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 principles of metallurgy concentration of ore concentration of ores general principles of metallurgy

Froth flotation is a process of _____________.

  1. oxidation

  2. reduction

  3. refining

  4. concentration
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Froth flotation is a process of  concentration. Froth floatation process is suitable for sulphide ores It is based on the difference in wetting properties of the ore and gangue with water and oil. This method is used for the concentration of $FeCr _2O _4$.

Multiple choice chemistry principles of metallurgy concentration of ore concentration of ores general principles of metallurgy

Bauxite is concentrated by:

  1. Chemical method

  2. Roasting

  3. Magnetic separation

  4. Froth flotation process
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The bauxite is purified by the Bayer Process. First the ore is mixed with a hot concentrated solution of sodium hydroxide. The $NaOH$ will dissolve the oxides of aluminum and silicon but not other impurities such as iron oxides, which remains insoluble. The insoluble materials are removed by filtration.This method is called the chemical method.

Multiple choice chemistry principles of metallurgy concentration of ore concentration of ores general principles of metallurgy

In the froth floatation process, for the beneficiation of ores, the ore particles float because ______________.

  1. they are light

  2. their surface is not easily wetted by water

  3. they bear electrostatic charge

  4. they are insoluble
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In the froth floatation process, for the benefaction of ores, the ore particles float because their surface is not easily wetted by water. This method is base on the difference in the wetting properties of ores and gangue particles with the water and oil.

Multiple choice chemistry principles of metallurgy concentration of ore concentration of ores general principles of metallurgy

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

  1. Gravity separation

  2. Froth flotation process

  3. Electromagnetic separation

  4. Smelting
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Smelting is not a method of concentration of metals.

Smelting is a process of extraction of metal in its molten state by any reducing agent in the presence of flux. 

For example: oxides of less electropositive metals like Pb, Zn, Fe, Cu are reduced by any other reducing agents.
Multiple choice chemistry principles of metallurgy concentration of ore concentration of ores general principles of metallurgy

Chemical leaching is not useful in the concentration of:

  1. copper pyrite

  2. bauxite

  3. galena

  4. cassiterite
Reveal answer Fill a bubble to check yourself
A,C,D Correct answer
Explanation
Chemical leaching is a process widely used in extractive metallurgy where ore is treated with chemicals to convert the valuable metals within into soluble salts while impurity remains insoluble.

Examples : copper pyrites, galena and cassiterite.

Hence options A,C & D are correct.
Multiple choice chemistry principles of metallurgy concentration of ore concentration of ores general principles of metallurgy

Froth floatation process is used to concentrate magnetic ores.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Froth floatation process is used to concentrate sulphide ores. In some cases, sulphide ores of copper, zinc and lead concentration are brought by this method. It is the referential wetting of the ore by an oil. A strong current of air is blown through the suspension producing a heavy froth e.g. Galena $(PbS)$ is associated with Sphalerite $(ZnS)$ and Pyrite $(FeS)$.

Multiple choice chemistry principles of metallurgy concentration of ore concentration of ores general principles of metallurgy

Sulphide ore of copper can be concentrated by froth floatation process.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Froth Floatation Process:- The process is best suitable for sulphide ores. The process is based on different wetting characteristics of the ore and gangue particles with water and pine oil. The ore is wetted by oil and impurities are wetted by water. Ore particles are adsorbed on potassium or sodium ethyl xanthate (as collector) and come at the surface along with the froth. Froth stabilisers (cresols, aniline) stabilise the froth. So sulphide of copper can be concentrated by froth floatation process.
Multiple choice chemistry principles of metallurgy concentration of ore concentration of ores general principles of metallurgy

Sulfide ores are usually dressed by the _____ process.

  1. sieve process

  2. froth floatation

  3. magnetic floatation

  4. none of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Froth floatation process is based on the principle that the metallic sulphide particles of ore are preferentially wetted by oil and the gangue particles by water.
Sulphide ores being lighter are easily wetted by oil to come on the surface of solution with froths during froth floatation process, leaving behind heavy matter of gangue wetted by water.
Sulphide ores are usually dressed by froth floatation process.

Multiple choice chemistry principles of metallurgy concentration of ore concentration of ores general principles of metallurgy

The oil used in the froth floatation method for the purification of ore is _________.

  1. Coconut oil

  2. Olive oil

  3. Pine oil

  4. Castor oil
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Froth Floatation process is suitable for sulphide ores. The process is based on different wetting characteristics of the ore and gangue particles with water and pine oil. 

The ore is wetted by oil and impurities are wetted by water. Ore particles are adsorbed on potassium or sodium ethyl xanthate (as a collector) and come at the surface along with the froth. Froth stabiliser (cresols, aniline) stabilise the froth. 

So, the correct option is $C$
Multiple choice chemistry principles of metallurgy concentration of ore concentration of ores general principles of metallurgy

During concentration of _____ ores by froth floatation process potassium ethyl xanthate is added.

  1. sulphide

  2. carbonate

  3. halide

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

During concentration of sulphide ores by froth floatation process potassium ethyl xanthate is added.
Ethyl xanthate, potassium ethyl xanthate and similar compounds compounds behaves as collector and attaches themselves by polar groups to ore particles making that hydrophobic and i.e., why ore particles are passed into froth.

Multiple choice chemistry principles of metallurgy concentration of ore concentration of ores general principles of metallurgy

Ores like magnetite or tungstates in tin ores are concentrated by ______.

  1. Froth floatation

  2. Magnetic separation

  3. Gravity separation

  4. Electrostatic separation
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Magnetic Separation:- This method is adopted when either ore or the impurities are magnetic in nature. They are separated from each other by means of magnetic separators.
Eg: $SnO _2$ (Non magnetic) in $Fe _3O _4$ (magnetic)
Multiple choice chemistry principles of metallurgy concentration of ore concentration of ores general principles of metallurgy

Ore dressing for iron is done by:

  1. froth floatation process

  2. magnetic separation

  3. hand picking

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

In the field of extractive metallurgy, mineral processing, also known as ore dressing, is the process of separating commercially valuable minerals from their ores. 

Ore dressing for iron is done by magnetic separation.
So answer is B.

Multiple choice chemistry principles of metallurgy concentration of ore concentration of ores general principles of metallurgy

Any physical and chemical process by which low grade ores are concentrated, is __________.

  1. froth flotation

  2. crushing and then screening

  3. hand picking

  4. washing in zigs
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Froth flotation is a process for selectively separating hydrophobic materials from hydrophilic. Any physical and chemical process by which low grade ores are concentrated is called froth flotation.