摘要 |
Feeders for use in the foundry industry comprising (a) rice husk ash containing, based on the total amount of the constituents detectable in the rice husk ash by quantitative phase analysis by means of x-ray diffractometry (i) crystalline modifications of silicon dioxide, (ii) monoclinic feldspar and (iii) amorphous silicon dioxide, a total content of at least 70 wt. %, preferably more than 75 wt. % of (i) crystalline modifications of silicon dioxide and (ii) monoclinic feldspar, wherein, based on the total weight of the shapeable composition of the feeder, the amount of this rice husk ash is in the range of from 5 to 50 wt. %, preferably 5 to 25 wt. %, (b) cured binder, (c) optionally fibre material, (d) optionally one or more further fillers, and (e) optionally an oxidizable metal and an oxidizing agent for the oxidizable metal are described. |