraction of +149 μm. Tungsten (W) and Copper (Cu) were the metals of interest with highest concentrations being 0.22 %WO3 and 0.11 %Cu. Feasible physical separation methods selected were Knelson concentrator, LIMS and HIMS, based on the knowledge from literature, tailings characteristics, and assessment of processes from which the Yxsjöberg HT were produced. Using the Knelson concentrator, the recovery of scheelite, which is the main W mineral, was enhanced, with 75 wt.% tungsten recovered in the 34 wt.% of concentrate produced. In magnetic separation, sulphur (S) was mostly recovered in the ferromagnetic and paramagnetic fractions with only 1.0 wt.% in the non-magnetic fraction, meaning pyrrhotite, the main Fe-sulphide mineral in the HT responsible for AMD, was separated to the desired magnetic fractions of the LIMS and HIMS. These results are fundamental in the development of methods for separation of valuable minerals from these HT in order to produce an inert and environmentally safe residue.

Keywords
Historical tailings, Tungsten, Scheelite, Geometallurgy, Reprocessing, Physical separation
National Category
Engineering and Technology
Research subject
Mineral Processing; Centre - Centre for Advanced Mining & Metallurgy (CAMM)
Identifiers
urn:nbn:se:ltu:diva-76407 (URN)
Conference
Minerals Engineering International (MEI) Conference_Physical Separation ’19, Falmouth, UK, June 13-14, 2019
Projects
REMinE (Improve Resource Efficiency and Minimize Environmental Footprint)
Funder
Vinnova, 215 06 631
Available from: 2019-10-16 Created: 2019-10-16 Last updated: 2019-10-22
Tohry, A., Dehghan, R., Chelgani, S. C., Rosenkranz, J. & Rahmani, O. (2019). Selective Separation of Hematite by a Synthesized Depressant in Various Scales of Anionic Reverse Flotation. Minerals, 9(2), Article ID 124.
Open this publication in new window or tab >>Selective Separation of Hematite by a Synthesized Depressant in Various Scales of Anionic Reverse Flotation
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2019 (English)In: Minerals, ISSN 2075-163X, E-ISSN 2075-163X, Vol. 9, no 2, article id 124Article in journal (Refereed) Published
Abstract [en]

Demand for high-quality iron concentrate is significantly increasing around the world. Thus, the development of the techniques for a selective separation and rejection of typical associated minerals in the iron oxide ores, such as phosphorous minerals (mainly apatite group), is a high priority. Reverse anionic flotation by using sodium silicate (SS) as an iron oxide depressant is one of the techniques for iron ore processing. This investigation is going to present a synthesized reagent “sodium co-silicate (SCS)” for hematite depression through a reverse anionic flotation. The main hypothesis is the selective depression of hematite and, simultaneously, modification of the pulp pH by SCS. Various flotation experiments, including micro-flotation, and batch flotation of laboratory and industrial scales, were conducted in order to compare the depression selectivity of SS versus SCS. Outcomes of flotation tests at the different flotation scales demonstrated that hematite depression by SCS is around 3.3% higher than by SS. Based on flotation experiment outcomes, it was concluded that SCS can modify the pH of the process at ~9.5, and the plant reagents (including NaOH, Na2CO3, and SS gel) can be replaced by just SCS, which can also lead to a higher efficiency in the plant. 

Place, publisher, year, edition, pages
MDPI, 2019
Keywords
anionic reverse flotation, phosphorus, depression, sodium co-silicate
National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-73481 (URN)10.3390/min9020124 (DOI)000460799000058 ()2-s2.0-85063594686 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-04-08 (svasva)

