Study on Purification Diatomite with nitric acid by Thermal Closed System

Abstract

Abstract.In this research, a purification approach using nitric acid leaching at thermal closed system was developed to improve the porous structure of raw diatomite by removal of impurities from its surface and clogged pores. The feasibility and efficiency of this approach were determined by XRF for chemical constitution of diatomite, SEM for morphology and BET for specific surface area of purified diatomite. The investigations indicated that the content of SiO 2 was in order of 85.14% for raw diatomite and 98% for purified diatomite, the content of Fe 2 O 3 decreases after purified; the integrity of the porous structure was confirmed by SEM, and increase in specific surface area from 18m 2 ·g -1 to 36m 2 ·g -1 .