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Modelling and Calculation of Raw Material Industry
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Modelling and Calculation of Raw Material Industry

A special issue of Energies (ISSN 1996-1073). This special issue belongs to the section "H: Geo-Energy".

Deadline for manuscript submissions: closed (30 November 2021) | Viewed by 33864

Printed Edition Available!
A printed edition of this Special Issue is available here.

Special Issue Editors

Dr. Robert Król

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Guest Editor
Department of Mining and Geodesy, Faculty of GeoEngineering Mining and Geology, Wroclaw University of Science and Technology, Wrocław, Poland
Interests: examination of mining facilities and systems (energy consumption, durability, reliability); management of exploitation of mining and transportation machines and devices; modelling and numerical simulations
Dr. Witold Kawalec

E-Mail Website
Guest Editor
Department of Mining, Faculty of GeoEngineering, Mining and Geology, Wroclaw University of Science and Technology, Na Grobli 15 St., 50-421 Wrocław, Poland
Interests: computational methods of spatial modelling of ore deposits and mine planning; modelling and calculation of mining transport systems
Special Issues, Collections and Topics in MDPI journals
Prof. Dr. Izabela Sówka

E-Mail Website
Guest Editor
Department of Environment Protection Engineering, Faculty of Environmental Engineering, Wroclaw University of Science and Technology, 27 Wybrzeże Wyspiańskiego st., 50-370 Wrocław, Poland
Interests: methods standardization; odor emission regulation; air quality monitoring; dynamic olfactometry; odor mapping; odor modeling
Special Issues, Collections and Topics in MDPI journals
Dr. Krzysztof M. Czajka

E-Mail Website
Guest Editor
Department of Mechanics, Machines, Devices and Energy Processes, Faculty of Mechanical and Power Engineering, Wroclaw University of Science and Technology, Wroclaw, Poland
Interests: thermal analysis (TGA, DSC, FTIR); pyrolysis, gasification and combustion of solid fuels; gasifiers and gas turbines; steam turbines, compressors and fans

Special Issue Information

The raw material mining and processing industry belongs to the most energy exhausting, environmental aggressive yet socially controversial branches of the economy. Therefore its optimisation should be targeted on both the overall efficiency and mitigating the environmental impact otherwise mining and fossil fuels based power generation would leak outside the most developed countries. The development of modelling and calculation methods incorporating advanced clouds computing, artificial intelligence algorithms and sophisticated sensors technology allows building comprehensive digital twins of objects, systems and processes representing the whole chain of the raw material mining and processing processes.

One of the most challenging industry processes in the modern economy is the sustainable power generation in its transition course from fossil fuels base to the “green” solutions to match carbon and toxic emissions limits and the other environmental impact like dust, noise, vast areas of terrain degradation. Because this industry is particularly capital and operational costly, it needs complex investigations that could return substantial savings measured in money, energy consumed and social benefits.

The proposed topics of this Special Issue of Energies are: 1. Sustainable processing of raw materials for an optimization of mining, energy production and environmental engineering. 2. Improved efficiency of the raw material mining and processing processes with the use of its quality control track from the deposit modelling, through modelling of mining, transport and final processing operations with regard to environmental issues. 3. Raw material solutions for a sustainable energy conversion and storage with “green power” sources. 4. Resource recycling, efficiency and secondary raw materials management as a contribution to climate change mitigation. 5. Strategies, identification of sources, dispersion modelling and methods of reducing and limiting air pollutant emissions to the atmosphere in the heating, mining and energy industry.

