Abstract

Feasibility to obtain ferric arsenate starting from arsenic containing gas in contact with Fe 2O 3 has been studied. Thermodynamic stability of the system Fe-As-O was analysed in order to verify conditions to form Fe xAs yO z type compounds. Experiments were made using a hematite sample suspended in a thermogravimetric device. As 4O 6 was generated starting from solid As 2O 3 which was circulating through the iron oxide. Final samples were analysed chemically and by means of DRX, verifying the formation of FeAsO 4, FeAsO 4·H 2O and FeAs 4O·(H 2O) 2 in small quantities. Tests in porous bed and pellets were carried out, studying the effect of: porosity, temperature and oxygen potential. The largest conversion obtained was 10 % at 800°C, pO 2 = 50 % and porosity = 0.883.