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Number of results: 11
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Abstract

The exploitation and processing of lignite in the Bełchatów region is connected with the formation of various mineral waste materials: varied in origin, mineral and chemical composition and raw material properties of the accompanying minerals, ashes and slags from lignite combustion and reagipsum from wet flue gas desulphurisation installations. This paper presents the results of laboratory tests whose main purpose was to obtain data referring to the potential use of fly ashes generated in the Bełchatów Power Plant and selected accompanying minerals exploited in the Bełchatów Mine in the form of self-solidification mixtures. The beidellite clays were considered as the most predisposed for use from the accompanying minerals , due to pozzolanic and sorption properties and swelling capacity. Despite the expected beneficial effects of clay minerals from the smectite group on the self-settling process as well as the stability of such blends after solidification, the results of physical-mechanical tests (compressive strength and water repellence) were unsatisfactory. It was necessary to use Ca (OH)2, obtained from the lacustrine chalk as an activator of the self-settling process It was necessary to use lacustrine chalk as an activator of the self-solidification process. The presence of calcium will allow the formation of cement phases which will be able to strongly bond the skeletal grains. Also, the addition of reagipsum to the composition of the mixture would contribute to the improvement of the physico-mechanical parameters. The elevated SO4 2– ion in the mixture during the solidification allows for the crystallization of the sulphate phases in the pore space to form bridges between the ash and clay minerals. The use of mixtures in land reclamation unfavourably transformed by opencast mining in the Bełchatów region would result in measurable ecological and economic benefits and would largely solve the problem of waste disposal from the from the operation and processing of lignite energy.

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Authors and Affiliations

Elżbieta Hycnar
Marek Waldemar Jończyk
Tadeusz Ratajczak
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Abstract

The problem of of the use of fly ash still constitutes a research and exploration area for scientists. This is due to the fact that, 6,000,000 Mg of coal combustion by-products (CCB) are storage on landfills yearly in Poland alone. One of the potential directions of using fly ash is to use it as a substrate in hydrothermal syntheses of mesoporous materials (synthetic zeolites). Zeolites are aluminosilicates with a spatial structure. Due to their specific structure they are characterized by a number of specific properties among others molecular-sieve, ion-exchange and catalytic that can be used in engineering and environmental protection. So far, the synthesis has been carried out using coal combustion by-products such as fly ash or microsphere. The article analyzes whether separation from the fly ash of the appropriate fraction (below 63 μm) will affect the formation of zeolite grains. The syntheses were carried out using class F fly ash and the fraction separated from it, which was obtained by sieving the ash through a 63 μm sieve. Chemical (XRF) and mineralogical (XRD, SEM-EDS) analyzes were carried out for substrates as well as the obtained reaction products. In the case of substrates, the analysis did not show any significant differences between the ash and the separated fraction. However, in products after synthesis (Na-X zeolite with a small amount of Na-P1 zeolite, and small amounts of quartz and unreacted aluminosilicate glass - mullite) higher aluminum and sodium contents were observed from the separated fraction, with a lower calcium and potassium content. A small proportion of illite was observed on the diffraction curve of the zeolite from the fraction. Observations of grain morphology showed no differences in formation. Based on the conducted analyzes, it can be stated that, considering the economics of the synthesis process, the separation of fine fractions from the fly ash does not affect the quality of the synthesis process.

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Authors and Affiliations

Dorota Czarna-Juszkiewicz
Piotr Kunecki
Rafał Panek
Magdalena Wdowin
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Abstract

Mine drainage and discharge of salt waters into water bodies belong to main environmental issues, which must be appropriately addressed by the underground coal mining industry. The large area of exploited and abandoned mine fields in the Upper Silesia Coal Basin, as well as the geological structure of the rock mass and its hydrogeological conditions require the draining and discharge of about 119 million m3/yr of mine waters. Increasing the depth of mining and the necessity of protection of mines against water hazard result in increased amounts of chlorides and sulphates in the mine waters, even by decreasing the total coal output and the number of mines. The majority of the salts are being discharged directly into rivers, partly under control of salt concentration, however from the point of the view of environment protection, the most favorable way of their utilization would be technologies allowing the bulk use of saline waters. Filling of underground voids represents a group of such methods, from which the filling of goaves (cavings) is the most effective. Due to large volume of voids resulting from the extraction of coal and taking the numerous limitations of this method into account, the potential capacity for filling reaches about 17.7 million m3/yr of cavings and unnecessary workings. Considering the limited availability of fly ash, which is the main component of slurries being in use for the filling of voids, the total volume of saline water and brines, which could be utilized, has been assessed as 3,5–6,5 million m3/yr

