Glass Ceramics Composites Fabricated from Coal Fly Ash and Waste Glass

Great quantities of coal ash are produced in thermal power plants which present a double problem to the society: economical and environmental. This waste is a result of burning of coal at temperatures between 1100-14500C. Fly ash available as fine powder presents a source of important oxides SiO2, Al2O3, Fe2O3, MgO, Na2O, but also consist of small amount of ecologically hazardous oxides such as Cr2O3, NiO, MnO. The combination of the fly ash with waste glass under controlled sintering procedure gave bulk glass-ceramics composite material. The principle of this procedure is presented as a multi barrier concept (1). Many researches have been conducted the investigations for utilization of fly ash as starting material for various glass–ceramics production (2-4). Using waste glass ecologically hazardous components are fixed at the molecular level in the silicate phase and the fabricated new glass-ceramic composites possess significantly higher mechanical properties. The aim of this investigation was to fabricate dense glass ceramic composites using fly ash and waste glass with the potential for its utilization as building material

Technical and radiological characterisation of fly ash and bottom ash from thermal power plant

Huge quantities of fly ash and bottom ash are generated from thermal power plants and it presents great concern for country, mainly due to the environmental effects. In this study, fly ashes and bottom ash were characterized from technical and radiological aspects. Health effect due to the activity of radionuclides 226Ra, 232Th and 40K was estimated via radium equivalent activity (Raeq), external hazards index (Hex), the external absorbed dose rate (D) and annual effective dose rate (EDR). The specific surface area (40.25 m2 g−1), particle density (1.88 g cm−3) and LOI (23.49%) were typical for bottom ash. Siliceous fly ash contained 32% reactive silica. The annual effective dose rate for all ashes is ≤ 0.2 mSv y−1. Both, fly ash and bottom ash present potential secondary raw materials to be used for building purposes as result of their technological and radiological assessment

Manual for use of Al-containing residues in low-carbon mineral binders

Our society can no longer be imagined without its modern infrastructure, which is inevitably based on the use of various mineral and metallic materials and requires a high energy consumption. Parallel to the production of materials, as well as the production of electricity, huge amounts of various industrial and mining residues (waste/by-product) are generated and many of them are sent to landfill. The European Union (EU) aims to increase resource efficiency and the supply of ”secondary raw materials“ through recycling [1], inventory of waste from extractive industries [2], and waste prevention, waste re-use and material recycling [3]. Much of the industrial and mining waste is enriched with aluminium (Al) and therefore has a potential to replace natural sources of Al in mineral binders with a high Al demand. However, the use of industrial residue in mineral binders requires an extensive knowledge of its chemical composition, including potential hazardous components (e.g. mercury), mineral composition, organic content, radioactivity and physical properties (moisture content, density, etc.). This manual addresses the legislative aspects, governing the use of secondary raw materials in construction products, description of the most common Al-containing industrial and mining residue (bauxite deposits, red mud, ferrous slag, ash and some other by products from industry), potentiality for their reutilisation and its economic aspects, potential requirements/barriers for the use of secondary raw materials in the cement industry and a description of belite-sulfoaluminate cements, which are a promising solution for implementing the circular economy through the use of large amounts of landfilled Al-rich industrial residue and mining waste cement clinker raw mixture. This manual was prepared by partners of the RIS-ALiCE project. It provides a popular content, which targets relevant stakeholders as well as the wider society. Moreover, it offers education material for undergraduate, master and PhD students.Other links: [http://www.zag.si/dl/manual-alice.pdf

Composites based on fly ash and clay

Fly ash is a waste generated from the coal combustion during the production of electricity in the thermal power plants. It presents industrial by-product containing Technologically Enhanced Natural Occurring Radioactive Materials (TENORM) with the great potential for valorisation (1). Fly ash is successfully utilized in cement and concrete industry (2), also in ceramics industry (3) as component for manufacturing bricks and tiles, and recently there are many investigations for production of glass-ceramics (4) from fly ash. Although the utilization of fly ash in construction and civil engineering is dominant, the development of new alternative application for its further exploitation into new products is needed. This work presents the possibility for fly ash utilization for fabricating dense composites based on clay and fly ash with the potential to be used in construction industry