Available from: 2019-04-05 Created: 2019-04-05 Last updated: 2019-09-13Bibliographically approved
Guntoro, P. I., Ghorbani, Y. & Rosenkranz, J. (2019). Use of X-ray Micro-computed Tomography (µCT) for 3-D Ore Characterization: A Turning Point in Process Mineralogy. In: : . Paper presented at 26th International Mining Congress and Exhibition (IMCET 2019), Antalya, April 16-19, 2019 (pp. 1044-1054).
Open this publication in new window or tab >>Use of X-ray Micro-computed Tomography (µCT) for 3-D Ore Characterization: A Turning Point in Process Mineralogy
2019 (English)Conference paper, Published paper (Refereed)
Abstract [en]

In recent years, automated mineralogy has become an essential enabling technology in the field of process mineralogy, allowing better understanding between mineralogy and the beneficiation process. Recent developments in X-ray micro-computed tomography (μCT) as a non-destructive technique have indicated great potential to become the next automated mineralogy technique. μCT’s main advantage lies in its ability to allow 3-D monitoring of internal structure of the ore at resolutions down to a few hundred nanometers, thereby eliminating the stereological error encountered in conventional 2-D analysis. Driven by the technological and computational progress, the technique is continuously developing as an analysis tool in ore characterization and subsequently it foreseen thatμCT will become an indispensable technique in the field of process mineralogy. Although several software tools have been developed for processing μCT dataset, but the main challenge in μCT data analysis remains in the mineralogical analysis, where μCT data often lacks contrast between mineral phases, making segmentation difficult. In this paper, an overview of some current applications of μCT in ore characterization is reviewed, alongside with it potential implications to process mineralogy. It also describes the current limitations of its application and concludes with outlook on the future development of 3-D ore characterization.

Keywords
X-ray micro-tomography (µCT), process mineralogy, ore characterization
National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-73716 (URN)
Conference
26th International Mining Congress and Exhibition (IMCET 2019), Antalya, April 16-19, 2019
Funder
EU, Horizon 2020
Available from: 2019-04-23 Created: 2019-04-23 Last updated: 2019-10-30Bibliographically approved
Guntoro, P. I., Ghorbani, Y., Koch, P.-H. & Rosenkranz, J. (2019). X-ray Microcomputed Tomography (µCT) for Mineral Characterization: A Review of Data Analysis Methods. Minerals, 9(3), Article ID 183.
Open this publication in new window or tab >>X-ray Microcomputed Tomography (µCT) for Mineral Characterization: A Review of Data Analysis Methods
2019 (English)In: Minerals, ISSN 2075-163X, E-ISSN 2075-163X, Vol. 9, no 3, article id 183Article in journal (Refereed) Published
Abstract [en]

The main advantage of X-ray microcomputed tomography (µCT) as a non-destructive imaging tool lies in its ability to analyze the three-dimensional (3D) interior of a sample, therefore eliminating the stereological error exhibited in conventional two-dimensional (2D) image analysis. Coupled with the correct data analysis methods, µCT allows extraction of textural and mineralogical information from ore samples. This study provides a comprehensive overview on the available and potentially useful data analysis methods for processing 3D datasets acquired with laboratory µCT systems. Our study indicates that there is a rapid development of new techniques and algorithms capable of processing µCT datasets, but application of such techniques is often sample-specific. Several methods that have been successfully implemented for other similar materials (soils, aggregates, rocks) were also found to have the potential to be applied in mineral characterization. The main challenge in establishing a µCT system as a mineral characterization tool lies in the computational expenses of processing the large 3D dataset. Additionally, since most of the µCT dataset is based on the attenuation of the minerals, the presence of minerals with similar attenuations limits the capability of µCT in mineral segmentation. Further development on the data processing workflow is needed to accelerate the breakthrough of µCT as an analytical tool in mineral characterization.

Place, publisher, year, edition, pages
Basel, Switzerland: MDPI, 2019
Keywords
X-ray microcomputed tomography, data analysis, mineral characterization, texture, mineralogy
National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-73224 (URN)10.3390/min9030183 (DOI)000464421700002 ()2-s2.0-85064225739 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-03-18 (svasva)

Available from: 2019-03-18 Created: 2019-03-18 Last updated: 2019-10-30Bibliographically approved
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