Question

A jaw crusher is mainly used for:

• A. Fine grinding
• B. Ultra-fine grinding
• C. Coarse crushing of hard materials
• D. Mixing of solids

Hint:

Logic Tip: Think of a Jaw Crusher exactly like a giant mechanical mouth. It takes massive, hard bites out of big rocks (coarse crushing) but leaves the fine chewing to other machines.

Answer 1

The Correct Option is C

Concept:
Industrial size reduction equipment is classified based on the size of the feed material it accepts and the mechanism it uses to break that material down.

Step 1: A jaw crusher operates using two heavy metal plates (jaws)—one stationary and one moving. It breaks material by brutal compression, essentially chewing the rock.

Step 2: Because of its massive, heavy-duty design and large opening, it is almost universally used as a "primary crusher"—the first machine to receive raw, oversized rocks directly from a mine or quarry.

Step 3: Jaw crushers cannot produce fine powders because the gap at the bottom of the jaws allows chunks to fall through once they are broken down to a manageable size (e.g., gravel size). Equipment like ball mills are needed for fine grinding.

Step 4: Therefore, its heavy-duty compressive action makes it specifically suitable for the initial, coarse crushing of large, hard lumps of material.