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Bengtsson, Magnus, DocentORCID iD iconorcid.org/0000-0002-3283-067x
Publications (10 of 38) Show all publications
Bengtsson, M. (2020). Understanding Mineral Liberation during Crushing Using Grade-by-Size Analysis—A Case Study of the Penuota Sn-Ta Mineralization, Spain. Minerals, 10(2), Article ID 164.
Open this publication in new window or tab >>Understanding Mineral Liberation during Crushing Using Grade-by-Size Analysis—A Case Study of the Penuota Sn-Ta Mineralization, Spain
2020 (English)In: Minerals, Vol. 10, no 2, article id 164Article in journal (Refereed) Published
Abstract [en]

Coarse comminution test-work and modeling are powerful tools in the design and optimization of mineral processing plants and provide information on energy consumption. Additional information on mineral liberation characteristics can be used for assessing the potential of pre-concentration stages or screens in the plant design. In ores of high-value metals (e.g., Ta, W), standard techniques—such as the mineralogical quantification of grain mounts by quantitative evaluation of minerals by scanning electron microscopy (QEMSCAN) or chemical analysis by X-ray fluorescence (XRF) can be challenging, due to the low relative abundance of such valuable minerals. The cost of QEMSCAN is also a limiting factor, especially considering the large number of samples required for the optimization of coarse comminution. In this study, we present an extended analytical protocol to a well-established mechanical test of interparticle breakage to improve the assessment of coarse mineral liberation characteristics. The liberation of ore minerals is a function of the rock texture and the difference in size and mechanical properties of the valuable minerals relative to gangue minerals and they may fraction in certain grain sizes if they behave differently during comminution. By analyzing the bulk-chemistry of the different grain size fractions produced after compressional testing, and by generating element by size diagrams, it is possible to understand the liberation characteristics of an ore. We show, based on a case study performed on a tantalum ore deposit, that element distribution can be used to study the influence of mechanical parameters on mineral liberation. This information can direct further mineralogical investigation and test work

National Category
Materials Engineering
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-22813 (URN)10.3390/min10020164 (DOI)
Available from: 2020-02-14 Created: 2020-02-14 Last updated: 2020-03-04Bibliographically approved
Davoodi, A., Bengtsson, M., Hulthén, E. & Evertsson, M. (2019). Effects of screen decks’ aperture shapes and materials on screening efficiency. Minerals Engineering, 139
Open this publication in new window or tab >>Effects of screen decks’ aperture shapes and materials on screening efficiency
2019 (English)In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 139Article in journal (Refereed) Published
Abstract [en]

Screening is a key unit operation for the large-scale separation of materials. There are certain different machine parameters and variables that affect the process of screening. The Discrete Element Method (DEM) is a suitable method to analyze parameters and variables. The main benefit of using the DEM for simulating the screening process is that, as a contact model, it provides the possibility of tracking each particle in the material flow and all collisions between particles and between particles and boundaries.

There are different types of materials used for screening media, such as rubber and polyurethane, which are used in modular systems as a panel, and such as steel, which are used as a wire in the mesh. This paper presents how different materials used in screen decks affect the screening process. The materials’ strength and elasticity have been examined in order to study how the aperture will change in different materials and how different shapes of the aperture and material of screening media affect the screening performance by analyzing the effect on material flow.

National Category
Mechanical Engineering
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-15871 (URN)10.1016/j.mineng.2019.01.026 (DOI)000487174400015 ()2-s2.0-85062264942 (Scopus ID)
Available from: 2019-03-05 Created: 2019-03-05 Last updated: 2020-01-29Bibliographically approved
Bengtsson, M. (2019). Modelling energy and size distribution in cone crushers. Minerals Engineering, 139
Open this publication in new window or tab >>Modelling energy and size distribution in cone crushers
2019 (English)In: Minerals Engineering, Vol. 139Article in journal (Refereed) Published
Abstract [en]

The modelling of breakage in compression breakage has traditionally been done using population balance modelling, and the research has been developed over the last decades into advanced dynamic models. This paper presents a model for predicting particle size distribution and energy consumption. The particle size distribution model is derived using a first-order differential equation for how the coefficient of variance depends on the compression length. The coefficient of variance model is combined with a bimodal Weibull distribution to predict the cumulative size distribution. The power consumption is modelled in a similar way using Weibull analysis to determine the relationship between power consumption and the coefficient of variance.

