APPLICATION OF AN ELECTRODE BINDING AGENT OF STONE CULTURES AS A BINDING MANUFACTURER IN THE MANUFACTURE OF ANODES FOR THE ALUMINUM INDUSTRY

摘要

1. The use of an electrode binder of coal tar with a softening point (Kraemer-Sarnow) of from 90 to 105 degrees C, a content of quinoline-insolubles (QI) of from 0.5 to 5% by weight, from 25 to 35% by weight of beta-resins, a content of ash formers of less than 0.2% by weight, preferably less than 0.1% by weight, and an Na content of less than 50 ppm, preferably less than 20 ppm, obtainable by the filtration of a coaltar pitch which is mixed with a 1 - to 2.5-fold quantity of an inorganic or organic filter aid, relative to the QI content of the pitch, by means of filter cartridges with a pore size of from 50 to 100 mu m at a temperature of from 250 to 300 degrees C at a pressure of up to 8 bar and where appropriate by distilling off oils from the filtered pitch in order to fix the softening point, as a binder in the manufacture of anodes with reduced burn-off for the aluminium industry, in particular in the manufacture of previously burned block anodes with an addition of up to 30% by weight of anode residues, relative to the solid-material portion of the anode material, with an Na content of more than 1500 ppm.