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Introduction
I hold Diploma in Mining and Metallurgical Engineering from the National Technical University of Athens and a Ph.D in Industrial Minerals Processing and Process Simulation also from NTUA under IKY fellowship. Currently, i am senior researcher at the Laboratory of Metallurgy of the NTUA, working on EC funded research projects in the field of mineral processing and beneficiation, and wastes' valorisation. I am Research, Technical and Marketing Consultant at the Perlite Institute
Current institution
Additional affiliations
October 2008 - May 2013
Education
October 2008 - May 2013
September 2002 - October 2007
School of Mining and Metallurgical Engineering
Field of study
Publications
Publications (49)
Apatite and rare earth elements (REEs) are vital to the European Union’s economic growth and resource security, given their essential roles in fertilizers, green technologies, and high-tech applications. To meet rising demand and reduce reliance on imports, the exploitation of domestic deposits has become increasingly important. This study investig...
In the current study plaster − expanded perlite microsphere composites, were investigated regarding their thermal insulation properties. In this context commercially available plaster powder was mixed with expanded perlite microspheres, of various grain size distribution and bulk density, aiming the investigation of the effect of ultrafines in the...
Apatite and rare earth elements (REEs) are vital to the European Union's economic growth and resource security, given their essential roles in fertilizers, green technologies, and high-tech applications. To meet rising demand and reduce reliance on imports, the ex-ploitation of domestic deposits has become increasingly important. This study investi...
The study investigated the potential use of expanded perlite microspheres as fillers in ABS composite filaments for 3d printing application, with a focus on the effect of the filler size and density on the major properties of the filament and printed objects. A Vertical Electrical Furnace (VEF) prototype was employed for the preparation of filler g...
Bauxite residue (BR) is major by-product of the Bayer process for aluminium production, and its accumulation confers environmental risk due to its high alkalinity and fineness. The high Fe content and the BR abundance render it an attractive secondary source of iron, with magnetic separation being the preferable beneficiation
technique applied for...
![(a,b) massive and flow banded perlitic textures [16], (c) perlitic...](publication/377608268/figure/fig3/AS:11431281418293207@1746148009374/a-b-massive-and-flow-banded-perlitic-textures-16-c-perlitic-fractures-the-width_Q320.jpg)
Perlite is a volcanic glass that, under thermal treatment, expands, producing a highly porous and lightweight granular material which finds application in the construction, horticulture, insulation and other industrial sectors. Proper control of the feed properties and the expansion conditions allows the production of purpose-oriented grades, while...
The partial replacement of a conventional limestone filler with sustainable perlite microspheres was investigated in the present study, by examining its effect on rheology, physical characteristics, mechanical properties and durability of Self-Compacting Concrete (SCC). Expanded perlite microspheres (EP) were produced after thermal treatment of the...
Froth flotation is known to be one of the keys enabling technologies allowing the selective separation of values from uneconomic mineral resources. Froth flotation utilizes the differences in the wettability of minerals in a three-phase system that consists of solids, gas, and water. Xanthates are currently the most used collectors in sulphide flot...
Bauxite residue is highly alkaline and very fine-grained by-product of the Bayer process with an increasing annual production of about 150 million tonnes. The management and safe disposal of bauxite residue are therefore a major issue for bauxite and alumina industries affecting the production cost. This study focuses on the environmental assessmen...
As copper (Cu), nickel (Ni) and cobalt (Co) are main components of the Li-ion batteries, rising demand from the battery sector will "have a disruptive impact" over the next 10 years. There is a high need for replacing existing flotation reagents with more-environmentally friendly products. An efficient, sustainable lignin-based flotation concept fo...
Since xanthates are toxic chemicals that are eventually disposed to the environment, the utilization of chemical collectors during the flotation of pyrite and arsenopyrite raises concerns about the sustainability of the process. The partial substitution of xanthate collectors with bio collector lignin turns out to be a viable option. In this study,...
The use of xanthates at the flotation of sphalerite raises questions about the sustainability of the process, due to the negative environmental impact. In addition, the development of local bio-collectors production is necessary to replace currently utilized flotation collectors and depressants, which are manufactured mostly in China. In this study...
The elevated increase of CO2 emissions related to activities of the extractive industry is becoming a challenging issue gradually affecting climate change and global warming. In this frame, the effective utilisation of CO2 through the techniques of Carbon Capture and Storage (CCS) as well as Carbon Capture and Utilisation (CCU) can alleviate the gr...
Extensive decarbonisation efforts result in major changes in energy demand for the extractive industry. In 2021, the extraction and primary processing of metals and minerals accounted for 4.5 Gt of CO2 eq. per year. The aluminium industry was responsible for 1.1 Gt CO2 eq. direct and indirect emissions. To reach the European milestone of zero emiss...
A model-based investigation of the interplay between furnace setup and spatio-temporal evolution of particles’ state variables is also presented. The effect of feed size distribution and processing of ultrafine ore are discussed. The process is controlled primarily by the wall temperature and secondarily the air feeding rate; an increase of furnace...
