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Chelgani, Saeed ChehrehORCID iD iconorcid.org/0000-0002-2265-6321
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Publications (10 of 74) 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
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
Jafari, M., Golzadeh, M., Shafaei, S. Z., Abdollahi, H., Gharabaghi, M. & Chelgani, S. C. (2019). Effects of Conventional Flotation Frothers on the Population of Mesophilic Microorganisms in Different Cultures. Processes, 7(10), Article ID 653.
Open this publication in new window or tab >>Effects of Conventional Flotation Frothers on the Population of Mesophilic Microorganisms in Different Cultures
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2019 (English)In: Processes, ISSN 2227-9717, Vol. 7, no 10, article id 653Article in journal (Refereed) Published
Abstract [en]

Bioleaching is an environment-friendly and low-investment process for the extraction of metals from flotation concentrate. Surfactants such as collectors and frothers are widely used in the flotation process. These chemical reagents may have inhibitory effects on the activity of microorganisms through a bioleaching process; however, there is no report indicating influences of reagents on the activity of microorganisms in the mixed culture which is mostly used in the industry. In this investigation, influences of typical flotation frothers (methyl isobutyl carbinol and pine oil) in different concentrations (0.01, 0.10, and 1.00 g/L) were examined on activates of bacteria in the mesophilic mixed culture (Acidithiobacillus ferrooxidans, Leptospirillum ferrooxidans, and Acidithiobacillus thiooxidans). For comparison purposes, experiments were repeated by pure cultures of Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans in the same conditions. Results indicated that increasing the dosage of frothers has a negative correlation with bacteria activities while the mixed culture showed a lower sensitivity to the toxicity of these frothers in comparison with examined pure cultures. Outcomes showed the toxicity of Pine oil is lower than methyl isobutyl carbinol (MIBC). These results can be used for designing flotation separation procedures and to produce cleaner products for bio extraction of metals.

Place, publisher, year, edition, pages
MDPI, 2019
Keywords
flotation, bioleaching, frother, mixed culture, machine learning
National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-76781 (URN)10.3390/pr7100653 (DOI)000495436200015 ()2-s2.0-85074239838 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-11-20 (johcin)

Available from: 2019-11-20 Created: 2019-11-20 Last updated: 2019-11-20Bibliographically approved
Hadavandi, E. & Chelgani, S. C. (2019). Estimation of coking indexes based on parental coal properties by variable importance measurement and boosted-support vector regression method. Measurement, 135, 306-311
Open this publication in new window or tab >>Estimation of coking indexes based on parental coal properties by variable importance measurement and boosted-support vector regression method
2019 (English)In: Measurement, ISSN 0263-2241, E-ISSN 1873-412X, Vol. 135, p. 306-311Article in journal (Refereed) Published
Abstract [en]

Coke as a fuel has a critical role for steel making industries. Since coke is a product of blended coals, it is essential to study relationships between parental coal components with quality of their coke products. Free swelling index (FSI) and maximum fluidity (MF) are standard coking indexes that widely used for blending coals and measuring quality of products. This study has been explored interdependencies between measured coal components by mutual information (MI) method and evaluated their importance in the prediction of coking indexes for a wide range of Illinois coal samples. MI results indicated that the set of moisture-organic sulfur and moisture-nitrogen-sulfate sulfur were the best variables for predictions of log(MF) and FSI, respectively. Adaptive Boosting method based on support vector regression (SVR), called Boosted-SVR, was used the selected variable sets for predictions of coking indexes. In testing stage of models, correlation of determination (R2) between actual and predicted values for the log(MF) and FSI were 0.89 and 0.90, respectively. These results indicated that Boosted-SVR model could quite satisfactory predict coking indexes. In general, outcomes of this investigation demonstrated an appropriate potential of coking quality prediction with limited numbers of input variables and suggested that a combination of MI with Boosted-SVR model as a new powerful tool which can be used for the computation of other complex fuel and processing problems based on measurement of conventional properties.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Free swelling index, Maximum fluidity, Feature selection, Mutual information, Boosted-SVR
National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-72227 (URN)10.1016/j.measurement.2018.11.068 (DOI)000468747300031 ()2-s2.0-85057353034 (Scopus ID)
Note

Validerad;2019;Nivå 2;2018-12-19 (svasva)

Available from: 2018-12-19 Created: 2018-12-19 Last updated: 2019-06-18Bibliographically approved
Chelgani, S. C., Hadavandi, E. & Hower, J. C. (2019). Estimation of heavy and light rare earth elements of coal by intelligent methods. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects
Open this publication in new window or tab >>Estimation of heavy and light rare earth elements of coal by intelligent methods
2019 (English)In: Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, ISSN 1556-7036, E-ISSN 1556-7230Article in journal (Refereed) Epub ahead of print
Abstract [en]

