Tag: general principles of metallurgy

Questions Related to general principles of metallurgy

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

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

  1. Froth floatation

  2. Magnetic separation

  3. Gravity separation

  4. Electrostatic separation

Show answer
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

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

  1. Olive oil

  2. Pine oil

  3. Coconut oil

  4. None of the above

Show answer
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:

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

  1. froth floatation process

  2. magnetic separation

  3. hand picking

  4. all of the above

Show answer
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?

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

  1. Mustard oil

  2. Coconut oil

  3. Olive oil

  4. Pine oil

Show answer
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 __________.

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

  1. froth flotation

  2. crushing and then screening

  3. hand picking

  4. washing in zigs

Show answer
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?

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

  1. Sublimation

  2. Magnetic separation

  3. Handpicking

  4. Winnowing

Show answer
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:

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

  1. chemical separation

  2. magnetic separation

  3. hydraulic washing

  4. froth floatation

Show answer
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?

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

  1. Hydraulic washing

  2. Froth floatation

  3. Magnetic seperation

  4. None of the above

Show answer
Correct Option: D
Explanation:

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

An ore on heating in air forms $SO _{2}$. State the process that will be used for its concentration.

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

  1. Hydrautic washing

  2. Magnetic separation

  3. Froth floatation

  4. None of the above

Show answer
Correct Option: C
Explanation:

Whenever a metal sulphide is heated in air, sulphur dioxide is formed as one of the products. A sulphide ore is concentrated by the froth floatation process.

In froth floatation process, gangue particles are wetted by pine oil.

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

  1. True

  2. False

Show answer
Correct Option: A
Explanation:
Froth flotation is a process to purify sulfide ores, in presence of pine oil. The oil acts as hydrophobic agent and forms froth with hydrophobic impurities (gangue) which is skimmed off from the surface leaving behind the concentrated mineral.
Wet pine oil is used in froth flotation process because it does not have an affinity towards water (because of the hydrophobic chemicals as its constituents)and it attracts impurities which can be washed away.
Hence, it is true.