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As a mineral processor (associate professor), I am working at the Lulea university of technology. Throughout collaborative works in mineral separation and metal extraction (industry and academia), I have gained a lot of experience in R&D, industrial teamwork, and management. I have received the most prestigious awards in Canada and other countries (OGS, NSERC, Outstanding researcher & reviewer). I am an editorial board member of some well-known journals within my research area.
Flotation separation, which is the most important mineral beneficiation technique, is dependent on gas dispersion (hydrodynamic conditions). Thus, many investigations have focused on the precise determination of hydrodynamic conditions such as Reynolds number of the bubbles, bubble velocity, and bubble diameter. However, few studies have examined their relationships with pressure fluctuations in a column flotation. This study introduced the differential pressure fluctuations as an actual variable that could be considered to determine the collection zone’s hydrodynamic conditions in a cyclonic microbubble flotation column. In general, the outcomes indicated that superficial gas velocity had the most substantial relationship with the differential pressure fluctuations among other flotation factors (such as pump speed, superficial gas velocity, superficial water velocity, and frother dosage). Furthermore, a high coefficient of determination (R2 > 0.77) for the equation generated to assess the relationships demonstrated that differential pressure fluctuations could be used as a promising tool to determine the hydrodynamic parameters’ characteristics in the flotation columns.
Xiangning Bu; Shaoqi Zhou; Meng Sun; Muidh Alheshibri; Shakhaoath Khan; Guangyuan Xie; Saeed Chehreh Chelgani. Exploring the Relationships between Gas Dispersion Parameters and Differential Pressure Fluctuations in a Column Flotation. ACS Omega 2021, 1 .
AMA StyleXiangning Bu, Shaoqi Zhou, Meng Sun, Muidh Alheshibri, Shakhaoath Khan, Guangyuan Xie, Saeed Chehreh Chelgani. Exploring the Relationships between Gas Dispersion Parameters and Differential Pressure Fluctuations in a Column Flotation. ACS Omega. 2021; ():1.
Chicago/Turabian StyleXiangning Bu; Shaoqi Zhou; Meng Sun; Muidh Alheshibri; Shakhaoath Khan; Guangyuan Xie; Saeed Chehreh Chelgani. 2021. "Exploring the Relationships between Gas Dispersion Parameters and Differential Pressure Fluctuations in a Column Flotation." ACS Omega , no. : 1.
Developing fuel resources is strategically crucial for Armenia. Far more than any other fossil fuel resource, coal roughly generates half the nation’s electricity. Although coal could play a critical role, no vast data is available about Armenia coal properties. Using robust modeling of energy indexes such as coal gross calorific value (GCV) by considering trivial existing datasets could be an essential clue for ensuring sustainable development. For the first time, this investigation is going to model GCV for Armenia coal samples. For this purpose, SHAP (SHapley Additive exPlanations) as a novel explainable artificial intelligence will be introduced. SHAP enables understanding the magnitude of relationships between each individual input record and its representative output and ranks input variables based on their effectiveness. SHAP was coupled by extreme gradient boosting (xgboost) as the most recently generated powerful predictive machine learning tool (SHAP-Xgboost). SHAP-Xgboost could accurately (R2=0.99) model GCV based on proximate and ultimate variables of Armenia coal samples. These significant outcomes open a new window for developing high interpretability models to assess coal properties and pinpoint the influential parameters.
Saeed Chehreh Chelgani. Estimation of gross calorific value based on coal analysis using an explainable artificial intelligence. Machine Learning with Applications 2021, 6, 100116 .
AMA StyleSaeed Chehreh Chelgani. Estimation of gross calorific value based on coal analysis using an explainable artificial intelligence. Machine Learning with Applications. 2021; 6 ():100116.
Chicago/Turabian StyleSaeed Chehreh Chelgani. 2021. "Estimation of gross calorific value based on coal analysis using an explainable artificial intelligence." Machine Learning with Applications 6, no. : 100116.
Talc is a naturally hydrophobic gangue mineral in most sulfide ores. However, talc has vast applications in the cosmetics, paper, and paint industries due to its high chemical stability, and its demand continues to grow. Since flotation is the most effective beneficiation technique for upgrading sulfides, the high hydrophobicity of talc has made its selective separation challenging. This paper explored the different properties of talc and the different factors that affect its flotation separation performance as a proven versatile beneficiation technique. Surface properties, zeta potential measurements, contact angles, and other factors affecting the talc flotation efficiency were discussed in detail. It was observed that the surface face/edge ratio (particle size) has a direct relationship with the level of talc hydrophobicity. Talc surfaces are negatively charged in a wide pH range (pH 2–12). Different depressants have already been studied; however, most of them showed low selectivity. The addition of ions such as Ca2+ could enhance talc depression. Pretreatment methods such as ultrasonic and thermal treatments were reported to decrease the talc floatability. It was demonstrated that the development of new selective depressants or pretreatment options for talc flotation requires attention in future investigations to improve its selective separation.
