Original Paper
DOI : https://doi.org/10.4491/KSEE.2015.37.6.371

J Korean Soc Environ Eng. 2015; 37(6): 371-379.

Published online 2015 June 30.

doi: https://doi.org/10.4491/KSEE.2015.37.6.371

A Study on the Characteristics of Chrysotile and Amosite by Acid and Heat Treatment

Jin Hyo Lee^1,2, Su Hyun Lee¹, Mi Hye Kang¹, Il Sang Bae¹, Ik Soo Kim¹, Kyu Mun Han¹, Soo Mi Eo¹, Kweon Jung¹, and Ja Yong Koo²

¹Atmospheric Research Department, Seoul Metropolitan Government Research Institute of Public Health and Environment
²Department of Environmental Engineering, University of Seoul

Corresponding Author: Email: jykoo@uos.ac.kr

Received 2015 May 15;    Accepted 2015 June 26.

This study is purposed to seek the characteristics of both asbestos in accordance with acid and heat treatment for chrysotile and amosite used mainly as building materials. Results of acid treatment, the refractive index, the elongation sign, the extinction of acid-treated chrysotile were mostly similar to those of untreated chrysotile regardless of pH, elapsed time. But the characteristics of acid-treated chrysotile were different from those of untreated chrysotile after 8 weeks, at pH 1.2 acidic solution. When chrysotile treated with acid, weight ratio (%) of O and Mg fluctuated greatly in accordance with acid treatment unlike Si. But the change of constituents ratio (%) was small as time passed after acid treatment. The refractive index, the elongation sign and the extinction of acid-treated amosite were mostly similar to those of untreated amosite regardless of pH, elapsed time. When amosite was treated with acid, weight ratio (%) of Fe slightly increased. But in case of O, a contrary tendency was seen. Results of heat treatment, the higher the temperature, the more increased the refractive index of chrysotile. When chrysotile was heated for 10 minutes at 1,100℃, the elongation sign of chrysotile changed from positive(+) to negative(-). The extinction of chrysotile didn't change apparently in accordance with heat treatment. Also weight ratio (%) of O and Mg fluctuated greatly in accordance with heat treatment unlike Si. The higher the temperature, the more increased the refractive index of amosite. The elongation sign and the extinction of amosite didn't change apparently in accordance with heat treatment. Also weight ratio (%) of O and Fe fluctuated greatly in accordance with heat treatment. But weight ratio (%) of Si and Mg of heated amosite were mostly similar to those of untreated amosite regardless of temperature, heating time.

Keywords : Asbestos, Acid Treatment, Heat Treatment, Polarized Light Microscope (PLM), Scanning Electron Microscope (SEM)