Tallinn University of Technology

Department of Materials and Environmental Technology

Table of Contents

About the Laboratory of Inorganic Materials

Laboratory of Inorganic Materials has developed from the Laboratory of Mineral Fertilizers established by academician Mihkel Veiderma in 1965 and leaded for a long time by Dr. Rein Kuusik (1941-2025). Later, due to expansion and changes in the research area, it existed as the Laboratory of Inorganic Technology and starting from January 2017, related to bigger structural changes in TalTech, the research group belongs to the Department of Materials and Environmental Technology as the Laboratory of Inorganic Materials.

The laboratory’s activities cover the field of inorganic materials within general materials science. Its area of focus is the chemistry and technology of inorganic materials, specifically fundamental and applied research in inorganic multicomponent systems aimed at developing new materials with novel properties, finding new applications for Estonia’s mineral resources, reducing and recycling industrial waste, and ensuring its environmentally sustainable storage.

During the current period, the laboratory's research is focused on waste management in industries related to oil shale—specifically, the utilization of deposited oil shale ash and the reduction of greenhouse gas emissions—as well as on novel processing methods for phosphate raw materials. The aim is to gain fundamental chemical and technological knowledge of the processes involved. The research directions include the production of precipitated calcium carbonate and solidified materials, the use of ash for producing various construction materials with simultaneous CO₂ capture (so-called accelerated carbonation processes), and phosphate chemistry, which also encompasses the development of new, environmentally friendly processing technologies for Estonian phosphorite and associated minerals. In addition, the work involves various thermal processes, with the goal of achieving feasible, sustainable, and optimized applications through both experimental methods and mathematical modeling.

The early research conducted in the laboratory up to 2002 has been analyzed in detail by the long-term scientific supervisor of the research group, Academician Mihkel Veiderma (1929-2018).

Prof. Andres Trikkel
Head of the lab
andres.trikkel@taltech.ee

KL 2024
Staff of the lab in 2024

Staff and Apparatus

Members of the research group (linked to ERIS - Estonian Research Information System):

Detailed list in  TalTech web (room numbers, phone numbers, etc)

Scientific apparatus involves:

  • TG-DTA + MS analysis unit (thermal analyzer Setaram Labsys Evo coupled to MS spectrometer Pfeiffer);
  • TG-DTA thermal analyzer Setaram Setsys Evo;
  • TG-DTA thermal analyzer Linseis STA-PT 1600 for pressurized experiments up to 5 bar;
  • Dilatometer (Setaram);
  • AAS spectrometer Varian SpectrAA 50/55;
  • UV-VIS spectrometer Biochrome Libra;
  • Sorptometer KELVIN 1042 for BET surface analysis by N2 adsorption method;
  • High-pressure Hg-porosimeter Poremaster 60-17 for porosity distribution analysis;
  • Laser analyzer Horiba LA-950V2 for size distribution measurements;
  • Carbon analyzer ELTRA CS-580 (TC ja TIC);
  • Reactor unit for solution chemistry in the environment of different gases Lara Controlled Laboratory Reactor (Radleys);
  • Automatic titrator Mettler Toledo T90;
  • Extruder Bonnot 2 1/4" for granulation;
  • Device for measuring granula strength CT3 25K (Brookfield Engineering);

Research

There are two main research directions in the laboratory:

Research in natural inorganic materials and industrial wastes

(Mai Uibu, Can Rüstü Yörük et al.)

  • Heterogeneous processes in the multicomponent system CaCO3 – CaO – SO2 – CO2 – O2 – CaSO4 - H2O or in its various subsystems being essential in materials and environmental technology;
  • Accelerated carbonation processes;
  • Building materials on the basis of landfilled oil shale ashes and other alkaline wastes;
  • Precipitated calcium carbonate (PCC) from landfilled oil shale ash;
  • Granulation technologies for oil shale ash;
  • Ceramic materials from oil shale ash and local clay minerals;
  • Carbonaceous materials and oil shale ashes as sorbents in various applications.

