Adsorption de l'azote sur l'amiante chrysotile phosphaté et lixivié

Abstract

Adsorption and desorption isotherms of nitrogen, obtained by the volumetric (B.E.T.) method, have been used to determine the specific surface and the porosity of a series of chrysotile asbestos fibers, before and after chemical treatments. It was shown that the phosphorus compounds that are formed by the reaction of POCl3 and chrysotile asbestos seal the surface of the fibrils and block the pores between the fibrils. These chemical modifications result in an important diminution of the specific surface and of the porosity of the fibers. Washing the fibers with 0.1 M HCl results in an increase of the specific surface and of the porosity. Solvation of the impurities and leaching of the brucitic surface of the fibers are responsible for this increase. [Journal translation]