Abstract: Pitch substantially free from primary and secondary QI components and solids comprising secondary QI components are prepared by centrifuging coal tar or coal tar pitch at a high temperature, heat-treating the separated supernatant liquid and centrifuging again the liquid at a high temperature.

Abstract: Pitch free from quinoline insoluble components is prepared by heat-treating coal tar or coal tar pitch in the absence or in the presence of carbonaceous particles and centrifuging at a high temperature the reaction product resulting from the heat treatment or a mixture of the reaction product from the heat treatment and coal tar-type light or middle oil.

Abstract: A method and an apparatus for automatic quantitative measurement of textures by image analysis for measuring textures of a material containing various optically anisotropic textures. An image of the material is divided into a plurality of sections and brightness of each section is classified into a plurality of stages to be stored as gray levels of the sections or pixels. Image patterns of the textures are recognized on the basis of gray level variations observed before and after a mask movement, and the textures of the material are determined according to predetermined criteria.