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 production of metals refining of metals basics of metallurgy basic metallurgical processes

Silver containing lead as an impurity is not purified by:

  1. Poling

  2. Cupellation

  3. Levigation

  4. Distillation
Reveal answer Fill a bubble to check yourself
A,C,D Correct answer
Explanation

Poling is a method employed in the purification of copper which contains cuprous oxide as an impurity. Silver containing lead as an impurity is not purified by polling.


Cupellation is a refining process in metallurgy, where ores or alloyed metals are treated under high temperatures and controlled operations to separate noble metals like gold and silver from base metals like lead, copper, zinc, arsenic or bismuth, present in the ore.

Levigation: The process of removal of heavy ore particles from lighter particles by washing with water. Silver containing lead as an impurity is not purified by levigation.in this process heavy ore particles are removed from a lighter particle. but not lighter particles from heavy particles.

Distillation is a process of separating the component substances from a liquid mixture by selective evaporation and condensation. Distillation may result in essentially complete separation (nearly pure components), or it may be a partial separation that increases the concentration of selected components of the mixture. Ex: zinc and mercury are distilled by a fractional distillation process.

So, silver-containing lead as an impurity is not purified by polling, levigation & distillation.

Hence options A, C, D are correct.

Multiple choice chemistry production of metals refining of metals basics of metallurgy basic metallurgical processes

Which of the following metals are obtained by electrolysis of their chlorides in molten state?
(i)   $Na$
(ii)  $Ca$
(iii) $Fe$
(iv) $Cu$

  1. (i) and (iv)

  2. (iii) and (iv)

  3. (i) and (iii)

  4. (i) and (ii)
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Sodium and calcium are the metals obtained by electrolysis of their chlorides in molten state. Both are reactive metals.

Multiple choice chemistry production of metals refining of metals basics of metallurgy basic metallurgical processes

In the electrolytic refining of zinc,

  1. graphite is at the anode

  2. the impure metal is at the cathode

  3. the metal ions gets reduces at the anode

  4. acidified zinc sulphate is the electrolyte
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In the electrolytic refining of zinc

Anode → impure zinc

Cathode → strip of pure zinc

Electrolyte → acidified zinc sulphate solution

At anode → Oxidation of metal

                     (i.e., $Zn \longrightarrow Zn^{2+} + 2e^–$)

                            (impure)

At cathode → reduction of metal ions

                       (i.e., $Zn^{2+} + 2e^– \longrightarrow Zn$)

                          (Form solution)    (pure)

Multiple choice chemistry production of metals refining of metals basics of metallurgy basic metallurgical processes

Anode mud is obtained in which of the following processes?

  1. Roasting

  2. Zone refining

  3. Electrolytic refining

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

Metals such as Cu, Ag, Zn, Sn, Pb, Al, Ni, Cr are refined by electrolytic refining method. The impure metal is made the anode of a electrolytic cell, while cathode is thin plate of pure metal. Electrolyte is the solution of a double salt of the metal. On passing the electric current pure metal from the anode dissolves and gets deposited at the cathode. The soluble impurities go into the solution while insoluble or less electropositive impurities settle down below the anode as anode mud or sludge. 

Multiple choice chemistry production of metals refining of metals basics of metallurgy basic metallurgical processes

Mark the correct option:
a) Pure metal from the electrolyte is deposited at the anode.
b) The soluble impurities go into the solution.
c) Insoluble impurities known as anode mud.

  1. a, b

  2. b, c

  3. a, c

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

On passing the current through the electrolyte, pure metal from the anode dissolves into the electrolyte. An equivalent amount of pure metal from electrolyte is deposited on the cathode.

Multiple choice chemistry production of metals refining of metals basics of metallurgy basic metallurgical processes

Refining of metal is:

  1. purification of metal

  2. concentration of metal

  3. conversion into oxides

  4. none of above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Refining consists of purifying an impure material, in this case, a metal. It is to be distinguished from other processes such as smelting and calcining in that those two involve a chemical change to the raw material, whereas in refining, the final material is usually identical chemically to the original one, only it is purer.

Multiple choice chemistry production of metals refining of metals basics of metallurgy basic metallurgical processes

The electrolyte used for copper refining is an acidic solution of:

  1. copper chloride

  2. copper sulphide

  3. copper sulphate

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

The purest copper is obtained by an electrolytic process, undertaken using a slab of impure copper as the anode and a thin sheet of pure copper as the cathode. The electrolyte is an acidic solution of copper sulphate.