July Ann Bazar; Milad Rahimi; Siavash Fathinia; Mohammad Jafari; Vitalis Chipakwe; Saeed Chehreh Chelgani. Talc Flotation—An Overview. Minerals 2021, 11, 662 .
AMA StyleJuly Ann Bazar, Milad Rahimi, Siavash Fathinia, Mohammad Jafari, Vitalis Chipakwe, Saeed Chehreh Chelgani. Talc Flotation—An Overview. Minerals. 2021; 11 (7):662.
Chicago/Turabian StyleJuly Ann Bazar; Milad Rahimi; Siavash Fathinia; Mohammad Jafari; Vitalis Chipakwe; Saeed Chehreh Chelgani. 2021. "Talc Flotation—An Overview." Minerals 11, no. 7: 662.
In cement mills, ventilation is a critical key for maintaining temperature and material transportation. However, relationships between operational variables and ventilation factors for an industrial cement ball mill were not addressed until today. This investigation is going to fill this gap based on a newly developed concept named “conscious laboratory (CL)”. For constructing the CL, a boosted neural network (BNN), as a recently developed comprehensive artificial intelligence model, was applied through over 35 different variables, with more than 2000 records monitored for an industrial cement ball mill. BNN could assess multivariable nonlinear relationships among this vast dataset, and indicated mill outlet pressure and the ampere of the separator fan had the highest rank for the ventilation prediction. BNN could accurately model ventilation factors based on the operational variables with a root mean square error (RMSE) of 0.6. BNN showed a lower error than other traditional machine learning models (RMSE: random forest 0.71, support vector regression: 0.76). Since improving the milling efficiency has an essential role in machine development and energy utilization, these results can open a new window to the optimal designing of comminution units for the material technologies.
Rasoul Fatahi; Rasoul Khosravi; Hossein Siavoshi; Samaneh Yazdani; Esmaiel Hadavandi; Saeed Chehreh Chelgani. Ventilation Prediction for an Industrial Cement Raw Ball Mill by BNN—A “Conscious Lab” Approach. Materials 2021, 14, 3220 .
AMA StyleRasoul Fatahi, Rasoul Khosravi, Hossein Siavoshi, Samaneh Yazdani, Esmaiel Hadavandi, Saeed Chehreh Chelgani. Ventilation Prediction for an Industrial Cement Raw Ball Mill by BNN—A “Conscious Lab” Approach. Materials. 2021; 14 (12):3220.
Chicago/Turabian StyleRasoul Fatahi; Rasoul Khosravi; Hossein Siavoshi; Samaneh Yazdani; Esmaiel Hadavandi; Saeed Chehreh Chelgani. 2021. "Ventilation Prediction for an Industrial Cement Raw Ball Mill by BNN—A “Conscious Lab” Approach." Materials 14, no. 12: 3220.
Processing of materials that originated from tailings of industrial plants (with a wide range of particle size distribution, “PSD”) without grinding has several advantages since mines are faced with a lot of pressure to minimize their environmental impacts. This article indicates that the introduction of submicron bubbles (known as nanobubbles, “NBs”) to conventional flotation could improve the separation efficiency of valuable minerals from their associated gangue phases. It was demonstrated that metallurgical responses (recovery, grade, selectivity, and kinetics) of NB flotation could improve compared to those of conventional tests. Various hydrodynamic cavitation setups for NB generation may lead to different metallurgical responses. In general, the addition of surfactants (frothers and collectors) for NB generation could increase both mass and water recoveries, which would be key factors on selectivity. Selectivity is also markedly dependent on the PSD of feed, and the selectivity of NB flotation is improved significantly by decreasing the feed size. In general, generation of NBs in the presence of a frother leads to higher flotation metallurgical responses than in the presence of a collector.
Vitalis Chipakwe; Rickard Jolsterå; Saeed Chehreh Chelgani. Nanobubble-Assisted Flotation of Apatite Tailings: Insights on Beneficiation Options. ACS Omega 2021, 6, 13888 -13894.
AMA StyleVitalis Chipakwe, Rickard Jolsterå, Saeed Chehreh Chelgani. Nanobubble-Assisted Flotation of Apatite Tailings: Insights on Beneficiation Options. ACS Omega. 2021; 6 (21):13888-13894.
Chicago/Turabian StyleVitalis Chipakwe; Rickard Jolsterå; Saeed Chehreh Chelgani. 2021. "Nanobubble-Assisted Flotation of Apatite Tailings: Insights on Beneficiation Options." ACS Omega 6, no. 21: 13888-13894.