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Authors and Affiliations

Grzegorz Strozik
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Abstract

Power production is the largest source of emissions of anthropogenic carbon dioxide. The main fuels in Poland are solid fuels - hard coal and lignite. Their combustion produces large quantities of waste, primarily fly ash. The ashes from lignite, due to the chemical and phase composition, and thus their properties, have - so far - limited economic use. Among their possible applications is the use of mineral sequestration of carbon dioxide - this is the result of their relatively high content of active CaO and MgO, which can react with carbon dioxide in aqueous suspensions. The paper presents maximum theoretical capacity of CO2 bonding for examined fly ashes and the results of the research on absorption of CO2 by the ash-water suspensions from fly ash resulting from the combustion of lignite from Pątnów and Turów power plants. Calculated for the examined fly ashes maximum theoretical capacity of CO2 bonding amounted to 14% for the ashes from Pątnów power plant and 14.4% for the fly ashes from Turów power plant. Studies have shown that most CO2 - 8.15 g/100 g of ash, was absorbed by suspension with ashes from Turów power plant with a mass ratio of ash to water of at 0.8:1. In the case of ash from Pątnów power plant absorption was lower and amounted to a maximum - 8.7 g CO2/100 g ash. The largest increase CO2 absorption was observed in the first 30 minutes of carbonation in the suspensions of fly ash from Pątnów power plant and the first 15 minutes in suspensions of fly ash from Turów power plant. After this time, the absorption has increased slowly. An increase in temperature in the chamber system, confirming the occurrence of the process of carbonation and its endothermic character. The highest temperature - 44.8 C recorded in the suspension with ashes from Turów power plant, which has also the greatest absorption of CO2. The results confirm the usefulness of these ashes to sequester carbon dioxide.

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Authors and Affiliations

Alicja Uliasz-Bocheńczyk
Marek Gawlicki
Radosław Pomykała
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Abstract

The use of biomass in the energy industry is the consequence of ongoing efforts to replace Energy from fossil fuels with energy from renewable sources. However, due to the diversity of the biomass, its use as a solid fuel generates waste with diverse and unstable chemical composition. Waste from biomass combustion is a raw material with a very diverse composition, even in the case of using only one type of biomass. The content of individual elements in fly ash from the combustion of biomass ranges from zero to tens of percent. This makes it difficult to determine the optimal recovery methods. The ashes from the combustion of biomass are most commonly used in the production of building materials and agriculture. This article presents the elemental composition of the most commonly used biomass fuels. The results of the analysis of elemental composition of fly ashes from the combustion of forest and agricultural biomass in fluidized bed boilers used in the commercial power industry were presented. These ashes are characterized by a high content of calcium (12.3–19.4%), silicon (1.2–8.3%), potassium (0.05–1.46%), chlorine (1.1–6.1%), and iron (0.8–6.5%). The discussed ashes contained no sodium. Aluminum was found only in one of the five ashes. Manganese, chromium, copper, nickel, lead, zinc, sulfur, bismuth, titanium and zirconium were found in all of the examined ashes. The analysis of elemental composition may allow for a preliminary assessment of the recovery potential of a given ash.

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Authors and Affiliations

Alicja Uliasz-Bocheńczyk
ORCID: ORCID
Eugeniusz Mokrzycki
ORCID: ORCID
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Abstract

W artykule zbadano możliwość wykorzystania popiołów lotnych klasy C (otrzymywanych w wyniku spalania węgla brunatnego w kotle pyłowym) i F (otrzymywanych w wyniku spalania węgla kamiennego metodą konwencjonalną) jako substratów do syntezy materiału zeolitowego z grupy filipsytu. W tym celu przeprowadzono szereg syntez hydrotermalnych z wykorzystaniem reagentów takich jak wodorotlenek sodu (NaOH) oraz bromek tetrapropyloamoniowy (TPABr). W wyniku reakcji otrzymano docelowy materiał zeolitowy, zarówno z popiołu klasy C, jak i F. Otrzymane produkty syntezy, jak też popiołowe substraty reakcji, poddano charakterystyce chemicznej i mineralogicznej. Badania wykazały, że popiół lotny powstały z węgla brunatnego i kamiennego może być substratem w reakcjach syntez zeolitu, jakim jest filipsyt. Analiza porównawcza dyfraktogramów rentgenowskich produktów z obu typów popiołów wykazała, że lepszym substratem jest popiół klasy C otrzymywany w wyniku spalania węgla brunatnego w kotle pyłowym (w reakcji syntezy otrzymano lepiej wykształcone formy zeolitowe). W pracy dokonano także analizy literaturowej potencjalnych kierunków zastosowania filipsytu w inżynierii i ochronie środowiska. Na podstawie zweryfikowanych danych stwierdzono, iż dalszym kierunkiem badań będzie analiza możliwości wykorzystania otrzymanych materiałów jako potencjalnych sorbentów amoniaku.
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Authors and Affiliations

Rafał Panek
Magdalena Wdowin
Piotr Kunecki
Justyna Cader
Dorota Czarna
Jarosław Madej
Patrycja Lipiec
Wojciech Franus
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Abstract

The cenospheres are formed during the mineral transformation stage in coal combustion. Their content in fly ashes from the combustion of different types of coals varies over a rather wide range from 0.01 to 35.6 wt.%. The cenospheres has three main elements, silicon, aluminium and iron, the oxides of which account for about 89% of the material. Mineralogical analysis using XRD shows that as-received cenospheres mainly contain mullite and quartz as main mineralogical phases. The size of cenospheres varies between 5 and 500 [...], as the most common dimension is 20-300 [...]. The cenospheres are characterized by a low bulk density (0.2-0.8 g/cm3) and can be easily separated by gravitational methods in the form of a concentrate in aqueous media or collected from a water surface of lagoons intended for storage of ash and slag waste. The unique properties of these hollow microspheres make them amenable for wide applications. For example the cenospheres can be used to produce various lightweight construction products, including lightweight cements and aggregates in lightweight concrete.

