Fill in the blanks choosing appropriate word/ words from those given in the brackets : (gravity separation, magnetic separation, absence, presence, `CuFeS_2`, `Cu_2S`, froth flotation, aluminium, iron, smelting, pure, impure, mines, copper, silver, sulfide, zinc, chromium nickel, tin, blister copper, Cus, Fes, thermal, electrical, argentite or silver glance `(Ag_2S)`, cuprous oxide, cuprous sulfide.)
The ores containing magnetic impurities can be separated by ................ process.

Explanation

**Step-by-Step Solution:**

1. **Identify the Process**: The question asks about the separation of ores containing magnetic impurities. The appropriate method for this is the magnetic separation process.

2. **Explain the Principle**: Magnetic separation is based on the differences in magnetic properties of the ore components. Ores that contain magnetic impurities can be attracted to a magnet, while non-magnetic materials can be separated out.

3. **Examples of Magnetic Ores**: Common examples of ores that can be separated using this method include iron ores like hematite, magnetite, and siderite. These ores have magnetic properties that allow them to be attracted to a magnet.

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