Tri-flo cyclone, as a dense-medium separation device, is one of the most typical environmentally friendly industrial techniques in the coal washery plants. Surprisingly, no detailed investigation has been conducted to explore the effectiveness of tri-flo cyclone operating parameters on their representative metallurgical responses (yield and recovery). To fill this gap, this work for the first time in the coal processing sector is going to introduce a type of advanced intelligent method (boosted-neural network “BNN”) which is able to linearly and nonlinearly assess multivariable correlations among all variables, rank them based on their effectiveness and model their produced responses. These assessments and modeling were considered a new concept called “Conscious Laboratory (CL)”. CL can markedly decrease the number of laboratory experiments, reduce cost, save time, remove scaling up risks, expand maintaining processes, and significantly improve our knowledge about the modeled system. In this study, a robust monitoring database from the Tabas coal plant was prepared to cover various conditions for building a CL for coal tri-flo separators. Well-known machine learning methods, random forest, and support vector regression were developed to validate BNN outcomes. The comparisons indicated the accuracy and strength of BNN over the examined traditional modeling methods. In a sentence, generating a novel BNN within the CL concept can apply in various energy and coal processing areas, fill gaps in our knowledge about possible interactions, and open a new window for plants' fully automotive process.
Mehdi Alidokht; Samaneh Yazdani; Esmaeil Hadavandi; Saeed Chehreh Chelgani. Modeling metallurgical responses of coal Tri-Flo separators by a novel BNN: a “Conscious-Lab” development. International Journal of Coal Science & Technology 2021, 1 -11.
AMA StyleMehdi Alidokht, Samaneh Yazdani, Esmaeil Hadavandi, Saeed Chehreh Chelgani. Modeling metallurgical responses of coal Tri-Flo separators by a novel BNN: a “Conscious-Lab” development. International Journal of Coal Science & Technology. 2021; ():1-11.
Chicago/Turabian StyleMehdi Alidokht; Samaneh Yazdani; Esmaeil Hadavandi; Saeed Chehreh Chelgani. 2021. "Modeling metallurgical responses of coal Tri-Flo separators by a novel BNN: a “Conscious-Lab” development." International Journal of Coal Science & Technology , no. : 1-11.
Selective attachment of nanobubles (NBs) generated in different conditions on the surface of valuable minerals during flotation separation was a challenge that needs to be addressed. This investigation filled this gap and proved the existence of NBs on the target mineral's surface and their selective effectiveness through the process. The bubble size analysis results showed that the mean diameter of bubbles was between 60 and 70 nm; thus, they could be correctly called “nanobubbles”. Flotation test results showed a significant increase in the flotation recovery (by 37%) and grade (more than 1%) of fine phosphate ore sample (d80: 37 µm) using NBs that generated in the presence of collector. Interestingly, surface analyses of flotation products showed that the amounts of flotation collector adsorbed onto the surface of floated particles was decreased in the presence of NBs compared with their absence. The change in the particle surface (zeta) potential in the presence of NBs also provides additional evidence of NBs “adsorbed” (i.e., the surface NBs) onto the particle surface. These results indicated that NBs produced by hydrodynamic cavitation could adsorb onto the target mineral particles. This adsorption could change their surface properties, improve their hydrophobicity and surface potentials, and enhanced the bubble-particle attachment in flotation.
Z. Pourkarimi; B. Rezai; M. Noaparast; A.V. Nguyen; S. Chehreh Chelgani. Proving the existence of nanobubbles produced by hydrodynamic cavitation and their significant effects in powder flotation. Advanced Powder Technology 2021, 32, 1810 -1818.
AMA StyleZ. Pourkarimi, B. Rezai, M. Noaparast, A.V. Nguyen, S. Chehreh Chelgani. Proving the existence of nanobubbles produced by hydrodynamic cavitation and their significant effects in powder flotation. Advanced Powder Technology. 2021; 32 (5):1810-1818.
Chicago/Turabian StyleZ. Pourkarimi; B. Rezai; M. Noaparast; A.V. Nguyen; S. Chehreh Chelgani. 2021. "Proving the existence of nanobubbles produced by hydrodynamic cavitation and their significant effects in powder flotation." Advanced Powder Technology 32, no. 5: 1810-1818.
