Process for curing sand moldings

US4886105A · kind A · utility

Assignee

• Daimler-Benz AG · DE

Inventors

• Dieter Nisi · Waiblingen, DE
• Helmut Paul · Sarreguemines, FR

Key dates

• Filing date: Oct 31, 1988
• Grant date: Dec 12, 1989
• Expiry date: Oct 31, 2008

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B22C9/123
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A process is described for curing sand moldings, in particular casting cores, by the cold box process. In this process a catalyst containing gas mixture escaping from the mold is passed over a mixture feed side of a semipermeable membrane while a pressure is maintained on the permeate side of the membrane which is less than the pressure on the mixture feed side, whereby the catalyst vapors preferentially permeate through the membrane, and a permeate carrier gas stream which is, in particular, 50 to 300 liters greater than the permeate stream passing through the membrane per m.sup.2 and per hour is passed over the permeate side of the membrane. The catalyst, in particular a tertiary amine, is greatly concentrated in the permeate carrier gas stream and can simply and inexpensively be removed from the latter by condensation. Inexpensive, virtually complete recovery of the expensive catalyst is possible using the process.