Since last two decades, several investigations in various countries have been started to discover new rare earth element (REE) resources. It was reported that coal can be considered as a possible source of them. REE of coal occur in low concentrations, and their detection is a complicated process; therefore, their predictions based on conventional coal properties (proximate, ultimate and major elements (ME)) may have several advantages. However, few studies have been conducted in this area. This study examined relationships between coal properties and REE (HREE and LREE) for a wide range of coal samples (708 samples). Variable importance measure (VIM) by Mutual information (MI) as a new feature selection method was applied to consider the heterogeneous structure of coal and assess the individual relation between coal parameters and REE to select the compact subsets as input variables for modeling and improve the performance of prediction. VIM by MI showed that Si-Carbon, and Al-Hydrogen are the best subsets for the prediction of HREE and LREE concentrations, respectively. A boosted neural network (BNN) model as a new predictive tool was used for REE prediction. BNN can significantly reduce generalization of error. Results of BNN models showed that the HREE and LREE concentrations can satisfactory estimate (R 2 : 0.83 and 0.89, respectively). Results of this investigation were approved that MI-BNN can be used as a potential tool for prediction of other complex problems in energy and fuel areas.

Place, publisher, year, edition, pages
Taylor & Francis, 2019
Keywords
Coal, combustion products, HREE, LREE, mutual information, boosted neural network
National Category
Mineral and Mine Engineering Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-74986 (URN)10.1080/15567036.2019.1623943 (DOI)
Available from: 2019-06-25 Created: 2019-06-25 Last updated: 2019-07-05
Salehin, S., Hadavandi, E. & Chelgani, S. C. (2019). Exploring relationships between mechanical properties of marl core samples by a coupling of mutual information and predictive ensemble model. Modeling Earth Systems and Environment
Open this publication in new window or tab >>Exploring relationships between mechanical properties of marl core samples by a coupling of mutual information and predictive ensemble model
2019 (English)In: Modeling Earth Systems and Environment, ISSN 2363-6203, E-ISSN 2363-6211Article in journal (Refereed) Epub ahead of print
Abstract [en]

Inappropriate evaluation of uniaxial compression indexes (E and UCS) of rocks in high seismic intensity areas such as dam regions can lead to underestimation of the load, and possible settlement of the structure. Indirect assessments of these rock mechanical indexes based on non-destructive experiments and by using intelligent models is a well-accepted method to overcome associated limitations with laboratory tests of E and UCS. This study introduces the mutual information (MI) method as a unique system for variable importance measurement (VIM) and feature selection. Conducting MI-VIM assessments between various analyses of marl core samples (depth, density, ultrasonic tests (νd, Vp and Vs), Brazilian test (σt), triaxial compression test (C and and ϕ) and point load test (Is(50)) indicated that Vs and σt had the highest importance for E and UCS prediction. adaptive boosting–neural network ensemble (Adaboost–NNE) was used for the prediction of E and UCS. Testing of the generated Adaboost–NNE indicated that this model could accurately predict UCS and E with correlations of determinations 0.98 and 0.92, respectively. These results showed that VIM of MI coupled with Adaboost–NNE could develop a robust model that can be used for the prediction and modeling of other indexes of rocks.

Place, publisher, year, edition, pages
Springer, 2019
Keywords
Marls, Dam, Variable importance, Maintenance, Brazilian test, Mutual information
National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-76808 (URN)10.1007/s40808-019-00672-1 (DOI)
Available from: 2019-11-21 Created: 2019-11-21 Last updated: 2019-12-05
Seyedhakimi, A., Bastami, S., Ghassa, S., Razavi, H. & Chelgani, S. C. (2019). Exploring relationships between various activations of granular activated carbon on silver and gold adsorption: A kinetic and equilibrium study. Separation science and technology (Print), 54(11), 1710-1721
Open this publication in new window or tab >>Exploring relationships between various activations of granular activated carbon on silver and gold adsorption: A kinetic and equilibrium study
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2019 (English)In: Separation science and technology (Print), ISSN 0149-6395, E-ISSN 1520-5754, Vol. 54, no 11, p. 1710-1721Article in journal (Refereed) Published
Abstract [en]

This investigation examined various kinetic and equilibrium models for gold (Au) and silver (Ag) adsorption from cyanide leach solution, onto surface of granular activated carbon (GAC) with 10, 35, 70 and 100% activities. Results indicated that the initial rate for Au and Ag adsorption is similar and increases by increasing the GAC activities. Outcomes showed that the adsorption for low activity GAC is proportional to the number of adsorption sites while the rate-limiting can be chemisorption for GAC with high activity. Thus, even low amount of contaminations on the fresh GAC can significantly decrease the capacity of precious metals adsorption.

