METHOD FOR PRODUCING, APPLYING ADDITIVE FOR CONTROLLING THE EMPTYING STRENGTH OF MOULDING AND/OR CORE MATERIAL OF WATER-GLASS BOUND MOULDINGS AND/OR CORES REMAINING AFTER CASTING

摘要

Additives to control the post-casting release properties of casting moulds and cores made with water glass binder are prepd. in a closed mixer by introducing 65 wt.% powdered iron-oxide, adding with slow stirring at 30 revolutions per minute 10-20 wt.%, pref. 15 wt.% dry powdered ammonium-ligno-sulphonate and homogenising the mixt. for 5 minutes. To this mixt. is added 20-25 wt.% pref. 20 wt.% powdered boric-acid and the mixt. is homogenised for 20 minutes. The homogenised prod. is packed in evacuated containers for storage or transport.