Which of the following pair can be refined using some basic principle?

Options

A. Cu,Ag
B. Si,Ge
C. Ti,Ni
D. All of these

Answer

To solve the question regarding which pairs can be refined using some basic principles, we will analyze each option step by step.

### Step 1: Understanding Refining
Refining in metallurgy refers to the process of purifying impure metals. Different metals require different refining techniques based on their properties.

### Step 2: Analyzing Each Option
1. **Copper and Silver**:
- Both copper and silver can be refined using **electrolytic refining**. This method involves using an electric current to separate the metal from impurities.
- **Hint**: Look for metals that can be purified using electrolysis.

2. **Silicon and Germanium**:
- Silicon and germanium are semiconductors and are typically refined using **zone refining**. This technique is effective for achieving high purity levels necessary for semiconductor applications.
- **Hint**: Consider the refining method suitable for semiconductors.

3. **Titanium and Nickel**:
- Titanium and nickel can be refined using **vapor phase refining**. This method involves converting the metal into a vapor and then condensing it back to purify it.
- **Hint**: Think about refining methods that involve vaporization.

4. **All of These**:
- Since all the pairs mentioned can be refined using their respective methods, the correct answer is that all of these pairs can be refined.

### Conclusion
After analyzing all the options, we conclude that the correct answer is **option 4: all of these**.

### Final Answer
**Option 4: All of these**