Change search
Link to record
Permanent link

Direct link
BETA
Chelgani, Saeed ChehrehORCID iD iconorcid.org/0000-0002-2265-6321
Alternative names
Publications (10 of 68) 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
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
Show others...
2019 (English)In: Journal of Materials Research and Technology, ISSN 2238-7854Article in journal (Refereed) Epub ahead of print
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)
Available from: 2019-08-20 Created: 2019-08-20 Last updated: 2019-08-20
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
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
Show others...
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
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
Show others...
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
Chelgani, S. C. (2019). Investigating the occurrences of valuable trace elements in African coals as potential byproducts of coal and coal combustion products. Journal of African Earth Sciences, 150, 131-135
Open this publication in new window or tab >>Investigating the occurrences of valuable trace elements in African coals as potential byproducts of coal and coal combustion products
2019 (English)In: Journal of African Earth Sciences, ISSN 1464-343X, Vol. 150, p. 131-135Article in journal (Refereed) Published
Abstract [en]

There is a growing attention in valuable trace elements (TEs) in coal and coal combustionproducts as they can potentially be future resources of valuable TEs. Therefore, understanding the mode of occurrences of valuable TEs in coal has several advantages for their economical and industrial extractions. Since there is limited information on the affinity of valuable TEs in the structure of African coals, this study explores correlations between conventional coal properties and concentration of vanadium, yttrium, gallium and lithium as valuable TEs for a wide range of African coal samples (139 samples) from South Africa, Botswana, Egypt, Tanzania, Nigeria and Zambia by statistical methods. Statistical assessments indicated that the concentrations of Y, V, Li and Ga for these countries are higher than their value in the world coal (on average). The outcomes of assessments showed that the Li, Ga and V are associated with the mineral matter fraction (inorganic affinity) of the coal where they have significant positive correlations with ash and Al (as a major element) and potentially clay minerals are their main bearing minerals. However, statistical explorations suggested that Y may have both the organic and inorganic occurrences in the African coal samples

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Coal, Yttrium, Lithium, Gallium, Vanadium, Africa
National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-71734 (URN)10.1016/j.jafrearsci.2018.11.011 (DOI)000460195100011 ()2-s2.0-85057148699 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-11-23 (johcin)

Available from: 2018-11-23 Created: 2018-11-23 Last updated: 2019-04-11Bibliographically approved
Sabzezari, B., Javad Koleini, S. M., Ghassa, S., Shahbazi, B. & Chelgani, S. C. (2019). Microwave-Leaching of Copper Smelting Dust for Cu and Zn Extraction. Materials, 12(11), Article ID 1822.
Open this publication in new window or tab >>Microwave-Leaching of Copper Smelting Dust for Cu and Zn Extraction
Show others...
2019 (English)In: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 12, no 11, article id 1822Article in journal (Refereed) Published
Abstract [en]

Industrial wastes may contain high concentrations of valuable metals. Extraction and recovery of these metals have several economic and environmental advantages. Various studies showed positive effects of microwaves as a pretreatment method before the leaching of minerals. However, there are empty rooms for exploring simultaneous microwave and leaching (microwave-leaching) of industrial waste material for the production of valuable metals. This investigation examined the microwave-leaching method to extract copper and zinc from a copper-smelter dust (CSD). The results of microwave-leaching mechanism were compared with conventional heating leaching based on kinetics modelling. The final Cu recovery in the conventional heating and microwave irradiation was 80.88% and 69.83%, respectively. Kinetic studies indicated that the leaching reactions follow diffusion across the product layer. Based on X-ray powder diffraction (XRD) analyses, during conventional experiments sulfate; components formed with high intensity as an ash layer which prevents reagent access to the solid surface and decreases the Cu dissolution. While the sulfate components did not detect in the microwave-leaching residuals which means that microwave irradiation helped to decrease the ash layer formation. Taking all mentioned results into consider it can be concluded that microwave-leaching can be considered as an efficient method for extraction of valuable metals from waste materials.

