Crystallation of sodium carbonate hydrates - by heat exchange using copper, nickel or chromium (coated) heat exchange tubes

摘要

Sodium carbonate hepta and decahydrate are obtd. in high purity by crystallisation from a nearby satd. soln. at normal, elevated or reduced atmospheric pressure using a heat exchanger, the surface of which is of Cu, Ni, Cr or an alloy with a high proportion of one of these metals. The encrustation which builds up when using other metals on surfaces is absent or greatly reduced.