1. Tallinn University of Technology ESTONIAN OIL SHALE ASH AS RAW MATERIAL FOR MANUFACTURING GLASS CERAMICS Rein KUUSIK Laboratory of Inorganic Materials, Tallinn University of Technology, Tallinn, Estonia Mauro MARAGNONI, Enrico BERNARDO Dipartimento di Ingegneria Industriale, Universita` degli Studi di Padova, Padova, Italy rein.kuusik@ttu.eerein.kuusik@ttu.ee, mauro.maragnoni@unipd.it, enrico.bernardo@unipd.itmauro.maragnoni@unipd.itenrico.bernardo@unipd.it

2. April 17, 2015Kuusik-Maragnoni-Bernardo, SVS20152 Location of Estonia in Europe Estonia

3. April 17, 2015Kuusik-Maragnoni-Bernardo, SVS20153 Main Estonian natural resources are phosphorite and oil shale

4. April 17, 2015Kuusik-Maragnoni-Bernardo, SVS201544 Estonian Oil Shale resource for oil, energy and chemicals We can produce from 1 ton of Estonian oil shale: From 1 ton of oil shale (2030 kcal/kg) 125 kg of shale oil (9 500 kcal/kg) 35 Nm³ of retort gas (11 200 kcal/m³) 850 kWh of electricity

5. April 17, 2015Kuusik-Maragnoni-Bernardo, SVS20155 AS Narva Elektrijaamad AS NARVA ELEKTRIJAAMAD

6. April 17, 2015Kuusik-Maragnoni-Bernardo, SVS20156 6 16.12.2008 Formation of ash Circulated fluidized bed combustion (CFBC) BA (bottom ash) ~30% INT (Intrex ash) ~11% ECO (economizer ash) ~6% PHA (air preheater ash) ~3% ESPA ~50% Pulverized firing (PF) BA (bottom ash) ~40% SHA (superheater ash) ~ 3% ECO (economizer ash) ~5 % CA (cyclone ash) ~35% ESPA ( electrostatic precipitator ash )~17% BA SHA ECO CA ESPA BA INT ECO PHA ESPA t=720-800 o C k CO2 = 0,65-0,75 t=1250-1400 o C, k CO2 = 0,97

7. April 17, 2015Kuusik-Maragnoni-Bernardo, SVS20157 Characterization of oil shale ashes CFBC ashPF ash Lime CaO 3.2-19.9% 14.3-29.3% Periclase MgO3.3-7.0% 3.8-7.9% Melilite (Ca,Na) 2 (Mg,Al)(Si,Al) 3 O 7 1.0-3.6%3.2-18.9% Merwinite Ca 3 Mg(SiO 4 ) 2 3.0-5.2% 6.5-13.2% Belite Ca 2 SiO 4 4.6-7.3%12.3-20.3% Wollastonite CaSiO 3 1.4-3.4% 0.7-2.6% Orthoclase, KAlSi 3 O 8 1.3-15.6%1.7-9.7% Quarz SiO 2 5.6-17.7% 1.6-10.4% Calcite CaCO 3 4.0-34.8%2.0-7.6% Anhydrite CaSO 4 8.8-29.9%4.6-24.1% more lime and secondary silicates more calcite and anhydrite

8. April 17, 2015Kuusik-Maragnoni-Bernardo, SVS20158 Oil Shale Ash Utilization Prospects 5 – 7 mln t/year of ash Backfilling at mining, 1 Building materials, 2 Road construction, soil stabilization, 3 Agricultural use: soil liming, 4 Sorbents for phosphorus capture, 5 Filler for polymers, 6 New products: PCC and sorbents, 7

9. April 17, 2015Kuusik-Maragnoni-Bernardo, SVS20159 The present work aims at evidencing the feasibility of a sintering approach for the production of strong and chemically stable glass-ceramics, based on glass frits. The impact of binders (of organic or inorganic nature), used to favour the shaping of fine powders, and recycled glass powders, considered in order to improve the chemical stability of the sintered bodies, has been also discussed.

10. April 17, 2015Kuusik-Maragnoni-Bernardo, SVS201510 SEM image of glass-ceramics from: (a) ASH2 with Kaolin; (b) ASH2 with PEG Details of sintered ceramics from the ASH2 glass with borosilicate glass: (a) visual appearance; (b) high magnification SEM image

11. April 17, 2015Kuusik-Maragnoni-Bernardo, SVS201511 Conclusions o Selected kinds of Estonian oil shale ash may be employed as the main raw material (being used in an amount exceeding 60%) in the formulation of waste-derived glasses, to be converted into glass-ceramics o Sinter-crystallization, found to be active for the investigated compositions, allowed the obtainment of glass-ceramics by very fast and cost effective firing treatments (temperatures <1000°C, holding time of 30 min, fast heating) o Optimized formulations, in terms of composition and selection of binders, led to strong glass-ceramics with a high reliability (Weibull’s modulus >10) o The chemical stability of the sintered glass-ceramics may be improved by mixing waste-derived glass with recycled borosilicate glass.

12. April 17, 2015Kuusik-Maragnoni-Bernardo, SVS201512 Thank You! 12