Tag: principles of metallurgy

Questions Related to principles of metallurgy

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

  1. sulphide

  2. carbonate

  3. halide

  4. amide


Correct Option: A
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.

Magnetic ores can be easily separated by gravity separation method.

  1. True

  2. False


Correct Option: B
Explanation:

The given statement is false as magnetic ores are separated by magnetic separation method.

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

  1. Froth floatation

  2. Magnetic separation

  3. Gravity separation

  4. Electrostatic separation


Correct Option: B
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)

The substance added in water in the froth floatation process is

  1. Olive oil

  2. Pine oil

  3. Coconut oil

  4. None of the above


Correct Option: B
Explanation:

Froth floatation process: This process is best suitable for sulphide ores. It 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 stabiliser (cresols, aniline) stabilises the froth.

Ore dressing for iron is done by:

  1. froth floatation process

  2. magnetic separation

  3. hand picking

  4. all of the above


Correct Option: B
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.

Which oil is used as frother in froth floatation process?

  1. Mustard oil

  2. Coconut oil

  3. Olive oil

  4. Pine oil


Correct Option: D
Explanation:

Pine oil enhances non-wettability of the mineral particles. So, it is used as frothier in froth-flotation process.

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


Correct Option: A
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.

How is scrap-iron separated from other wastes in a scrap yard?

  1. Sublimation

  2. Magnetic separation

  3. Handpicking

  4. Winnowing


Correct Option: B
Explanation:

Scarp Iron is a magnetic substance whereas others are not. So, they are separated by Magnetic Separation.

Chromite is concentrated by:

  1. chemical separation

  2. magnetic separation

  3. hydraulic washing

  4. froth floatation


Correct Option: B
Explanation:

Chromite is $[Fe(CrO _{2}) _{2}]$
Magnetic separation depends on its difference in the magnetic separation of the ores and gangues.

Which of the following is not a method of enrichment of ore?

  1. Hydraulic washing

  2. Froth floatation

  3. Magnetic seperation

  4. None of the above


Correct Option: D
Explanation:

Enrichment of ore means concentration or purification of ore. It can be done by hydraulic washing, magnetic separation, chemical separation.