Sintering of sepiolite-rich by-products for the manufacture of lightweight aggregates: technological properties, thermal behavior and mineralogical changes




Aggregate, Ceramic, Waste treatment, X-ray Diffraction (XRD), Sepiolite


A sepiolite mining by-product (SEP) has been studied as major component for lightweight aggregate (LWA) manufacture. Pellet bursting during firing was avoided by the addition of 2.5 wt% of thermoplastic waste (P) and 2.5 wt% P + 2.5 wt% carbon fiber residue (FC) in powder form. The mixtures were pelletized and then sintered at 1225º˚C for 4 minutes in a rotary kiln. Highly porous white LWAs with good mechanical strength were produced. A mineralogical study revealed the formation of amorphous phase ( > 50%) and minor proportions of enstatite, protoenstatite and diopside. Quartz was the only inherited mineral, appearing in the form of isolated phenocrysts within a general porphyritic texture. The result of this study suggests the promising use of sepiolite (whether or not in residue form) for the manufacture of high quality LWAs.


Download data is not yet available.


Goktas, A.A.; Misirli, Z.; Baykara, T. (1997) Sintering behaviour of sepiolite. Ceram. Int. 23, 305-311.

Zhang, Y.; Wang, L.; Wang, F.; Liang, J.; Ran, S.; Sun, J. (2017) Phase transformation and morphology evolution of sepiolite fibers during thermal treatment. Appl. Clay Sci. 143, 205-211.

Pascual, C.; Criado, E.; Recio, P.; Martínez, R.; De Aza, A.H.; Valle, F.J.; Mañueco, C. (2011) La porcelana de sepiolita de Bartolomé Sureda (1802-1808). Investigación arqueométrica sobre la Real Fábrica de Buen Retiro. Bol. Soc. Esp. Ceram. Vidrio. 50 [6], 311-328.

Ran, S-s.; Wang. L-j.; Zhang, Y-d.; Liang, J-s. (2016) Reinforcement of bone china by the addition of sepiolite nano-fibers. Ceram. Int. 42, 13485-13490.

Li, J.; Liang, J.; Wang, F.; Wang, L. (2015) Effect of sepiolite fibers addition on sintering behavior of sanitary bodies. Appl. Clay Sci. 105-106, 231-235.

Noda, H.; Miyagawa, K.; Kobayashi, M.; Horiguchi, H.; Ozawa, K.; Kumada, N.; Yonesaki, Y.; Takei, T.; Kinomura, N. (2009) Preparation of cordierite from fibrous sepiolite. J. Ceram. Soc. Jpn. 117 [1371] 1236-1239.

Zhou, J-e.; Dong, Y.; Hampshire, S.; Meng, G. (2011) Utilization of sepiolite in the synthesis of porous cordierite ceramics. Appl. Clay Sci. 52 [3], 328-332.

Suárez, S.; Coronado, J.M.; Portela, R.; Martín, J.C; Yates, M.; Avila, P.; Sánchez B. (2008) On the preparation of TiO2-sepiolite hybrid materials for the photocatalytic degradation of TCE: influence of TiO2 distribution in the mineralization. Environ. Sci. Technol. 42 [16], 5892-5896.

Moreno-Maroto, J.M.; González-Corrochano, B.; Alonso-Azcárate, J.; Rodríguez, L.; Acosta, A. (2017) Development of lightweight aggregates from stone cutting sludge, plastic wastes and sepiolite rejections for agricultural and environmental purposes. J. Environ. Manage. 200, 229-242.

Moreno-Maroto, J.M; González-Corrochano, B.; Alonso- Azcárate, J.; Rodríguez, L.; Acosta, A. (2017) Manufacturing of lightweight aggregates with carbon fiber and mineral wastes. Cem. Concr. Compos. 83, 335-348.

Moreno-Maroto, J.M.; González-Corrochano, B.; Alonso-Azcárate, J.; Martínez García, C. (2019) A study on the valorization of a metallic ore mining tailing and its combination with polymeric wastes for lightweight aggregates production. J. Cleaner Prod. 212, 997-1007.

