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Consider the following statements : Roas...

Consider the following statements : Roasting is carried out to
1. convert sulphide to oxide and sulphate
2. remove water of hydration
3. melt the ore
4. remove arsenic and sulphur impurities
Of these statements

A

1, 2, and 3 are correct

B

1 and 4 are correct

C

1, 2 and 4 are correct

D

2, 3 and 4 are correct

Text Solution

AI Generated Solution

The correct Answer is:
To determine which of the given statements about roasting are correct, we will analyze each statement based on the principles of metallurgy and the roasting process. ### Step-by-Step Solution: 1. **Understanding Roasting**: - Roasting is a metallurgical process where ore is heated in the presence of excess air. This process is primarily used to convert metal sulfides into oxides or sulfates and to remove impurities. 2. **Analyzing Statement 1**: - **Statement**: Roasting is carried out to convert sulfide to oxide and sulfate. - **Analysis**: This statement is correct. During roasting, metal sulfides react with oxygen to form metal oxides and sulfur dioxide or sulfates. For example, lead sulfide (PbS) can be converted to lead oxide (PbO) and sulfur dioxide (SO₂). 3. **Analyzing Statement 2**: - **Statement**: Remove water of hydration. - **Analysis**: This statement is also correct. Roasting can help in removing water of hydration from hydrated ores, thus purifying the ore. 4. **Analyzing Statement 3**: - **Statement**: Melt the ore. - **Analysis**: This statement is incorrect. Roasting is conducted below the melting point of the ore, so it does not melt the ore. Instead, it prepares the ore for further processing. 5. **Analyzing Statement 4**: - **Statement**: Remove arsenic and sulfur impurities. - **Analysis**: This statement is correct. Arsenic and sulfur are volatile and can be removed during the roasting process as they evaporate when heated. 6. **Conclusion**: - Based on the analysis, statements 1, 2, and 4 are correct, while statement 3 is incorrect. Therefore, the correct option includes statements 1, 2, and 4. ### Final Answer: The correct statements regarding roasting are: - Statement 1: True - Statement 2: True - Statement 3: False - Statement 4: True Thus, the correct statements are 1, 2, and 4. ---
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