Research in phosphatic materials

(Kaia Tõnsuaadu, Tiit Kaljuvee et al.)

  • ~50 years of experience in natural apatites - composition, structure, chemistry and processing technologies;
  • Synthesis of cation and anion substituted apatites by precipitation and sol-gel methods;
  • Applications of ion-substituted apatites in catalysis and for binding of heavy metals - chemistry and mechanism of the processes;
  • Properties and enrichment possibilities of Estonian phosphorite;
  • New processing technologies of Estonian phosphorite and accompanying minerals (graptolite-argillite);
  • Possibilities of extraction of REEs from Estonian phosphorite.

Most important projects

Since 2017 after structural changes in TalTech, the projects of the laboratory are not anymore registered separately by ERIS, as the lab belongs now to the Dept. of Materials and Environmental Technology. Short abstracts of the newer projects are presented here below, descriptions of the older projects are linked to ERIS web.

TK228: Centre of Excellence in Circular Economy for Strategic Mineral and Carbon Resources (2024-2030, HTM, R.Aav). Coordinator project. TK228U3: Strategic Mineral Resources (SMR) Workgroup (2024-2030, HTM, A.Trikkel) 

This Centre of Excellence (CoE) focuses on fostering innovation in resource efficiency, promoting circular economy practices, utilizing local resources, ensuring safe material circulation, and educating researchers to reduce environmental impacts. It centers around four key areas: Strategic Mineral Resources (SMR), Carbon-Based Resources (CBR), Circular Technologies Upscaling (CTU), and Circular Business Eco-System and Modeling (CBEM). The SMR group maps critical materials in waste streams, including renewables, for extraction and reuse while minimizing hazardous waste. The CBR group develops eco-friendly pathways for essential chemicals and plastics, also assessing their environmental impact. The CTU group pioneers waste reduction and recycling methods for aqueous, and solid waste, incl. water purification. The CBEM group analyzes sustainable business ecosystems and value chains. This CoE's interdisciplinary approach will benefit both Estonia and Europe by advancing circular economy. (Project in ERIS web) 

Tem-TA87: Complex recovery of mineral mining and industrial waste as secondary raw material in the context of eco-conscious building materials and hydrometallurgy (2024-2028, ETAG, M.Uibu)

Pressure for new waste-free and CO2-neutral technologies remain high and, in the context of commodity security, the landfills of the past must become the deposits of the future. The objective of the proposed project is the complex valorisation of mineral waste streams, which will be carried out through the development of waste-based building materials and critical raw material resources, as well as the reduction of the carbon footprint based on carbonization technologies.
The expected results are basic and applied knowledge about 
(a) the valorisation of local mineral industrial waste as a lightweight building material based on the necessary technical characteristics such as strength and thermal insulation, sound attenuation, durability and environmental performance, and CO2 sequestration; 
(b) integration of extraction optimized for raw materials with a low Mg content (4-6% MgO) in the key of critical raw material resources into a potentially waste-free ash hill valorisation complex. (Project in ERIS web)

Tem-TA100: Variability of Properties of Associated Resources of Shelly Phosphorite and Opportunities for Beneficiation (2024-2028, ETAG, R.Hints)

Complexes associated with shelly phosphorite contain critical raw materials for energy technologies and essential resources for sustainable agriculture, such as V in graptolite argillite and K-rich minerals in glauconitic sandstone. The development of phosphorite mining depends on the capability to find ways for waste-free mining and generating profits through sustainable co-products. The project explores technologies for valorising graptolite argillite and glauconitic sandstone, focusing on the Toolse and Aseri areas. Based on previous studies, the project advances the hydrometallurgical pathways for extracting enriched metals from graptolite argillite, including perspective high-pressure acid leaching. Secondly, innovative mechanical activation of glauconite for synthesising green agrochemicals is tested. Based on geological and physicochemical characteristics, models are created to predict the properties of the poorly studied glauconitic sandstone.

