Match List I with List II : (Both having metallurgical terms)

List I
(A) Concentration of Ag ore
(B

Q: Why do we use $NaCN$ specifically for silver ore?

Silver and gold are noble metals. They don't easily react with acids or bases. However, they form highly stable, soluble cyanide complexes (like $Na[Ag(CN)_2]$) in the presence of oxygen. This allows us to separate the precious metal from the insoluble gangue.

Q: What exactly is the difference between pig iron, cast iron, and wrought iron?

It's all about the carbon content! Pig iron, obtained directly from the blast furnace, has the highest carbon content ($\approx 4\%$) and is very brittle. Cast iron has slightly less carbon ($\approx 3\%$), and wrought iron is the purest commercial form with less than $0.5\%$ carbon.

Q: Why is the reverberatory furnace linked to blister copper instead of the Bessemer converter?

While blister copper is *produced* in the Bessemer converter, the reverberatory furnace is a crucial preceding step where the copper ore is roasted and smelted to form copper matte ($Cu_2S$ and $FeS$). The question links the overall extraction process of blister copper to the furnaces involved in its journey.

Q: Why does froth floatation only work for sulphide ores?

Sulphide ores have a unique physical property: they are hydrophobic (water-repelling) but are easily wetted by oils (like pine oil). Oxide or carbonate ores are hydrophilic (water-attracting). The froth floatation method exploits this exact difference to lift sulphide particles to the surface in a froth.

Q: Can we use carbon reduction for extracting silver?

No, carbon reduction requires high temperatures, and silver compounds can easily decompose or don't require such aggressive reducing agents. Hydrometallurgy (leaching) is much more efficient, economical, and yields higher purity for noble metals like silver and gold.

Question

Match List I with List II : (Both having metallurgical terms)

\begin{array}{ll}
	ext{List I} & 	ext{List II} \
	ext{(A) Concentration of Ag ore} & 	ext{I. Reverberatory furnace} \
	ext{(B) Blast furnace} & 	ext{II. Pig iron} \
	ext{(C) Blister copper} & 	ext{III. Leaching with dilute NaCN solution} \
	ext{(D) Froth floatation method} & 	ext{IV. Sulphide ores}
\end{array}

Choose the correct answer from the options given below.

Options:

(A) A $ightarrow$ III, B $ightarrow$ II, C $ightarrow$ I, D $ightarrow$ IV

(B) A $ightarrow$ III, B $ightarrow$ IV, C $ightarrow$ I, D $ightarrow$ II

(C) A $ightarrow$ IV, B $ightarrow$ I, C $ightarrow$ III, D $ightarrow$ II

(D) A $ightarrow$ IV, B $ightarrow$ III, C $ightarrow$ II, D $ightarrow$ I

Sigma Percentile · Accepted Answer

### The Art of Extracting Metals

Metallurgy is the fascinating science of extracting pure, gleaming metals from the dirt and rocks of the Earth. It is a journey that involves crushing, washing, roasting, and melting. In this problem, we are tasked with matching four distinct metallurgical processes or terms with their corresponding industrial applications. Let's dive deep into the chemistry and engineering behind each of these terms.

### The Magic of Cyanide Leaching

First on our list is the **concentration of silver ($Ag$) ore**. Silver, much like gold, is a noble metal. It doesn't easily react with common acids or bases. So, how do we separate it from the massive amounts of useless rock (gangue) it is embedded in?

We use a brilliant hydrometallurgical technique known as the **Mac-Arthur Forrest cyanide process**. The crushed ore is treated with a dilute solution of sodium cyanide ($NaCN$) in the presence of atmospheric oxygen. The silver reacts to form a highly stable, water-soluble complex:

$$Ag_2S + 4NaCN \rightleftharpoons 2Na[Ag(CN)_2] + Na_2S$$

Because the silver is now dissolved in the liquid, we can simply filter out the solid rock impurities. Later, we add a more reactive metal like zinc to displace the silver and precipitate it out in its pure form. Therefore, the concentration of $Ag$ ore perfectly matches with **leaching with dilute $NaCN$ solution**.

### The Mighty Blast Furnace

Next, we encounter the **blast furnace**, the towering behemoth of the iron industry. Iron ore (like haematite, $Fe_2O_3$) is fed into the top of the furnace along with coke (carbon) and limestone. As a blast of hot air is blown from the bottom, a series of intense reduction reactions occur at varying temperature zones.

