scholarly journals Evaluation of the Possibility of the Hard Coal Sludge Enrichment by Flotation

Author(s):  
Joanna Całus Moszko ◽  
Krzysztof Wierzchowski ◽  
Agnieszka Klupa

Abstract Coal sludges are the smallest fraction of post-mining waste. Their grain size is less than 1 mm, and most grains have size below 60 μm. These wastes are mainly separated from the water-sludge circulations of the mines. Coal sludges are generally characterized by worse quality parameters in relation to the coal grades produced by mines. The fight against smog and the more stringent provisions in this area make it possible to monitor and control the quality of solid fuels, with particular emphasis on fuels directed for use in households and combustion plants with a rated thermal output of less than 1 MW which eliminated from the municipal and living market the coal sludges and post-flotation wastes containing less than 85% of hard coal, which are nuisance materials in the development process and their separation from the water-sludge circulation and dewatering requires many technological operations. The publication presents results of laboratory tests on the determination of conditions and possibilities of coal recovery from thermal coal sludges with an ash content of about 64%, using the froth flotation method. The experiments were conducted using a single operation method (fractional flotation) and a multiple operation method (main flotation, cleaning flotation). The tests were carried out using three types of the flotation reagents: standard (reference): ON MBIC (mixture consisting of diesel oil ON and 2-ethylhexanol OKT), specialized: Centroflot and proprietary: Klim III (non-ionic surfactants, auxiliary agents in a form of block copolymer of propylene and ethylene oxide and wetting additives, 2-ethylhexanol and a mixture of dioxane alcohols) to obtain the optimal concentrate.

Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 644
Author(s):  
Do-Yeong Kim ◽  
Boram Kim ◽  
Han-Seung Shin

The effect of cellulosic aerogel treatments used for adsorption of four polycyclic aromatic hydrocarbons (PAHs)—benzo[a]anthracene, chrysene, benzo[b]fluoranthene, and benzo[a]pyrene [BaP])—generated during the manufacture of sesame oil was evaluated. In this study, eulalia (Miscanthus sinensis var. purpurascens)-based cellulosic aerogel (adsorbent) was prepared and used high performance liquid chromatography with fluorescence detection for determination of PAHs in sesame oil. In addition, changes in the sesame oil quality parameters (acid value, peroxide value, color, and fatty acid composition) following cellulosic aerogel treatment were also evaluated. The four PAHs and their total levels decreased in sesame oil samples roasted under different conditions (p < 0.05) following treatment with cellulosic aerogel. In particular, highly carcinogenic BaP was not detected after treatment with cellulosic aerogel. Moreover, there were no noticeable quality changes in the quality parameters between treated and control samples. It was concluded that eulalia-based cellulosic aerogel proved suitable for the reduction of PAHs from sesame oil and can be used as an eco-friendly adsorbent.


2021 ◽  
Vol 6 (1) ◽  
pp. 22
Author(s):  
Malibongwe S. Manono ◽  
Katlego Matibidi ◽  
Kirsten C. Corin ◽  
Catherine K. Thubakgale ◽  
Iyiola O. Otunniyi ◽  
...  

Inorganic electrolytes present in the process water used during froth flotation may have both beneficial and detrimental effects. These effects are said to be ion specific, as some ions may result in enhanced froth stability, increased mineral recoveries and decreased concentrate grades, while others may bring the opposite effects. Onsite process water quality variations have intensified the need to understand the relationship between inorganic electrolytes and flotation reagents on flotation performance. The use of mixtures of thiol collectors in sulfide flotation is a common practice across the globe; however, very few investigations have considered these in process waters of varying compositions. This study considers the effect of common cations, Na+ and Ca2+, in process water on the behavior of mixtures of thiol collectors. Single-salt solutions of NaCl and CaCl2 at an ionic strength of 0.0213 mol·dm−3 were used to investigate the behavior of mixtures of two thiol collectors. These were carefully selected to understand how mixtures of thiol collectors behave in the presence of a monovalent cation versus a polyvalent cation. Bench-scale froth flotation tests were conducted using a Cu-Ni-PGM ore from the Merensky Reef. The results have shown that the divalent cation, Ca2+, resulted in higher %Cu and %Ni recoveries at all collector mixtures compared to the monovalent cation, Na+. The concentrate grades were, however, slightly compromised, as slightly more gangue reported to the concentrate in the presence of Ca2+. This behavior is attributed to the effect of polyvalent cations on bubble coalescence and froth stability.


2020 ◽  
Author(s):  
D. Yu. Muromtsev ◽  
A. N. Gribkov ◽  
N. Yu. Zalukaeva ◽  
O. A. Belousov ◽  
V. P. Belyaev ◽  
...  

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2416
Author(s):  
Marina Dorokhova ◽  
Fernando Ribeiro ◽  
António Barbosa ◽  
João Viana ◽  
Filipe Soares ◽  
...  

