Physicochemical stability under inert and reductive atmospheres of Li_2TiO_3 produced from Li_2CO_3 obtained from Argentinean brines

摘要

Lithium metatitanate (Li2TiO3) is one of the most promising candidates as tritium breeder material in a fusion reactor due to its physical and chemical properties. In this paper, the syntheses of Li2TiO3 by combustion in solution (SCS) and solid-solid (SSS) were developed using as raw material Li2CO3 produced from Argentinean brines and TiO2. In SCS, aqueous solution of Li2CO3 and TiO2 as metal precursors, citric/tartaric acids as complexing agent/fuel and HNO3 as oxidant was formed, heated to dryness and then self-combusted. The solid obtained was calcined at 550 degrees C for 12 h to obtain nanometric Li2TiO3 (monoclinic phase, 90%), with particle sizes 0.5 mu m and meso/macropores. In SSS, Li2CO3-TiO2 mixture was ball milled in air at room temperature and subsequently annealed. The effect of milling time and calcined temperature in the formation of Li2TiO3 was studied. High yields of Li2TiO3 ( 90% and 99%) were obtained even at low heating temperatures (400 and 600 degrees C for 24 h, respectively). The synthesized powders show mean grain sizes in the nanometric range, particle sizes 0.7 mu m and macropores. Changes that occur during heat treatment in inert and slightly reductive atmospheres (5% H-2/Ar) were identified.