Murray, H.H.; Pozo, M.; Galán, E. (2011) An introduction to palygorskite and sepiolite deposits-location, geology and uses. In: Galán, E., Singer, A. (Eds.), Developments in Palygorskite-Sepiolite Research. A New Outlook on These Nanomaterials. Developments in Clay Science. 3, 85-99. Elsevier, Amsterdam.

Estadística Minera de España (2016) Gobierno de España. Ministerio de Energía, Turismo y Agenda Digital. Secretaría de Estado. Dirección General de Política Energética y Minas. (Mining Statistics of Spain in 2016, Spanish Government).

BGS (2018) World Mineral Production 2012-2016. Brithish Geological Survey, Natural Evironmental Research Council. ISBN:978-0-85272-882-6 (website version).

European Commission (2014) Commission Decision 2014/955/EU of 18 December 2014 amending Decision 2000/532/EC on the list of waste pursuant to Directive 2008/98/EC of the European Parliament and of the Council Text with EEA relevance. Official Journal of the European Union, 30/12/2014.

Yasuda, Y. (1991) Sewage-sludge utilization in Tokyo. Water Sci. Technol. 23 [10-12], 1743-1752.

De Santiago Buey, C.; Raya García, M. (2008) Análisis del peso específico y porosidad de materiales porosos mediante picnometría de helio. Ing. Civil. 151, 95-103. ISSN 0213-8468.

Buurman, P.; Pape, Th.; Reijneveld, J. A.; de Jong, F.; van Gelder, E. (2001) Laser-diffraction and pipette-method grain sizing of Dutch sediments: correlations for fine fractions of marine, fluvial, and loess samples. Neth. J. Geosci. 80 [2], 49-57.

Eshel, G.; Levy, G.J.; Mingelgrin, U.; Singer, M.J. (2004) Critical evaluation of the use of laser diffraction for particle-size distribution analysis. Soil Sci. Soc. Am. J. 68 [3], 736-743.

Ferro, V.; Mirabile, S. (2009) Comparing particle size distribution analysis by sedimentation and laser diffraction method. J. Ag. Eng. - Riv. Ing. Agr. 2, 35-43.

EN-933-9 (1999) Tests for geometrical properties of aggregates. Part 9: Assessment of fines. Methylene blue test. European Committee for Standardization.

Santamarina, J.C.; Klein, K.A.; Wang, Y.H.; Prencke, E. (2002) Specific surface: determination and relevance. Can. Geotech. J. 39 [1], 233-241.

Ingamells, C.O. (1970) Lithium metaborate flux in silicate analysis. Anal. Chim. Acta. 52, 323-334.

Riley, C.M. (1951) Relation of chemical properties to the bloating of clays. J. Am. Ceram. Soc. 34 [4], 121-128.

Fakhfakh, E.; Hajjaji, W.; Medhioub, M.; Rocha, F.; López- Galindo, A.; Setti, M.; Kooli, F.; Zargouni, F.; Jamoussi, F. (2007) Effects of sand addition on production of lightweight aggregates from Tunisian smectite-rich clayey rocks. Appl. Clay Sci. 35 [3-4], 228-237.

UNE 103-103-94 (1994) Determinación del límite líquido de un suelo por el método del aparato de Casagrande. Asociación Española de Normalización y Certificación AENOR Norma española.

Moreno-Maroto, J.M.; Alonso-Azcárate, J. (2015) An accurate, quick and simple method to determine the plastic limit and consistency changes in all types of clay and soil: The thread bending test. Appl. Clay Sci. 114, 497-508.

Moreno-Maroto, J.M.; Alonso-Azcárate, J. (2016) A bending test for determining the atterberg plastic limit in soils. J. Vis. Exp. 112, e54118.

Moreno-Maroto, J.M.; Alonso-Azcárate, J. (2017) Plastic limit and other consistency parameters by a bending method and interpretation of plasticity classification in soils. Geotech. Test. J. 40 [3], 467-482.

ASTM D 4318-10e1 (2014) Standard test methods for liquid limit, plastic limit, and plasticity index of soils. Annual Book of ASTM Standards, ASTM International, West Conshohocken, PA.