Assoc. Prof. Robert Król
Dr. Witold Kawalec
Assoc. Prof. Izabela Sówka
Assoc. Prof. Krzysztof M. Czajka
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Energies is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Mining, heating and energy processes
  • process modelling
  • multi-purpose deposit modelling
  • digital twin
  • quality tracking
  • raw material sustainable use
  • fossil fuels
  • green power
  • air pollution, climate change mitigation
  • carbon emission costs
  • energy efficiency certificates
  • waste disposal charges
  • energy conversion and storage

Published Papers (15 papers)

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Editorial

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6 pages, 218 KiB  
Editorial
Modelling and Calculation of Raw Material Industry
by Krzysztof Czajka, Witold Kawalec, Robert Król and Izabela Sówka
Energies 2022, 15(14), 5035; https://doi.org/10.3390/en15145035 - 10 Jul 2022
Cited by 4 | Viewed by 1206
Abstract
Scientific and technical issues related to the extraction and processing of raw materials are inextricably linked with environmental concerns. The extraction, transportation and processing of raw materials and the creation of new products place a heavy burden on the environment. Therefore, the development [...] Read more.
Scientific and technical issues related to the extraction and processing of raw materials are inextricably linked with environmental concerns. The extraction, transportation and processing of raw materials and the creation of new products place a heavy burden on the environment. Therefore, the development of new technologies for the extraction and processing of raw materials which meet the demand for specific products while respecting environmental resources and saving energy can be considered one of the key challenges of modern science. The development of methods to optimize the course of certain processes related to the raw materials industry, limiting its impact on the environment, and the use of modern measurement techniques or modeling are key areas of research and development for the economy. The aim of this Special Issue was to identify certain important issues, including those related to the raw materials industry and the optimization of its processes, obtaining energy from alternative fuels and research on environmental aspects of industrial activities. The results of the research and analyses presented in the articles show that meeting the objectives in the context of sustainable raw materials industry requires: the optimization of the use of mine deposits and the recovery of materials, reductions in energy consumption, minimizations in emissions of pollutants, the perfection of quieter and safer processes and the facilitation of the recovery of materials-, water- and energy-related modern techniques and technologies. Full article
(This article belongs to the Special Issue Modelling and Calculation of Raw Material Industry)

