MODIFICATION OF DIATOMITES BY THERMAL TREATMENT

ELSA M. FARFÁN TORRES; FÁTIMA LÓPEZ; EDGARDO L. SHAM

Neuquén

Jornada; XI Jornadas Argentinas de Tratamiento de Minerales; 2012

Facultad de Ingeniería (UNCo), IDEPA (CONICET-UNCo), CETMIC (CONICET La Plata-CIC), CINDEFI (CONICET La Plata-UNLP)

Diatomites from the Puna salteña, DC, were calcined at different temperatures using two types of thermal treatment: 1) at constant temperature and 2) by means of thermal shock. The obtained materials were characterized by means of Scanning Electronic Microscopy (SEM), Infrared Spectroscopy with Fourier Transform (FTIR), evaluation of their specific surface and textural characteristics using B.E.T. isotherms and determination of the content of Fe2+. The studies MEB show that at calcination temperatures between 800ºC and 1000ºC, it is clearly observed that the breakage of frustules and the sinterization of internal pores is higher for the treatment of thermal shock. In agreement with this observation the specific surface decreases drastically after the thermal treatment, going on from 21 m2/g to 2 m2/g. Both the natural diatomitas as the ones thermally treated are mesoporous dusts, that increase their pore size when the temperature of treatment increases. The content of iron also decreases drastically with the temperature of calcination being lower than 0,042 % from temperatures of calcination of 650ºC, which make these materials suitable for its use in the food industry.