PI of the project is Rutt Hints, the role of the Laboratory of inorganic materials is to study the possibilities of extraction of Vanadium from graptolite-argillite. (Project in ERIS web)

PRG1779: Phosphorus Fertilisers and Rare Metals from Estonian Phosphorite in a Waste-Free Way (2023-2027, ETAG, A.Trikkel)

To expand the resource base of critical raw materials for EU and Estonia, new sustainable and waste-free methods for valorising Estonian phosphorite – to obtain phosphorus fertilisers and separate valuable components such as rare earth elements (REEs) are worked out. Using hydrochloric acid treatment of phosphate rock, both phosphorus and REEs can be separated together with value added by-products like pure gypsum and quartz-sand.
The main goal of this project is to find out the optimal processing conditions through a combination of laboratory experiments and computational models, applying both technological calculations and simulations as well as molecular modelling to achieve feasible and acceptable methods for processing phosphate rock at the most up-to-date level and with minimal impact on the environment. (Project in ERIS web) 

ResTA23: Quality and properties of Estonian shelly phosphorite as a potential source for phosphorus and rare earth elements and its complex processing technologies (2020-2023, ETAG, A.Trikkel)

Both rare earths and phosphorus are on the list of European critical raw materials, necessitating the discovery, exploitation and research of new resources. Estonian shelly phosphorites are the largest known phosphorite resource in Europe, containing also rare earth elements in elevated concentrations. From the perspective of phosphorite valorisation, it is critical to develop new technologies for the production of phosphoric acid and phosphorous fertilizers in order to find suitable, innovative and environmentally friendly solutions for high-quality end products. The aim of the study, based on integrated geological and mineralogical methods, modeling of geometallurgical characteristics of this resource and technological experiments, is to clarify the classification possibilities of shelly phosphorites, depending on their phosphorus and rare earths content, to interpret the distribution of such raw materials, and to analyze their potential processing technologies (Project in ERIS web)

IUT3319: Fundamentals of multicomponent mineral-organic systems: Chemistry, modeling and sustainable processing (2015-2020, ETAG, A.Trikkel)

The project is focused on waste management in oil shale industry – to reuse oil shale ash and diminish GHG emissions through a complex of ideas and closely related methods in solution and thermochemistry combined with modeling. The primary aim is to clarify chemical-technological fundamentals of the processes in the multicomponent heterogeneous mineral-organic aqueous or gas – solid systems related to PCC production, oil shale or semicoke oxy-combustion and recycling of phosphorus together with extended chemistry of cation-substituted apatites for chemical synthesis, enabling to reach feasible, environmentally sound, optimized applications and generalize the novel know-how. (Project in ERIS web) (Summary of the Main Results)

RITA 1: Climate change mitigation with CCS and CCU technologies [ClimMIT] (2019-2021, ETAG, M.Uibu, A.Trikkel)

Estonia has one of the highest per capita greenhouse gas (GHG) emission rates and carbon-intensity levels in the EU. To decrease GHG emissions sharply best options for implementing carbon capture and utilization (CCU) technologies must be identified. The main goal of the project is to assess the suitability of various CCU technologies and develop scenarios for adopting these in the Estonian oil shale industry. Also, environmental effects of the most promising solutions are studied along with the technological and economic capacities for utilizing captured CO2 in other industries. Economic analysis focuses on differences in per unit costs of alternative capturing technologies, their sensitivity to CO2 quota and electricity prices and investment subsidising needs as well as export markets for Estonian captured CO2. The project results in a multifaceted overview of the feasibility of investing in carbon capture infrastructure to help to minimize GHG from the oil shale industry in Estonia. (Project web-page)

FLAME: Fly Ash to Valuable Minerals (2017-2020, EIT-KIC, A.Trikkel, C.R.Yörük)

