scholarly journals Editorial for Special Issue “Minerals and Elements from Fly Ash and Bottom Ash as a Source of Secondary Raw Materials”

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 438
Author(s):  
Alexandra Guedes ◽  
Bruno Valentim
Keyword(s):  
Fly Ash ◽  
Raw Materials ◽  
Bottom Ash ◽  
Resource Efficiency ◽  
Special Issue ◽  
Secondary Raw Materials ◽  
Alternative Materials

The sustainability of primary resources depends on recycling, resource efficiency and the search for alternative materials [...]

Porosity Evaluation of Alternative Materials Based on Portland Cement

2014 ◽  
Vol 1000 ◽  
pp. 314-317 ◽  
Author(s):  
Ladislav Pařízek ◽  
Eva Bartoníčková ◽  
Vlastimil Bílek Jr. ◽  
Jiří Kratochvíl
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Coal Combustion ◽  
Mercury Intrusion Porosimetry ◽  
Raw Materials ◽  
High Energy ◽  
Energy Requirements ◽  
Mercury Intrusion ◽  
Secondary Raw Materials ◽  
Alternative Materials

High energy requirements and the resulting economic demands due to the production of Portland cement leads to tendency to replace a portion of cement with secondary raw materials or to use other alternative binders. Among the commonly used cements replacements is currently fly ash which is produced during the coal combustion. In this paper the influence of cement/ash ratio in a paste on paste’s porosity is investigated using mercury intrusion porosimetry.

Silicate Sprayed Mixture Based on Secondary Raw Materials

2019 ◽  
Vol 808 ◽  
pp. 129-135
Author(s):  
Petr Figala ◽  
Rostislav Drochytka ◽  
Radek Hermann ◽  
Jiří Kolísko
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Temperature ◽  
Fly Ash ◽  
Raw Materials ◽  
Positive Influence ◽  
Foundry Sand ◽  
Secondary Raw Materials ◽  
Fundamental Research

This paper studies the fundamental research and development of sprayed cement-based mixture designed to withstand the chemically aggressive conditions. The aim of this paper is to verify the possibilities of usage of suitable secondary raw materials as a substitution of a binder and filler of the original mixture while preserving or improving the physical-mechanical properties. In this part of the research was studied the possibility to substitute the binder in rate of 20-60 wt.% by high temperature fly ash and the whole filler by foundry sand and slag. Test samples were made from nine recipes, in which was monitored the influence of secondary raw materials on the compressive strength and the water absorption after 28 days of curing. The results of this paper show, it is possible to successfully substitute part of the binder by high temperature fly ash and the filler wholly by foundry sand in the sprayed mixture. These optimized recipes showed positive influence mainly in the long-term on mechanical properties.

scholarly journals Possibilities of Use of Isothermal and Isoperibolic Calorimetry to Study the Effect of Zinc on Hydration of Cement Blended with Fly Ash

2020 ◽  
Author(s):  
Pavel Šiler ◽  
Iva Kolářová ◽  
Rdoslav Novotný ◽  
Jiří Másilko ◽  
Jan Bednárek ◽  
...  
Keyword(s):  
Fly Ash ◽  
Alternative Fuels ◽  
Raw Materials ◽  
Alternative Fuel ◽  
Zinc Ions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Secondary Raw Materials ◽  
Isoperibolic Calorimetry ◽  
Poorly Soluble

Increasing utilization of secondary raw materials and alternative fuels results in increasing contents of metals in cements. One of elements, the content of which keeps rising in cement is zinc. It comes to cement with secondary raw materials such as slag or fly ash or by the utilization of used tires as an alternative fuel. Zinc ions significantly prolong the hydration process in cement. This work deals with the influence of zinc ions in the form of very poorly soluble ZnO salt and easily soluble ZnCl2 and Zn(NO)3 on the hydration of cement blended with fly ash. Zinc was dosed in the range of 0.05, 0.1, 0.5 a 1% of cement weight. Final products were next analyzed using X-Ray Diffraction.