Moreno-Maroto, J.M.; Alonso-Azcárate, J. (2018) What is clay? A new definition of “clay” based on plasticity and its impact on the most widespread soil classification systems. Appl. Clay Sci. 161, 57-63.

Gippini, E. (1969) Contribution à l’étude des proprietés de molage des argiles et des mélanges optimaux de matières premières. L’Indus. Céram. 619, 423-435.

EN-1097-3 (1998) Tests for mechanical and physical properties of aggregates. Part 3: Determination of loose bulk density and voids. European Committee for Standardization.

EN-1097-6 (2013) Tests for mechanical and physical properties of aggregates. Part 6: Determination of particle density and water absorption. European Committee for Standardization.

Bernhardt, M.; Tellesbø, H.; Justnes, H.; Wiik, K. (2013) Mechanical properties of lightweight aggregates. J. Eur. Ceram. Soc. 33, 2731-2743.

Yashima, S.; Kanda, Y.; Sano, S. (1987) Relationship between particle size and fracture energy or impact velocity required to fracture as estimated from single particle crushing. Powder Technol. 51 [3], 277-282.

Li, Y.; Wu, D.; Zhang, J.; Chang, L.; Dihua, W.; Fang, Z.; Shi, Y. (2000) Measurement and statistics of single pellet mechanical strength of differently shaped catalysts. Powder Technol. 113 [1-2], 176-184.

Moreno-Maroto, J.M.; González-Corrochano, B.; Alonso- Azcárate, J.; Rodríguez, L.; Acosta, A. (2018) Assessment of crystalline phase changes and glass formation by Rietveld-XRD method on ceramic lightweight aggregates sintered from mineral and polymeric wastes. Ceram. Int. 44, 11840-11851.

NIST (2012) Certificate of analysis. Standard reference material 676a. Alumina powder for quantitative analysis by X-ray diffraction. National Institute of Standards and Technology.

Bish, D.L.; Post, J.E. (1993) Quantitative mineralogical analysis using the Rietveld full pattern fitting method. Am. Mineral. 78, 932-940.

Yasukawa, K.; Terashi, Y.; Nakayama, A. (1998) Crystallinity analysis of glass-ceramics by the Rietveld method. J. Am. Ceram. Soc. 81 [11] 2978-2982.

De la Torre, A.G.; Bruque, S.; Aranda, M.A.G (2001) Rietveld quantitative amorphous content analyses. J. Appl. Crystallogr. 34 [2], 196-202.

Raith, M.M.; Raase, P.; Reinhardt, J. (2012) Guide to thin section microscopy. Second Edition. ISBN 978-3-00-037671-9 (PDF) (2012)

Barnes, G.E. (2013) An apparatus for the determination of the workability and plastic limit of clays. Appl. Clay Sci. 80-81, 281-290.

Moreno-Maroto, J.M.; Cobo-Ceacero, C.J.; Uceda- Rodríguez, M.; Cotes-Palomino, T.; Martínez García, C.; Alonso-Azcárate, J. (2020) Unraveling the expansion mechanism in lightweight aggregates: Demonstrating that bloating barely requires gas. Constr. Build. Mater. 247, 118583.

Cougny, G. (1990) Specifications for clayey raw materials used to produce expanded lightweight aggregates. Bull. Int. Assoc. Eng. Geol. 41, 47-55.

Földvári, M. (2011) Handbook of thermogravimetric system of minerals and its use in geological practice. Occasional Papers of the Geological Institute of Hungary. Geological Institute of Hungary. Volume 213. (2011)

Heller-Kallai, L.; Miloslavski, I.; Grayevsky, A. (1989) Evolution of hydrogen on dehydroxylation of clay minerals. Am. Mineral. 74, 818-320.

Mathur, A.; Varma, I.K. (1992) Effect of structure on thermal behaviour of nadimide resins: 1. Polymer. 33 [22], 4845-4850.

Piquero, T.; Vincent, H.; Vincent, C.: Bouix, J. (1995) Influence of carbide coatings on the oxidation behavior of carbon fibers. Carbon. 33 [4], 455-467.

