Tag: basics of metallurgy

Questions Related to basics of metallurgy

Which of the following statements is/are correct regarding metallurgy?

  1. Both calcination and roasting are generally carried out in the same furnace, i.e., reverberatory furnace.

  2. The slag formed during the extraction of Copper metal from Chalcopyrites ore is $CaSiO _3$.

  3. Mond's process involved in the extraction of nickel is related with formation and decomposition of a square planner complex of nickel metal.

  4. In case of electrolytic refining of extracted metals, generally impure metal rod is made the anode and pure metal rod is made the cathode.


Correct Option: A,D
Explanation:

Both calcination and roasting are generally carried out in the this furnace, one in absence of air and other in presence of air.
The slag formed during the extraction of Copper metal from Chalcopyrites ore is $FeSiO _3$.
Mond's process involved in the extraction of Nickel is related with formation and decomposition of a tetrahedral complex of nickel metal $[Ni(CO) _4]$. 

In case of electrolytic refining of extracted metals, generally impure metal rod is made the anode and pure metal rod is made the cathode. This is evident as at anode, we get impure slag and at cathode, we get pure metal.

Silver can be separated from lead by:

  1. Distillation

  2. Amalgamation

  3. Filtration

  4. Cupellation


Correct Option: D
Explanation:

Cupellation is a process where ores are treated under high temperatures and controlled operations to separate noble metals like gold and silver from base metals like lead, copper, zinc, and others present in the ore or alloyed metal.

Refining of silver is done by___________.

  1. liquidation

  2. poling

  3. cupellation

  4. van Arkel method


Correct Option: C
Explanation:

Cupellation is a process where ores are treated under high temperatures and controlled operations to separate noble metals like gold and silver, from base metals like led, copper, zinc, and others present in the ore or alloyed metal.

Refining of silver is done by________.

  1. liquidation

  2. Poling

  3. cupellation

  4. van Aekel method


Correct Option: C
Explanation:

Cupellation is a process where ores are treated under high temperatures and controlled operations to separate noble metals like gold and silver, from base metals like led, copper, zinc, and others present in the ore or alloyed metal.

Cupellation process is used in the metallurgy of:

  1. Copper

  2. Silver

  3. Aluminium

  4. Iron


Correct Option: B
Explanation:

Cupellation is a process where ores are treated under high temperatures and controlled operations to separate noble metals like gold and silver, from base metals like led, copper, zinc, and others present in the ore or alloyed metal.

When alloy of silver and lead is rich in silver:

  1. Cupellation process is used

  2. Parke's method is used

  3. Pattinson's method is used

  4. Any of the above methods can be used


Correct Option: A
Explanation:

When alloy of silver and lead is rich in silver, cupellation process is used.
The silver metal can be obtained in when alloy of silver and lead is rich in lead is:
i) Parke's process
ii) Pattinson's process

Softening of lead means:

  1. Melting pure lead at high temperature

  2. Removal of impurities, except silver, present in commercial lead

  3. Formation of lead alloy

  4. Formation of 100% pure lead


Correct Option: B
Explanation:

We know the melting point of pure lead is very high. Softening of lead means removal of metallic impurities, except silver, present in the commercial lead. 


B  is the correct answer

Tin is not refined by:

  1. Liquidation

  2. Zone refining

  3. Poling

  4. None of the above


Correct Option: B
Explanation:
Poling is a [metallurgical] method employed in the purification of copper which contains copper oxide as an impurity and also in the purification of tin ("Sn") which contains tin oxide (stannic oxide or "$SnO _2$") as an impurity. It was the use of these greenwood poles gave rise to the term "poling."

Liquidation is suitable for metals with low melting points for example, tin. In this process, we heat the impure metal and then we let it flow on a sloped surface. The impurities will remain behind and the pure metal will collect at the bottom of the slope.


Zone refining is a special method we use to purify metals. It was the invention of William Pfann. It purifies metals to a very high degree. A rod of impure metal is placed in a container which we fill with inert gas. Then we place a circular heater around the rod at the top.

The melting point of tin is low. So zone refining is not suitable for Tin.

Hence, option B is correct.

When alloy of silver and lead is rich in silver :

  1. CupelIation process is used

  2. Parke's method is used

  3. Bett's method is used

  4. All of the above method


Correct Option: A
Explanation:
Cupellation: Pb impurities present in Ag are removed by this method. The impure metal is heated in a cupel or oval shaped crucible made of bone ash or cement and blast of air is passed over the molten mass. The impurities get oxidised and removed with the blast of air.

Refining of tin can be done by :

  1. cupellation

  2. liquation

  3. poling

  4. electrorefining


Correct Option: B,C,D
Explanation:
Poling is a method employed in the purification of copper which contains copper oxide as an impurity and also in the purification of tin ("Sn") which contains tin oxide (stannic oxide or "SnO2") as an impurity. It was the use of these greenwood poles gave rise to the term "poling."

Liquation is suitable for metals with low melting points, for example, tin. In this process, we heat the impure metal and then we let it flow on a sloped surface. The impurities will remain behind and the pure metal will collect at the bottom of the slope.

Electrorefining, producing pure tin from waste materials in cheap acid electrolytes can be effectively operated with parameters set to provide for the stability of the solution and high current efficiencies and the use of the periodical current reversal (PCR) technique.

Cupellation is a refining process in metallurgy where ores or alloyed metals are treated under very high temperatures and have controlled operations to separate noble metals, like gold and silver, from base metals, like lead, copper, zinc, arsenic, antimony, or bismuth, present in the ore.

Cupellation is used for purifying of metal under high temperature. so it is not suitable for tin(low melting point metal).