Browsing by Author "Múgica, J. C."
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Item Development of a new process to recover aluminium from thin complex aluminium scrap to employ for primary aluminium alloys(2022-03-01) Vicario, I.; Antoñanzas, J.; Yurramendi, L.; Múgica, J. C.; Abuin, A.; PROMETAL; VALORIZACIÓN DE RESIDUOS; Tecnalia Research & Innovation; SGCurrent thermal processes for the treatment of metals contaminated with impurities, especially with high contents of organic compounds, present problems in obtaining the metal fraction: the metal fraction oxidises with increasing process temperature and the contact with organic compounds. Often, the quality of aluminium obtained from "dirty" raw materials does not allow using it for applications requiring high metal purity or low metal oxidation (alloying tablets, aluminium shots, ...), or for HPDC structural parts. Some aluminium scrap streams cannot be recovered with existing processes and new developments are needed. A new two-step continuous process has been developed. It consists of a heating process at 300°C in a controlled oxidising atmosphere furnace, followed by a second heating process at 400-550°C in an inert atmosphere, which results in a combined thermo-mechanical action. The obtained clean material can be continuously sintered under pressure, obtaining a product with a density close to 2.7 g/cc. Several "dirty" materials with initial contents up to 15% wt. C and up to 1.5% wt. O have been studied, reaching to final products containing as low as 0.15% wt. C and 0.3% wt. O. An example with a filter dust from shredding of aluminium profiles is described. The final composition of the product obtained after the treatment allows using the recycled aluminium as a high quality secondary raw material for aluminium alloying tablets, aluminium powder and high-performance aluminium casting alloys.Item Hydrolysis of animall fats by lipase at temperatures below their melting points(1992-08) de Renobales, Mertxe; Agud, I.; Lascaray, J. M.; Múgica, J. C.; Landeta, L. C.; Solozábal, R.; Centros PRE-FUSION TECNALIA - (FORMER); Tecnalia Research & InnovationWe have studied the hydrolysis of high melting animal fats by the lipase from Candidarugosa at temperatures between 20°C and 37°C without the addition of surfactants or organic solvents. To establish the practical applications of this process we investigated the optimal conditions of the reaction at high substrate concentrations (50% fat w/v) to achieve 95% hydrolysis (or better) in 24 hours. Experiments were conducted in solid emulsions without constant stirring (500 ml total reaction volume). Under all conditions tested, edible pork lard was a better substrate than inedible beef tallow yielding up to 96% hydrolysis with as low as 0.3 g lipase/Kg fat or 98% hydrolysis with 0.5 g lipase/Kg fat. The optimum temperature for the hydrolysis of edible pork lard was around 30°C. Inedible beef tallow and pork lard did not exhibit a clear optimum temperature. Inedible lard gave results intermediate between those of edible lard and inedible beef tallow.Item Treatment and immobilization of low and intermediate level radioactive waste by plasma(1999) Múgica, J. C.; Aguirre, P.; Alvarez-Mir, F.; Del Río, S.; Zuloaga, P.; Tecnalia Research & InnovationThe thermal treatment of waste based on plasma technology allows the destruction of organics by a pyrolysis or air controlled process, and the introduction of the inorganic material into a molten pool. As a result, the new products tapped from the reactor are obtained with a significant volume reduction and with appropriate properties to be stored safety. Plasma technology permits the use of different gases at low flow. Consequently the process of organic oxidation can be controlled and compact equipment allows high productivity. Many countries have, or will have in the near future, a major problem in stocking these wastes in their existing installations. The proposed process is an alternative which reduces the volume of waste to be disposed of.