Place, publisher, year, edition, pages
MDPI, 2019
Keywords
copper smelting dust; microwave-leaching; recycling; kinetics; optimization
National Category
Materials Engineering Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-74983 (URN)10.3390/ma12111822 (DOI)000472638600096 ()31195613 (PubMedID)2-s2.0-85067283276 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-06-28 (svasva)

Available from: 2019-06-25 Created: 2019-06-25 Last updated: 2019-08-15Bibliographically approved
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
Show others...
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: 2019-04-15Bibliographically approved
Jafari, M., Chelgani, S. C., Shafaie, S., Abdollahi, H. & Hadavandi, E. (2019). Study effects of conventional flotation reagents on bioleaching of zinc sulfide. Journal of Industrial and Engineering Chemistry, 78, 364-371
Open this publication in new window or tab >>Study effects of conventional flotation reagents on bioleaching of zinc sulfide
Show others...
2019 (English)In: Journal of Industrial and Engineering Chemistry, ISSN 1226-086X, E-ISSN 1876-794X, Vol. 78, p. 364-371Article in journal (Refereed) Published
Abstract [en]

Although flotation and bio-extraction of metals from its products are extensively investigated, there are few studied which evaluated the effects of reagents on bioleaching process. Both structure and concentration of flotation reagents are effective factors on microorganism activities. In this study, Kendall’s tau (τ) as a statistical method was used to statistically access the effect of typical sulfide flotation surfactants (collectors: potassium amyl-xanthate, potassium isobutyl-xanthate, sodium ethyl-xanthate, potassium isopropyl-xanthate, and Dithiophosphate), and frothers: pine oil and methyl isobutyl carbinol) on the bioleaching of Zn sulfides in a mixed culture (Leptospirillum ferrooxidans, Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans). To consider both structure and concentration of these reagents, their molarities were used for the statistical evaluations. The Kendall assessments indicated that by increasing in the molarity of reagents, the pH value (the most effective factors of bioleaching) was increased (τ: 0.56) while the ORP value (τ: -0.54), Fe ratio (τ: -0.51) and numbers of oxidizing bacteria (τ: -0.38) in the solution were decreased. Therefore, as a result of these multi-interactions, by increasing the molarity of reagents, Zn recovery was decreased (τ: -0.45). These results potentially can be used for selection of flotation reagents when bioleaching would be the metallurgical metal extraction method.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Flotation, Bioleaching, Collector, Frother, Toxicity, Kendell’s tau
National Category
Mineral and Mine Engineering Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-74985 (URN)10.1016/j.jiec.2019.05.033 (DOI)000477689400039 ()2-s2.0-85066601266 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-07-12 (johcin)

Available from: 2019-06-25 Created: 2019-06-25 Last updated: 2019-08-20Bibliographically approved
Jafari, M., Shafaie, S. Z., Abdollahi, H., Gharabaghi, M. & Chelgani, S. C. (2019). Study of the effects of conventional reagents for sulfide flotation on bio-oxidation activity of Acidithiobacillus ferrooxidans. Chemical Engineering Communications, 206(3), 365-377
Open this publication in new window or tab >>Study of the effects of conventional reagents for sulfide flotation on bio-oxidation activity of Acidithiobacillus ferrooxidans
Show others...
2019 (English)In: Chemical Engineering Communications, ISSN 0098-6445, E-ISSN 1563-5201, Vol. 206, no 3, p. 365-377Article in journal (Refereed) Published
Abstract [en]

Bioleaching as a low cost and environment-friendly process could be a promising option for the enrichment of froth flotation products. Flotation reagents (collectors, frothers, etc.) are effective on the bacteria growth and oxidation activity; however, their impact has not been widely investigated. In this study, the effect of conventional reagents for sulfide flotation; collectors: potassium amylxanthate (KAX), potassium isobutyl-xanthate (KIBX), sodium ethylxanthate (NaEX), potassium isopropyl xanthate (KIPX) and Dithiophosphate (Aero3477), and frothers; pine oil (PO) and methyl isobutyl carbinol (MIBC) in various concentrations have been examined on Acidithiobacillus ferrooxidans activities. The results of this study demonstrate these flotation surfactants may have positive or negative influences on the bio-oxidation, based on their chemical compositions and/or concentrations. In general, the inhabitation effects of collectors would be increased in higher dosages and based on differences between results of various conditioning tests with the control test (without reagent) in different days, this effect could be considered by the following order: for 0.01 g/L: KAX > KIPX > KIBX > Aero3477 > NaEX, 0.1 g/L: NaEX > KIPX > KAX > KIBX > Aero3477, and 1 g/L: NaEX > KIPX > KIBX > KAX > Aero3477, and for frothers: MIBC > PO in all concentrates. These outputs potentially can be used for the selection of flotation surfactants when the flotation products are going to be further processed by bioleaching for the metallurgical extraction.

Place, publisher, year, edition, pages
Taylor & Francis, 2019
Keywords
Bioleaching, Collector, Flotation, Frother, Thiobacillus, Toxicity
National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-72231 (URN)10.1080/00986445.2018.1494578 (DOI)000459588400008 ()
Available from: 2019-01-21 Created: 2019-01-21 Last updated: 2019-04-24Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-2265-6321

Search in DiVA

Show all publications