Improved Process for the Manufacture of Industrial and other Objects from Volcanic or other Fusible Rock.

摘要

19,808. Ribbe, F. Aug. 24. Earthenware and like pipes.-These are made of volcanic or other fusible rock insufflated with air or gas when in a melted condition, so as to form pores in the cast object. Before the temperature has fallen to 500‹ C., the material is reheated and annealed at 800‹ C.; it is then slowly cooled. Air may be introduced through tuyeres into the melting-pot or through quartz or other non-fusible pipes; or substances that produce gas at the temperature employed may be introduced into the molten mass, suitable materials being carbonate of lime, bi-carbonate of soda, gypsum, sawdust carbon, graphite, and some kinds of basalt. Crucibles made of or lined with plumbago, coke, or carbon may be used to give the gas; or the pores may be created by using cores or by blowing like glass.