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 thermodynamic principles of metallurgy general principles and processes of isolation of elements metallurgy chemistry

Which of the following processes involves the smelting process?

  1. $ZnCO _3 \rightarrow ZnO + CO _2$
  2. $2PbS +3O _2 \rightarrow 2PbO + 2SO _2$
  3. $Fe _2O _3 + 3C \rightarrow 2Fe + 3CO$
  4. $Al _2O _3.2H _2O \rightarrow Al _2O _3 + 2H _2O$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In smelting, Iron ore is reduced to iron.

$Fe _{2}O _{3}+3C{\rightarrow}Fe+3CO$

Multiple choice thermodynamic principles of metallurgy general principles and processes of isolation of elements metallurgy chemistry

Which of the following methods is not involved in metallurgy of iron?

  1. Calcination

  2. Smelting

  3. Concentration of ore

  4. None of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
(1) Calcination is the process in which the ore is heated below its melting point, either in the absence or in a limited supply of air, in an aim to drive off volatile expunges, moisture, water of hydrates and organic matter from the ore. All ores are minerals but all minerals are not ores.

(2)Smelting is a process when a metal which is more reactive than copper needs to be extracted. For example, zinc is more reactive than copper so it has to be extracted by smelting.

(3)Ores are solid material from which a pure metal can be obtained. The process of removal of unwanted material from the ore is known as concentration or dressing or benefaction of ores.

So Calcination, Smelting, Concentration of ore all the processes used in metallurgy.
Multiple choice thermodynamic principles of metallurgy general principles and processes of isolation of elements metallurgy chemistry

Iron is used in different forms, like, cast iron, steel, and alloys. The iron-carbon diagram is the basis for the branch of science known as:

  1. ferrous metallurgy

  2. stereochemistry

  3. carbon metallurgy

  4. organic chemistry
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The percentage of Iron and Carbon determine whether it is cast Iron, Pig Iron, Steel or Alloys. Hence this is known as Ferrous Metallurgy. The main contribution is given by Iron as every type of Iron contains more than 90% of Iron.

Multiple choice thermodynamic principles of metallurgy general principles and processes of isolation of elements metallurgy chemistry

In which of the following pair(s), the minerals are converted in to metals by self-reduction process?

  1. $Cu _2S, PbS$
  2. $PbS, HgS$
  3. $PbS, ZnS$
  4. $Ag _2S, Cu _2S$
Reveal answer Fill a bubble to check yourself
A,B Correct answer
Explanation

In the self reduction process, metal sulfide reacts with metal oxide to form free metal.
The conversion of metal ore to crude metal by self reduction process is carried for the pairs $Cu _2S, PbS$ and $PbS, HgS$.
For example cupric oxide reacts with cupric sulphide to form crude copper metal.
$2PbS+3O _2\rightarrow 2PbO+2SO _2$
$PbS+2PbO\rightarrow 3Pb+SO _2$ (self reduction)
$Cu _2S+2Cu _2O\rightarrow 6Cu+SO _2$
$HgS+2HgO\rightarrow 3Hg+SO _2$ 

Multiple choice thermodynamic principles of metallurgy general principles and processes of isolation of elements metallurgy chemistry

Which of the following steps are involved in hydrometallurgical process?

  1. $Cu _2S + 2Cu _2O \longrightarrow 6Cu + SO _2$
  2. $CuFeS _2 + 2H _2SO _4 \longrightarrow CuSO _4 + FeSO _4 + 2H _2S$
  3. $Ag _2S + 2NaCN \longrightarrow [Ag(CN) _2]^- + Na _2S$
  4. $CuCO _3 + H _2SO _4 \longrightarrow CuSO _4 + H _2O +CO _2$
Reveal answer Fill a bubble to check yourself
B,C,D Correct answer
Explanation

Hydro metallurgy is a process of extraction of metals by converting their ores into aqueous solutions of metal compounds and reduction of these solutions using suitable reducing agents.Less electropositive metals like gold and silver are extracted by this method . 
Water, dilute acids or sodium cyanide solution are used to convert the metal present in the ore into solution.
Hence, the following steps are involved in hydrometallurgical process.
(B) $CuFeS _2 + 2H _2SO _4 \longrightarrow CuSO _4 + FeSO _4 + 2H _2S$
(C) $Ag _2S + 2NaCN \longrightarrow [Ag(CN) _2]^- + Na _2S$
(D) $CuCO _3 + H _2SO _4 \longrightarrow CuSO _4 + H _2O +CO _2$

Multiple choice thermodynamic principles of metallurgy general principles and processes of isolation of elements metallurgy chemistry

Formation of metallic copper from the sulphide ore in the normal thermo-metallurgical process essentially involves which one of the following reaction? 

  1. $\displaystyle CuS+\frac { 3 }{ 2 } { O } _{ 2 }\longrightarrow CuO+{ SO } _{ 2 };\quad CuO+C\longrightarrow Cu+CO$
  2. $\displaystyle CuS+\frac { 3 }{ 2 } { O } _{ 2 }\longrightarrow CuO+{ SO } _{ 2 };\quad 2CuO+CuS\longrightarrow 3Cu+{ SO } _{ 2 }$
  3. $\displaystyle CuS+{ 2O } _{ 2 }\longrightarrow { CuSO } _{ 4 };\quad { CuSO } _{ 4 }+CuS\longrightarrow 2Cu+{ 2SO } _{ 2 }$
  4. $\displaystyle CuS+\frac { 3 }{ 2 } { O } _{ 2 }\longrightarrow CuO+{ SO } _{ 2 };\quad CuO+CO\longrightarrow Cu+{ CO } _{ 2 }$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Thermo-metallurgical process:

Here first sulphide ore coverts into oxide and then self reduction occurs as:
$\displaystyle CuS+\frac { 3 }{ 2 } { O } _{ 2 }\longrightarrow CuO+{ SO } _{ 2 }$
$\ 2CuO+CuS\longrightarrow 3Cu+{ SO } _{ 2 }$

Multiple choice

What is the purpose of annealing in metalworking?

  1. To increase hardness

  2. To increase strength

  3. To relieve internal stresses

  4. To improve corrosion resistance
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Annealing is a heat treatment process used to relieve internal stresses and improve the ductility of metals.

Multiple choice

What is the name of the process by which a metal loses electrons?

  1. Oxidation

  2. Reduction

  3. Corrosion

  4. Electrolysis
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Oxidation is the process by which a metal loses electrons, resulting in an increase in its oxidation state.

Multiple choice

What is the process of separating valuable minerals from waste rock called?

  1. Beneficiation

  2. Smelting

  3. Refining

  4. All of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Beneficiation is the process of separating valuable minerals from waste rock.

Multiple choice

Which technology is used to extract minerals from low-grade ores?

  1. Flotation

  2. Gravity Separation

  3. Magnetic Separation

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Flotation, gravity separation, and magnetic separation are all used to extract minerals from low-grade ores.

Multiple choice

What is the process of removing impurities from minerals called?

  1. Smelting

  2. Refining

  3. Electrolysis

  4. All of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Refining is the process of removing impurities from minerals.