Copper is isolated from copper glance (a sulphide ore) through a process involving heating the ore, which leads to its conversion to copper(I) oxide followed by a reaction with residual sulphide to produce copper metal.
The isolation process involves heating the copper sulphide ore alone, which is a self-reduction method. This method leverages the properties of copper(I) sulphide (Cu₂S) and copper(I) oxide (Cu₂O) at high temperatures.
Here's a breakdown of the key steps as described in the process:
Process for Isolating Copper from Copper Glance
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Roasting: The copper glance ore, which is primarily copper(I) sulphide (Cu₂S), is heated in the presence of air.
- During this step, the copper(I) sulphide is partially oxidised.
- The reference specifically states that Copper (I) sulphide is converted to copper (I) oxide during roasting.
- Simplified Reaction (partial): Cu₂S (solid) + O₂ (gas) → Cu₂O (solid) + SO₂ (gas) (This is a simplified representation based on the description).
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Self-Reduction: After roasting, the heating continues, but crucially, this subsequent stage occurs in the absence of air.
- The copper(I) oxide (Cu₂O) that was formed during roasting reacts with the remaining non-oxidised copper(I) sulphide (Cu₂S) ore.
- This reaction between the oxide and the sulphide results in the formation of copper metal.
- Simplified Reaction: Cu₂O (solid) + Cu₂S (solid) → Cu (solid) + SO₂ (gas)
In essence, the process relies on the initial partial roasting of the sulphide ore to produce copper(I) oxide, which then acts as an oxidizing agent to react with the remaining sulphide ore, leading to the final isolation of copper metal.
This method is highlighted in the reference: "Copper is extracted by heating its sulphide ore alone." It further details the two phases: Roasting in air converts Cu₂S to Cu₂O, and subsequently, the Copper (I) oxide, so formed, reacts with non-oxidised copper (I) sulphide ore in the absence of air to form copper metal.
This technique is a specific type of pyrometallurgy used for certain metal sulphides where the metal oxide can react directly with the metal sulphide to produce the metal.