The energy efficiency requirements of most energy-consuming sectors have increased recently in response to climate change. For buildings, this means targeting both facility managers and building users with the aim of identifying potential energy savings and encouraging more energy-responsible behaviors. The Information and Communication Technology (ICT) platform developed in Horizon 2020 FEEdBACk project intends to fulfill these goals by enabling the optimization of energy consumption, generation, and storage and control of flexible devices without compromising comfort levels and indoor air quality parameters. This work aims to demonstrate the real-world implementation and functionality of the ICT platform composed of Load Disaggregation, Net Load Forecast, Occupancy Forecast, Automation Manager, and Behavior Predictor applications. Particularly, the results obtained by individual applications during the test phase are presented alongside the specific metrics used to evaluate their performance.


2020 ◽  
Vol 66 (No. 6) ◽  
pp. 249-256
Author(s):  
Lukáš Hlisnikovský ◽  
Milan Vach ◽  
Zdeněk Abrhám ◽  
Ladislav Mensik ◽  
Eva Kunzová

In the years 2011–2014, winter wheat grain yield, qualitative and economic parameters were evaluated according to different fertiliser treatments: (1) control: unfertilised treatment; (2) farmyard manure (FYM) and (3) FYM + NPK (farmyard manure applied together with mineral NPK). The highest yields (8.10 t/ha) were recorded in the FYM + NPK treatment, while significantly lower yields (6.20 t/ha and 5.73 t/ha) were recorded in FYM and control treatments, respectively. Similarly, statistically significantly higher values of the quality parameters were found in the FYM + NPK treatment (13.55% of crude protein content and 43.56 mL of Zeleny’s sedimentation test), compared to control (10% and 22.44 mL, respectively). The modelling expert system (AGROTEKIS-Crop Technology and Economy) was used for the evaluation of economy. This software is based on technological methods of cultivation and norms of material input costs and costs of individual mechanised works. The economic benefits and profitability were evaluated for three different levels of grain market price. The highest gross profit per ha was recorded in the FYM + NPK treatment. According to the gross profit, the control treatment provided better results than the FYM treatment.


2018 ◽  
Vol 1 (1) ◽  
pp. 361-368
Author(s):  
Dawid Szurgacz ◽  
Jarosław Brodny

Abstract Mining machines suitable for hard coal mining, due to the specifics of this industry must be characterized by very high technical parameters. In particular, it concerns their durability, reliability and availability. Currently used machines approved for operation in underground conditions meet such requirements. Nevertheless, during their operation it is reasonable to conduct supervision and control of work parameters. This applies to both machine manufacturers and users, which is especially important in the event of a failure. Mine employees should be able control of the entire operation process. This control can be effective thanks to a visualization system developed to monitor the working parameters of mining systems. The paper discusses the innovative system and presents the results of efficiency tests. They concerned the visualization of the operation of a powered roof support. The obtained results indicate that the assumed goal of the system has been achieved. The system is built on elements of industrial automation, which guarantees the reliability of the indicated values. Its graphic layout and selection of the presented parameters are also approved. It should also be emphasized that the system can work with currently operating systems and is easy to expand. According to the Authors, the system should find a wide application in practice.


Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 525
Author(s):  
Mirosław Wyszkowski ◽  
Jadwiga Wyszkowska ◽  
Natalia Kordala ◽  
Agata Borowik

Petroleum hydrocarbons, as aggressive components of diesel oils, after migration to the land environment can alter the activity and efficiency of ecosystems. They can also be dangerous to animal and human health. Eco-friendly methods for the reclamation of affected soils is necessary to manage degraded lands. One such method is the use of ashes. The aim of this research was to determine how soil pollution with diesel oil (brand name, Eco-Diesel) affects the chemical composition of maize (Zea mays L.) and whether the application of ash from a combined heat and power plant, as well as from sewage sludge incineration, could reduce the potentially adverse impact of diesel oil on plants. The research results demonstrated that soil contamination with Eco-Diesel oil modified the content of selected macronutrients in the analyzed crop plant. Eco-Diesel oil had a negative effect on maize yield. The highest diesel oil dose in a series without neutralizing substances had a positive effect on the accumulation of most elements, except nitrogen and sodium. Soil enrichment with ash differentiated the content of macronutrients, mainly nitrogen and phosphorus, in the aerial biomass of maize. The ashes increased the yield of maize and content of some macronutrients, mainly nitrogen but also calcium, the latter in a series where soil was treated with ash from sewage sludge thermal recycling. Both types of ash also resulted in a decrease in the plant content of phosphorus, while ash from hard coal caused a slight reduction in the content of potassium in maize. Ash of different origins can be an effective solution in the reclamation of degraded soils, which may then be used for growing energy crops.


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