The modern boron applications have adsorbed the mineral processors’ attention to improve typical boron mineral’s (BM) beneficiation methods. In this regard, dry treatment and pretreatment processes—such as magnetic separation and calcination as environmentally friendly methods, due to their minimal or zero adverse effect on the environment—need more consideration. Over the years, anionic flotation has become the main technique for beneficiation of friable BMs; however, there is a gap in the investigation of cationic flotation separation since BMs’ surface negatively charges in a wide pH range. At present, enriching BMs’ flotation via surface modification is taking center stage, which can also be considered for reprocessing long-forgotten BM tailings. As a comprehensive review, this work is going to provide a synopsis of the processes, techniques, optimum parameters, and conditions—such as size reduction, zeta potential, pH, and reagents—which have been employed in the processing of BMs. Gaps in our understanding of BM’s flotation are presented in the context of addressing the existing processes, considering possibilities and rooms for efficiency improvement. Considering these gaps may improve the performance of existing methods for processing fine and ultrafine BMs, and help in the development of new technologies to improve flotation recoveries.
Soehoe-Panhyonon Powoe; Varney Kromah; Mohammad Jafari; Saeed Chehreh Chelgani. A Review on the Beneficiation Methods of Borate Minerals. Minerals 2021, 11, 318 .
AMA StyleSoehoe-Panhyonon Powoe, Varney Kromah, Mohammad Jafari, Saeed Chehreh Chelgani. A Review on the Beneficiation Methods of Borate Minerals. Minerals. 2021; 11 (3):318.
Chicago/Turabian StyleSoehoe-Panhyonon Powoe; Varney Kromah; Mohammad Jafari; Saeed Chehreh Chelgani. 2021. "A Review on the Beneficiation Methods of Borate Minerals." Minerals 11, no. 3: 318.
Innovative tungsten (W) extraction techniques are continually being sought because of challenges of low leaching efficiencies, despite using advanced processing units such as autoclaves operating high temperatures and pressures. Compared to conventional leaching, mechanochemical treatment improves the efficiency of leaching. Therefore, in this study, an innovative mechanochemical treatment method, referred to as leaching while grinding (LWG), was employed as a reprocessing option to optimize W recovery from historical tungsten tailings. Experiments were run using the regular two-level factorial design to screen through the four factors of stirrer speed, liquid/solid ratio, temperature, and digestion time to assess their criticality and effects in the LWG process. The stirrer speed and the liquid/solid ratio were the most critical factors in the optimization of W recovery. The maximum W recovery (91.2%) was attained at the highest stirrer speed (410 rpm), low liquid/solid ratio (0.8), long digestion time (6 h), and low leaching temperature (60 °C). The attained low leaching temperature (60 °C) was due to the mechanical activation of scheelite resulting from the simultaneous grinding and leaching. For such low- grade W material, liquid/solid ratio optimizing is critical for maintaining the digestion mixture fluidity, and for environmental and economic sustainability regarding the sodium hydroxide (NaOH) consumption, which was low.
Jane Mulenshi; Saeed Chelgani; Jan Rosenkranz. Mechanochemical Treatment of Historical Tungsten Tailings: Leaching While Grinding for Tungsten Extraction Using NaOH. Sustainability 2021, 13, 3258 .
AMA StyleJane Mulenshi, Saeed Chelgani, Jan Rosenkranz. Mechanochemical Treatment of Historical Tungsten Tailings: Leaching While Grinding for Tungsten Extraction Using NaOH. Sustainability. 2021; 13 (6):3258.
Chicago/Turabian StyleJane Mulenshi; Saeed Chelgani; Jan Rosenkranz. 2021. "Mechanochemical Treatment of Historical Tungsten Tailings: Leaching While Grinding for Tungsten Extraction Using NaOH." Sustainability 13, no. 6: 3258.
It is well documented that chemical additives (grinding aid “GA”) during grinding can increase mill throughput, reduce water and energy consumption, narrow the particle size distribution of products, and improve material flowability. These advantages have been linked to their effects on the rheology, although there is a gap in understanding GA effectiveness mechanism on the flow properties. The present study aims to fill this gap using different GAs (Zalta™ GR20-587, Zalta™ VM1122, and sodium hydroxide) through batch grinding experiments of magnetite ore and addressing the mechanisms of their effects on the rheology by an FT4 Powder Rheometer as a unique system. Experimental results showed that GA improved grinding efficiency (energy consumption and product fineness), which were well-correlated with basic flow energy, specific energy, aerated basic flow energy, and aerated energy. Moreover, the rheometry measurement showed strong linear correlations between basic flow energy, specific energy, and the resulting work index when GAs was considered for grinding, which confirmed the effect of GA on ground particles’ flowability. Zalta™ VM1122, a polysaccharide-based grinding aid, showed the best performance with 38.8% reduction of basic flow energy, 20.4% reduction of specific energy, 24.6% reduction of aerated basic flow energy, and 38.3% reduction of aerated energy. It also showed the strongest correlation between the grinding parameters and flow parameters (r > 0.93). The present investigation shows a strong indication that the predominant mechanism of GAs is based on the alteration of rheological properties and identify Zalta™ VM1122 as the best GA.
