Decomposition of Chrysotile Asbestos by Fluorosulfonic Acid
Industrial & Engineering Chemistry Research
The effect of a fluorosulfonic acid (FSO 3 H) aqueous solution on decomposing the chrysotile asbestos fibers was investigated by using FT-IR, XRD, and XPS. From the equilibrium of FSO 3 H in an aqueous medium (FSO 3 H + H 2 O ) HF + H 2 SO 4 ), the resulting H 2 SO 4 had a strong affinity for the external Mg(OH) 2 layers in the tubular, scroll-like chrysotile structure. This acid-base reaction led to the precipitation and lixiviation of MgSO 4 'H 2 O, MgO, and Mg 2+ ion. Once the breakage of
... the breakage of the outer Mg(OH) 2 layers occurred, HF readily diffused into the inner silicious layers and then reacted with silicates, converting them into SiO 2 hydrate and H 2 SiF 6 , while the ionic reaction between lixiviated Mg 2+ and Fresulted in precipitating MgF 2 , thereby destroying the fibrous nature of the asbestos. An optimum combination of HF and H 2 SO 4 contributed significantly to enhancing the rate of conversion of asbestos into nonfibrous materials in a short treatment time without any physical agitation.