The molten iron that collects at the very bottom hearth of the blast furnace is known as **pig iron**. It is the most impure form of commercial iron, containing approximately **$4\%$ carbon** along with traces of sulfur, phosphorus, and silicon. Because of this high carbon content, pig iron is extremely hard but very brittle. Thus, the blast furnace is directly associated with the production of **pig iron**.

### The Journey to Blister Copper

Our third term is **blister copper**. The extraction of copper from its primary ore, copper pyrites ($CuFeS_2$), is a multi-step pyrometallurgical process. After initial concentration, the ore is roasted and smelted.

This crucial smelting step takes place in a **reverberatory furnace**. Here, the ore is heated strongly, and volatile impurities escape. The iron impurities form a slag ($FeSiO_3$), leaving behind a molten mixture of copper sulphide ($Cu_2S$) and iron sulphide ($FeS$), known as **copper matte**.

This matte is then transferred to a Bessemer converter, where a self-reduction reaction occurs. As the copper solidifies, dissolved sulfur dioxide ($SO_2$) gas escapes, leaving blister-like eruptions on the surface of the metal—hence the name "blister copper." Because the reverberatory furnace is the essential preparatory stage for this, it is the correct match for blister copper in our list.

### Froth Floatation: The Power of Bubbles

Finally, we look at the **froth floatation method**. This is one of the most elegant physical separation techniques in metallurgy. It is almost exclusively used for the concentration of **sulphide ores** (such as zinc blende, $ZnS$, or galena, $PbS$).

The principle is based on the difference in wetting properties. Sulphide ore particles are **hydrophobic** (water-repelling) but are easily wetted by oils (like pine oil). The gangue particles are hydrophilic (water-attracting). When air is blown through a suspension of the ore in water and oil, the sulphide particles attach to the oil-coated air bubbles and rise to the surface as a rich froth, which is then skimmed off. Therefore, the froth floatation method matches perfectly with **sulphide ores**.

### Final Conclusion

By understanding the fundamental chemistry and industrial application of each process, the matching becomes incredibly intuitive:
- **(A) Concentration of Ag ore** $\rightarrow$ **(III) Leaching with dilute $NaCN$ solution**
- **(B) Blast furnace** $\rightarrow$ **(II) Pig iron**
- **(C) Blister copper** $\rightarrow$ **(I) Reverberatory furnace**
- **(D) Froth floatation method** $\rightarrow$ **(IV) Sulphide ores**

This leads us directly to the correct option, proving that a solid grasp of metallurgical principles makes these matrix match questions highly scoring!

Select Answer:

Visualized Solution

Matrix Match: Metallurgy

Concentration of $A g$ Ore

Blast Furnace

Blister Copper

Froth Floatation

Final Answer

The Sigma Insight: Principles of Metallurgy and Extraction

The Art of Extracting Metals

The Magic of Cyanide Leaching

The Mighty Blast Furnace

The Journey to Blister Copper

Froth Floatation

Final Conclusion

Similar Questions

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Extraction of copper from copper pyrite ( $CuFeS_{2}$ ) involves

Which one of the following ores is best concentrated by froth-floatation method ?

The correct statement is

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Select Answer:

Visualized Solution

Matrix Match: Metallurgy

Concentration of .math-text-wrapper .katex { font-size: 1.05em !important; } .math-text-wrapper .katex-display { margin: 1rem 0 !important; } Ag Ore

Blast Furnace

Blister Copper

Froth Floatation

Final Answer

The Sigma Insight: Principles of Metallurgy and Extraction

The Art of Extracting Metals

The Magic of Cyanide Leaching

The Mighty Blast Furnace

The Journey to Blister Copper

Froth Floatation

Final Conclusion

Similar Questions

The correct statement(s) related to processes involved in the extraction of metals is(are)

The process that involves the removal of sulphur from the ores is

.math-text-wrapper .katex { font-size: 1.05em !important; } .math-text-wrapper .katex-display { margin: 1rem 0 !important; } Extraction of copper from copper pyrite (CuFeS2​) involves

Which one of the following ores is best concentrated by froth-floatation method ?

The correct statement is

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Extraction of copper from copper pyrite ( $CuFeS_{2}$ ) involves

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