Identification and Characterization of Ti-Spheres (Titanspheres) in Cork Powder Fly Ash

  • Renato Guimarães
  • Alexandra Guedes
  • Bruno ValentimEmail author
Original Paper


During the treatment of cork powder from different products, for example, the production of cork stoppers, cork powder is generated and used as fuel. However, the combustion of cork powder produces ash, specifically fly ash, which is the object of this study, with the aim of valorization. Previous studies showed that this ash contains, Ti-spheres (hereinafter referred to as titanspheres), among other morphotypes, which may be the most valuable ash component if they have application in ink industry as white pigment. Therefore, cork powder fly ash was sampled in the combustion unit of the champagne stoppers producer “RELVAS II”. Wet and dry sieving trials combined with ultrasound and a polycarboxylate bath were performed to obtain size fractions and concentrations of the titanspheres. A combination of analytical techniques (SEM/EDS, XRD, XRF, ICP-MS, reflected light microscopy, and Raman microspectroscopy) was used to characterize the bulk ash, size fractions, and, in particular, titanspheres. It was concluded that dry sieving is not an efficient method for cork powder fly ash size fractionating. However, with a combination of wet sieving, ultrasound, a polycarboxylate solution and acid reflux, it was possible to obtain a < 25 µm concentrate that mostly comprised amorphous aluminosilicate material, quartz, and titanspheres. The titanspheres in this concentrate have a 15–25 µm diameter, and the phases determined by XRD include rutile, perovskite and priderite.


