Tag: principles of metallurgy

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Questions Related to principles of metallurgy

Multiple choice chemistry principles of metallurgy extraction of metal from concentrated ore basics of metallurgy extraction of metals from ore

The major step involved in extraction of a metal after its ore is :

  1. concentration

  2. reduction

  3. purification

  4. all of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

 The three steps involved in extraction are:
1) Concentration of the ore to remove impurities.
2) Reduction of the ore to get the metal.
3) Purification of the ore.

Multiple choice chemistry principles of metallurgy extraction of metal from concentrated ore basics of metallurgy extraction of metals from ore

Which phenomenon occurs during the following change?
Solid wax left out in the sun.

  1. Sublimation

  2. Melting

  3. Condensation

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

Melting (Change of solid into liquid) - The change of solid into liquid due to increase in temperature is known as melting. Ice, which is a solid melts, i.e. changes into water. 
Similarly, when solid wax gets heated it converts into liquid and this is melting process.

Multiple choice chemistry principles of metallurgy extraction of metal from concentrated ore basics of metallurgy extraction of metals from ore

Which of the following is not a method of extraction of metals?

  1. Enrichment of ore

  2. Refining

  3. Magnetic separation

  4. None of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Refining and magnetic separation are methods of extraction of metals .Enrichment of ore is also known as concentration of ore. It means purification of ore.

Multiple choice chemistry principles of metallurgy extraction of metal from concentrated ore basics of metallurgy extraction of metals from ore

Process of removal of gangue from the ore are based on:

  1. differences between physical and chemical properties of the gangue and the ore

  2. difference between densities of gangue and ore

  3. difference between melting point between of gangue and ore

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

Impurities are removed prior to the extraction of metal. The process used for removal of gangue from the ore are based on the differences between physical and chemical properties of the gangue.

Multiple choice chemistry principles of metallurgy extraction of metal from concentrated ore basics of metallurgy extraction of metals from ore

What will happen during roasting?

  1. The sulphide ores are converted into oxides

  2. The oxide ores are converted into sulphides

  3. The sulphide ores are converted into carbonates

  4. The oxide ores are converted into carbonates.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

During roasting, the sulphide ores are converted into oxides by heating strongly in excess of air.
$ZnS + 3O _2 \rightarrow 2ZnO + 2SO _2$

Multiple choice chemistry principles of metallurgy extraction of metal from concentrated ore basics of metallurgy extraction of metals from ore

Which if the following is a common reducing agent for extracting metals from ore?

  1. $CO$

  2. Carbon

  3. Hydrogen

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

Reduction is the process of removal of oxygen for extraction of metals from their oxide ores. The common reducing agents used for reduction of metal oxides are: Carbon monoxide,  Carbon, Hydrogen.

Multiple choice chemistry principles of metallurgy extraction of metal from concentrated ore basics of metallurgy extraction of metals from ore

During electrolysis, electrons are being added directly to the metal ions at the ___________.

  1. anode

  2. cathode
  3. both $A$ and $B$

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

During electrolysis, electrons are being added directly to the metal ions at the cathode (the negative electrode). The downside (particularly in the aluminum case) is the cost of the electricity. An advantage is that it can produce very pure metals.

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

What is the process of leaching in case of low grade copper ores?

  1. Leaching is carried out with $NaOH$ and $O _2$
  2. Leaching is carried out with $NaCN$
  3. Leaching is carried out with acids in presence of $O _2$

  4. Leaching is carried out by boiling the ore with water
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Leaching of low grade copper ores is carried out with acid or bacteria, when copper goes into solution as $Cu^{2+} _{(aq) }+ H _{2(g)}\rightarrow Cu _{(s)}+2H^+ _{(aq)}$ 

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

How do we separate two sulphide ores by froth floatation method?

  1. By using excess of pine oil.

  2. By adjusting proportion of oil to water or using depressant.

  3. By using collectors and froth stabilities like xanthates.

  4. By using some solvent in which one of the sulphides is soluble.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

By using depressants or adjusting proportion of oil to water, selective prevention of one sulphide ore from coming to the froth is possible.

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

An ore of tin containing, $FeCrO _4$ is concentrated by:

  1. gravity separation

  2. magnetic separation

  3. forth floatation

  4. leaching
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • Magnetic separation based on differences in magnetic properties of the ore components.
  •  If either the ore or the gangue is attracted towards the magnetic field, then the separation is carried out by this method. 
  • For example, iron ores are attracted towards the magnet, hence, non–magnetic impurities can be separated from them using magnetic separation.
  • Here,$FeCrO _4$ being an iron ore can be separated by magnetic separation.