Deep renovation of buildings should cut 36% of their energy consumption by 2030, and thus reducing EU's energy import dependency, creating growth, innovation, and employment, reducing fuel poverty, and resulting in more comfortable and healthier buildings. According to the existing Energy Performance of Buildings Directive, European countries need...
With an annual global CO2 emission of 34 billion tonnes due to fossil fuel usage, the need for a worldwide gradual decarbonisation plan is urgent. To meet the environmental milestones of 2050, the world needs to contribute an annual 6 % decrease in fossil fuel use, accounting for 73 % of global CO2 emissions. For achieving these goals, Energy Inten...
Different fine materials that constitute either industrial or mining by-products were incorporated as filler materials in self-compacting (SC) mortars, aiming at improving their sustainability. More specifically, two common by-products of the cement industry-cement kiln dust (CKD) and bypass dust (BPD)-were evaluated together with the fine content...
![Dimensions of dogbone samples in accordance with ASTM D638-14 [17]. All...](publication/362095499/figure/fig1/AS:11431281407172588@1745751280930/Dimensions-of-dogbone-samples-in-accordance-with-ASTM-D638-14-17-All-dimensions-in-mm_Q320.jpg)
The use of amorphous microspheres as filler in composites is promising due to their light weight, low cost, incombustibility, and the ability to alter relevant properties of the final composite. Contrary to glass spheres, perlite microspheres are much cheaper and can be tailor-made to facilitate purpose-oriented alteration of the final composite. W...
The presented paper deals with the influence of the heating rate on combustion characteristics (reactivity and reactivity evaluation, ignition index (D i), burnout index (D f), the combustion performance index (S), and the combustion stability index (R W)) of the protective coronavirus face masks. Two types of commonly used face masks in different...
The current trend in the construction industry is the development of ever lighter-weight elements and components that can maintain the good mechanical properties of traditional construction materials. The addition of lightweight aggregates, including expanded perlite, in concrete is one of the most common techniques used for density reduction of ce...
Bauxite Metallurgical Residue (BR) is a highly alkaline and very fine-grained by-product of the Bayer process for alumina production. Its huge global annual production has resulted in increasing accumulation of BR, causing deposition problems and serious environmental issues. RM contains oxides and salts of the main elements Fe, Al, Ca, Na, Si, Ti,...
Kaolin is an industrial mineral used in a wide variety of applications due to its crystalline structure, mineral and elemental composition. After kaolin undergoes heat treatment in a specific temperature range, metakaolin, which exhibits a strong pozzolanic reaction, is formed. This paper examines the effects of different kaolin qualities on the th...
Spent potlining (SPL) consists of the carbon cathodes (1st cut), aluminosilicate refractories, and the insulation lining of Hall–Héroult cells (2nd cut) used in aluminum smelting. SPL is classified as hazardous material due to its high content in soluble fluoride salts and the presence of cyanides. The 1st cut contains considerable amount of carbon...
Thermal decomposition of hydrous volcanic glass occurs through the release of different water species under overlapping processes over wide temperature range. Its investigation is of practical interest since it constitutes integral processing part towards its valorization as source for the production of high-quality porous material for various appl...
![Fig. 1. Depiction of FDM technique [3].](profile/Panagiotis-Angelopoulos-2/publication/353063841/figure/fig1/AS:1043640092733440@1625834596051/Depiction-of-FDM-technique-3_Q320.jpg)
3D printing constitutes a revolutionary technology that experiences continuously expanding applicability to numerous industrial sections. However, the predefined physicochemical, thermal and mechanical properties of existing thermoplastic filaments set strong limitations to the application of 3D printing manufacturing method for the production of f...
Each tonne of aluminium produced in aluminium smelters generates approximately 20 kg of hazardous waste, known as spent pot lining (SPL)`which is a mix of the carbon lining and the refractory lining. The waste contains high levels of leachable cyanides and fluorides, as well as components that form combustible gases (mainly CH4). The current practi...
Rhyolite is an extrusive, igneous rock of aluminosilicate composition that upon rapid cooling forms obsidian. Obsidian is amorphous and contains limited water portions (< 2 mass%); however, secondary hydration turns it either to perlite (H2O ≈ 2–5 mass%) or pitchstone (> 5 mass%). In the current study, kinetics of hydrous rhyolite dehydration were...
![Fig. 1. FDM technique and its main components [5].](profile/Panagiotis-Angelopoulos-2/publication/343360446/figure/fig1/AS:928798757376000@1598454288191/FDM-technique-and-its-main-components-5_Q320.jpg)
Fused Deposition Modelling (FDM or Fused Filament Fabrication, FFF) constitutes the most widespread 3D printing technology because it uniquely combines simplicity, cost and speed. One of the major drawbacks of this promising technology that hinders its applicability to various industrial fields constitutes the lack of variation of feedstock materia...
The optimization of the autogenous diffusion copper bonding via thermocompression at vacuum environment was investigated. The influence of various bonding parameters on the interdiffusion efficiency was studied in detail at the micro (SEM-EBSD) and nano (TEM) scales. Bonding at 1000 °C for 90 min under pressure (10 MPa) presented optimum structural...