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Authors and Affiliations

Elżbieta Haustein
Bernard Quant
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Abstract

The issue of mercury emission and the need to take action in this direction was noticed in 2013 via the Minamata Convention. Therefore, more and more often, work and new law regulations are commencing to reduce this chemical compound from the environment. The paper presents the problem of removing mercury from waste gases due to new BREF/BAT restrictions, in which the problem of the need to look for new, more efficient solutions to remove this pollution was also indicated. Attention is paid to the problem of the occurrence of mercury in the exhaust gases in the elemental form and the need to carry out laboratory tests. A prototype installation for the sorption of elemental mercury in a pure gas stream on solid sorbents is presented. The installation was built as part of the LIDER project, financed by the National Center for Research and Development in a project entitled: “The Application of Waste Materials From the Energy Sector to Capture Mercury Gaseous Forms from Flue Gas”. The installation is used for tests in laboratory conditions in which the carrier gas of elemental mercury is argon. The first tests on the zeolite sorbent were made on the described apparatus. The tested material was synthetic zeolite X obtained as a result of a two-stage reaction of synthesis of fly ash type C with sodium hydroxide. Due to an increase, the chemical affinity of the tested material in relation to mercury, the obtained zeolite material was activated with silver ions (Ag+) by an ion exchange using silver nitrate (AgNO3). The first test was specified for a period of time of about 240 minutes. During this time, the breakthrough of the tested zeolite material was not recorded, and therefore it can be concluded that the tested material may be promising in the development of new solutions for capturing mercury in the energy sector. The results presented in this paper may be of interest to the energy sector due to the solution of several environmental aspects. The first of them is mercury sorption tests for the development of new exhaust gases treatment technologies. On the other hand, the second aspect raises the possibility of presenting a new direction for the management and utilization of combustion by-products such as fly ash.

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Authors and Affiliations

Piotr Kunecki
Dorota Czarna-Juszkiewicz
Rafał Panek
Magdalena Wdowin
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Abstract

Strength and permeability properties along with microstructural evolution of hardened slurries composed of fly ash from fluidal bed combustion of brown coal and an addition of OPC/BFSC is assessed in this paper. An increase in the amount of fly ash in slurries influences the development of mechanical strength and a decrease of hydraulic conductivity. SEM, XRD, and porosity analyses confirmed formation of watertight microstructures. The structure of slurries is composed of ettringite, C-S-H phase, AFt, and AFm phases. Ettringite crystallises as relatively short needles forming compact clusters or intermixed with the C-S-H phase. The occurring C-S-H phases are mainly of type I – fibrous and type II – honeycomb

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Authors and Affiliations

Z. Kledyński
P. Falaciński
A. Machowska
J. Dyczek
Ł. Kotwica
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Abstract

The introduction of the sustainable development elements in the construction industry leads to finding new ways of using waste minerals that are difficult in storage and recycling. Coal combustion products have been already introduced into building materials as a part of cement or concrete but they have been thought insufficiently compatible with the polymer-cement binders [7]. The paper presents results of the mechanical properties of polymer-cement composites containing two types of mineral additives: waste perlite powder that is generated during the perlite expanding process, and calcium fly ash which is the byproduct of burning coal in conventional furnaces. Mechanical tests of polymer-cement composites modified with wastes were carried out after 28 and 90 days of curing. As a part of preliminary study specific surface area and particle size distribution of mineral wastes were determined.

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Authors and Affiliations

B. Jaworska
J.J. Sokołowska
P. Łukowski
J. Jaworski
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Abstract

The durability characteristics of Engineered Cementitious Composites (ECC) with various fibers such as polypropylene and glass were investigated in view of developing composites with high resistance to cracking. ECC offer large potential for durable civil infrastructure due to their high tensile strain capacity and controlled micro-crack width. In this study, fibre volume fractions (0.5%, 1%, 1.5%, and 2%) of both polypropylene and glass fibers varied and durability measures such as a rapid chloride penetration test, sorptivity, water absorption, acid attack, and sulphate attack were measured. Increasing the fiber content up to 1.5% improved the durability properties of ECC. The test results indicate that the glass fiber-reinforced Engineered Cementitious Composites have better durability characteristics than polypropylene fiber-reinforced ECC.

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Authors and Affiliations

S. Ranjith
R. Venkatasubramani
V. Sreevidya

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