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 geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

During smelting, an additional substance is added which combines with impurities to form a fusible mass. The additional substance is called__________.

  1. Flux

  2. Slag

  3. Gangue

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

In the process of smelting, inorganic chlorides, fluorides, limestone and other materials are designated as "fluxes" when added to the contents of a smelting furnace or a cupola for the purpose of purging the metal of chemical impurities such as phosphorus, and of rendering slag more liquid at the smelting temperature.

Multiple choice geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

$SnO _2$ is reduced to metallic Sn on smelting oxide with anthracite and lime. In this, the function of lime is :

  1. it acts as a flux

  2. it removes acidic impurities as slag

  3. it removes ,basic impurities as slag

  4. it acts as a slag
Reveal answer Fill a bubble to check yourself
A,B Correct answer
Explanation

In the smelting process the black Sn is mixed with anthracite and little limestone which acts as flux, now this mixture is heated to a degree centigrade of 1200-1300, as a result, $SnO _2$ is reduced to Sn. This crude is having many acid impurities which can be removed as slag.$SnO _2+2C \Rightarrow Sn+2C$.

Multiple choice geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

Which statement is correct?

  1. Gangues are carefully chosen to combine with the slag present in the ore to produce easily fusible flux to carry away the impurities

  2. Slags are carefully chosen to combine with the flux present in the ore to produce easily fusible gangue to carry away the impurities

  3. Gangues are carefully chosen to combine with the flux present in the ore to produce easily fusible slag to carry away the impurities

  4. Fluxes are carefully chosen to combine with the gangue present in the ore to produce easily fusible slag to carry away the impurities
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Flux: The substance which is added to remove the gangue from the concentrated ore in its molten state is called Flux and the substance formed with flux is called Slag. Hence, fluxes have to be carefully chosen.

Acidic Flux
$SiO _2 + CaO \rightarrow CaSiO _3$
Acidic flux removes basic impurities.

Basic Flux
$SiO _2 + MgO \rightarrow MgSiO _3$
Basic flux removes acidic impurities
Multiple choice geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

Here an extraction process is given in steps. Identify the suitable ores corresponding to the process.
Pulverisation $\rightarrow$ Calcination $\rightarrow$ Smelting $\rightarrow$ Vacuum $\rightarrow$ Distillation

  1. Zinc blend

  2. Calamine

  3. Magnesite

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

Zinc Sulphide and Calamine responds for the process because, in $ZnS$, only zinc comes at smelting and after process, high purity comes after distillation. similar to Calamine, after distillation, the metal obtained is pure.

Multiple choice geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

The ore that can be concentrated by magnetic separation method is:

  1. bauxite $(Al _{2}O _{3}.xH _{2}O)$
  2. pyrolusite $(MnO _{2})$
  3. cuprite $(Cu _{2}O)$
  4. zincite $(ZnO)$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The ore that can be concentrated by magnetic separation method is pyrolusite $(MnO _{2})$.
In this method, the ferromagnetic and non-magnetic particles in the ore are separated by an electromagnetic separator.

Multiple choice geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

The waste, or slag, that comes out at the bottom of a blast furnace for making iron from its ore, is no thrown away. It is used for making?

  1. Dental powder

  2. Roads

  3. Plastics

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

Solution:- (B) Roads

Slag is valuable raw material for preparation of macadam materials and mineral blinders serving as a base for asphalt concrete mixture and manufacturing of cement emulsions, which are widely used in road paving.

Multiple choice geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

Pig iron can be converted into steel by removing a lot of carbon contained in it, in a/ an:

  1. electrolytic chamber

  2. bessemer converter

  3. blast furnace

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

Solution:- (B) bessemer converter

The Bessemer process was the first inexpensive industrial process for the mass production of steel from molten pig iron before the development of the open hearth furnace. The key principle is removal of impurities from the iron by oxidation with air being blown through the molten iron.

Multiple choice geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

Calcium silicate slag formed in extraction of iron :

  1. prevents the reoxidation of molten iron.

  2. catalyses the combustion of carbon
  3. reduces $CO _2$ to $CO$ at the bottom of the furnace

  4. is used in cement industry
Reveal answer Fill a bubble to check yourself
A,D Correct answer
Explanation

Slag formed in extraction of iron is consists of $CaSiO _3$ which is further used for making cement.
Also, formation of this slag prevents the re-oxidation of molten iron.

Multiple choice chemistry chemical effects of electric current applications of electrolysis electroplating extraction of metals by electrolysis

The electrical process of coating an inexpensive conductor with a metal is called electroplating.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Electroplating is a process that uses electric current to deposit/reduce dissolved metal cations so that they form a thin coherent metal coating on an electrode.

It is used to coat a relatively mundane metal, such as copper, with a thin layer of another, more precious metal, such as gold or silver. 

Hence, option $\text{A}$ is correct.