Research

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22 pages, 2573 KiB  
Article
Linear and Non-Linear Regression Analysis for the Adsorption Kinetics of SO2 in a Fixed Carbon Bed Reactor—A Case Study
by Anna M. Kisiela-Czajka and Bartosz Dziejarski
Energies 2022, 15(2), 633; https://doi.org/10.3390/en15020633 - 17 Jan 2022
Cited by 7 | Viewed by 2130
Abstract
Here, we determined the kinetic parameters of SO2 adsorption on unburned carbons from lignite fly ash and activated carbons based on hard coal dust. The model studies were performed using the linear and non-linear regression method for the following models: pseudo first [...] Read more.
Here, we determined the kinetic parameters of SO2 adsorption on unburned carbons from lignite fly ash and activated carbons based on hard coal dust. The model studies were performed using the linear and non-linear regression method for the following models: pseudo first and second order, intraparticle diffusion, and chemisorption on a heterogeneous surface. The quality of the fitting of a given model to empirical data was assessed based on: R2, R, Δq, SSE, ARE, χ2, HYBRID, MPSD, EABS, and SNE. It was clearly shown that the linear regression more accurately reflects the behaviour of the adsorption system, which is consistent with the first-order kinetic reaction—for activated carbons (SO2 + Ar) or chemisorption on a heterogeneous surface—for unburned carbons (SO2 + Ar and SO2 + Ar + H2O(g) + O2) and activated carbons (SO2 + Ar + H2O(g) + O2). Importantly, usually, each of the approaches (linear/non-linear) indicated a different mechanism of the studied phenomenon. A certain universality of the χ2 and HYBRID functions has been proved, the minimization of which repeatedly led to the lowest SNE values for the indicated models. Fitting data by any of the non-linear equations based on the R or R2 functions only cannot be treated as evidence/prerequisite of the existence of a given adsorption mechanism. Full article
(This article belongs to the Special Issue Modelling and Calculation of Raw Material Industry)
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19 pages, 3621 KiB  
Article
Assessment of GHG Interactions in the Vicinity of the Municipal Waste Landfill Site—Case Study
by Maciej Górka, Yaroslav Bezyk and Izabela Sówka
Energies 2021, 14(24), 8259; https://doi.org/10.3390/en14248259 - 8 Dec 2021
Cited by 7 | Viewed by 2370
Abstract
Landfills have been identified as one of the major sources of greenhouse gas (GHG) emissions and as a contributor to climate change. Landfill facilities exhibit considerable spatial and temporal variability of both methane (CH4) and carbon dioxide (CO2) rates. [...] Read more.
Landfills have been identified as one of the major sources of greenhouse gas (GHG) emissions and as a contributor to climate change. Landfill facilities exhibit considerable spatial and temporal variability of both methane (CH4) and carbon dioxide (CO2) rates. The present work aimed to evaluate the spatial distribution of CH4 and CO2 and their δ13C isotopic composition originating from a municipal landfill site, to identify its contribution to the local GHG budget and the potential impact on the air quality of the immediate surroundings in a short-term response to environmental conditions. The objective was met by performing direct measurements of atmospheric CO2 and CH4 at the selected monitoring points on the surface and applying a binary mixing model for the determination of carbon isotopic ratios in the vicinity of the municipal waste landfill site. Air samples were collected and analysed for isotopic composition using flask sampling with a Picarro G2201-I Cavity Ring-Down Spectroscopy (CRDS) technique. Kriging and Inverse distance weighting (IDW) methods were used to evaluate the values at unsampled locations and to map the excess of GHGs emitted from the landfill surface. The large off-site dispersion of methane from the landfill site at a 500 m distance was identified during field measurements using isotopic data. The mean δ13C of the landfill biogas emitted to the surrounded atmosphere was −53.9 ± 2.2‰, which corresponded well to the microbial degradation processes during acetate fermentation in the waste deposits. The calculated isotopic compositions of CO2 (δ13C = −18.64 ± 1.75‰) indicate the domination of biogenic carbon reduction by vegetation surrounding the landfill. Finally, amounts of methane escaping into the air can be limited by the appropriate landfill management practices (faster covers active quarter through separation layer), and CH4 reduction can be achieved by sealing the cover on the leachate tank. Full article
(This article belongs to the Special Issue Modelling and Calculation of Raw Material Industry)
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16 pages, 1110 KiB  
Article
Characteristics of Waste Generated in Dimension Stone Processing
by Paweł Strzałkowski
Energies 2021, 14(21), 7232; https://doi.org/10.3390/en14217232 - 2 Nov 2021
Cited by 6 | Viewed by 3594
Abstract
Natural dimension stone processing generates large volumes of stone waste, which have a significant impact on the environment, as well as on the efficiency and profitability of the stone-processing plant. The article presents the characteristics of waste produced as a result of natural [...] Read more.
