Question

Blister copper is:
A. Impure copper
B. Obtained in the self-reduction process during bessemerisation
C. Both are correct
D. None is correct

Answer 1

In the question, the copper is undergone through the process which makes it blister copper. The meaning of blister is a process where swelling of material happens due to friction, burning, or other damage. One can think about this concept and analyze the given options to develop an approach to solve the question.

Complete step by step answer:
-First of all we will learn what blister copper means. The blistered copper is a metallic copper which has a black blistered appearance of its surface.
-Now let's see the reaction where it takes place in a blast furnace at very high temperature as follows,
$C{u_2}S + 2C{u_2}O\xrightarrow{{}}6Cu + S{O_2}$
-The copper obtained in the product after bessemerisation process on copper, it gets solidified and contains the number of impurities in it such as of ${\text{Fe}}$,${\text{Ni}}$, ${\text{Zn}}$, etc. The blister copper is about $98\%$ pure and the other percentage consists of impurities.
-The bessemerisation process involves the self-reduction of copper metal which gives out the $S{O_2}$ gas as evolution and gives the blistered appearance to the copper.
Therefore, the blister copper is impure copper and obtained in the self-reduction process during bessemerisation which shows option C is the correct choice of answer.

Note: The copper formed in the product is present in molten form. The molten form copper metal is then cooled in sand molds where the gas form $S{O_2}$​ escapes from the mixture. This gives the copper a black blistered appearance of its surface and the impure copper metal is called Blister copper.