Out of these the correct match is

Options

A. Bayer's method `-Na_2CO_3`
B. Matte - 98% `Cu_2S+2%FeS`
C. van Arkel method - Agl
D. Thoms slag - Raw material for cement industry

Answer

To solve the question, we need to analyze each option provided and determine which one correctly matches the method or compound with its corresponding description.

### Step-by-Step Solution:

1. **Analyze Bayer's Method:**
- Bayer's method is used to extract pure aluminum oxide (Al2O3) from bauxite ore.
- The reagent used in Bayer's method is sodium hydroxide (NaOH), not sodium carbonate (Na2CO3).
- Therefore, the first option (Bayer's method with Na2CO3) is incorrect.

**Hint:** Bayer's method is specifically associated with NaOH for extracting Al2O3.

2. **Examine Matt:**
- Matt is a term used in metallurgy, specifically referring to a type of ore that consists mainly of copper sulfide (Cu2S) along with some iron sulfide (FeS).
- The given composition of 98% Cu2S and 2% FeS matches the typical composition of Matt.
- Thus, this option is correct.

**Hint:** Matt primarily consists of copper sulfide with a small percentage of iron sulfide.

3. **Check Venarkal Method:**
- The Venarkal method is used for the extraction of zirconium, typically involving zirconium iodide (ZrI4).
- The mention of AgI (silver iodide) in this context is incorrect.
- Therefore, this option is also incorrect.

**Hint:** Venarkal method is related to zirconium extraction, not silver iodide.

4. **Evaluate Thoms Slag:**
- Thoms slag is primarily composed of calcium phosphate (Ca3(PO4)2) and is used as a fertilizer.
- The description provided does not match its use in the cement industry, making this option incorrect as well.

**Hint:** Thoms slag is used as a fertilizer, not in cement production.

### Conclusion:
After analyzing all options, the only correct match is the second option, which describes Matt correctly.

### Final Answer:
The correct match is: **Matt - 98% Cu2S and 2% FeS.**