Natural dimension stone processing generates large volumes of stone waste, which have a significant impact on the environment, as well as on the efficiency and profitability of the stone-processing plant. The article presents the characteristics of waste produced as a result of natural dimension stone processing and the structure of the waste production process. Solid stone scraps and sludge were distinguished. On the basis of the performed analyses, it was shown that stone waste constitutes 10–35% in relation to the quantity of the processed stone material, with the quantity of sludge being even threefold greater than the volume of solid scraps. According to the circular economy principles, the aim should be to reduce the amount of waste generated by reducing primary resources in favour of secondary material. Reducing the volume of stone waste is possible through rational planning of stone production while at the same time maximising the efficiency of stone material usage and introducing the most modern processing machines. This significant volume of stone waste encourages efforts to find solutions for both its management and reduction. This paper reviews the utility potential of stone waste. Sensible use of waste is important to increase the profitability and productivity of processing plants while incentivising environmental protection. Full article
(This article belongs to the Special Issue Modelling and Calculation of Raw Material Industry)
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19 pages, 4401 KiB  
Article
Discrete Simulations in Analyzing the Effectiveness of Raw Materials Transportation during Extraction of Low-Quality Deposits
by Zbigniew Krysa, Przemysław Bodziony and Michał Patyk
Energies 2021, 14(18), 5884; https://doi.org/10.3390/en14185884 - 17 Sep 2021
Cited by 6 | Viewed by 1411
Abstract
The article presents an analysis of the influence of selected operating environment parameters on the operation of a technological system in a mine and examines the profitability of exploiting a deposit of low quality. A model based on a cyclical transportation system in [...] Read more.
The article presents an analysis of the influence of selected operating environment parameters on the operation of a technological system in a mine and examines the profitability of exploiting a deposit of low quality. A model based on a cyclical transportation system in a surface limestone mine, developed in the Haulsim software, served to evaluate—from an economic perspective—several material transportation scenarios depending on the quality of the deposit. A discrete simulation of machine operation allowed a detailed analysis of the technological, operating and economic parameters for selected solutions. The results may be the basis for a decision to begin or to resign from mineral extraction. The simulation results demonstrate that maintaining the operating environment in good technical condition positively influences machine operating cycle times, the required total time of the transportation task and the operating costs. The analysis was performed for the production period of one full year, allowing for the effective work and technological downtimes. This approach allowed the usefulness of the model to be demonstrated in evaluating not only the effectiveness of individual technological procedures but also its economic aspect, related to a decision on the exploitation of “difficult” deposits. Full article
(This article belongs to the Special Issue Modelling and Calculation of Raw Material Industry)
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12 pages, 3738 KiB  
Article
Dynamic Analysis for the Hydraulic Leg Power of a Powered Roof Support
by Dawid Szurgacz
Energies 2021, 14(18), 5715; https://doi.org/10.3390/en14185715 - 10 Sep 2021
Cited by 14 | Viewed by 1809
Abstract
This paper presents the results of a study conducted to determine the dynamic power of a hydraulic leg. The hydraulic leg is the basic element that maintains the position of a powered roof support. It is located in the structure between the canopy [...] Read more.
This paper presents the results of a study conducted to determine the dynamic power of a hydraulic leg. The hydraulic leg is the basic element that maintains the position of a powered roof support. It is located in the structure between the canopy and the floor base. The analysis assumes that its power must be greater than the energy of the impact of the rock mass. The energy of the rock mass is generated by tremors caused mainly by mining exploitation. The mining and geological structure of the rocks surrounding the longwall complex also have an influence on this energy generation. For this purpose, stationary tests of the powered roof support were carried out. The analysis refers to the space under the piston of the leg, which is filled with fluid at a given pressure. The bench test involved spreading the leg in the test station under a specified pressure. It was assumed that the acquisition of dynamic power would be at the point of pressure and increase in the space under the piston of the leg under forced loading. Based on the experimental studies carried out, an assessment was made with the assumptions of the methodology adopted. The results of the theoretical analysis showed consistency with the experimental results. Full article
(This article belongs to the Special Issue Modelling and Calculation of Raw Material Industry)
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22 pages, 3994 KiB  
Article
Gasification of Coal by CO2: The Impact of the Heat Transfer Limitation on the Progress, Reaction Rate and Kinetics of the Process
by Krzysztof M. Czajka
Energies 2021, 14(17), 5569; https://doi.org/10.3390/en14175569 - 6 Sep 2021
Cited by 5 | Viewed by 1703
Abstract