Vitalis Chipakwe; Christopher Hulme-Smith; Tommy Karlkvist; Jan Rosenkranz; Saeed Chehreh Chelgani. Effects of Chemical Additives on Rheological Properties of Dry Ground Ore - a Comparative Study. Mineral Processing and Extractive Metallurgy Review 2021, 1 -10.
AMA StyleVitalis Chipakwe, Christopher Hulme-Smith, Tommy Karlkvist, Jan Rosenkranz, Saeed Chehreh Chelgani. Effects of Chemical Additives on Rheological Properties of Dry Ground Ore - a Comparative Study. Mineral Processing and Extractive Metallurgy Review. 2021; ():1-10.
Chicago/Turabian StyleVitalis Chipakwe; Christopher Hulme-Smith; Tommy Karlkvist; Jan Rosenkranz; Saeed Chehreh Chelgani. 2021. "Effects of Chemical Additives on Rheological Properties of Dry Ground Ore - a Comparative Study." Mineral Processing and Extractive Metallurgy Review , no. : 1-10.
Starch, dextrin, sodium silicate (SS), and recently sodium co-silicate (SCS) are the most known depressants for the depression of iron oxides through the traditional reverse flotation. However, all these depressants’ adsorption mechanisms on the surface of iron oxides and their main associated minerals (silicate and phosphates) through the reverse anionic flotation did not yet been thoroughly investigated. For filling this gap, as a comparative investigation, this study implemented Fourier Transform Infrared Spectroscopy (FTIR), zeta potential measurement, and micro-flotation tests to determine the adsorption mechanisms of these depressants and explored their effects on the floatabilities of pure hematite, quartz, and fluorapatite. Micro-flotation test results illustrated that all the examined depressants could depress hematite in the presence of an anionic collector. Still, the efficiencies of SS and SCS were higher than those of starch and dextrin. SCS had the lowest depression effect on quartz, and fluorapatite floatability compared to other depressants. Surface analyses depicted that dextrin and starch decreased the collector adsorption on the fluorapatite surface, where SCS and SS had a negligible effect on its floatability. The co-existence of physical and chemical bonds created between dextrin/starch and fluorapatite was the reason for its depression through the anionic reverse flotation.
A. Tohry; R. Dehghan; P. Hatefi; S. Chehreh Chelgani. A comparative study between the adsorption mechanisms of sodium co-silicate and conventional depressants for the reverse anionic hematite flotation. Separation Science and Technology 2021, 1 -18.
AMA StyleA. Tohry, R. Dehghan, P. Hatefi, S. Chehreh Chelgani. A comparative study between the adsorption mechanisms of sodium co-silicate and conventional depressants for the reverse anionic hematite flotation. Separation Science and Technology. 2021; ():1-18.
Chicago/Turabian StyleA. Tohry; R. Dehghan; P. Hatefi; S. Chehreh Chelgani. 2021. "A comparative study between the adsorption mechanisms of sodium co-silicate and conventional depressants for the reverse anionic hematite flotation." Separation Science and Technology , no. : 1-18.
Humic acid (HA), as an environmentally friendly depressant, absorbed significant attention for possible cleaner production within mineral separation by selective separation, especially for reverse flotation of iron oxides. However, a few systematic studies were addressed its effect on the iron ore reverse cationic flotation in the presence of complex silicates and its adsorption mechanism on the surface of these minerals. This work is going to fill this gap by exploring the depression mechanisms of HA through the reverse cationic flotation (separation of hematite from complex silicates; augite and hornblende). Wettability analyses, micro and batch flotation scale tests were employed for such a purpose. Adsorption test, turbidity measurement, zeta potential measurement, and Fourier Transform Infrared (FTIR) analyses were conducted to understand HA adsorption's mechanism on these minerals' surface. Results relieved that at the low concentration of HA (20 mg/L), adsorption on the examined minerals' surface occurred. Based on the micro-flotation test results, HA's depression impact has the following order: hematite ≫ augite > hornblende. The surface analysis results suggested that HA can interact with the Fe ions on the hematite surface by chemical and hydrogen bonding. The same mechanism was observed for HA adsorption on the considered silicates; however, the adsorption rate was lower, while lower polyvalent cations are available on these silicates' surface.
A. Tohry; R. Dehghan; M. Zarei; S. Chehreh Chelgani. Mechanism of humic acid adsorption as a flotation separation depressant on the complex silicates and hematite. Minerals Engineering 2020, 162, 106736 .
AMA StyleA. Tohry, R. Dehghan, M. Zarei, S. Chehreh Chelgani. Mechanism of humic acid adsorption as a flotation separation depressant on the complex silicates and hematite. Minerals Engineering. 2020; 162 ():106736.