Combustion Waste Rutile Titanium 



  1. 1.
    APCOR: Associação Portuguesa da Cortiça (Portuguese Cork Association) APCOR’s Cork Yearbook 17/18. (accessed on 26/06/2018) (2018)Google Scholar
  2. 2.
    Gil, L.: Cork powder waste: an overview. Biomass Bioenerg. 13, 59–61 (1997)CrossRefGoogle Scholar
  3. 3.
    Matos, A.M., Nunes, S., Sousa-Coutinho, J.: Cork waste in cement based materials. Mater. Des. 85, 230–239 (2015)CrossRefGoogle Scholar
  4. 4.
    Haglund, N.: Technical Report—guideline for classification of ash from solid biofuels and peat utilized for recycling and fertilizing in forestry and agriculture. Olso, Norway: Nordic Innovation Centre. (2008) Accessed 27 June 2018
  5. 5.
    Insam, H., Knapp, B.: Recycling of Biomass Ashes. Springer, New York (2011)CrossRefGoogle Scholar
  6. 6.
    Loo, S.V., Koppejan, J.: The Handbook of Biomass Combustion and Co-firing. Earthscan, London (2012)Google Scholar
  7. 7.
    Obernberger, I., Supancic, K.: Possibilities of ash utilization from biomass combustion plants. Proceedings of the 17th European Biomass Conference & Exhibition. Hamburg, Germany: (2009)Google Scholar
  8. 8.
    Obernberger, L., Biedermann, F., Widmann, W., Riedi, R.: Concentrations of inorganic elements in biomass fuels and recovery in the different ash fractions. Biomass Bioenerg. 12(3), 211–224 (1997)CrossRefGoogle Scholar
  9. 9.
    Ochecova, P., Tlustos, P., Szakova, J.: Wheat and soil response to wood fly ash application in contaminated soils. Agron. J. 106(3), 995–1002 (2014)CrossRefGoogle Scholar
  10. 10.
    Ramos, T., Matos, A., Sousa-Coutinho, J.: Strength and durability of mortar using cork waste ash as cement replacement. Mater. Res. 17, 183–193 (2014)CrossRefGoogle Scholar
  11. 11.
    Guimarães, R., Guedes, A., Rocha, R., Valentim, B.: Characterization and concentration of Ti-spheres in fly ash cork powder. In: 5th PYCheM. Portugal, Guimarães (2016)Google Scholar
  12. 12.
    Valentim, B., Rocha, R., Guedes, A.: Quercus suber cork and respective fly ash characterization by FEG-ESEM/EDS. In: 10th European Conference on Industrial Furnaces and Boilers: (2015)Google Scholar
  13. 13.
    Valentim, B., Flores, D., Guedes, A., Guimarães, R., Shreya, N., Paul, B., Ward, C.: Notes on the occurrence of phosphate mineral relics and spheres (phosphospheres) in coal and biomass fly ash. Int. J. Coal Geol. 154–155, 43–56 (2016)CrossRefGoogle Scholar
  14. 14.
    Vassilev, S., Baxter, D., Vassileva, C., Morgan, T.: An overview of the organic and inorganic phase composition of biomass. Fuel 94, 1–33 (2012)CrossRefGoogle Scholar
  15. 15.
    Vassilev, S., Baxter, D., Andersen, L., Vassileva, C.: An overview of the composition and application of biomass ash. Part 1: Phase-mineral and chemical composition and classification. Fuel 10, 40–76 (2013)CrossRefGoogle Scholar
  16. 16.
    Gao, R., Jiao, Z., Wang, Y., Xu, L., Xia, S., Zhang, H.: Eco-friendly synthesis of rutile TiO2 nanostructures with controlled morphology for efficient lithium-ion batteries. Chem. Eng. J. 304, 156–164 (2016)CrossRefGoogle Scholar
  17. 17.
    Costa, A., Vilar, M., Lira, H., Kiminami, R., Gama, L.: Síntese e caracterização de nanopartículas de TiO2. Cerâmica 52, 255–259 (2006)Google Scholar
  18. 18.
    Koukouzas, N., Ward, C., Papanikolaou, D., Li, Z., Ketikidis, C.: Quantitative evaluation of minerals in fly ashes of biomass, coal and biomass–coal mixture derived from circulating fluidised bed combustion technology. J. Hazard. Mater. 169, 100–107 (2009)CrossRefGoogle Scholar
  19. 19.
    Dabler, A., Feltz, A., Jung, J., Ludwig, W., Kaiserberger, E.: Characterization of rutile and anatase powders by thermal analysis. J. Therm. Anal. Calorim. 33(3), 803–809 (2005)CrossRefGoogle Scholar
  20. 20.
    Saleiro, G., Cardoso, S., Toledo, R., Holanda, J.: Avaliação das fases cristalinas de dióxido de titânio suportado em cerâmica vermelha. Cerâmica 56, 162–167 (2010)CrossRefGoogle Scholar
  21. 21.
    Baudys, M., Krysa, J., Zlámal, M., Mills, A.: Weathering tests of photocatalytic facade paints containing ZnO and TiO2. Chem. Eng. J. 261, 83–87 (2015)CrossRefGoogle Scholar
  22. 22.
    Grinis, L., Kotlyar, S., Ruhle, S., Grinblat, J., Zaban, A.: Conformal nano-sized inorganic coatings on mesoporous TiO2 films for low-temperature dye-sensitized solar cell fabrication. Adv. Funct. Mater. 20, 282–288 (2010)CrossRefGoogle Scholar
  23. 23.