Keywords
Modelling, Weibull analysis, Piston and die test
National Category
Engineering and Technology Materials Engineering
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-21756 (URN)10.1016/j.mineng.2019.105869 (DOI)2-s2.0-85069603383 (Scopus ID)
Available from: 2019-09-22 Created: 2019-09-22 Last updated: 2020-01-29Bibliographically approved
Camuz, S., Bengtsson, M. & Söderberg, R. (2019). Reliability based design optimization of surface-to-surface contact for cutting tool interface designs. Journal of manufacturing science and engineering
Open this publication in new window or tab >>Reliability based design optimization of surface-to-surface contact for cutting tool interface designs
2019 (English)In: Journal of manufacturing science and engineering, ISSN 1087-1357, E-ISSN 1528-8935Article in journal (Refereed) Published
Abstract [en]

In recent year, cutting tool manufacturers are moving towards improving the robustness of the positioning of an insert in the tool body interface. Increasing the robustness of the interface involves designs with both chamfered and serrated surfaces. These designs have a tendency to over-determine the positioning and cause instabilities in the interface. Cutting forces generated from the machining process will also plastically deform the interface, consequently, altering the positioning of the insert. Current methodologies within positioning and variation simulation use point-based contacts and assume linear material behaviour. In this article, a first order reliability-based design optimization framework that allows robust positioning of surface-to-surface-based contacts is presented. Results show that the contact variation over the interface can be limited to pre-defined contact zones, consequently allowing successful positioning of inserts in early design phases of cutting tool designs.

Place, publisher, year, edition, pages
ASME: , 2019
Keywords
Cutting tools, Reliability-based optimization, Robustness, Design, Cutting, Machining, Simulation
National Category
Natural Sciences
Identifiers
urn:nbn:se:hb:diva-15739 (URN)10.1115/1.4042787 (DOI)
Available from: 2019-02-11 Created: 2019-02-11 Last updated: 2019-02-13Bibliographically approved
Leon, L. G., Bengtsson, M. & Evertsson, M. (2018). Analysis of the concentration in rare metal ores during compression crushing. Minerals Engineering, 120, 7-18
Open this publication in new window or tab >>Analysis of the concentration in rare metal ores during compression crushing
2018 (English)In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 120, p. 7-18Article in journal (Refereed) Published
Abstract [en]

Given the increasing global demand for rare metals, there is a need for the development of fundamental predictive models to improve extraction processes. Comminution models commonly predict particle size reduction based on the compressive breakage behaviour; however, few of them include mineral concentration or mineral liberation at a coarse scale. This paper focuses on developing a model to predict the mineral concentration of rare metals as a function of the particle size distribution after a cycle of the compression crushing process. In this study, compressive breakage and geochemical analysis experiments were conducted on four different rare metal ores of tantalum and tungsten. The work is divided into two stages: the methodology of modelling particle size and modelling concentration by selecting a bimodal Weibull distribution for calibration. A novel model for simulating the concentration of rare metals as a function of the compression ratio is presented.