Chicago/Turabian StyleA. Tohry; R. Dehghan; M. Zarei; S. Chehreh Chelgani. 2020. "Mechanism of humic acid adsorption as a flotation separation depressant on the complex silicates and hematite." Minerals Engineering 162, no. : 106736.
This study, for the first time, is going to introduce the boosted neural network (BNN) as a robust artificial intelligence for filling gaps related to the modeling of energy consumption (power draw) in the industrial scale high-pressure grinding rolls (HPGR). For such a purpose, a new concept called “Conscious Laboratory (CL)” has been developed. CL would be the modeling of variables based on real databases that are collected from the industrial-scale plants. Although using HPGRs have been absorbed attention in many processing plants, a few investigations have been conducted to model the power draw of HPGRs. In this article, BNN was used for modeling relationships between HPGR operational variables, and their representative power draws based on an industrial database. This investigation indicated that the generated CL based on BNN could accurately assess the multivariable relationships between monitoring variables of an HPGR from an iron ore plant.
A. Tohry; S. Yazdani; E. Hadavandi; E. Mahmudzadeh; S. Chehreh Chelgani. Advanced modeling of HPGR power consumption based on operational parameters by BNN: A “Conscious-Lab” development. Powder Technology 2020, 381, 280 -284.
AMA StyleA. Tohry, S. Yazdani, E. Hadavandi, E. Mahmudzadeh, S. Chehreh Chelgani. Advanced modeling of HPGR power consumption based on operational parameters by BNN: A “Conscious-Lab” development. Powder Technology. 2020; 381 ():280-284.
Chicago/Turabian StyleA. Tohry; S. Yazdani; E. Hadavandi; E. Mahmudzadeh; S. Chehreh Chelgani. 2020. "Advanced modeling of HPGR power consumption based on operational parameters by BNN: A “Conscious-Lab” development." Powder Technology 381, no. : 280-284.
Washburn Method (WM) as a typical contact angle measurement (θ) method can be used for assessment of powder wettability (especially representative particle size range for flotation separation). However, as an indirect method, WM has several limitations. This investigation is going to introduce an Enhanced Washburn Method (EWM), which fills the gap of those WM obstacles, and can be applied for the meaningful indirect θ measurement of powders. For such a purpose, the wettability of quartz powders (d80: 62 μm) was measured in the absence and in the presence of the cationic surfactant Flotigam®EDA at pH 10. EWM by using pre-conditioning of hydrophobized particles via unblock capillaries measured the θ of powders in different conditions. Statistical evaluations indicated that EWM could quite accurately measure θ of the hydrophobized powders, where there is a significant coefficient of determination (R2 above 0.96) between EWM outcomes and other examined direct θ measurement methods (the captive bubble and sessile drop methods).
Arash Tohry; Reza Dehghan; Alexandre Vale Oliveira; Saeed Chehreh Chelgani; Laurindo De Salles Leal Filho. Enhanced Washburn Method (EWM): A comparative study for the contact angle measurement of powders. Advanced Powder Technology 2020, 31, 4665 -4671.
AMA StyleArash Tohry, Reza Dehghan, Alexandre Vale Oliveira, Saeed Chehreh Chelgani, Laurindo De Salles Leal Filho. Enhanced Washburn Method (EWM): A comparative study for the contact angle measurement of powders. Advanced Powder Technology. 2020; 31 (12):4665-4671.
Chicago/Turabian StyleArash Tohry; Reza Dehghan; Alexandre Vale Oliveira; Saeed Chehreh Chelgani; Laurindo De Salles Leal Filho. 2020. "Enhanced Washburn Method (EWM): A comparative study for the contact angle measurement of powders." Advanced Powder Technology 31, no. 12: 4665-4671.
Jarosite precipitation process (JPP) is the most frequently used procedure for iron removal in the hydrometallurgical zinc extraction process. However, there is a gap in the knowledge of the relationship between operational parameters and the low contaminant JPP on the industrial scale. This study will address these issues by investigating the behavior of zinc calcine (ZC) as a neutralizing agent, exploring the source of zinc and iron through leaching experiments, and simulating the Jarosite process of the Bafgh Zinc Smelting Company (BZSC). The results showed that the zinc dissolution efficiency was 90.3% at 90 °C, and 73% of the iron present in the calcine can be solubilized. The main outcome was the iron removal of about 85% by alkaline ions present in ZC without the addition of any precipitating agent. The second target was to evaluate the effect of operational parameters on jarosite precipitation. Results revealed that increasing the temperature to 90 °C and the stirring rate to 500 RPM as well as adjusting the ZC’s pH during the jarosite precipitation remarkably improved iron removal. Considering all these factors in the plant could improve Fe precipitation to around 80% on average.
