Method of concentrating sulfuric acid using a boiler of improved cast iron

US4032622A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Helmold von Plessen · Kelkheim, DE
• Grete Petrich

Key dates

• Filing date: Oct 27, 1976
• Grant date: Jun 28, 1977
• Expiry date: Oct 27, 1996

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C22C37/10
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

When distilling or boiling concentrated sulfuric acid in a vessel of gray cast iron the corrosion resistance of the apparatus is improved by using an alloy containing from PA1 0.2 to 1.6 % of silicon PA1 0 to 0.2 % of phosphorus PA1 0.6 to 2.5 % of copper PA1 0 to 3.5 % of nickel Besides the usual elements for gray cast iron and a graphite portion in a finely divided form in a pearlitic skeleton.