logo nano spa 1
  • Cabecera 1
    nanoscience and nanotechnology: small is different


“Closing the loop” in the industrial plant is one of the main targets of this research line. Recycling should begin already in the origin, meaning that industries should be able of reentering valuable recycled residues in the production line, instead of paying third parties for removal of wastes containing useful elements.

On the basis of the high demand for permanent magnets (PMs), recycling of the residues generated in the manufacturing process is beneficial from an environmental point of view but also economically interesting to reduce costs at the permanent magnet company while additionally guaranteeing sustainability. One of the main results that we have achieved in close collaboration with the PMs company IMA S.A. (Barcelona) is the recycling of ferrite residues generated during the fabrication of ferrite-based magnets. Ferrites are the most widely used PMs throughout the world, which account for about 90wt.% of all PMs on a weight base. Traditional uses are foreseen to expand by improvement of their properties through the application of phenomena at the nanoscale. The study has been published in one of the prestigious journals from the American Chemical Society [ACS Sustainable Chem. Eng. 5, 3243 (2017)] and shows two highlights closely interconnected and of importance from fundamental and technological points of view:
(i) Possibility of tuning microstructural and magnetic properties in ferrite powder, making possible the upgrade of a low-to-high quality magnetic ferrite powder. In this manner, saving costs are guaranteed for the company.
(ii) Successful recycling of ferrite powder residues.
Among the industrial highlights that have allowed scalability and implementation, the following ones can be remarked:
(a) The recycling process makes use of the facilities already existing in the company. No chemicals need to be added in the process.
(b) The parameters comprising the recycling process are comparable to those used in the processing of the ferrite starting powder.
(c) The magnetic quality of the recycled material is by far superior to that of the starting brand new material, resulting in a more competitive product.

The developed process guarantees sustainability by demonstrating a recycling method that can be cost-efficiently implemented in a permanent magnet manufacturing plant.

Figure 1. The quality of the recycled ferrite powder has been tested and compared to that of the new starting ferrite material. The magnetic properties of the recycled powder not only match those of the starting material acquired by the company for the production of magnets but exceed them. A coercivity value 3.5 times larger than that of the new starting ferrite powder, accompanied by a 25% increase in remanence, makes this material a new and improved ferrite product to re-enter the production chain in the factory with an extended applications range.

  • Prof. Alberto Bollero Real

    PhD: Technical University of Dresden. Germany
    Previous Position: Spintec CEA, Grenoble (France)
    Research: Permanent Magnets and Applications
    ORCID: 0000-0002-3282-0981
    Joining Date: July, 2010
    User Name: alberto.bollero
    Telephone: +34 91 299 87 58
    Bollero Real

    Alberto Bollero got his B.Sc degree in Physics from Universidad Complutense de Madrid. He was a PhD student at IFW-Dresden, working on nanocrystalline permanent magnets and got his PhD degree at Technical University of Dresden in 2003. He was Postdoc at University of Leipzig, studying magnetic and magnetotransport properties of thin films, and Marie Curie Fellow at SPINTEC (CEA-Grenoble) on exchange-bias systems for spintronics and sensing applications. Dr. Bollero was researcher at CIEMAT-Madrid working on flexible photovoltaic films and solar control coatings for architectural applications. He began his research activity at IMDEA Nanociencia in 2010 as Ramón y Cajal fellow and got the I3 Certification of scientific and technological excellence by MINECO in 2012.
In 2012 Dr. A. Bollero settled at IMDEA the laboratory of Permanent Magnets and since then he is Head of the Division of Permanent Magnets and Applications [http://www.nanoscience.imdea.org/division-permanent-magnets-applications].

    Research Lines

    • A. Bollero is Coordinator of the EU M-era.Net Project “NEXMAG” [www.nexmag.net], focused in the research of Mn-based permanent magnets alternatives to the controversial rare earth-based magnets. [Ref. MAT2014-56955-R]
    •  He is P.I. in the industrial project “GAMMA” together with the company Höganäs AB (Sweden), for development and implementation of novel permanent magnets solutions.
    • He is P.I. in the bilateral project “ENMA” between the Northeastern University Boston (Prof. Laura H. Lewis’ Group) and IMDEA Nanociencia, involving also the company IMA S.A. (Barcelona). [Ref. PCIN-2015-126]
    • He is also P.I. by IMDEA in the project “NANOFRONTMAG-CM” (coordinated by Prof. Rodolfo Miranda, Universidad Autónoma de Madrid) [www.nanofrontmag-cm.es]. [Ref. S2013/MIT-2850]
    • A. Bollero has been Coordinator of the EU Project NANOPYME [www.nanopyme-project.eu], dealing with the search of new permanent magnets based on hybrid ferrites; P.I. in a Bilateral (Germany-Spain) Project [Ref. 57050243] focused in the development of functional exchange-coupled permanent magnets bilayers with sensing applications, P.I. in a National Project SIESPER [MAT2011-25598] dealing with the exchange-bias phenomenon in nanostructured films.

    These projects position A. Bollero as P.I. on research projects that total over 5.5 M€.

    Relevant publications

    •  High coercive isotropic MnAl powders produced by ultrafast milling of gas atomized particles, J. Rial et al., J. Phys. D: Appl. Phys. 50, 105004 (2017).
    • Recycling of Strontium ferrite waste in a permanent magnet manufacturing plant, A. Bollero et al., ACS Sustainable Chem. Eng. 5, 3243 (2017).
    • Tunable nanocrystalline CoFe2O4 isotropic powders obtained by co-precipitation and ultrafast ball milling for permanent magnet applications, F.J. Pedrosa et al., RSC Adv. 6, 87282 (2016).
    • Inter-grain effects on the magnetism of M-type strontium ferrite, E. Céspedes et al., J. of Alloys and Compounds 692, 280 (2017).