This paper presents the impact of thermal lag on the progress of different coal types’ gasification by CO2. The analysis was performed using thermogravimetry and numerical modeling. Experiments were carried out at a heating rate of 1–50 Kmin−1 and a [...] Read more.
This paper presents the impact of thermal lag on the progress of different coal types’ gasification by CO2. The analysis was performed using thermogravimetry and numerical modeling. Experiments were carried out at a heating rate of 1–50 Kmin−1 and a temperature ranging from 383 to 1173 K. The developed numerical model enabled the determination of a true sample temperature considering the gasification process to consist of two single-step consecutive reactions. Analysis revealed that the average thermal lag in CO2 is about 11% greater than that in N2, which is related to the properties of CO2 itself and the occurrence of the char–CO2 reaction. The onset temperature of the reverse Boudouard reaction depends on the type of fuel; however, no simple relationship with the coal rank was found. Thermal lag has an impact on the kinetic parameter Aα0.5 describing devolatilization, up to 19.8%, while in the case of the char–CO2 reaction, this influence is expected to be even greater. The performed analysis proved that disregarding thermal lag may significantly hinder the interpretation of the analyzed processes; thus, TG experiments should be carried out with a low heating rate, or at the post-processing stage, a thermal lag model needs to be employed. Full article
(This article belongs to the Special Issue Modelling and Calculation of Raw Material Industry)
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18 pages, 2984 KiB  
Article
Cascade Membrane System for Separation of Water and Organics from Liquid By-Products of HTC of the Agricultural Digestate—Evaluation of Performance
by Agnieszka Urbanowska, Małgorzata Kabsch-Korbutowicz, Christian Aragon-Briceño, Mateusz Wnukowski, Artur Pożarlik, Lukasz Niedzwiecki, Marcin Baranowski, Michał Czerep, Przemysław Seruga, Halina Pawlak-Kruczek, Eduard Bramer and Gerrit Brem
Energies 2021, 14(16), 4752; https://doi.org/10.3390/en14164752 - 5 Aug 2021
Cited by 5 | Viewed by 2031
Abstract
New regulations aimed at curbing the problem of eutrophication introduce limitations for traditional ways to use the by-product of anaerobic digestion—the digestate. Hydrothermal carbonisation (HTC) can be a viable way to valorise the digestate in an energy-efficient manner and at the same time [...] Read more.
New regulations aimed at curbing the problem of eutrophication introduce limitations for traditional ways to use the by-product of anaerobic digestion—the digestate. Hydrothermal carbonisation (HTC) can be a viable way to valorise the digestate in an energy-efficient manner and at the same time maximise the synergy in terms of recovery of water, nutrients, followed by more efficient use of the remaining carbon. Additionally, hydrothermal treatment is a feasible way to recirculate recalcitrant process residues. Recirculation to anaerobic digestion enables recovery of a significant part of chemical energy lost in HTC by organics dissolved in the liquid effluent. Recirculating back to the HTC process can enhance nutrient recovery by making process water more acidic. However, such an effect of synergy can be exploited to its full extent only when viable separation techniques are applied to separate organic by-products of HTC and water. The results presented in this study show that using cascade membrane systems (microfiltration (MF) → ultrafiltration (UF) → nanofiltration (NF)), using polymeric membranes, can facilitate such separation. The best results were obtained by conducting sequential treatment of the liquid by-product of HTC in the following membrane sequence: MF 0.2 µm → UF PES 10 → NF NPO30P, which allowed reaching COD removal efficiency of almost 60%. Full article
(This article belongs to the Special Issue Modelling and Calculation of Raw Material Industry)
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21 pages, 16369 KiB  
Article
3D Spatial Analysis of Particulate Matter (PM10, PM2.5 and PM1.0) and Gaseous Pollutants (H2S, SO2 and VOC) in Urban Areas Surrounding a Large Heat and Power Plant
by Robert Cichowicz and Maciej Dobrzański
Energies 2021, 14(14), 4070; https://doi.org/10.3390/en14144070 - 6 Jul 2021
Cited by 13 | Viewed by 2404
Abstract
In many regions of the world, the winter period is a time of poor air quality, due primarily to the increased use of individual and district heating systems. As a consequence, the atmospheric air contains increased concentrations of both particulate matter and gaseous [...] Read more.
In many regions of the world, the winter period is a time of poor air quality, due primarily to the increased use of individual and district heating systems. As a consequence, the atmospheric air contains increased concentrations of both particulate matter and gaseous pollutants (as a result of “low” emissions at altitudes of up to 40 m and “high” emissions more than 40 m above ground level). In winter, the increased pollution is very often exacerbated by meteorological conditions, including air temperature, pressure, air speed, wind direction, and thermal inversion. Here, we analyze the concentrations of particulate matter (PM10, PM2.5, and PM1.0) and gaseous pollutants (H2S, SO2, and VOC) in the immediate vicinity of a large solid fuel-fired heat and power plant located in an urban agglomeration. Two locations were selected for analysis. The first was close