Preamble

Smelting is a unit process for pyro metallurgical extraction of metal in which gangue minerals are separated from the metal in liquid state. The components of the materials are heated above the melting points so that they are separated in the liquid state. When metal is separated as molten sulphides, the process is called matte smelting and when metal is separated as liquid metal it is called reduction smelting. This lecture concerns with the matte smelting and few other lectures will be devoted on materials and heat balance in matte smelting. Brief description of matte smelting is given so that readers can apply to solve materials and heat balance problems. For details consult any book on non-ferrous metals extraction.

Matte smelting

Matte is a molten mixture of sulphides. Iron-copper is of greatest industrial importance which is the intermediate product in the extartion of copper from sulphide ores. In production of nickel, matte of copper-nickel is an intermediate product.

One advantage of matte smelting is its low melting point which makes it possible to smelt sulphide ores at lower temperatures than required for metals. Thus a matte with equal amounts of copper and iron sulphide melts below , whereas an alloy of  and   would melt at around . This leads to lower thermal energy requirements and gangue minerals can be separated easily as slag. Thus matte smelting comprises of the following inputs and outpust

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