Place, publisher, year, edition, pages
Taylor & Francis, 2019
Keywords
Activated carbon, activation, equilibrium, kinetic, precious metals
National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-71719 (URN)10.1080/01496395.2018.1540635 (DOI)000470885100002 ()2-s2.0-85055706559 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-06-26 (johcin)

Available from: 2018-11-22 Created: 2018-11-22 Last updated: 2019-06-26Bibliographically approved
Chelgani, S. C. (2019). Exploring relationships of gross calorific value and valuable elements with conventional coal properties for North Korean coals. International Journal of Mining Science and Technology, 29(6), 867-871
Open this publication in new window or tab >>Exploring relationships of gross calorific value and valuable elements with conventional coal properties for North Korean coals
2019 (English)In: International Journal of Mining Science and Technology, ISSN 2095-2686, Vol. 29, no 6, p. 867-871Article in journal (Refereed) Published
Abstract [en]

Coal in North Korean (NKC) is one of the most important products; however, based on various strategic policies its detail properties remain opaque even for general researchers. Since there are some signs for opening of the North Korea economy, this investigation as a modest effort is going to explore principle relationships among some essential parameters of NKCs such as gross calorific value (GCV), valuable elements and conventional properties by different statistical methods. Correlations indicated that ultimate parameters (carbon, nitrogen, and hydrogen) are the best GCV predictors for NKCs in comparison with proximate parameters (ash, moisture and volatile matter). Multivariable regression demonstrated that predicted GCV based on ultimate properties has a quite accuracy when correlation of determination was 0.99. Descriptive statistics processes showed that on average, the contents of valuable elements such as Ga and V for NKCs are higher than the world coal ranges and they can be considered as byproducts of combustion of NKCs. Pearson correlations indicated that Y may have a mixed organic-inorganic affinity while Ga and V mainly occur in the inorganic part (mineral matter) of NKCs. High inter-correlations between Ga-V and Al showed that aluminosilicates can be considered as their main bring minerals.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Yttrium, Gallium, Vanadium, Calorific value, Energy, By product
National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-76205 (URN)10.1016/j.ijmst.2019.09.005 (DOI)000497386600007 ()
Note

Validerad;2019;Nivå 2;2019-12-06 (johcin)

Available from: 2019-10-02 Created: 2019-10-02 Last updated: 2019-12-06Bibliographically 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
Nazari, S., Chelgani, S. C., Shafaei, S., Shahbazi, B., Matin, S. & Gharabaghi, A. (2019). Flotation of coarse particles by hydrodynamic cavitation generated in the presence of conventional reagents. Separation and Purification Technology, 220, 61-68
Open this publication in new window or tab >>Flotation of coarse particles by hydrodynamic cavitation generated in the presence of conventional reagents
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2019 (English)In: Separation and Purification Technology, ISSN 1383-5866, E-ISSN 1873-3794, Vol. 220, p. 61-68Article in journal (Refereed) Published
Abstract [en]

Hydrodynamic cavitation (HC) (typically used to generate submicron bubbles) are frequently examined to improve froth flotation efficiency of ultrafine particles (−38 µm); however, the study of their effects on flotation parameters during the process of coarse particles (+100 µm) was not significantly explored. The main aim of this investigation is to discover the impacts of HC on effective flotation variables and flotation recovery of coarse particles (FRCP). Various surfactants (frothers: Methyl isobutyl carbinol (MIBC) and pine oil (PO), and dodecyl amine (DDA)) were used for the HC conditions. For comparison purposes, two series of flotation experiments in the absence and presence of HC were conducted by using coarse pure quartz particles (−425 + 106 µm). Variable importance measurements (VIMs) of random forest were applied to compare and assess impacts of flotation parameters (particle size, flotation conventional bubble (CB) size, impeller speed, and air flow rate) on FRCP in the absence and presence of HC. Outputs of VIMs indicated that the negative effect of particle size on FRCP was decreased and the capability of CB for floating coarse particles was improved in the presence of HC. Moreover, VIM results showed that in the presence of HC, the highest FRCP can be achieved when turbulent is lower. Generally, variations in the airflow rate had negligible impacts on FRCP. Flotation experiments suggested that HC in the presence of the collector can overcome the absence of frothers in a flotation system. These results can be used for enhancement of selective separation via froth flotation.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Airflow rate, Conventional flotation bubbles, Impeller speed, Nanobubble, Particle size
National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-73371 (URN)10.1016/j.seppur.2019.03.033 (DOI)000466250100008 ()2-s2.0-85063106077 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-04-01 (svasva)

Available from: 2019-04-01 Created: 2019-04-01 Last updated: 2019-05-15Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0002-2265-6321

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