to an air quality measurement station in the center of a multi-family housing estate. The second was the intersection of two main communication routes. To determine the impact of “low” and “high” emissions on air quality, the selected pollutants were measured at heights of between 2 and 50 m using an unmanned aerial vehicle. The results were compared with permissible standards for the concentration of pollutants. Temperature inversion was found to have a strong influence on the level of pollutants at various heights, with higher concentrations of particulate matter registered at altitudes above 40 m. The source of PM, H2S, and SO2 pollutants was confirmed to be “low emission” from local transport, industrial plant areas, and the housing estate comprising detached houses located in the vicinity of the measuring points. “High emission” was found to be responsible for the high concentrations of VOC at altitudes of more than 40 m above the intersection and in the area of the housing estate. Full article
(This article belongs to the Special Issue Modelling and Calculation of Raw Material Industry)
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11 pages, 2230 KiB  
Article
Generating of Electric Energy by a Declined Overburden Conveyor in a Continuous Surface Mine
by Witold Kawalec and Robert Król
Energies 2021, 14(13), 4030; https://doi.org/10.3390/en14134030 - 4 Jul 2021
Cited by 14 | Viewed by 2170
Abstract
Exploitation of lignite in continuous surface mines requires removing masses of overburden, which are hauled to a dumpsite. There are some technological arrangements where the overburden is transported several dozen meters down to a spreader operating on a lower located dumping level. Depending [...] Read more.
Exploitation of lignite in continuous surface mines requires removing masses of overburden, which are hauled to a dumpsite. There are some technological arrangements where the overburden is transported several dozen meters down to a spreader operating on a lower located dumping level. Depending on an angle of a declined transportation route, there is a possibility to convert the potential gravitational energy of conveyed down overburden masses into electric energy. To recover the maximum percentage of stored energy, an energy-effective and fully loaded belt conveyor should work in a generator mode. Due to the implementation of such a solution, a lignite continuous surface mine, which is a great electric energy consumer, can obtain the status of an electricity prosumer and reduce its environmental impact, in particular demonstrating significant savings in primary energy consumption. Though lignite surface mining is phasing out in Europe, the recuperative, overburden conveyors for downhill transport match up the targets of sustainable mining, understood as getting the maximum benefits from the exploited natural resources. According to the analyzed case study, an investment into the installation of regenerative inverters for the electric power supply of the declined overburden conveyor would pay off within 3–4 years. Full article
(This article belongs to the Special Issue Modelling and Calculation of Raw Material Industry)
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12 pages, 4007 KiB  
Article
Removal of Zn(II) and Mn(II) by Ion Flotation from Aqueous Solutions Derived from Zn-C and Zn-Mn(II) Batteries Leaching
by Agnieszka Sobianowska-Turek, Katarzyna Grudniewska, Paweł Maciejewski and Małgorzata Gawlik-Kobylińska
Energies 2021, 14(5), 1335; https://doi.org/10.3390/en14051335 - 1 Mar 2021
Cited by 4 | Viewed by 1943
Abstract
The Zn(II) and Mn(II) removal by an ion flotation process from model and real dilute aqueous solutions derived from waste batteries was studied in this work. The research aimed to determine optimal conditions for the removal of Zn(II) and Mn(II) from aqueous solutions [...] Read more.
The Zn(II) and Mn(II) removal by an ion flotation process from model and real dilute aqueous solutions derived from waste batteries was studied in this work. The research aimed to determine optimal conditions for the removal of Zn(II) and Mn(II) from aqueous solutions after acidic leaching of Zn-C and Zn-Mn waste batteries. The ion flotation process was carried out at ambient temperature and atmospheric pressure. Two organic compounds used as collectors were applied, i.e., m-dodecylphosphoric acid 32 and m-tetradecylphosphoric 33 acid in the presence of a non-ionic foaming agent (Triton X-100, 29). It was found that both compounds can be used as collectors in the ion flotation for Zn(II) and Mn(II) removal process. Process parameters for Zn(II) and Mn(II) flotation have been established for collective or selective removal metals, e.g., good selectivity coefficients equal to 29.2 for Zn(II) over Mn(II) was achieved for a 10 min process using collector 32 in the presence of foaming agent 29 at pH = 9.0. Full article
(This article belongs to the Special Issue Modelling and Calculation of Raw Material Industry)
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14 pages, 1473 KiB  
Article
Application of the Mechanical and Pressure Drop Tests to Determine the Sintering Temperature of Coal and Biomass Ash
by Karol Król and Dorota Nowak-Woźny
Energies 2021, 14(4), 1126; https://doi.org/10.3390/en14041126 - 20 Feb 2021
Cited by 7 | Viewed by 1570
Abstract
The aim of this paper is to investigate the mechanical properties of coal and biomass ash during the sintering process. For this study, bituminous coal, lignite, wheat straw, barley straw, and rye straw were selected. The proximate, ultimate, and oxide analyses were performed. [...] Read more.
