| Popis: |
Publisher Summary This chapter presents the analysis of coal tar binders for electrodes. The chemical and physical properties of a coal tar pitch binder depend on the process used in its manufacture. Pitches are normally classified as being derived from the corresponding coal tar. Products of high temperature treatment, especially the coke oven pitch, as electrode binders earlier gave less shrinkage on baking and a coke of lower porosity than a vertical retort pitch. The literature on electrode binders is replete with references to techniques for thermally and chemically modifying coal tar pitch to improve its performance, but conclusive data to substantiate improvement are rare. The specifications adopted by various companies, based on practical experience, have had the effect of selecting the most aromatic pitches. The optimum binder content adopted in practice is usually a compromise between two optima: (1) one for paste flow and (2) the other for electrode properties. To minimize anode consumption during electrolysis, the reactivities of the binder coke and the dry aggregate should not be too dissimilar. |
