Tag: general principles of metallurgy

Quizzes (6) Questions (151)

Questions Related to general principles of metallurgy

Multiple choice chemistry general principles of metallurgy extraction of copper and zinc extraction of copper and zinc from their oxides basics of metallurgy

In the extraction of Cu, the reaction takes place in bessemer converter is:

  1. $2Cu _2O\, +\, Cu _2S\, \rightarrow\, 6Cu\, +\, SO _2$
  2. $2CuFeS _2\, +\, O _2\, \rightarrow\, Cu _2S\, +\, FeS\, +\, SO _2$
  3. $2Cu _2S\, +\, 3O _2\, \rightarrow\, 2Cu _2O\, +\,2SO _2$
  4. $2FeS\, +\, 3O _2\, \rightarrow\, 2FeO\, +\, 2SO _2$
Reveal answer Fill a bubble to check yourself
A,C Correct answer
Explanation

The sulphide ore of copper is heated in the air until a part is converted to oxide and then further heating in the absence of air to let the oxide react with unchanged sulphide.


Self-reduction of CuS to Cu can be carried out in either Bessemer converter or Pierce-Smith converter.

$2Cu _2S+3O _2 \rightarrow 2Cu _2O + 2SO _2$
$2Cu _2O+Cu _2S \rightarrow 6Cu+SO _2$

Multiple choice chemistry general principles of metallurgy extraction of copper and zinc extraction of copper and zinc from their oxides basics of metallurgy

The final step for the extraction of copper pyrites in Bessemer converter involves the reaction__________.

  1. $Cu _2S\,+\,2FeO\,\rightarrow\,2Cu\,+\,2Fe\,+\,SO _2$
  2. $Cu _2S\,+\,2Cu _2O\,\rightarrow\,6Cu\,+\,SO _2$
  3. $4Cu _2O\,+\,FeS\,\rightarrow\,8Cu\,+\,2FeSO _4$
  4. $2Cu _2O\,+\,FeS\,\rightarrow\,4Cu\,+\,Fe\,+\,SO _2$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The sulphide ore of copper is heated in air until a part is converted to oxide and then further heating in the absence of air to let the oxide react with unchanged sulphide.
Self-reduction of CuS to Cu can be carried out in either Bessemer converter or Pierce-Smith converter.
$2Cu _2S+3O-2 \rightarrow 2Cu _2O + 2SO _2$
$2Cu _2O+Cu _2S \rightarrow 6Cu+SO _2$
This is the final step in Bessemer converter.

Multiple choice chemistry general principles of metallurgy extraction of copper and zinc extraction of copper and zinc from their oxides basics of metallurgy

Self-reduction of CuS to Cu can be carried out in :

  1. Bessemer converter

  2. Blast furnace

  3. Both (A) and (B)

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The following reaction takes place in Bessemer converter :


$ Cu _2S + \dfrac{3}{2}O _2 \rightarrow Cu _2O + SO _2$

$2Cu _2O + Cu _2S \longrightarrow 6Cu + SO _2$

Multiple choice chemistry general principles of metallurgy extraction of copper and zinc extraction of copper and zinc from their oxides basics of metallurgy

Which of the following statement is correct regarding Cu-extraction ?

  1. In the smelting step, carbon reduction takes places
  2. During roasting, $Cu _2S$ remains almost unaffected

  3. In Bessemer converter, only self reduction occurs, not slag formation
  4. Blister formed in the blister Cu is due to dissolved $CO _2$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
In the extraction of copper, metal is formed in the Bessemer converter due to self reduction as

${ Cu } _{ 2 }S+2{ Cu } _{ 2 }O\rightarrow 6Cu+S{ O } _{ 2 }$
So Option C is correct
Multiple choice chemistry general principles of metallurgy extraction of copper and zinc extraction of copper and zinc from their oxides basics of metallurgy

Extraction of zinc from zinc blende is achieved by:

  1. electrolytic reduction

  2. roasting followed by reduction with carbon

  3. roasting followed by reduction with another metal

  4. none of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Zinc blende (ZnS) is first roasted to form zinc oxide (ZnO), which is then reduced to zinc metal using carbon (coke).

Multiple choice chemistry general principles of metallurgy extraction of copper and zinc extraction of copper and zinc from their oxides basics of metallurgy

In the extraction of copper, metal is formed in the Bessemer converter due to a reaction:-

  1. ${Cu _2S+2Cu _2O\rightarrow 6Cu+SO _2}$
  2. ${Cu _2S\rightarrow 2Cu+S}$
  3. ${Fe+Cu _2O\rightarrow 2Cu+FeO}$
  4. ${2Cu _2O\rightarrow 4Cu+O _2}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
In the extraction of copper, metal is formed in the Bessemer converter due to self reduction.

Reaction:
$Cu _2S + 2Cu _2O \longrightarrow 6Cu + SO _2$
Multiple choice chemistry general principles of metallurgy extraction of copper and zinc extraction of copper and zinc from their oxides basics of metallurgy
The slag obtained during the extraction of copper pyrites is composed mainly of ${ FeSiO } _{ 3 }$.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Copper is mainly extracted from copper pyrites. After the concentration of its ore by froth flotation process, the ore is roasted in a current of air to remove arsenic, antimony and much of sulphur.

The ore is then mixed with a little coke and sand and smelted in a water-jacketed blast furnace. The minor reactions that occured during roasting continue here. Ferrous oxide combines with sand to form a fusible slag.

$FeO + SiO _2 \rightarrow FeSiO _3$ slag