Question

Question (marks) a) Explain the role of the metallurgical slags in pyrometallurgical processing, give examples (4 marks) b) Identify key properties of metallurgical slags that must be controlled, and briefly explain why? (3 marks)

Answer 1

(a) Role of metallurgical slags:

Metallurgical slags are a type of melts (after solidifying, a rocklike or glasslike substance) usually covering the surface of molten metal in met-allurgicalprocesses, as the smelting of raw material, the processing of molten intermediates, and the refining of metals. Slags arealloys of oxides of various compositions. The major components of slags are the acidic oxide SiO₂ and the basic oxidesCaO, FeO, and MgO, as well as the neutral Al₂O₃ and (less often) ZnO.

During the pyrometallurgical processes the metallurgical melets are further processed through calcining, roasting, smelting, refining to obatin useful minerals from melts. .

(b) Key properties of metallurgical slags:

Viscosity, thermal and electrical conductivity, pH (acidity and basicity), oxidizing power and surface tension are the propertie of slags that must be controlled for effective utilization and separation useful minerals from slags.