Keywords
Compression crushing, Rare metals, Element concentration analysis, Concentration modelling, Weibull analysis, Critical metals
National Category
Materials Engineering
Identifiers
urn:nbn:se:hb:diva-14932 (URN)10.1016/j.mineng.2018.01.041 (DOI)000430901200002 ()2-s2.0-85042194909 (Scopus ID)
Available from: 2018-08-10 Created: 2018-08-10 Last updated: 2018-08-10Bibliographically approved
Bengtsson, M., Bhadani, K., Asbjörnsson, G., Evertsson, M. & Hulthén, E. (2018). Comparative Study of Optimization Schemes in Mineral Processing Simulations. In: : . Paper presented at XXIX International Minerals Processing Congress Moscow, September 17-20, 2018.
Open this publication in new window or tab >>Comparative Study of Optimization Schemes in Mineral Processing Simulations
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2018 (English)Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

Modelling and simulations for mineral processing plants have been successful in replicating and predicting predefined scenarios of an operating plant. However, there is a need to explore and increase the potential of such simulations to make them attractive for users. One of the tools to increase the attractiveness of the simulations is through applying optimization schemes. Optimization schemes, applied on mineral processing simulations, can identify non-intuitive solutions for a given problem. The problem definition itself is subjective in nature and is dependent on the purpose of the operating plant.The scope of this paper is to demonstrate two optimization schemes: Multi-Objective Optimization (MOO) using a Genetic Algorithm (GA) and Multi-Disciplinary Optimization (MDO) using an Individual Discipline Feasible (IDF) approach. A two stage coarse comminution plant is used as a case plant to demonstrate the applicability of the two optimization schemes. The two schemes are compared based on the problem formulations, types of result and computation time. Results show that the two optimization schemes are suitable in generating solutions to a defined problem and both schemes can be used together to produce complementary results.

National Category
Mechanical Engineering
Identifiers
urn:nbn:se:hb:diva-15654 (URN)
Conference
XXIX International Minerals Processing Congress Moscow, September 17-20, 2018
Available from: 2019-01-11 Created: 2019-01-11 Last updated: 2019-01-14Bibliographically approved
Davoodi, A., Evertsson, M., Hulthén, E. & Bengtsson, M. (2018). The effect of different aperture shape and material of screen deck on screening efficiency. In: : . Paper presented at Comminution '18, Cape Town, 15-19 April, 2018.
Open this publication in new window or tab >>The effect of different aperture shape and material of screen deck on screening efficiency
2018 (English)Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

Screening is a key unit operation for the large-scale separation of materials. There are a number of different machine parameters and variables which affect the process of screening. The Discrete Element Method (DEM) is a suitable method to analyze all parameters and variables. The main benefit of using DEM for simulating the screening process is that as a particle contact model it gives the possibility to track each particle in the flow and all collisions between particles and between particles and boundaries.<br />There are a number of different materials commonly used for screen media such as rubber and polyurethane which are used in modular systems as a panel and steel is usually used as steel wire mesh but sheet metal can also be used. This paper presents how different materials used in screen decks affect the screening process. The strength and elasticity has been examined in order to study how the aperture will change with different materials and also how different shapes of the aperture and the material of screen media affect the screening performance by analyzing different material flow.

National Category
Mechanical Engineering
Identifiers
urn:nbn:se:hb:diva-14934 (URN)
Conference
Comminution '18, Cape Town, 15-19 April, 2018
Available from: 2018-08-10 Created: 2018-08-10 Last updated: 2018-08-17Bibliographically approved
Johansson, M., Bengtsson, M., Evertsson, M. & Hulthén, E. (2017). A fundamental model of an industrial-scale jaw crusher. Minerals Engineering, 105, 69-78
Open this publication in new window or tab >>A fundamental model of an industrial-scale jaw crusher
2017 (English)In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 105, p. 69-78Article in journal (Refereed) Published
Abstract [en]

In this study, an analytical perspective is used to develop a fundamental model of a jaw crusher. Previously, jaw crushers were modelled in regard to certain aspects, for example, energy consumption (Legendre and Zevenhoven, 2014) or kinematics (Oduori et al., 2015). Approaches to date have been mainly property specific. In this work a physical modelling approach has been used to derive the modules, which are based on established facts of comminution machines, from the literature. A modelling methodology mainly inspired by Evertsson has been applied (Evertsson, 2000). The modules are divided into kinematics, flow, breakage, capacity, pressure and power. Each module has been derived and tested decoupled from the other modules to provide increased transparency of the module and its behaviour. The results of the modelling are presented for a baseline case of one industrial-scale jaw crusher and compared to manufacturer data. Future work will include validation and DEM simulations.

