Abstract: Method and apparatus for obtaining the average aspect ratio of non-spherical particles in suspension. The particles are caused to orient generally in one direction and the conductivity of the particles are measured in such direction while simultaneously measuring the conductivity of the particles in a traverse direction. The difference between the two conductivity measurements is indicative of the average aspect ratio of the particles in suspension.

Abstract: A method and apparatus are disclosed for obtaining a measurement indicative of the aspect ratio of non-spherical particles in suspension. Conductivity of the suspension is measured for two different orientations of the particles between measuring points and the difference between the conductivities measured is used as an indication of the particle aspect ratio. The particle orientation will be aligned in one measurement and in the other may be aligned and transverse to the first orientation direction or random. Alternatively, there may be a single aligned orientation but transversely directed conductivity measurements.

Abstract: In order to make talc more readily dispersible in an aqueous medium, it is contacted, in a finely divided form, with an aqueous solution of an alkali metal hydroxide or ammonium hydroxide, it is then washed with clean water, whereafter it is thermally dried to remove at least a substantial proportion of the water associated therewith. The talc thus treated can be suspended in water containing a dispersing agent.