Browsing by Author "Yurramendi, Lourdes"
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Item Bioleaching of metals from secondary materials using glycolipid biosurfactants(2021-03-15) Castelein, Martijn; Verbruggen, Florian; Van Renterghem, Lisa; Spooren, Jeroen; Yurramendi, Lourdes; Du Laing, Gijs; Boon, Nico; Soetaert, Wim; Hennebel, Tom; Roelants, Sophie; Williamson, Adam J.; VALORIZACIÓN DE RESIDUOSWith the global demand for economically important metals increasing, compounded by the depletion of readily accessible ores, secondary resources and low-grade ores are being targeted to meet growing demands. Novel technologies developed within biobased industries, such as microbial biosurfactants, could be implemented to improve the sustainability of traditional hydrometallurgy techniques. This study investigates newly developed microbial biosurfactants (acidic- and bolaform glycolipids) for the leaching of metals (particularly Cu and Zn) from a suite of mine tailings, metallurgical sludges and automotive shredder residues. Generally, acidic sophorolipids were the most performant, and optimal Cu leaching was observed from a fayalite slag (27%) and a copper sulfide mine tailing (53%). Further investigation of the leached fayalite material showed that leaching was occurring from small metallic Cu droplets in this material via a corrosion-based mechanism, and/or from Cu-Pb sulfides, selective against dominant Fe-silicate matrices. This study highlights that acidic sophorolipid microbial biosurfactants have the potential to leach Cu and Zn from low-grade secondary materials. It also provides important fundamental insights into biosurfactant-metal and mineral interactions that are currently unexplored. Together, the convergence of leaching and mining industries with bio-industries can improve material recovery and will positively impact the bio- and circular economies and the environment.Item Enhancing rare-earth recovery from lamp phosphor waste(2019-08) Yurramendi, Lourdes; Gijsemans, Lukas; Forte, Federica; Aldana, Jose Luis; del Río, Carmen; Binnemans, Koen; VALORIZACIÓN DE RESIDUOSIn the present work rare-earth recovery was performed from a residue of a hydrometallurgical process based on sulphuric acid leaching of lamp phosphor waste by which the red phosphor Y2O3:Eu3+ was removed for further recovery. The undissolved residue is rich in lanthanum, cerium and the valuable terbium, present as phosphates and aluminates in the green and blue phosphors. The process here proposed is based on an integrated pyro-hydrometallurgical approach involving a thermal treatment (roasting in the presence of sodium carbonate) aimed at converting rare-earth phosphates into oxides, which can be more easily leached by mineral acids (HCl and H2SO4) in a further leaching step. Rare-earth recovery from the leachate was then performed by solvent extraction with the extractant di-(2-ethylhexyl)phosphoric acid, D2EHPA, followed by precipitation with oxalic acid and calcination. 82% Ce, 75% La and 82% Tb were recovered as mixed La2O3 + CeO2 oxide (99% purity) and Tb4O7 (64% purity).Item Integrated process for the recovery of yttrium and europium from CRT phosphor waste(2019) Forte, Federica; Yurramendi, Lourdes; Aldana, José Luis; Onghena, Bieke; Binnemans, Koen; VALORIZACIÓN DE RESIDUOSAn integrated process flow sheet for the recovery of yttrium and europium from waste cathode-ray tube (CRT) phosphors was developed. This flow sheet is based on a sequence of roasting, leaching with organic acids and precipitation steps. Zinc was efficiently removed from the roasted CRT phosphors by leaching with acetic acid, giving access to the rare earth content. Yttrium and europium were quantitatively leached from the residue by a 1 mol L−1 methanesulphonic acid (MSA) solution. Precipitation with oxalic acid gave a mixed Y/Eu oxalate of high purity (>99 wt%). Co-precipitation of zinc was less than 2 wt%.Item Rare Earths and the Balance Problem: How to Deal with Changing Markets?: How to Deal with Changing Markets?