Development of a technique for measuring the degree of dispersion of chrysotile fibre in aqueous systems

Abstract

AbstractChrysotile asbestos, when dispersed in an aqueous solution of a soap or a detergent by high shear mixing, results ultimately in a colloidal dispersion consisting of fibrils of approximately 30 nm in diameter and very high aspect ratio. In the intermediate stages of the dispersion process, slurries are produced which are represented by a wide range of colloidal concentrations and conversely a wide range of undispersed, macroscopic fibre concentrations. The degree of dispersion in these slurries and the dispersion mechanism cannot be assessed by existing methods of analysis. A new method capable of estimating the degree of fibre dispersion has been developed and has been termed Load Impulse Analysis. In the dispersion process, the disappearance of macroscopic fibres may be estimated and the development and destruction of a colloidal structure has been illustrated through this type of analysis. The meaning of the viscosity of a fibre dispersion measured at a low shear rate is also made clearer.