The aim of this paper is to investigate the mechanical properties of coal and biomass ash during the sintering process. For this study, bituminous coal, lignite, wheat straw, barley straw, and rye straw were selected. The proximate, ultimate, and oxide analyses were performed. The ash from these fuels was prepared in a special way that ensured the physicochemical invariability of the initial state of the mineral matter of coal and biomass. The purpose of this selection was to obtain widely available and clearly diversified materials. Based on the results of ash composition and ultimate analysis the most common ash deposition, indices were determined. Certain conflict of index indications was observed. Then, the mechanical test and pressure drop test were performed. During the mechanical test, the fracture stress as a function of sintering temperature was measured. During the pressure drop test, the pressure before and behind the sample was measured as a function of sintering temperature. Both tests showed that the characteristic changes (the occurrence of a maximum on the pressure drop curve and the inflection point at the mechanical curve) dependencies were at nearly the same temperatures. These results were compared with the initial deformation temperature (IDT) from the standard Leitz method. A linear relationship between sintering temperatures determined by the mechanical test, pressure drop test, and IDT Leitz test was obtained. The obtained results are promising in terms of the application of the mechanical methods (fracture stress test and pressure drop test) as methods of the early stage prediction of slagging/fouling risks. Full article
(This article belongs to the Special Issue Modelling and Calculation of Raw Material Industry)
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11 pages, 3340 KiB  
Article
Energy-Saving Inertial Drive for Dual-Frequency Excitation of Vibrating Machines
by Volodymyr Gursky, Igor Kuzio, Pavlo Krot and Radoslaw Zimroz
Energies 2021, 14(1), 71; https://doi.org/10.3390/en14010071 - 25 Dec 2020
Cited by 14 | Viewed by 2324
Abstract
The low energy efficiency and excessive power of electric motors of large-scale vibrating machines for processing bulk materials motivated a new design of the inertial drive. This drive consists of one motor and two coaxial unbalanced masses, whose rotational frequencies are related in [...] Read more.
The low energy efficiency and excessive power of electric motors of large-scale vibrating machines for processing bulk materials motivated a new design of the inertial drive. This drive consists of one motor and two coaxial unbalanced masses, whose rotational frequencies are related in the ratio 2:1. This approach allows for a generation of the excitation force with variable amplitude and frequency, which changes depending on the inertial characteristics and shaft rotation frequency and does not relate to the phase difference of the unbalanced masses. Because of this, the symmetry axis of the resulting vector hodograph can be changed. The spectral composition of the exciting force up to 200 Hz contains higher harmonics, the energy share of which is 25.4% from the 2nd harmonic and 14.1% from the 3rd and higher harmonics that correspondingly improves bulk material treatment in comparison to single-frequency vibrators. The finite element model is used for checking the strength capacity of the most loaded units of a dual-frequency drive. Its use allows the realization of complex trajectories of motion that are more technologically efficient for variable parameters of the treated media and energy saving in sieving screens and other vibrating machines. Full article
(This article belongs to the Special Issue Modelling and Calculation of Raw Material Industry)
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15 pages, 10032 KiB  
Article
Investigation of the Physico-Chemical Properties of the Products Obtained after Mixed Organic-Inorganic Leaching of Spent Li-Ion Batteries
by Weronika Urbańska and Magdalena Osial
Energies 2020, 13(24), 6732; https://doi.org/10.3390/en13246732 - 20 Dec 2020
Cited by 10 | Viewed by 2645
Abstract
Lithium-ion batteries are currently one of the most important mobile energy storage units for portable electronics such as laptops, tablets, smartphones, etc. Their widespread application leads to the generation of large amounts of waste, so their recycling plays an important role in environmental [...] Read more.
Lithium-ion batteries are currently one of the most important mobile energy storage units for portable electronics such as laptops, tablets, smartphones, etc. Their widespread application leads to the generation of large amounts of waste, so their recycling plays an important role in environmental policy. In this work, the process of leaching with sulfuric acid for the recovery of metals from spent Li-ion batteries in the presence of glutaric acid and hydrogen peroxide as reducing agents is presented. Experimental results indicate that glutaric-acid application improves the leaching performance compared to the use of just hydrogen peroxide under the same conditions. Obtained samples of leaching residues after mixed inorganic-organic leaching were characterized with Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy, and X-ray diffraction. Full article
(This article belongs to the Special Issue Modelling and Calculation of Raw Material Industry)
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Review