scholarly journals Mineral Raw Materials’ Resource Efficiency in Selected ESEE Countries: Strengths and Challenges

2021 ◽  
Vol 5 (1) ◽  
pp. 83
Author(s):  
Stavroula Giannakopoulou ◽  
Fotini Chalkiopoulou ◽  
Katerina Adam
Keyword(s):  
Gap Analysis ◽  
Raw Materials ◽  
Mineral Resources ◽  
Business Environment ◽  
Resource Efficiency ◽  
International Standards ◽  
Raw Material ◽  
Mineral Raw Materials ◽  
Economies In Transition ◽  
Secondary Raw Materials

The mineral raw materials’ resource efficiency is currently recognized in Europe as the way for the future development of the European mining economies. With this aim, a West Balkan Mineral Register was created in the EIT Raw Materials RESEERVE Project, including Primary and Secondary Raw Materials of six Eastern and South-Eastern Europe (ESEE) countries, i.e., Albania, Bosnia and Herzegovina, Croatia, Montenegro, North Macedonia, and Serbia. Within the Project, a Strengths, Weaknesses, Opportunities, and Threats (SWOT) and Gap Analysis was also performed for the development of the raw material sector in the region. This paper summarizes the main strengths to be exploited, i.e., the significant geological potential, the presence of critical raw materials (e.g., Sb, Co, REEs) in primary and secondary raw materials, and the challenges to address, i.e., compliance of resources/reserves classification with international standards, integration of state’s mineral policy with spatial planning strategies, improvement of the business environment, capacity building of the raw materials workforce and enhancement of the public acceptance of the sector, in order to achieve the sustainable development of the mineral resources of the six ESEE countries. These opportunities comply with the objectives of the EU Raw Materials Initiative and are expected to contribute in the further enhancement of those economies in transition for the upcoming years.

Development of Ultra High Performance Concrete Using Fly Ash

2020 ◽  
Vol 987 ◽  
pp. 33-38
Author(s):  
Rudolf Hela ◽  
Lenka Bodnárová
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Experimental Work ◽  
High Performance ◽  
High Performance Concrete ◽  
Raw Materials ◽  
Economic Cost ◽  
Ultra High Performance Concrete ◽  
Secondary Raw Materials ◽  
Successful Design

The experimental work presented in this article examines the possibility of lowering the economic cost of UHPC. The UHPC were designed using the Linear Packing Density Model. After 7 days, the UHPC compressive strength exceeded 120 MPa. Level of compressive strength after 90 days reaching 150 MPa had been obtained with a lower dose of cement (700 kg/m3) and with the use of secondary raw materials (fly ash), without the use of dispersed reinforcement. The successful design and production proved that the use of secondary raw materials is possible, thereby decreasing the economic cost of UHPC production.

Influence of Lignite Bottom Ash on Pyroplastic Deformation of Stoneware Ceramic Tiles

2018 ◽  
Vol 766 ◽  
pp. 264-269 ◽  
Author(s):  
Tarit Prasartseree ◽  
Thanakorn Wasanapiarnpong ◽  
Charusporn Mongkolkachit ◽  
Noppasint Jiraborvornpongsa
Keyword(s):  
Fly Ash ◽  
Water Absorption ◽  
High Temperatures ◽  
Ceramic Tile ◽  
Glassy Phase ◽  
Raw Materials ◽  
Bottom Ash ◽  
High Strength ◽  
Chemical Compositions ◽  
Ceramic Tiles