    Guimarães, R., Carvalho, J., Leal, V., Dias, A.: Caracterização, proposta de tratamento e recuperação de metais dos resíduos dos dispositivos médicos de implante ativo. Comunicações Geológicas 101, 1011–1014 (2014)Google Scholar
  24. 24.
    Junkar, I., Kulkarni, M., Drašler, B., Rugelj, N., Mazare, A., Flašker, A., Iglič, A.: Influence of various sterilization procedures on TiO2 nanotubes used for biomedical devices. Bioelectrochemistry 109, 79–96 (2016)CrossRefGoogle Scholar
  25. 25.
    Smijs, T., Pavel, S.: Titanium dioxide and zinc oxide nanoparticles in sunscreens: focus on their safety and effectiveness. Nanotechnol. Sci. Appl. 2011, 4, 95–112 (2011)CrossRefGoogle Scholar
  26. 26.
    Visa, M., Isac, L., Duta, A.: New fly ash TiO2 composite for the sustainable treatment of wastewater with complex pollutants load. Appl. Surf. Sci. 339, 62–68 (2015)CrossRefGoogle Scholar
  27. 27.
    Wang, C., Hwang, W., Chu, H., Lin, H., Ko, H., Wang, M.: Kinetics of anatase transition to rutile TiO2 from titanium dioxide precursor powders synthesized by a sol-gel process. Ceram. Int. 42, 13136–13143 (2016)CrossRefGoogle Scholar
  28. 28.
    Wojciechowski, K., Zukowska, G., Korczagin, I., Malanowski, P.: Effect of TiO2 on UV stability of polymeric binder films used in waterborne facade paints. Prog. Org. Coat. 85, 123–130 (2015)CrossRefGoogle Scholar
  29. 29.
    Zhang, L., Zhang, J., Jiu, H., Zhang, X., Xu, M.: Graphene-based hollow TiO2 composites with enhanced photocatalytic activity for removal of pollutants. J. Phys. Chem. Solids 86, 82–89 (2015)CrossRefGoogle Scholar
  30. 30.
    Hwang, J., Sun, X., Li, Z.: Unburned carbon from fly ash for mercury adsorption: I. Separation and characterization of unburned carbon. J. Miner. Mater. Charact. Eng. 1, 39–60 (2002)Google Scholar
  31. 31.
    Batra, V., Urbonaite, S., Svensson, G.: Characterization of unburned carbon in bagasse fly ash. Fuel 87, 2972–2976 (2008)CrossRefGoogle Scholar
  32. 32.
    Valentim, B., Hower, J., Guedes, A., Flores, D.: Scanning electron microscopy and energy-dispersive X-ray spectroscopy of low-sulfur coal fly ash. Int. J. Energy Clean Environ. 10, 147–166 (2009)CrossRefGoogle Scholar
  33. 33.
    ISO 7404-2: Methods for the Petrographic Analysis of Bituminous Coal and Anthracite — Part 2: Preparation of Coal Samples. International Organization for Standardization, 12 pp: (2009)Google Scholar
  34. 34.
    Suárez-Ruiz, I., Valentim, B., Borrego, A.G., Bouzinos, A., Flores, D., Kalaitzidis, S., Malinconico, M.L., Marques, M., Misz-Kenan, M., Predeanu, G., Montes, J.R., Rodrigues, S., Savalas, G., Wagner, N.: Petrographic Classification of Fly Ash Components. In: International Committee for Coal and Organic Petrology (ICCP; 203 pp. (2015)Google Scholar
  35. 35.
    Suárez-Ruiz, I., Valentim, B., Borrego, A.G., Kalaitzidis, S., Flores, D., Malinconico, M.L., Marques, M., Misz-Kennan, M., Predeanu, G., Montes, J.R., Rodrigues, S., Savalas, G., Wagner, N.: Development of a petrographic classification of fly-ash components from coal combustion and co-combustion. (An ICCP Classification System, Fly-Ash Working Group – Commission III). Int. J. Coal Geol. 183, 188–203 (2017)CrossRefGoogle Scholar
  36. 36.
    Valentim, B., Białecka, B., Gonçalves, P.A., Guedes, A., Guimarães, R., Cruceru, M., Całus-Moszko, J., Popescu, L.G., Predeanu, G., Santos, A.C.: Undifferentiated inorganics” in coal fly ash and bottom ash: calcispheres, magnesiacalcispheres, and magnesiaspheres. Minerals 2018 8, 140 (2018)Google Scholar
  37. 37.
    Norrish, K., Hutton, J.: An accurate X-ray spectrographic method for the analysis of a wide range of geological samples. Geochim. Cosmochim. Acta 33, 431–453 (1969)CrossRefGoogle Scholar
  38. 38.
    Taylor, J.: Computer programme for standard less quantitative analysis of minerals using the full power diffraction profile. Power Diffraction 6(1), 2–9 (1991)CrossRefGoogle Scholar
  39. 39.
    Ward, C.R., French, D.: Determination of glass content and estimation of glass composition in fly ash using quantitative X-ray diffractometry. Fuel 85, 2268–2277 (2006)CrossRefGoogle Scholar

Copyright information

© Springer Nature B.V. 2019

Authors and Affiliations

  • Renato Guimarães
    • 1
  • Alexandra Guedes
    • 1
  • Bruno Valentim
    • 1
    Email author
  1. 1.Instituto de Ciências da Terra (ICT)Faculdade de Ciências da Universidade do PortoPortoPortugal

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