Chemistry · Science General

Metallurgical Processes

1,403 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 nitrogen and sulfur sulfur and its oxides acid deposition natural resources- air, water and land

A solution of chromium oxide in concentrated sulphuric acid is used for cleaning glass in laboratories because it:

  1. Removes sand particles

  2. Oxidises grease

  3. Dissolves glass

  4. Reacts with dust
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Because a solution of chromium oxide in sulfuric acid (also known as a sulfochromic mixture or chromosulfuric acid) is a powerful oxidizing agent, it can be used to clean laboratory glassware, particularly of otherwise insoluble organic residues.They oxidize the grease present on the glass surfaces and hence thus it can be cleaned.

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

In which of the following pair of metals, both are commercially extracted from their respective ores by carbon reduction method?

  1. $Zn$, $Cu$
  2. $Fe$, $Cu$
  3. $Sn$, $Zn$
  4. $Al$, $Ag$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Tin and zinc are commercially extracted from their respective ores by carbon reduction method.
The oxide ores of tin and zinc are reduced with carbon to form metals.

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

In the metallurgy of iron using blast furnace, the slag is :

  1. $FeSiO _3$
  2. $CaSiO _3$
  3. $CaCO _3$
  4. $CaSO _3$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Slag is a glass like by product left over after a desired metal has been separated from its ore.Slag is usually a mixture of metal oxides and silicon dioxide.These slags can contain metal sulfides and elemental metals.

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

If steel is heated bright red hot and is then cooled slowly, the process is called:

  1. quenching

  2. annealing

  3. tempering

  4. smelting
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Annealing is heat process whereby a metal is heated to a specific temperature/color and then allowed to cool slowly. This softens the metal which means it can be cut and shaped more easily. Mild steel is heated to a red heat and allowed to cool slowly.

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

Iron :

  1. is a metal i.e. magnetic in nature

  2. forms an alloy called steel

  3. is brittle(cast iron)

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

Iron is the metal of transition series which oxidizes in air to give hydrated iron oxides. Crude iron metal is produced in blast furnaces where ore is reduced by coke to pig iron which has high carbon content.

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

(a) Cast iron is very hard and brittle because of higher carbon content.
(b) Iron obtained from the blast furnace is know as pig iron.
(c) The carbon content in wrought iron is the least.
(d) The melting point of cast iron is higher than that of wrought iron.
Which of the following regarding the above statements is correct?

  1. a, b and c

  2. c and d

  3. only b

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

Cast iron is iron that has been shaped by being poured into a cast. It has 5% or more carbon, and the carbon separates out into flakes. This reduces the tensile strength, but not the compressive strength. Pig iron is iron as cast after smelting from ore and has a high carbon content and is an intermediate product for making steel. Wrought iron is iron with a low carbon content.Pig iron and cast iron have have a lower melting point than wrought iron or steel.

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

The reaction which is not associated with the middle region of blast furnace during smelting is _______ .

  1. ${CO} _{2}+C\rightarrow 2CO$
  2. $Ca{CO} _{3}\rightarrow CaO+{CO} _{2}$
  3. $CaO+Si{O} _{2}\rightarrow CaSi{O} _{3}$
  4. $C+{O} _{2}\rightarrow {CO} _{2}$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A blast furnace is a type of metallurgical furnace used for smelting to produce industrial metals, generally iron, but also others such as lead or copper. With the first being that preheated blast air blown into the furnace reacts with the carbon in the form of coke to produce carbon monoxide and heat.
$2 C _{(s)} + {O _2} _{(g)} \rightarrow 2 CO _{(g)}$
All other reactions are associated with the middle region of blast furnace during smelting.The hot carbon monoxide is the reducing agent for the metal ore and reacts with the metal oxide to produce molten metal and carbon dioxide. 

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

Compound $X$ and aluminium are used to join railway tracks.

Identify the compound $X$ :

  1. $FeO$
  2. $ Fe _{2}O _{3}$
  3. $Fe _{3}O _{4}$

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

The reaction of iron oxide with aluminium is used to join railway tracks. 


Aluminium powder is used for the thermite reaction as it reacts with iron $(II) $ oxide to give molten $Fe$.

Hence the correct option is B.

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

Which of the following processes is involved in the smelting process?

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

In smelting process, ferric oxide gets reduced to Iron with the help of coke. The redox reaction is given by the option C.

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

In the metallurgical extraction of iron, which of the following processes takes place in reverberatory furnace?

  1. Conversion of iron oxide to iron

  2. Conversion of cast iron to wrought iron

  3. Conversion of cast iron to steel

  4. Conversion of pig iron to cast iron
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Wrought iron or malleable iron is the purest form of commercial iron and is prepared from cast iron by oxidising impurities in a reverberatory furnace lined with haematite.

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

Compound $X$ and aluminium are used to join railway tracks.
Name the reaction.

  1. Galvanic reaction

  2. Thermal reaction

  3. Thermite reaction

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

The reaction is called thermite reaction, in which $Al$ reduces the oxide of another metal as it forms stronger and more stable bonds with oxygen than the other metal.

$Fe _2O _3 + 2 Al \rightarrow  2 Fe + Al _2O _3$

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

The electrolytic reduction technique is used in the extraction of:

  1. Metalliods

  2. Highly electro positive metals

  3. Transition metals

  4. Highly electronegative metals
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Oxides of strong elecropositive metals such as K, Ca, Na, Al and Mg are very stable. It is difficult to reduce them into metallic state by carbon reduction.
Such metals are extracted by passing electricity through their fued chlorides/oxides/hydroxides.
So electrolytic extraction technique is used in extraction of highly electro positive metals.

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

Which of the following is not correctly matched?

  1. Red bauxite - Purification by Serpeck's method

  2. Iron from haematite - Carbon monoxide reduction

  3. Calamine - Carbonate ore
  4. $FeSiO _3$ - Slag obtained in the extraction of copper
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Red bauxite is purified by Bayer's process, not Serpeck's method. Serpeck's method is typically used for the purification of white bauxite (containing silica as impurity).

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

Which one of the following is not a method of concentration of ore? 

  1. Electromagnetic separation

  2. Smelting

  3. Gravity separation

  4. Froth floatation process
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The process of removal of unwanted materials from the ore is known as ore concentration. 


Froth floatation, electromagnetic separation, and gravity separation are few of the processes used for ore concentration.

 
Smelting, however, is a process of heating the ore in order to extract the base metal. 


Hence B is the correct answer