The chief ores of iron are haemalite `(Fe_2O_3)` , magnetite `(Fe_3O_4)` , limonite `(FeO(OH))` and siderite `(FeCO_3)`.In the extraction of iron , oxides ores of iron, after concentration through calcination/roasting in reverberatory furnace are mixed with lime stone and coke and fed into a blast furnace. Here, the oxide is reduced to the metal.
Which of the following is obtained as a slag in the extraction of iron from haematite ore ?

Options

A. `FeSiO_3`
B. `CaSiO_3`
C. `CaCO_3`
D. `MgSiO_3`

Explanation

To determine which slag is obtained in the extraction of iron from haematite ore, we can follow these steps:

### Step 1: Understand the Process of Iron Extraction
Iron is extracted from its ores through a process that involves calcination or roasting, followed by reduction in a blast furnace. The chief ores of iron include haematite (Fe₂O₃), magnetite (Fe₃O₄), limonite (FeO(OH)), and siderite (FeCO₃).

### Step 2: Calcination/Roasting
In the first step, the iron ore (haematite in this case) is subjected to calcination or roasting to remove impurities and make the ore more porous. This process prepares the ore for the subsequent reduction step.

### Step 3: Mixing with Limestone and Coke
After calcination, the haematite ore is mixed with limestone (CaCO₃) and coke (carbon) and fed into a blast furnace. The limestone acts as a flux, which helps in the formation of slag.

### Step 4: Reaction in the Blast Furnace
In the blast furnace, the following reactions occur:
- The limestone decomposes into calcium oxide (CaO) and carbon dioxide (CO₂):
\[ \text{CaCO}_3 \rightarrow \text{CaO} + \text{CO}_2 \uparrow \]
- The calcium oxide then reacts with the impurities (like silica, SiO₂) present in the ore to form slag:
\[ \text{CaO} + \text{SiO}_2 \rightarrow \text{CaSiO}_3 \]
This product, calcium silicate (CaSiO₃), is the slag formed during the extraction process.

### Step 5: Identify the Slag
From the above reactions, we conclude that the slag obtained from the extraction of iron from haematite ore is calcium silicate (CaSiO₃).

### Final Answer
The slag obtained in the extraction of iron from haematite ore is **calcium silicate (CaSiO₃)**.

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