Process used to extract underground deposits of sulphur. Superheated steam is piped into the sulphur deposit and melts it. Compressed air is then pumped down to force the molten sulphur to the surface. The process was developed in the USA in 1891 by German-born Herman Frasch (18511914).
The yellow of the emblem is said to denote Angola's natural wealth. Red is said to stand for the blood spilt by the freedom fighters. Black represents Africa. Effective date: 11 November 1975.