Glass Ceramics Composites Fabricated from Coal Fly Ash and Waste Glass

Great quantities of coal ash are produced in thermal power plants which present a double problem to the society: economical and environmental. This waste is a result of burning of coal at temperatures between 1100-14500C. Fly ash available as fine powder presents a source of important oxides SiO2, Al2O3, Fe2O3, MgO, Na2O, but also consist of small amount of ecologically hazardous oxides such as Cr2O3, NiO, MnO. The combination of the fly ash with waste glass under controlled sintering procedure gave bulk glass-ceramics composite material. The principle of this procedure is presented as a multi barrier concept (1). Many researches have been conducted the investigations for utilization of fly ash as starting material for various glass–ceramics production (2-4). Using waste glass ecologically hazardous components are fixed at the molecular level in the silicate phase and the fabricated new glass-ceramic composites possess significantly higher mechanical properties. The aim of this investigation was to fabricate dense glass ceramic composites using fly ash and waste glass with the potential for its utilization as building material

Sustainable technology and natural environment

Sustainable technology is usually connected with the design and analysis of complex, integrated management systems and sustainable development and it is a central target in environmental science and growth of global economies. The minimization of waste and reductions in material and energy inputs are the most important environmental aims. Sustainable technological development and innovations do not automatically lead to total reduction of environmental burden of industrial production. However, technological innovation is an important factor and seems to play a central role in the long-term initiation of cleaner production. Environmental improvement of companies strategy by application the idea of cleaner production linked with sustainable technologies leads to produce environmentally friendly products and leads to increas the position of company on the market. Key words: sustainable technology; sustainable development, environmental effects

Sintering of ceramics based on mechanicaly activated fly ash

This paper presents the results for the influence of the mechanical activation on the properties of the sintered fly ash compacts. By varying the time of mechanical activation (short time of 10, 20 and 30 min) and temperature of sintering: 1050, 1100 and 1130/60 min the spectrum of properties were obtained, but as an optimal defined was the mechanical activation of 20 min prior to the sintering at 11300C

Carotid surgery under blockade cervical plexus

The evidence from retrospective trials suggests that regional anaesthesia reduces the risks of major complications associated with carotid endarterectomy compared with general anaesthesia, namely: myocardial infarction, stroke, and death. A cervical plexus block the regional anaesthetic technique of choice. Aim: the aim of this retrospective study was to report the early results of carotid surgery performed with loco-regional anaesthesia by blocking of the cervical plexus

Production and Characterization of Porous Ceramics From Coal Fly Ash and Clay

The disposal of coal fly ash obtained in thermal power plants presents the general problem all over the world. Significant research on the utilization of fly ash has been carried out in the area of construction materials. The aim of this study was to develop porous ceramics based on coal fly ash and clay (60wt.%clay and 40wt.% fly ash). Three types of pore creators: two types of wood cutting (Quercus and Facus sylvatica) and C-powder were used for creating of the porous ceramics. The mixtures based on fly ash and clay and different content of pore creators (2, 5, 10 and 20wt.%) were consolidated (P=45 MPa, T = 900, 1000, 1050 and 1100oC/1h) to obtain porous ceramic (PC). The results indicate that the properties of the porous ceramics depend on the type and content of the pore creators. Furthermore, the sintering temperature was found to be main factor affecting the properties of the sintered products. The maximal bending strength (26 MPa) was achieved by using 2wt% P3 (C-powder) and the porous ceramics has the density and porosity of 1.90g/cm3 and 22%, respectively. By using the highest content (20wt.% ) of each pore creator (P1, P2 and P3) the lowest bending strength cca 5 MPa was achieved and the variation of the density and porosity was in the range from 1.22 to 1.32 g/cm3 and 44 to 48%, respectively. Water absorption, durability and the microstructure of the obtained porous ceramics are also reported in this paper

Investigation of the possibilities for application of NORM into polymer materials

There is growing trend towards the development of composites with low environmental impact and good commercial viability. Over the last few years different kinds of waste materials have been successfully utilized as filler in polymer composites with various applications. This not only reduces the production costs but also offers an opportunity for utilization of waste materials thereby reducing environmental pollution. Due to the environmental concerns and disposal difficulties, the utilization of fly ash (FA) as NORM material has become of great importance. Fly ash is promising for fabricating composites which can be widely used in various important fields especially for buildings. The granulometry of fly ash filler and filler blends are reported to be attractive as filler material in polymer composites. The main aim of this work was to perform estimate the possibilities for preparing of the composites based on fly ash as NORM material and polymers