Keywords
Jaw crusher, Flow model, Physical modelling, Primary crushing
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:hb:diva-14939 (URN)10.1016/j.mineng.2017.01.012 (DOI)000397374600010 ()2-s2.0-85011588772 (Scopus ID)
Available from: 2018-08-10 Created: 2018-08-10 Last updated: 2018-08-10Bibliographically approved
Davoodi, A., Evertsson, M., Hulthén, E. & Bengtsson, M. (2017). Analysis of Screening Performance using Discrete Element Modeling. In: : . Paper presented at Conference in Minerals Engineering, Luleå, 7-8 February, 2017.
Open this publication in new window or tab >>Analysis of Screening Performance using Discrete Element Modeling
2017 (English)Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

Screening is an important process in size classification of granular materials. It is a complex process due to the collision between particles and also a number of different operational parameters that effect the screening process. The aim of this paper is to evaluate screening performance in one of the LKAB crushing platforms.

In this work an industrial vibration screen has been simulated by using Discrete Element Method (DEM). The simulations were validated with data from experiments and the screening performance has been analyzed by changing the parameters such as feeding rate.

The result shows that DEM simulation is an effective tool for understanding the process of screening and because of the contact model between individual particles and particles and geometries the result is comparable with real process. It is shown that by increasing the feeding rate to 100 ton/h the screening efficiency can be improved by 20 percent.

Keywords
classification efficiency, dem, discrete element method
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:hb:diva-14935 (URN)
Conference
Conference in Minerals Engineering, Luleå, 7-8 February, 2017
Available from: 2018-08-10 Created: 2018-08-10 Last updated: 2018-08-17Bibliographically approved
Bhadani, K., Skön, J., Bengtsson, M., Evertsson, M. & Hasselblad, H. (2017). Application of Structural Optimization for an Early Stage Product Development. In: NAFEMS World Congress 2017: Summary of Proceedings. Paper presented at NAFEMS World Congress 2017, Stockholm, 11 June, 2017.
Open this publication in new window or tab >>Application of Structural Optimization for an Early Stage Product Development
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2017 (English)In: NAFEMS World Congress 2017: Summary of Proceedings, 2017Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

In today’s automotive industry there is a growing demand for more fuel efficient vehicles and reduced development times. These trends are driven by stricter environmental regulations, a growing environmental awareness, and increasing technological development and competitiveness. Finding an optimized and balanced component that fulfils the requirements in an early phase of the product development is a prerequisite for enabling more competitive lead times, costs, weights and minimizing the risk for late design changes. The aim with this paper is to show a process capturing CAE driven development for an early stage development of components in a complex system. The process utilizes structural optimization techniques to generate knowledge, optimize and balance packaging volumes of adjacent components in complex systems. The paper also highlight the organizational challenges and technical challenges involving the use of structural optimization for realizing the process completely. The paper will illustrate the simultaneous use of topology and shape optimization to generate knowledge for the optimized design volume for multiple adjacent components linked together. The linking of the multiple component is carried out using morphing technique and the design space between the multiple components is dynamic in nature during simulation. The mesh in one component is allowed to change according to the mesh of the other component during the simulation. The result from the simultaneous topology and shape optimization simulation generates the knowledge if it is feasible to change design volume to meet the weight and performance targets. The process also indicates how much performance increase is possible if the design volume is allowed to change and thus generating a trade-off between the components performance. The new process has a potential to be extended to other conflicting scenarios in adjacent components which exists in early stages of development process especially, cases involving conflicting structural requirements in various industries.

Keywords
Topology Optimization, CAD CAE Integration, Wheel Suspension, CAE Driven Product Design, Engineering Design, Optimization, Product Development
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:hb:diva-14936 (URN)
Conference
NAFEMS World Congress 2017, Stockholm, 11 June, 2017
Available from: 2018-08-10 Created: 2018-08-10 Last updated: 2018-08-17Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-3283-067x

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