Chemistry · Science General

Metallurgical Processes

1,436 Questions

This section explores key metallurgical processes including ore concentration, pyrometallurgy, and metal refining. It also covers corrosion and the properties of refractory materials. These chemistry questions are relevant for engineering and science entrance tests.

Pyrometallurgy furnacesMetal refining techniquesCorrosion protection methodsOre concentrationAuto reduction process

Metallurgical Processes Questions

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

Can we store copper sulphate in iron container and why?

  1. No, because Cu is more reactive than iron

  2. No, because iron is more reactive than copper, therefore reaction will take place.

  3. Yes, because copper is less reactive than iron.

  4. Yes, because copper is more reactive than iron.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$Fe + CuSO _4\rightarrow FeSO _4 + Cu$
Reaction has taken place because Fe is more reactive than Cu, therefore we cannot store.

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

Which process use in smelting during metallurgy of coper

  1. Self reduction of copper
  2. $Cu _2S$ is converted into $Cu _2O$
  3. $FeS$ convert into $FeO$
  4. Reduction of $Fe$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Smelting of Cu result in slag formation and matle formation
FeS+Cu2O→FeP+Cu2SFeS+Cu2O→FeP+Cu2S
FCO+SiO2→FesiO3FCO+SiO2→FesiO3(slage)

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

The balance reaction involved during extraction of zinc from its ore by roasting of zinc ore :

  1. $ZnS (s) + O _{2} \xrightarrow{Heat} ZnO(s) + 2SO _{2}(g)$
  2. $ZnS (s) + 3O _{2} \xrightarrow{Heat} ZnO(s) + 2SO _{2}(g)$
  3. $2ZnS (s) + 3O _{2} \xrightarrow{Heat} 2ZnO(s) + 2SO _{2}(g)$
  4. $ZnS (s) + 3O _{2} \xrightarrow{Heat} 2ZnO(s) + SO _{2}(g)$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The balanced chemical reaction for extraction of zinc from its ore by roasting of zinc ore is;

$2ZnS(s)+3{ O } _{ 2 }\xrightarrow { heat } 2ZnO(s)+2S{ O } _{ 2 }(g)$

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

Aluminium and copper are extracted from their oxide and sulphide ores respectively. Which of the following is correct ? 
I. Copper is extracted by the auto reduction of copper oxide by copper sulphide.
II. Aluminium cannot be obtained by chemical reduction due to its strong affinity for oxygen.
III. In electrometallurgy of $Al$, graphite is used as cathode to avoid reoxidation of $Al$ into $Al _2O _3$ by preventing formation of $O _2$.
IV. Sulphide ores of copper are difficult to be reduced than the oxide ores.

  1. $I , II ,IV$
  2. $II$ and $III$
  3. $III$
  4. $II$ and $IV$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In the electrometallurgy of $Al$, graphite is used as anode as oxygen being a non-metal is liberated at the anode and the reoxidation of $Al$ into $Al _2O _3$ is avoided.

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 steps correctly depicts the self-reduction of $Cu _2S$ to $Cu$?

  1. Roasting

  2. Smelting

  3. Bessemeriztion

  4. Poling
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In the extraction of copper, the self-reduction reaction of Copper taking place in a Bessemer converter is as follows:


$2Cu _{2}S+3O _{2} \rightarrow 2Cu _2O+2SO _{2}$

$Cu _{2}S+2Cu _{2}O\rightarrow 6Cu+SO _{2}$ (self reduction)

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

STATEMENT-1: Extraction of zinc from sphalerite ore involves the roasting followed by reduction with coke.
STATEMENT-2 : Zinc can be commercially extracted by hydrometallurgy.

  1. STATEMENT-1 is True, STATEMENT-2 is True; STATEMENT-2 is a correct explanation for STATEMENT-1

  2. STATEMENT-1 is True, STATEMENT-2 is True; STATEMENT-2 is NOT a correct explanation for STATEMENT-1

  3. STATEMENT-1 is True, STATEMENT-2 is False

  4. STATEMENT-1 is False, STATEMENT-2 is True
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Sphalerite ((Zn,Fe)S) is a chief ore of zinc. It consists largely of zinc sulfide in crystalline form but almost always contains variable iron.
Extraction of Zinc follows:
Roasting followed by reduction with carbon; then electro-fining of Zn.

Hydrometallurgy:
In this process, desired metal is extracted from its solution by addition of more electro positive metal.
But there are very few metals which are more electro positive than Zn so it can not be extracted by hydrometallurgy

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 process(s) occur(s) during the extraction of copper from chalcopyrites?

  1. froth floatation

  2. roasting

  3. bessemerisation

  4. leaching
Reveal answer Fill a bubble to check yourself
A,B,C Correct answer
Explanation

In the extraction of copper, following methods are used
froth floatation
roasting
smelting
bessemerisation and 
electrolytic refining

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, the smelt formed in the blast furnace contains:

  1. $Cu _{2}S\ +$ little $FeS$
  2. $Cu _{2}S\ +$ little $FeO$
  3. $Cu _{2}O\ +$ little $FeS$
  4. $Cu _{2}O\ +$ little $FeO$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In the extraction of copper, raw material used for the Bessemer converter is matte ($Cu _2S+FeS (little)$), where matte is formed in the blast furnace.

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

Formation of metallic copper from the sulphide ore in the commercial metallurgical process involves:

  1. $Cu _{2}S$ $+\frac{3}{2} O _{2}$ $\rightarrow$ $Cu _{2}O+$$SO _{2}$ ; $Cu _{2}O$+$C$ $\rightarrow$ $2Cu$+$CO$
  2. $Cu _{2}S+$ $\frac{3}{2}O _{2}$ $\rightarrow$ $Cu _{2}O+$ $SO _{2}$; $2Cu _{2}O+$ $Cu _{2}S$ $\rightarrow$ $6Cu+$$SO _{2}$
  3. $Cu _{2}S+2O _{2}\rightarrow CuSO _{4}$; $CuSO _{4} + Cu _{2}S\rightarrow 3Cu + 2SO _{2}$
  4. $Cu _{2}S+ \frac{3}{2}O _{2} \rightarrow 2Cu+ SO _{2}$ ; $Cu _{2}O+CO\rightarrow2Cu+CO _{2}$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The commercial metallurgical process for the formation of metallic copper from the sulphide ore involves oxidation of $Cu _2S$ to $Cu _2O$  and auto reduction of a mixture of $Cu _2S$ and $Cu _2O$ to copper metal.

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

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

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

Blister copper is refined by stirring molten impure metal with green logs of wood because such a wood liberate hydrocarbon gases (like $CH {4}$). This process $X$ is called _____ and the metal contains impurities of $Y$ is ___________ .

  1. $X$= cupellation, $Y$= $CuO _{2}$
  2. $X$= polling, $Y$= $Cu _{2}O$
  3. $X$= polling, $Y$= $CuO$
  4. $X$= cupellation, $Y$= $CuO$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The refining process of blister copper is known as polling.
The $Cu _2O$ impurities are present in the copper metal.
In presence of heat of molten metals, the green logs liberate hydrocarbon gases which reduce copper oxide into copper.