The FLAME project develops the dusty plasma separation (DPS) technology to enable dry (ultra)fine mineral classification and extraction of valuable minerals from both primary and secondary resources in order to minimize losses of unused materials. The provision of large amounts of high-quality (ultra)fine minerals to the market is expected to engender the development of more durable and sustainable materials and products in related markets such as high-value construction materials and composite materials. The first DPS technology users are coal/oil shale power stations which produce fly ash, and have to dispose it or find markets for it. The project targets the development of at least three added value products. The main product is the DPS equipment, but also the value of the DPS output products – the ultrafine and very fine fractions of fly ash. To the end of the FLAME project the system prototype will be demonstrated in an operational environment (level TRL 7).

CLEANKER: Clean Clinker Production by Calcium Looping Process (2017-2021, Horizon 2020, M.Uibu)

The cement industry is a key-sector for the reduction of CO2 emissions. Cement production is responsible for about 27% of global anthropogenic CO2 emissions from industrial sources worldwide. The focus of CLEANKER is demonstrating the feasibility of the integrated Ca-Looping process at industrial scale in a new demo system treating 4,000 m3/h of flue gas emitted by the Buzzi Unicem cement plant in Vernasca (Piacenza, Italy). Project is coordinated by L.E.A.P. (Laboratory for Energy and Environment) from Italy. Project consortium is composed from 13 partners from 7 countries including two departments from Tallinn University of Technology (Department of Geology and Department of Materials and Environmental Technology: Laboratory of Inorganic Materials). TTÜ is a coordinator of the Work Package 7 (Transport, utilization and storage study) including 7 tasks and 7 deliverables. Among these tasks are: Techno-economic modelling of selected local and regional CCUS scenarios for Vernasca, Kunda and Slantsy cement plants (TTÜ-GI); Lab-scale experiments on waste oils shale ash and CDW carbonation and recommendations for the design of the mineralization reactor in Vernasca (TTÜ-MK); Producing of concrete using waste materials from cement plants and Ca-Looped CO2 trapped in the Vernasca demo system will be finaly demostrated in the project. (Project web-page)

RITA 1: Efficient, environmentally friendly and sustainable use of Earth Resources (2017-2020, ETAG, K.Tõnsuaadu, M.Uibu, A.Trikkel)

Aim of this interdisciplinary project is to provide information on the best available and new innovative technologies for utilization of existing mineral resources and information on properties and possible processing technologies for potential resources in Estonia. Subtask RITA1/01-01-07 elaborates the properties of oil shale (OS) processing solid waste materials formed in new boilers and retorts put into use in last years. It focuses on reusability and environmental impact of these materials and provides the basis for choosing the most effective, profitable and environmentally less harmful reuse technologies for Estonian OS wastes. Subtask RITA1/01-01-11 studies the possibilities of application of novel methods for enrichment of Estonian shelly phosphorite ore and processing its concentrates into final products, and the distribution and removal of potentially harmful and/or useful accompanying components. (About the project)

Lep19098: Põlevkivituha väärindamise ja ringlusse suunamise võimaluste rakendusuuring / Applied research of the possibilities of oil shale ash valorisation and recycling (2019−2021, R-OSA Service OÜ, M.Uibu).
(About the project)

Earlier projects:

  • Uuring tööstusjäätmetest ehituslike täitematerjalide saamiseks koos CO2 sidumisega / Production of construction materials from industrial wastes and CO2 (2016-2018, KIK, M.Uibu).
  • Earlier projects and contracts (Link to ERIS web)

For students

It is possible to carry out practically oriented master’s and doctoral theses in the laboratory, focusing on environmental protection as well as various other topics related to the technology of inorganic materials.

Many of the research topics are connected to environmental issues in the energy sector, particularly oil shale energy in the Estonian context — such as the reduction of CO₂ emissions, oil shale and other types of ash and their novel utilization possibilities, and mineral carbonation processes. Another line of research involves questions related to natural and synthetic apatites, as well as the development of new, more environmentally friendly, and as waste-free as possible technologies for processing Estonian phosphorite and its associated minerals (glauconite, graptolitic argillite), which have once again become a subject of interest. Attention is also given to possibilities for extracting rare earth elements needed for green energy production from Estonian phosphorite.

