Tag: in the land of kerala

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Multiple choice geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

The process of extraction of metal from its ores, is known as :

  1. concentration

  2. calcination

  3. purification

  4. metallurgy
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The process of extracting metals from their ores is called as metalurgy.The process employed in the extraction of the ore depends on the nature of the ore and the impurities present in it.The following are the basic steps for a metallurgical operation;

  1. Crushing and grinding of the ore.
  2. Concentration of the ore 
  3. Working of the ore 
  4. Purification or refining of the metal

Multiple choice geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

In metallurgy, the concentration of ore is followed by the dressing of ore.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Dressing of ore is followed by concentration of ore. 
Steps of metallurgy  are:
  • Crushing of the ore
  • Concentration of ore also known as Dressing of the ore
  • Conversion of concentrated ore to oxide 
  • Reduction of oxide to metal 
  • Refining of metal or Purification
Multiple choice geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala
Phosphorus mostly exists in free state.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The given statement is false.
Phosphorus does not exists in free state. It mostly exists in combined state. It occurs in the minerals of apetite family such as fluorapatite $\displaystyle Ca _9[PO _4] _6CaF _2$ which is main constituent of phosphate rocks. Phosphorous is essential constituent of animal and plant matter.

Multiple choice geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

Which of the following oxides react to form slag in open hearth process?

  1. $CaO,CO$
  2. ${ P } _{ 2 }{ O } _{ 4 }, CaO$
  3. ${ P } _{ 2 }{ O } _{ 5 }, Si{ O } _{ 2 }$
  4. $CaO, { CO } _{ 2 }$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
${CaCO _3} _{(s)}\longrightarrow CaO _{(s)}+{CO _2} _{(g)}$
$SiO _2+CaO \longrightarrow {CaSiO _3} _{(slag)}$
The calcium oxide formed by the decomposition reacts with various acidic impurities in the iron (mainly silica) to form slag which is essentially calcium silicate $(CaSiO _3)$ .
Multiple choice geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

Identify $x,\ y \ and \ z$ for the following metallurgical process :


$Metal\ sulphide\overset { x }{ \rightarrow  } Metal\ oxide\overset { y }{ \rightarrow  } Impure\ metal$

$x,\ y$ and $z$ are respectively :

  1. roasting, smelting, electrolysis

  2. roasting, calcination, smelting

  3. calcination, auto-reduction, basemerisation

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

Roasting $\rightarrow $ It is a process in metallurgy
in which sulphide are is heated in 
air and transforms into oxides.

Smelting $\rightarrow $ It is a process of extracting
a base metal from corresponding
metal oxides.

electrolysis $ \rightarrow $ It is used in metallurgical
process, such as in extraction or purification
of metals from ores or compounds.

Therefore, the correct option is A.