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Consider the following statements : Ro...

Consider the following statements :
Roasting is carried out to :
1. Convert sulphide into oxide
2. Melt the ore
3. Remove moisture, water of hydration and expel organic matter
4. Remove sulphur and arsenic in the form of volatile oxides
Out of these statements :

A

1, 3 and 4 are correct

B

1, 2 and 3 are correct

C

2, 3 and 4 are correct

D

1, 2 and 4 are correct

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question regarding the roasting process, let's analyze each statement step by step: ### Step 1: Understanding Roasting Roasting is a metallurgical process used primarily for sulfide ores. It involves heating the ore in the presence of oxygen (air) to convert the sulfide minerals into oxides. **Hint:** Remember that roasting is specifically done in the presence of air and is mainly applicable to sulfide ores. ### Step 2: Evaluating Statement 1 **Statement 1:** Convert sulphide into oxide. - This statement is true. During roasting, sulfide ores are converted into their respective oxides. For example, zinc sulfide (ZnS) is converted into zinc oxide (ZnO) and sulfur dioxide (SO2). **Hint:** Focus on the chemical transformation that occurs during roasting. ### Step 3: Evaluating Statement 2 **Statement 2:** Melt the ore. - This statement is somewhat misleading. While roasting can lead to some melting of the ore, it does not typically melt the ore completely. The melting point of the ore is generally higher than the temperatures used in roasting. **Hint:** Consider the conditions under which roasting occurs and the temperatures involved. ### Step 4: Evaluating Statement 3 **Statement 3:** Remove moisture, water of hydration, and expel organic matter. - This statement is true. Roasting helps in removing moisture and any water of hydration present in the ore, as well as expelling organic matter. **Hint:** Think about the physical changes that occur during the heating process. ### Step 5: Evaluating Statement 4 **Statement 4:** Remove sulphur and arsenic in the form of volatile oxides. - This statement is true. During roasting, sulfur is converted to sulfur dioxide (SO2), and arsenic can be converted to arsenic pentoxide (As2O5), both of which are volatile and can be removed from the system. **Hint:** Recall the gaseous products formed during the roasting of sulfide ores. ### Conclusion Based on the evaluation of each statement: - Statement 1 is correct. - Statement 2 is misleading (not entirely correct). - Statement 3 is correct. - Statement 4 is correct. Thus, the correct options are 1, 3, and 4. ### Final Answer **The correct answer is Option A: 1, 3, and 4 are correct.**
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