Question

What is the composition of ‘Copper matte’?

Answer 1

The term matte is used in the field of pyro metallurgy in this process molten metal sulfide phases basically formed by the smelting of copper, nickel and other base metals and it is generally present in the phase in which the metal being extracted is recovered firstly to a final reduction process which is generally a converting to produce a crude metal.

Complete step by step answer:
- In the metallurgy of copper the product of smelting stage is a mixture of copper, iron and sulfur that is enriched in copper and it is termed as matte or copper matte. Copper Matte is said to be the mixture of copper sulphide represented by the formula $C{{u}_{2}}S$ and some iron sulphide which is represented by the formula $FeS$. Matte is the phase where copper is extracted prior to the final reduction process in which the roasted ore is mixed with coke and silica represented by the formula $Si{{O}_{2}}$ is put into a blast furnace. The hot air is blasted and iron oxide i.e. $FeO$ is converted into ferrous silicate $FeSi{{O}_{3}}$ known as slag which floats over the molten matte of copper.
- Thus the composition of copper matte can be defined as: 80– 95 % coppers sulphide, 5 – 17 % ​metallic copper, $Fe-Co$ alloys, metallic silver, galena, $Pb-Ag$ alloys, $Pb-Ni$ alloys, $Pb-Cu$ alloys and arsenides.

Note: Mattes can also be used to collect impurities from a metal phase for example in the case of antimony smelting. Molten mattes are insoluble in both slag and metal phases. This insolubility is related with differences in specific gravities between mattes, slags and metals which allows them for separation.