摘要 |
100 parts by weight of water glas shaving a modules of 2-10 is mixed with up to 10 parts by weight of carbamide. 50-170 parts by weight of a catalyst complex of an ion-silicon eutectic and calcium compounds in a colloidal silicon dioxide matrix is added. The mixt. is moulded at a temp. of up to 100 deg. C. Moulded items are removed and stored at a temp. of at least 50 deg. C for at least 48 hours. The moulding are heat treated at a temperature of 100-900 deg. C (the heating rate is 15-100 deg. C/minute). |