Which step is not involved in hydrometallurgical process ?

Options

A. `Cu_(2)S + 2Cu_(2)O rarr 6 Cu + SO_(2)`
B. `CuSO_(4) + Fe rarr Cu + FeSO_(4)`
C. `CuFeS_(2)+2H_(2)SO_(4) rarr CuSO_(4) + FeSO_(4) + H_(2)S`
D. `CuCO_(3) + H_(2)SO_(4) rarr CuSO_(4) + CO_(2) + H_(2)O`

Answer

To determine which step is not involved in the hydrometallurgical process, we first need to understand what the hydrometallurgical process entails.

### Step-by-Step Solution:

1. **Definition of Hydrometallurgical Process**:
The hydrometallurgical process is a method of extracting metals from their ores by converting them into aqueous solutions. This involves leaching the ore to dissolve the metal, followed by recovery of the metal from the solution.

2. **Identifying the Steps in Hydrometallurgy**:
The main steps involved in the hydrometallurgical process are:
- **Leaching**: The ore is treated with a solvent to dissolve the desired metal.
- **Separation**: The metal-rich solution is separated from the undissolved residue.
- **Recovery**: The metal is recovered from the solution, often through reduction or precipitation.

3. **Analyzing the Given Reactions**:
We analyze the reactions provided in the video transcript to identify which one does not fit the hydrometallurgical process:
- **First Reaction**: Cu2S + 2 Cu2O → 6 Cu + SO2
- This reaction involves the direct conversion of copper sulfide and copper oxide into elemental copper and does not involve an aqueous solution. Hence, it does not fit the hydrometallurgical process.
- **Second Reaction**: CuSO4 + Fe → Cu + FeSO4
- This reaction involves the reduction of copper sulfate in an aqueous solution, fitting the hydrometallurgical process.
- **Third Reaction**: CuFeS2 + 2 H2SO4 → CuSO4 + FeSO4 + H2S
- This reaction involves sulfuric acid, which is an aqueous solution, and fits the hydrometallurgical process.
- **Fourth Reaction**: CuCO3 + H2SO4 → CuSO4 + Cu2 + H2O
- This reaction also involves sulfuric acid as an aqueous solution and fits the hydrometallurgical process.

4. **Conclusion**:
Based on the analysis, the first reaction (Cu2S + 2 Cu2O → 6 Cu + SO2) is the only one that does not involve the formation of an aqueous solution and is not part of the hydrometallurgical process. Therefore, the answer to the question is:
- **Answer**: The step that is not involved in the hydrometallurgical process is the first reaction.