Electricity generation at Mae Moh Power Plant in Lampang, Thailand, uses lignite as fuel. The output is 3.0 to 3.5 million tons of fly ash per year and 1.5 to 2.0 million tons of bottom ash per year. Fly ash is widely used in concrete application but for bottom ash, it is not very useful. When considering the phase of bottom ash containing quartz, anorthite and hematite, it was found that there are suitable chemical compositions for replacement of raw materials in ceramic tile. Generally, the stoneware tiles are composed of quartz, mullite, feldspar, and glass phase. Water absorption of stoneware ceramic tiles is below 5%, high strength, fire resistance, and low warpage. Firing or sintering at rather high temperature as 1000-1250 °C is the manufacturing process for this type of tile. The changes in crystal structure and glassy phase formation in tile texture during sintering will be often result the tile to warpage or bent. The more or less lean depends on the viscosity of the glassy phase that occurs at high temperatures in the tile if less viscosity will cause higher warping rate that effect on the shape, and quality of the workpiece. The research has reported that anorthite phase improves the viscosity of a liquid phase or glassy phase when the tile is sintering at high temperatures and lead to high density and low water absorption. This research is interested in studying the effect of using lignite bottom ash as an ingredient in ceramic tile texture to produce low water absorption type by analyzing the effect of percentage of lignite bottom ash to warpage and important properties of ceramic tiles.

Preparation and Properties of Pressed Metakaolin and Fly Ash Based Alkali-Activated Binders

2014 ◽  
Vol 897 ◽  
pp. 65-68 ◽  
Author(s):  
Jana Boháčová ◽  
Stanislav Staněk ◽  
Pavel Mec
Keyword(s):  
Tensile Strength ◽  
Fly Ash ◽  
High Temperatures ◽  
Frost Resistance ◽  
Raw Materials ◽  
Fly Ashes ◽  
Secondary Raw Materials ◽  
Alkali Activated Binders ◽  
Alkali Activated

Metakaolin, fly ashes and other secondary raw materials serves as suitable input in preparation of alkali-activated binders. This work deals with preparation of alkali-activated materials based on metakaoline and fly ash. Mixtures were prepared with a minimum of mixture water, ready for pressing. Prepared specimens were tested for tensile strength and pressure strength, resistance to high temperatures, frost resistance and resistance to water and salt.

Radiometric measurement of lignite coal and its by-products and assessment of the usability of fly ash as raw materials in Turkey

2018 ◽  
Vol 106 (7) ◽  
pp. 611-621 ◽  
Author(s):  
Şeref Turhan ◽  
Elif Gören ◽  
Ahmed M.K. Garad ◽  
Aydan Altıkulaç ◽  
Aslı Kurnaz ◽  
...  
Keyword(s):  
Fly Ash ◽  
Gamma Ray ◽  
Raw Materials ◽  
Bottom Ash ◽  
Chemical Components ◽  
The Public ◽  
Activity Concentrations ◽  
Lignite Coal ◽  
Major Chemical ◽  
By Products

Abstract Lignite coal (LC) is a key energy source for electricity generation in Turkey. During lignite burning, huge amounts of fly ash (FA), bottom ash and slag are produced as by-products which contain radionuclides in the natural radioactive series of uranium and thorium, and radioactive potassium. These radionuclides may lead to radiological exposure of workers and the public and cause environmental problems. Therefore, finding diverse uses for the by-products in the construction sector and earthwork applications has considerable economic and environmental importance. In this study, the activity concentrations of 226Ra, 232Th and 40K in and radon emanating power (EP) and radon mass exhalation rate (EXRM) from LC, slag and FA obtained from the Kangal lignite-burning power plant with a power of 457 MWe were measured using gamma-ray spectroscopy. The major chemical components (SiO2, Al2O3, Fe2O3, CaO and MgO) of fly ash samples were analysed using an energy dispersive X-ray fluorescence spectrometer. The annual effective doses received by workers and members of the public were estimated using different scenarios specified in Radiation protection 122. The average activity concentrations of 226Ra, 232Th and 40K in LC, slag and FA samples were 187±21, 16±1 and 99±9 Bq kg−1, 620±18, 41±2 and 330±13 Bq kg−1, and 937±30, 38±2 and 272±17 Bq kg−1, respectively. The average values of EP and EXRM of the lignite, slag and FA samples were 8 %, 7 % and 10 %, and 0.1, 0.3 and 0.7 Bq kg−1 h−1, respectively. The highest average of the total annual effective dose is estimated at 153 μSv for members of the public and 74 μSv for workers, lower than the recommended annual limit of 1000 μSv.

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