| abstract |
The filter aid according to the invention is intended for use particularly in the alkaline range. In order to bond the filter-active substances into the granular shape, a hydraulically setting cement is used in combination with sodium metasilicate, the sum of the proportions of cement and sodium metasilicate being below approximately 50 % by weight, and the proportion of sodium metasilicate to the proportion of cement being from 1:2 to 1:4. The granular filter aid comprises, as the filter-effective substances, at least one surface-active substance, preferably activated carbon, and expediently also comprises calcium hydroxide and, optionally, catalytically active substances. |