Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
576945 | Journal of Hazardous Materials | 2014 | 7 Pages |
Abstract
In this study, we have investigated the feasibility of using a thermochemical technique on â¼17% chrysotile-containing roofing sheet or slate (ACS), in which 5 N sulfuric acid-digestive destruction was incorporated with 10-24-h heating at 100 °C. The X-ray diffraction (XRD) and the polarized light microscopy (PLM) results have clearly shown that raw chrysotile asbestos was converted to non-asbestiform material with no crystallinity by the low temperature thermochemical treatment. As an alternative to the use of pricey sulfuric acid, waste sulfuric acid discharged from a semiconductor manufacturing process was reused for the asbestos-fracturing purpose, and it was found that similar removals could be obtained under the same experimental conditions, promising the practical applicability of thermochemical treatment of ACWs. A thermodynamic understanding based on the extraction rates of magnesium and silica from a chrysotile structure has revealed that the destruction of chrysotile by acid-digestion is greatly influenced by the reaction temperatures, showing a 80.3-fold increase in the reaction rate by raising the temperature by 30-100 °C. The overall destruction is dependent upon the breaking-up of the silicon-oxide layer - a rate-limiting step. This study is meaningful in showing that the low temperature thermochemical treatment is feasible as an ACW-treatment method.
Related Topics
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Authors
Seong-Nam Nam, Seongkyeong Jeong, Hojoo Lim,