Mourad, A-H.I.; Akkad, R.O.; Soliman, A.A.; Madkour, T.M. (2009) Characterisation of thermally treated and untreated polyethylene-polypropylene blends using DSC, TGA and IR techniques. Plast. Rubber Compos. 38 [7], 265-278.

Selladurai, M.; Sundararajan, P.R.; Sarojadevi, M. (2012) Synthesis, thermal and mechanical properties of modified PMR/carbon fiber composites. Chem. Eng. J. 203, 333-347.

Kim, J.; Moon, T.J.; Howell, J.R. (2002) Cure kinetic model, heat of reaction, and glass transition temperature of AS4/3501-6 graphite-epoxy prepregs. J. Compos. Mater. 36 [21], 2479-2498.

Liu, W.; Varley, R.J.; Simon, G.P. (2007) Understanding the decomposition and fire performance processes in phosphorus and nanomodified high performance epoxy resins and composites. Polymer. 48 [8], 2345-2354.

Li, S.; Zhang, Y.M.; Zhou, Y.F. (2012) Preparation and characterization of sol-gel derived zirconia coated carbon fiber. Surf. Coat. Technol. 206 [23], 4720-4724.

Conley, J.E.; Wilson, H.; Kleinfelter, T.A.; and others (1948) Production of lightweight concrete aggregates from clays, shales, slates and other materials. US Bureau of mines report of investigation, 4401, 121 pp.

EN-13055-1 (2002) Lightweight aggregates. Part 1: Lightweight aggregates for concrete, mortar and grout. European Committee for Standardization.

Lo, T.Y.; Cui, H.Z. (2004) Effect of porous lightweight aggregate on strength of concrete. Mater. Lett. 58 [6], 916-919.

Soriano-Carrillo, J. (1980) Influencia de la naturaleza mineralógica de las adiciones en el comportamiento de la pasta endurecida del cemento Portland. Rev. Obras Públ. 127 [3186], 861-867.

Gadea, J.; Soriano, J.; Martín, A.; Campos, P.L.; Rodríguez, A.; Junco, C.; Adán, I.; Calderón, V. (2010) The alkali-aggregate reaction for various aggregates used in concrete. Mater. Construcc. 60 [299], 69-78.

Wasserman, R.; Bentur, A. (1997) Effect of lightweight fly ash aggregate microstructure on the strength of concretes. Cem. Concr. Res. 27 [4], 525-537.

Nguyen, L.H.; Beaucour, A-L.; Ortola, S.; Noumowé, A. (2014) Influence of the volume fraction and the nature of fine lightweight aggregates on the thermal and mechanical properties of structural concrete. Constr. Build. Mater. 51, 121-132.

Kourti, I.; Cheeseman, C.R. (2010) Properties and microstructure of lightweight aggregate produced from lignite coal fly ash and recycled glass. Resour. Conserv. Recycl. 54 [11], 769-775.

González-Corrochano, B.; Alonso-Azcárate, J.; Rodas, M.; Luque, F.J.; Barrenechea, J.F. (2010) Microstructure and mineralogy of lightweight aggregates produced from washing aggregate sludge, fly ash and used motor oil. Cem. Concr. Compos. 32 [9], 694-707.

Erol, M.; Küçükbayrak, S.; Ersoy-Meriçboyu, A.; Öveçoḡlu, M.L. (2001) Crystallization behaviour of glasses produced from fly ash. J. Eur. Ceram. Soc. 21, 2835-2841.

Swanson, S.E. (1977) Relation of nucleation and crystalgrowth rate to the development of granitic textures. Am. Mineral. 62 [9-10] 966-978.



How to Cite

Moreno-Maroto, J. M. ., González-Corrochano, B. ., Alonso-Azcárate, J. ., & Martínez-García, C. . (2021). Sintering of sepiolite-rich by-products for the manufacture of lightweight aggregates: technological properties, thermal behavior and mineralogical changes. Materiales De Construcción, 71(341), e241.



Research Articles

Funding data

Junta de Comunidades de Castilla-La Mancha
Grant numbers PEII-2014-025-P

European Social Fund
Grant numbers 2014/10620

European Social Fund
Grant numbers 2016/12998