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Review
Non-Destructive Diagnostic Methods for Fire-Side Corrosion Risk Assessment of Industrial Scale Boilers, Burning Low Quality Solid Biofuels—A Mini Review
by Tomasz Hardy, Amit Arora, Halina Pawlak-Kruczek, Wojciech Rafajłowicz, Jerzy Wietrzych, Łukasz Niedźwiecki, Vishwajeet and Krzysztof Mościcki
Energies 2021, 14(21), 7132; https://doi.org/10.3390/en14217132 - 1 Nov 2021
Cited by 8 | Viewed by 2549
Abstract
The use of low-emission combustion technologies in power boilers has contributed to a significant increase in the rate of high-temperature corrosion in boilers and increased risk of failure. The use of low quality biomass and waste, caused by the current policies pressing on [...] Read more.
The use of low-emission combustion technologies in power boilers has contributed to a significant increase in the rate of high-temperature corrosion in boilers and increased risk of failure. The use of low quality biomass and waste, caused by the current policies pressing on the decarbonization of the energy generation sector, might exacerbate this problem. Additionally, all of the effects of the valorization techniques on the inorganic fraction of the solid fuel have become an additional uncertainty. As a result, fast and reliable corrosion diagnostic techniques are slowly becoming a necessity to maintain the security of the energy supply for the power grid. Non-destructive testing methods (NDT) are helpful in detecting these threats. The most important NDT methods, which can be used to assess the degree of corrosion of boiler tubes, detection of the tubes’ surface roughness and the internal structural defects, have been presented in the paper. The idea of the use of optical techniques in the initial diagnosis of boiler evaporators’ surface conditions has also been presented. Full article
(This article belongs to the Special Issue Modelling and Calculation of Raw Material Industry)
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