Question

Answer in one word or one sentence:
Give the composition of copper matte.

Answer 1

We know that minerals are naturally occurring substances in the crust of Earth which can be obtained by mining. Out of all minerals, only some minerals are used as the source of that metal, and such minerals are known as ores.

Complete step by step answer:
Let’s understand the copper matter in detail. On heating, a mixture of copper ore with silica in a furnace results in iron oxide (slag of iron silicate) and copper in the form of copper matte. The composition of copper matter is ${\rm{C}}{{\rm{u}}_{\rm{2}}}{\rm{S}}$ and FeS.
So, the composition of copper matte is ${\rm{C}}{{\rm{u}}_{\rm{2}}}{\rm{S}}$ and FeS.

Additional Information:
Let’s learn how to extract copper.

1. First step is roasting of sulphide ore in a furnace to give a mixture of FeS and ${\rm{C}}{{\rm{u}}_{\rm{2}}}{\rm{S}}$.
   ${\rm{2CuFe}}{{\rm{S}}_{\rm{2}}} + {{\rm{O}}_{\rm{2}}} \to {\rm{C}}{{\rm{u}}_{\rm{2}}}{\rm{S}} + {\rm{2FeS}}$
   $2{\rm{FeS}} + {\rm{3}}{{\rm{O}}_2} \to 2{\rm{FeO}} + {\rm{2S}}{{\rm{O}}_2}$
   $2{\rm{C}}{{\rm{u}}_{\rm{2}}}{\rm{S}} + {\rm{3}}{{\rm{O}}_2} \to 2{\rm{C}}{{\rm{u}}_{\rm{2}}}{\rm{O}} + {\rm{2S}}{{\rm{O}}_2}$

2. Due to more reactivity of iron, FeS is oxidized preferentially to FeO than ${\rm{C}}{{\rm{u}}_{\rm{2}}}{\rm{S}}$to ${\rm{C}}{{\rm{u}}_{\rm{2}}}{\rm{O}}$.
   ${\rm{C}}{{\rm{u}}_{\rm{2}}}{\rm{O}} + {\rm{FeS}} \to {\rm{C}}{{\rm{u}}_{\rm{2}}}{\rm{S}} + {\rm{FeO}}$

Thus, roasted ore consists of ${\rm{C}}{{\rm{u}}_{\rm{2}}}{\rm{S}}$ and FeO with some unreacted FeS.
3) Next, roasted ore is to be mixed with silica and coke (powder) and strongly heated in the furnace. The ferrous silicate slag is produced in this process.
${\rm{FeO}} + {\rm{Si}}{{\rm{O}}_2} \to {\rm{FeSi}}{{\rm{O}}_{\rm{3}}}$

At the temperature of the furnace, the melting of the entire solid takes place and the formation of two layers of solid takes place. As slag formed is lighter so it forms the upper layer and can be separated from the slag hole. The lower layer of molten solid is termed as copper matte consisting of ${\rm{C}}{{\rm{u}}_{\rm{2}}}{\rm{S}}$ and FeS.
4) Next step is the transferring of copper to the Besemer converter to remove the impurities like S, As, Sb. They escape in the form of respective volatile oxide. There is also oxidation of FeS to FeO which combines with silica to form ${\rm{FeSi}}{{\rm{O}}_{\rm{3}}}$.
$2{\rm{FeS}} + {\rm{3}}{{\rm{O}}_2} \to 2{\rm{FeO}} + {\rm{2S}}{{\rm{O}}_2}$
${\rm{FeO}} + {\rm{Si}}{{\rm{O}}_{\rm{2}}} \to {\rm{FeSi}}{{\rm{O}}_{\rm{3}}}\left( {slag} \right)$

5. Then the slag melted and floated on the top and removed. All the iron is removed in the form of slag. Some of the copper sulphide undergoes oxidation to produce copper oxide which then undergoes reaction with cuprous sulphide to result in copper metal.
   $2{\rm{C}}{{\rm{u}}_{\rm{2}}}{\rm{S}} + {\rm{3}}{{\rm{O}}_2} \to 2{\rm{C}}{{\rm{u}}_{\rm{2}}}{\rm{O}} + {\rm{2S}}{{\rm{O}}_2}$
   $2{\rm{C}}{{\rm{u}}_{\rm{2}}}{\rm{O}} + {\rm{C}}{{\rm{u}}_2}{\rm{S}} \to {\rm{6Cu}} + {\rm{S}}{{\rm{O}}_2}$

6. Then the copper metal is cooled to separate sulphur dioxide gas. During the solidification, some gas bubbles got trapped which results in a blister appearance of the metal (copper). So, The copper formed is termed as blister copper.

7. Last step is the purification of blister copper by the method of electrolytic refining.

Note:
Always remember that three major steps included in the extraction of metals, first is, the concentration of ore, the second is, isolation of metal from the ore, and the third is the purification of metal. The entire technological process of extraction of metal from its ore is termed metallurgy.