Pitchstone is a naturally occurring volcanic glass that contains considerable amount of chemically bound water (> 6 % wt). Due to its high water content, its direct thermal processing in conventional expansion furnaces towards the production of lightweight material, similar to expanded perlite, is practically impossible. In the current research pap...
Diaspore [α-AlO(OH)] is the main constituent of greek bauxite and a major source of corundum [α-Al2O3], that is obtained through dehydroxylation process. In the current research study, thermogravimetric analysis was implemented to study the thermal decomposition kinetics of greek diasporic bauxite under inert atmosphere (N2) and various heating sce...
![Table 4 . Thermal properties of traditional construction materials [17]...](profile/Panagiotis-Angelopoulos-2/publication/311739491/figure/tbl2/AS:668317954105349@1536350825349/Thermal-properties-of-traditional-construction-materials-17-and-inorganic-polymers_Q320.jpg)
The need to minimise wastes generated throughout EU while securing the necessary raw material resources has triggered recently an intense research activity on waste exploitation. Especially regarding industrial wastes, their vast volume as well as the lack of efficient and environmentally friendly disposal ways, led to efforts aiming at their reuse...
Refractory sulphide gold ores cannot be effectively processed via hydrometallurgy without a pre-treatment stage as gold is disseminated in a fine form, as submicron size inclusions, in the lattice of the sulphide minerals. Pre-treatment techniques, comprising oxidation roasting, chlorination and aqueous pressure oxidation, which are widely applied...
Red mud is generated during alumina production through Bayer process; it is the insoluble product obtained after bauxite digestion with sodium hydroxide at elevated temperature and pressure. In recent years, various attempts have been made to exploit red mud for the extraction of its valuable components or its usage in the fabrication of cement, ce...
Expanded perlite is a popular lightweight material widely used due to its outstanding insulating properties. The expansion conditions directly affect perlite characteristics and its suitability for use in various applications. The conventional industrial expansion technique suffers disadvantages that adversely affects product quality and limit the...
Expanded perlite constitutes one of the most competitive insulating materials that is widely used in construction and manufacturing industry due to its unique properties combination; it is white, natural, lightweight, chemically inert, and exhibits superior insulating properties (thermal and acoustic) and fire resistance. Conventionally, perlite ex...
In the current study, the kinetic of the thermal decomposition of a composite diasporic-boehmitic bauxite is investigated under non-isothermal heating conditions by means of thermogravimetric analysis. The calculation of activation energy (Ea) has been performed by various methods and the attained values range from 185000 to 190000 J∙mol-1 for conv...
Dense multi-walled carbon nanotubes (CNT) have been successfully fabricated on expanded perlite particles by the pyrolysis of a camphor-ferrocene mixture at 800 oC. Scanning electron microscopy images show that the CNTs’ growth is strongly affected by the specific surface area of perlite samples and it is more efficient in the case of perlite parti...
The new vertical electrical furnace which has been designed and operated at NTUA successfully produces expanded perlite of superior quality, unleashing its potential for high-performance thermal and acoustic insulation applications in the manufacturing and construction industries. A detailed sensitivity analysis has been performed on the basis of o...
Expanded perlite is a lightweight material with remarkable thermal and acoustic insulation properties, rendering it widely useful in the construction and manufacturing industries. Currently applied perlite expansion technology suffers numerous technical disadvantages, which adversely affect product quality and limit the range of its applications. T...
Conventional perlite expansion suffers shortcomings which compromise its viability and the adherence of expanded perlite to modern high-quality technical specifications. A new perlite expansion process has been designed and a vertical electrical furnace for perlite expansion has been constructed in our laboratory to overcome drawbacks. Having alrea...
Expanded perlite has outstanding thermal and acoustic insulating properties and is widely used in the manufacturing and construction industries. The conventional perlite expansion method has certain disadvantages which affect the quality of expanded perlite products, thus limiting their performance and range of applications. A new perlite expansion...
Expanded perlite has outstanding thermal and acoustic insulating properties and is widely used in the
manufacturing and construction industries. The conventional perlite expansion method suffers disadvantages which affect the quality of expanded perlite products, thus limiting their performance and range of applications.
A new perlite expansion pro...
Expanded perlite has outstanding thermal and acoustic insulating properties and is widely used in the manufacturing and construction industries. The conventional perlite expansion method suffers disadvantages which affect the quality of expanded perlite products, thus limiting their performance and range of applications. A new perlite expansion pro...
Expanded perlite is widely used in construction and manufacturing industry mainly due to its good thermal and acoustical insulating properties. Nevertheless, the currently applied expansion technology has some disadvantages, which affect the product quality and limit the range of its applications. To overcome these drawbacks a new expansion process...
Questions
Questions (2)
I am running some flotation experiments with limited sample availability. One alternative i have is to recombine the products, destroy the chemicals and use it again as feed in other flotation experiments. I wonder if there is any method that can be used to destroy the chemicals absodbed on the surface of minerals effectively. The collector that i use is an alkyl hydroxamate (Aero 6494).
Thanks
Goodmorning.
Is there any procedure for quantitative determining the diaspore and boehmite in a bauxite sample? Or at least to determine the ratio in the samples? Thanks in advance