Below is a list of doctoral theses completed and defended in the laboratory.

  • Ana Jurkeviciute. Synthesis of modified resins based on resorcinol and oil shale alkylresorcinols: structure and properties / Modifitseeritud vaikude süntees resortsinooli ja põlevkivi alküülresortsinoolide alusel: struktuur ja omadused (supervisors L. Grigorieva, K.Tõnsuaadu, defended in 2024)
  • Mustafa Cem Usta. Accelerated Carbonation of Ca-rich Fly Ashes in Non-Cement Applications / Kaltsiumirikka lendtuha kiirendatud karboniseerimine tsemendivabades rakendustes (supervisors M.Uibu, C.R.Yörük, defended in 2023)
  • Hakan Berber. Accelerated Carbonation Treatment of Industrial Wastes: Physicochemical, Environmental and Economic Aspects / Hinnang Iru elektrijaamas olmejäätmete põletamisel tekkiva lendtuha kasutusvõimalustele (supervisors V. Voronova, M.Uibu, defended in 2020)
  • Can Rüstü Yörük. Experimental and Modeling Studies of Oil Shale Oxy-fuel Combustion / Põlevkivi hapnikus põletamise eksperimentaalne uurimine ja modelleerimine (supervisors A.Trikkel, R.Kuusik, defended in 2016)
  • Kadriann Tamm. Leaching of the Water-Soluble Calcium Components of Oil Shale Waste Ash / Kaltsiumiühendite leostumine põlevkivituha vesisüsteemides (supervisors M.Uibu, J.Kallas, R.Kuusik, defended in 2016)
  • Irina Klimova. Modification of Ammonium Nitrate Fertilizer / Ammooniumnitraatväetiste modifitseerimine (supervisors T.Kaljuvee, A.Trikkel, defended in 2014)
  • Aleksandr Käkinen. The role of physico-chemical properties and test environment on biological effects of copper and silver nanoparticles / Vase ja hõbeda nanoosakeste füüsikalis-keemiliste omaduste ja testikeskkonna mõju nende bioloogilisele toimele (supervisors A.Kahru, KBFI; R.Kuusik, defended in 2014)
  • Karin Viipsi. Impact of EDTA and humic substances on the removal of Cd and Zn from aqueous solutions by apatite / EDTA ja humiinaine mõju Cd ja Zn eraldamisele vesilahusest apatiidiga (supervisor K.Tõnsuaadu, defended in 2012)
  • Riina Salmimies, Lappeenranta University of Technology.  Acidic dissolution of iron oxides and regeneration of a ceramic filter medium (supervisor J.Kallas, defended in 2012)
  • Olga Velts. Oil Shale Ash as a Source of Calcium for Calcium Carbonate: Process Feasibility, Mechanism and Modeling / Põlevkivituhk kaltsiumkarbonaadi toormena: protsessi teostatavus, mehhanism ja modelleerimine (supervisors R.Kuusik, J.Kallas, defended in 2011)
  • Mai Uibu. Abatement of CO2 emissions in Estonian oil shale-based power production / CO2 emissiooni vähendamisvõimalused põlevkivienergeetikas (supervisors R.Kuusik, A.Trikkel, defended in 2008)
  • Merike Peld. Substituted Apatites as Sorbents for Heavy Metals /Asendustega apatiidid raskmetallide sidujatena (supervisor K.Tõnsuaadu, defended in 2005)
  • Andres Trikkel. Estonian Calcareous Rocks and Oil Shale Ash as Sorbents for SO2 / Eesti karbonaatsed kivimid ja põlevkivituhk vääveldioksiidi sorbendina (supervisors R.Kuusik, M.Veiderma, defended in 2001)
In the lab