process for iron ore the chemistry of gold ore

Process for Iron Ore Extraction and the Chemistry of Gold Ore

# 1. Iron Ore Processing (Extraction of Iron)
Iron is primarily extracted from its ores, mainly hematite (Fe₂O₃) and magnetite (Fe₃O₄), through a process called smelting in a blast furnace. The key steps are:

## (a) Concentration of Ore (Beneficiation)
– Crushing & Grinding: The ore is crushed and ground into fine particles.
– Magnetic Separation: Used for magnetite (Fe₃O₄), which is magnetic.
– Gravity Separation & Fr Flotation: Used for hematite to remove silica and other impurities.

## (b) Roasting & Calcination
– If the ore contains carbonate or hydrated oxides, it is heated to remove water and CO₂:
\[
\text{FeCO}_3 \rightarrow \text{FeO} + \text{CO}_2 \quad (\text{Calcination})
\]
\[
4\text{FeS}_2 + 11\text{O}_2 \rightarrow 2\text{Fe}_2\text{O}_3 + 8\text{SO}_2 \quad (\text{Roasting})
\]

## (c) Blast Furnace Smelting
The concentrated ore is mixed with coke (C) and limestone (CaCO₃) and fed into a blast furnace:
– Reduction Reactions:
\[
\text{C} + \text{O}_2 \rightarrow \text{CO}_2
\]
\[
\text{C} + \text{CO}_2 \rightarrow 2\text{CO} \quad (\text{Carbon monoxide reduces iron oxide})
\]
\[
3\text{Fe}_2\text{O}_3 + \text{CO} → 2\text{Fe}_3\text{O}_4 + \text{CO}_2
\]
\[
\text{Fe}_3\text{O}_4 + 4\text{CO} → 3\text{Fe} + 4\text{CO}_2
\]
– Slag Formation:
\[
\text{CaCO}_3 → \text{CaO} + \text{CO}_2
\]
\[
\text{CaO}