Ali Asimi; Khodakaram Gharibi; Emad Abkhoshk; Farhad Moosakazemi; Saeed Chehreh Chelgani. Effects of Operational Parameters on the Low Contaminant Jarosite Precipitation Process-an Industrial Scale Study. Materials 2020, 13, 4662 .
AMA StyleAli Asimi, Khodakaram Gharibi, Emad Abkhoshk, Farhad Moosakazemi, Saeed Chehreh Chelgani. Effects of Operational Parameters on the Low Contaminant Jarosite Precipitation Process-an Industrial Scale Study. Materials. 2020; 13 (20):4662.
Chicago/Turabian StyleAli Asimi; Khodakaram Gharibi; Emad Abkhoshk; Farhad Moosakazemi; Saeed Chehreh Chelgani. 2020. "Effects of Operational Parameters on the Low Contaminant Jarosite Precipitation Process-an Industrial Scale Study." Materials 13, no. 20: 4662.
A. Tohry; M. Jafari; M. Farahani; M. Manthouri; S. Chehreh Chelgani. Variable importance assessments of an innovative industrial-scale magnetic separator for processing of iron ore tailings. Mineral Processing and Extractive Metallurgy 2020, 1 -8.
AMA StyleA. Tohry, M. Jafari, M. Farahani, M. Manthouri, S. Chehreh Chelgani. Variable importance assessments of an innovative industrial-scale magnetic separator for processing of iron ore tailings. Mineral Processing and Extractive Metallurgy. 2020; ():1-8.
Chicago/Turabian StyleA. Tohry; M. Jafari; M. Farahani; M. Manthouri; S. Chehreh Chelgani. 2020. "Variable importance assessments of an innovative industrial-scale magnetic separator for processing of iron ore tailings." Mineral Processing and Extractive Metallurgy , no. : 1-8.
Dry grinding as an alternative to wet grinding is one of Sweden's strategic research areas to promote dry beneficiation. However, dry grinding has remained unpopular due to its higher specific energy consumption (Ec), wider particle size distribution (PSD), difficult material handling, and purported effects on downstream processes. In this work, the effects of the new additives (Zalta™ GR20–587, Zalta™ VM1122, and Sodium hydroxide) employed as grinding aids (GA) on dry grinding and product characteristics of a magnetite ore were studied in light of possible downstream effects. The grinding efficiency of Magnetite increased after using GAs in comparison without the GAs; however, an optimal dosage exists for each of the chemical additives investigated. Comparing to grinding without GA, Zalta™ VM1122, a viscosity modifier was selected as the most effective GA where by using this GA; the Ec decreased by 31.1% from 18.0 to 12.4 kWh/t, the PSD became narrower and finer (the P80 decreasing from 181 to 142 µm), and the proportion of the particles (38–150 µm) increased from 52.5 to 58.3%. Zalta™ VM1122 resulted in increased surface roughness and minimum microstructural defects. Further, it was found that Zalta™ VM1122 resulted in similar zeta potentials and pH values for the product compared to grinding without GA. These comparable product properties are advantageous as they minimize any potential negative effects on all possible downstream processes such as flotation.
Vitalis Chipakwe; P. Semsari; T. Karlkvist; J. Rosenkranz; S Chehreh Chelgani. A comparative study on the effect of chemical additives on dry grinding of magnetite ore. South African Journal of Chemical Engineering 2020, 34, 135 -141.
AMA StyleVitalis Chipakwe, P. Semsari, T. Karlkvist, J. Rosenkranz, S Chehreh Chelgani. A comparative study on the effect of chemical additives on dry grinding of magnetite ore. South African Journal of Chemical Engineering. 2020; 34 ():135-141.
Chicago/Turabian StyleVitalis Chipakwe; P. Semsari; T. Karlkvist; J. Rosenkranz; S Chehreh Chelgani. 2020. "A comparative study on the effect of chemical additives on dry grinding of magnetite ore." South African Journal of Chemical Engineering 34, no. : 135-141.
Grinding typically is the most cost-intensive stage of mineral beneficiation plants. Besides other design and operational parameters, grinding media have a crucial effect on the energy consumption of tumbling mills and generally on their operating costs. Steel balls are the most typical grinding media. However, in recent years, various media shapes with different properties have gained interest in the market, and their efficiencies were compared with balls. This study presents a comprehensive review of the impact of various media geometries on grinding factors (load behavior, power draw, toe, shoulder, contact mechanism, kinetic energy) and the product particle size in tumbling mills.
B. Shahbazi; M. Jafari; M. Parian; J. Rosenkranz; S. Chehreh Chelgani. Study on the impacts of media shapes on the performance of tumbling mills – A review. Minerals Engineering 2020, 157, 106490 .