(2018-03-01) Binnemans, Koen; Jones, Peter Tom; Müller, Torsten; Yurramendi, Lourdes; VALORIZACIÓN DE RESIDUOSThe balance between the market demand and the natural abundance of the rare-earth elements (REEs) in ores, often referred to as the Balance Problem (or the Balancing Problem), is a major issue for REE suppliers. The ideal situation is a perfect match between the market demand for and the production of REEs, so that there are no surpluses of any of the REEs. This means that the rare-earth industry must find new uses for REEs that are available in excess and search for substitutes for REEs that have either limited availability or are high in demand. We present an overview of the trends in the applications for the different REEs and show that the demand for REEs for use in magnets, catalysts, and alloys is still increasing, while the application of REEs in polishing agents, glass, and ceramics are stable. On the other hand, the use of REEs in nickel–metal-hydride (NiMH) batteries and lamp phosphors is decreasing. These changes in the REE market have an influence on the Balance Problem, because the REEs that can be recycled from fluorescent lamps, cathode-ray tubes (CRTs), and NiMH batteries have to be at least partly reused in other applications. Magnesium and aluminum alloys offer an opportunity to mitigate the Balance Problem caused by these changes in the REE market. This is illustrated for REEs that can be recycled from fluorescent-lamp phosphor waste, CRT phosphors, and NiMH batteries. At present, five REEs (Nd, Eu, Tb, Dy, and Y) are being considered as very critical by Europe, the United States, and Japan, but we forecast that in the medium term, only neodymium will remain a critical REE. This paper discusses the relationship between criticality and the Balance Problem and shows how this relationship influences the market for specific REEs.Item Selective leaching of copper and zinc from primary ores and secondary mineral residues using biogenic ammonia(2021-02-05) Williamson, Adam J.; Verbruggen, Florian; Chavez Rico, Vania S.; Bergmans, Jef; Spooren, Jeroen; Yurramendi, Lourdes; Laing, Gijs Du; Boon, Nico; Hennebel, Tom; VALORIZACIÓN DE RESIDUOSWith the number of easily accessible ores depleting, alternate primary and secondary sources are required to meet the increasing demand of economically important metals. Whilst highly abundant, these materials are of lower grade with respect to traditional ores, thus highly selective and sustainable metal extraction technologies are needed to reduce processing costs. Here, we investigated the metal leaching potential of biogenic ammonia produced by a ureolytic strain of Lysinibacillus sphaericus on eight primary and secondary materials, comprised of mining and metallurgical residues, sludges and automotive shredder residues (ASR). For the majority of materials, moderate to high yields (30–70%) and very high selectivity (>97% against iron) of copper and zinc were obtained with 1 mol L−1 total ammonia. Optimal leaching was achieved and further refined for the ASR in a two-step indirect leaching system with biogenic ammonia. Copper leaching was the result of local corrosion and differences in leaching against the synthetic (NH4)2CO3 control could be accounted for by pH shifts from microbial metabolism, subsequently altering free NH3 required for coordination. These results provide important findings for future sustainable metal recovery technologies from secondary materials.Item TOXICOLOGICAL AND ENVIRONMENTAL PROPERTIES OF A CrIII/CHOLINE CHLORIDE BASED CHROME PLATING ELECTROLYTE(FEDERACION ASOCIACIONES INGENIEROS INDUSTRIALES ESPANA, ALAMEDA DE MAZARREDO, BILBAO, 69-48009, SPAIN, 2015-03) Yurramendi, Lourdes; Caballero, Susana; Alvarez, Noelia; Izagirre, Usoa; Cano, F.J.At present, industrial application of hard chromium electroplating is based on electrolytic baths of sulphuric acid and chromium trioxide solutions in water. Toxicological and environmental properties of these chromium (VI) baths show the convenience of searching for new CrVI free formulations. Research activities have shown that chromium metallic coatings from an ionic liquid (IL) using trivalent chromium salts can be successfully produced. A highly promising CrVI free, bright, thick and hard chromium deposition process has been developed based on an ionic liquid composed of Chromium chloride and Choline chloride. Jointly with technological properties evaluation, a methodological study on environmental risk analysis and on implications in health & safety for the referred ionic liquid bath has been carried out. With that aim, experimental tests on the basis of toxicological properties, of effects on human health and of environmental effects were conducted. Comparisons of the obtained results with the behaviour of traditional baths used for the same purpose were also accomplished, showing for the ionic liquid formulation a lower toxicity and less environmental risk than for the CrVI formulation.