Corey Poppe, Superior Industries, describes best practices for jaw crushers, such as identifying maximum feed size, determining desired product size, and defining tonnage goals.
Selecting the right crusher for an application depends on material characteristics, processing requirements, and desired output. Jaw crushers excel as primary crushers due to their ability to handle large feed sizes and high throughput.
They are particularly effective for:
- Hard and abrasive materials: jaw crushers are designed to crush hard, abrasive rocks efficiently, making them ideal for mining and quarrying applications.
- Simplicity and reliability: their straightforward design ensures reliable operation with minimal maintenance, a key consideration for producers seeking consistent performance.
- Cost-effective reduction: with high reduction ratios, jaw crushers efficiently reduce material size in a single pass, minimising the need for multiple crushing stages.
In contrast, cone crushers are often preferred for secondary or tertiary stages, where precise gradation control is critical. Impact crushers, on the other hand, are ideal for softer materials or applications requiring high-quality, cubical products. By offering a variety of crusher types, Superior Industries enables producers to tailor their crushing circuits to specific needs, optimising performance and cost-efficiency.
Sizing the right jaw crusher: key rules
Identify maximum feed size
The crusher opening determines the maximum size of material that can enter the machine. For example, a 30 in. gape jaw crusher can handle material up to 24 in., adhering to the industry standard of limiting feed size to 80% of the opening. Oversized material can lead to production interruptions, excessive wear, and costly damage.
Determine desired product size
The closed-side setting (CSS) dictates the crusher’s output size. For instance, a 40 x 51 in. jaw crusher might have a CSS range of 4 – 8 in., producing material within that range. A reduction ratio of 6:1 is typical for jaw crushers, meaning the feed size is reduced to one-sixth in a single pass. Properly matching the CSS to the material flow ensures consistent downstream processing.
Define tonnage goals
Production capacity depends on the width of the jaw and the CSS. For instance, a 42 in.-wide crusher might process 165 – 550 tph, while a 55 in.-wide unit can handle 265 – 855 tph. Material hardness and fine content also influence capacity.
Accurate data on feed size, product size, and production goals allows manufacturers to recommend the best-fit crusher for the application, ensuring efficiency and cost savings. Selecting and maintaining closed-side settings (CSS)
Maintaining the proper CSS is crucial for efficient crushing. Incorrect settings can disrupt material flow throughout the plant, reducing productivity. Regular CSS checks and adjustments prevent issues such as oversized material overwhelming secondary crushers or inefficient downstream circuits. Modern crushers simplify CSS adjustments with hydraulic systems, such as:
- Hydraulic wedge adjustments: opposing wedges adjust CSS with the push of a button.
- Hydraulic toggle plates: these systems retract CSS during tramp events, avoiding damage and resetting quickly for continuous operation.
Frequent monitoring of CSS and jaw liners ensures consistent output, optimum plant performance, and reduced downtime.
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