AMA StyleB. Shahbazi, M. Jafari, M. Parian, J. Rosenkranz, S. Chehreh Chelgani. Study on the impacts of media shapes on the performance of tumbling mills – A review. Minerals Engineering. 2020; 157 ():106490.
Chicago/Turabian StyleB. Shahbazi; M. Jafari; M. Parian; J. Rosenkranz; S. Chehreh Chelgani. 2020. "Study on the impacts of media shapes on the performance of tumbling mills – A review." Minerals Engineering 157, no. : 106490.
Grinding aids (GAs) have been an important advent in the comminution circuits. Over the last few decades, in order to address the high energy consumption and scarcity of potable water for mineral processing, chemical additives have become a promising alternative. Using GAs can have some advantages such as enhancing grinding efficiency, reducing water usage, improving material flowability, and narrowing the particle size distribution of the grinding products. A study on the effect of GAs on size reduction units is crucial for the beneficiation value chain of minerals and the impact on downstream processes. However, our understanding of the effects of these materials on the particle size reduction is quite limited. This article analyses the literature, which used GAs and provides a comprehensive review of their applications in the ore beneficiation processes. The outcomes of this investigation indicated that the current understanding on the mechanism of GA effects focuses only on their impacts on the product fineness and size distribution, and neglecting the aspect of energy expended and physicochemical environment. The application of GAs is mainly for rationalisation of energy where the type of reagent, pH, and ionic strength of the grinding environment is important. Gaps in knowledge of GAs are discussed in the context of addressing their use in the mineral industry, considering the mechanism of their effect, effect on grinding efficiency, and effect on the downstream processes. Addressing these gaps will pave the way for the application of GAs in improving size reduction efficiencies, which ultimately reduces environmental impacts.
V. Chipakwe; P. Semsari; T. Karlkvist; J. Rosenkranz; S. Chehreh Chelgani. A critical review on the mechanisms of chemical additives used in grinding and their effects on the downstream processes. Journal of Materials Research and Technology 2020, 9, 8148 -8162.
AMA StyleV. Chipakwe, P. Semsari, T. Karlkvist, J. Rosenkranz, S. Chehreh Chelgani. A critical review on the mechanisms of chemical additives used in grinding and their effects on the downstream processes. Journal of Materials Research and Technology. 2020; 9 (4):8148-8162.
Chicago/Turabian StyleV. Chipakwe; P. Semsari; T. Karlkvist; J. Rosenkranz; S. Chehreh Chelgani. 2020. "A critical review on the mechanisms of chemical additives used in grinding and their effects on the downstream processes." Journal of Materials Research and Technology 9, no. 4: 8148-8162.
The use of granular activated carbon (GAC) is a typical and sustainable technique for recovering precious metals from a cyanide leaching solution (CLS). The level of GAC activity is a fundamental factor in assessing the rate of precious metal adsorption; thus, it is essential to determine the efficiency of carbon elution for reproducing GACs. Since mercury (Hg) adsorption plays a critical role, economically and environmentally, in GAC efficiency, we conducted various laboratory and industrial experiments to explore the effect of different rates of GAC activation (10%, 35%, 70% and 100%) on Hg adsorption from CLS. Assessments of laboratory test results showed a direct relationship between the Hg adsorption and GAC activity; by increasing the GAC activity from 10% to 100%, the recovery of Hg was increased from 20% to 41%. Kinetic modeling results indicated that the Hg adsorption for all GAC activities followed chemisorption mechanisms. There was good agreement between the laboratory test results and the results of experiments on the industrial scale (that used a continuous circuit). These outcomes indicate that by increasing the frequency of carbon reactivation and using GAC with a high level of activity in the first tank, Hg desorption was meaningfully decreased and recovery was improved (for 10% GAC activity vs. 35% GAC activity, recovery was 40% vs. 90%, respectively).
Sina Bastami; Sina Ghassa; Amin Seyedhakimi; Saeed Chehreh Chelgani. Adsorption of Mercury from a Cyanide Leaching Solution Using Various Activation Rates of Granular Activated Carbon: A Laboratory- and Industrial-Scale Study. Sustainability 2020, 12, 3287 .
AMA StyleSina Bastami, Sina Ghassa, Amin Seyedhakimi, Saeed Chehreh Chelgani. Adsorption of Mercury from a Cyanide Leaching Solution Using Various Activation Rates of Granular Activated Carbon: A Laboratory- and Industrial-Scale Study. Sustainability. 2020; 12 (8):3287.
Chicago/Turabian StyleSina Bastami; Sina Ghassa; Amin Seyedhakimi; Saeed Chehreh Chelgani. 2020. "Adsorption of Mercury from a Cyanide Leaching Solution Using Various Activation Rates of Granular Activated Carbon: A Laboratory- and Industrial-Scale Study." Sustainability 12, no. 8: 3287.