Tag: principles of metallurgy

Questions Related to principles of metallurgy

The purpose of stream of air in leaching process of $Ag _2S$ is to?

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

  1. Oxidises $Na _2S$ formed into $Na _2S _2O _3$

  2. Oxidises $Na _2S$ formed into $Na _2S _2O _4$

  3. Oxidises $Na _2S$ formed into $Na _2O$

  4. Act as catalyst

Show answer
Correct Option: A
Explanation:

In the leading of ${ Ag } _{ 2 }S$ (silver sulphide) with $NaCN$, a stream of air is passed because reversible nature of reaction between ${ Ag } _{ 2 }S$ and $NaCN$ and to oxidise ${ Na } _{ 2 }S$ formed into ${ Na } _{ 2 }{ SO } _{ 4 }$ and sulphur.

${ Na } _{ 2 }{ SO } _{ 4 }$ and sulphur $\Rightarrow { Na } _{ 2 }{ S } _{ 2 }{ O } _{ 4 }$

Froth flotation process is based upon :

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

  1. Magnetic property of gangue

  2. Specific gravity of ore particle

  3. Preferential wetting of ore particle by oil

  4. Preferential wetting of gangue particle by oil

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Correct Option: C

Leaching is commercially carried out for in the concentration of:

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

  1. galena

  2. argentite

  3. copper pyrites

  4. tin stone

Show answer
Correct Option: B
Explanation:

Leaching is a process in which the ore is dissolved in a suitable solvent, where the impurities remain undissolved. This method is used in the extraction of $Ag$ from Argentite where is, the ore is dissolved in sodium cyanide solution.

Which of the following method used for the concentration of copper pyrites?

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

  1. Magnetic seperation

  2. Gravity seperation

  3. Froth Floatation process

  4. None

Show answer
Correct Option: C
Explanation:
This method is used when a higher ore contains impurities with higher density. This method is used for the concentration of Sulphide ores. (Eg: Copper pyrites, iron pyrites, Galena, Zinc blende etc.) Copper is mainly extracted from copper pyrites. After the concentration of its ore by froth flotation process, the ore is roasted in a current of air to remove arsenic, antimony and much of sulphur.

Which of the following process is used for concentration of ore?

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

  1. Froth flotation

  2. Electrolytic methods

  3. Smelting

  4. Hoop's process

Show answer
Correct Option: A
Explanation:

Froth flotation method is used for the concentration of sulphide ores. 


The method is based on the preferential wetting properties with the frothing agent and water. In the given options, Galena (PbS) is the only sulphide ore.

Hence, option A is correct.

Which ore is concentrated by froth flotation method?

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

  1. Horn silver

  2. Bauxite

  3. Cinnabar

  4. Haemattie

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Correct Option: C
Explanation:

Generally sulphide ores are concentrated by "Froth floatation" and cinnabar(HgS) is a sulphide ore.

Collectors are the substances which combine with sulphide ore and make them water repellant. Which of the following substance can act as collector?

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

  1. Sodium ethyl xanthate

  2. Sodium xenate

  3. Sodium pyrophosphate

  4. Adsorption

Show answer
Correct Option: A
Explanation:

Sodium ethyl xanthate is used as collector in froth floatation process.

During concentration of Tin stone separation of wolframates of $Fe^({II})$ and $Mn^({II})$ is based on the fact that:

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

  1. $SnO _2$ is paramagnetic

  2. $SnO _2$ is diamagnetic

  3. $FeWO _4$ and $MnWO _4$ are paramagnetic

  4. Both B and C

Show answer
Correct Option: D
Explanation:

During concentration of Tin stone separation of wolframates of $Fe({II})$ and $Mn({II})$ is based on the fact $SnO _2$ is diamagnetic and both $FeWO _4$ & $MnWO _4$ are paramagnetic so magnetic separation method is used for concentration of ore.

An ore containing the impurity of $FeCr 2 O _4$ is concentrated by _________.

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

  1. magnetic-separation

  2. gravity separation

  3. froth-floatation method

  4. electrostatic method

Show answer
Correct Option: A
Explanation:

As impurity $FeCr _2 O _4$ contains iron so magnetic-separation process is used.

Which compound is used to separate two metal sulphide in forth flotation process :

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

  1. $ Na _2CO _3 $

  2. KCI

  3. NaCN

  4. $ (SCN) _2 $

Show answer
Correct Option: C