Crushing slag with a jaw crusher is a common method in recycling and processing applications, especially in industries dealing with metallurgical by-products (e.g., steel mills). Here’s a detailed breakdown of the process:
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1. Why Use a Jaw Crusher for Slag?
– Hardness & Abrasiveness: Slag (e.g., blast furnace slag, steel slag) is often hard and abrasive. Jaw crushers are robust machines designed to handle tough materials.
– Primary Crushing: Jaw crushers excel at primary crushing, reducing large chunks of slag (up to 1–1.5 meters) into smaller, manageable pieces (typically 50–150 mm).
– Simplicity & Reliability: Minimal moving parts and straightforward operation make jaw crushers ideal for harsh slag environments.
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2. Key Considerations for Slag Crushing
# A. Material Properties
– Type of Slag:
– *Blast furnace slag* is less abrasive but may contain moisture.
– *Steel slag* is harder and may contain metal remnants (e.g., iron pieces), requiring pre-screening or magnetic separation.
– Feed Size: Ensure the jaw crusher’s inlet can accommodate the largest slag chunks.
# B. Crusher Specifications
– Jaw Plate Material: Use manganese steel or hardened alloy jaws to resist wear from abrasion.
– Adjustable Discharge Gap: Control output size by adjusting the crusher’s closed-side setting (CSS).
– Overload Protection: Hydraulic toggle systems can prevent damage from uncrushable metals in the slag.
# C. Pre-Processing Steps
– Remove oversized debris or tramp metal (e.g., with a grizzly screen or magnet).
– Pre-dry wet slag to avoid clogging.
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3. Operational Steps
1. Feeding: Use a vibrating feeder or conveyor to evenly supply slag into the jaw crusher.
2. Crushing: The movable jaw compresses slag against the fixed jaw, breaking it into smaller fragments.
3. Discharge: Crushed material exits through the bottom discharge gap.
4. Post-Crushing Screening/Processing: Secondary crushing (e.g., cone crusher) or screening may follow for finer grading.
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4. Advantages of Jaw Crushers for Slag
– High reduction ratio (~6:1 to 8:1).
– Low maintenance compared to impact crushers.
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