TL;DR
- Montana Resources used bolt-down rubber screen decks with only 20% open area, leading to severe blinding and inefficient screening.
- Undersized material in the crusher feed was causing ring bounce, fines packing, and equipment damage.
- Polydeck Screening Experts converted the secondary screen to a modular system using PIPETOP™ stringersand RUBBERDEX® XTREME modular steel-backed rubber media.
- The conversion reduced undersized feed to the crusher, increased throughput capacity by 20%, and enabled a finer, more stable crusher product.
- Power consumption was reduced, screen efficiency improved, and downtime related to plugging and maintenance decreased significantly.
Why Undersized Feed Can Disrupt Crushing Circuit Efficiency
In high throughput crushing circuits, the quality of the feed going into the secondary crusher can make or break performance. If excessive undersized material bypasses the screen and ends up in the crusher feed, it can create several problems: fines packing, ring bounce, elevated power draw, and increased wear on components like socket liners and bushings.
These issues not only reduce crushing efficiency but also limit the ability to maintain a tight closed side setting, reducing control over product size. In worst-case scenarios, undersized feed can compromise the downstream milling circuit, where consistency and volume are critical for process stability.
The Challenge: Blinding, Plugging, and Inefficient Screening
Montana Resources was experiencing significant challenges on their secondary screen, which was outfitted with bolt-down rubber media:
- Severe blinding and plugging on competitor panels
- Only 20% open area (before accounting for blinding)
- Excessive power use and stress on the crusher
- Fines packing and ring bounce events
- Accelerated wear of socket liners and eccentric bushings
- Reduced control over crusher output
- Time-consuming media replacements
With roughly 800 TPH of material flowing through the circuit and a grinding mill downstream, the secondary screen was becoming a bottleneck. The plant needed to reduce undersized feed and improve screening efficiency to stabilize downstream operations.
The Solution: Structural Conversion and Modular Media Installation
Polydeck Screening Experts proposed converting the existing bolt-down layout to a modular configuration using PIPETOP™ stringers, enabling the use of high open area modular panels.
The site was upgraded with RUBBERDEX® XTREME—Polydeck’s modular steel-backed rubber media designed for demanding, high-impact applications where durability and open area must be carefully balanced.
Key upgrades included:
- Converting the screen structure with PIPETOP™ stringers
- Installing RUBBERDEX® XTREME panels to increase open area and reduce plugging
- Eliminating the need for bolting strips and large, rigid rubber sections
- Enhancing particle size control before material entered the crusher
This change gave the plant a more efficient way to manage material flow while also easing maintenance demands.
The Results: Higher Throughput, Lower Downtime, and Better Crusher Control
The results were clear and immediate:
- Throughput capacity increased by 20%
- Less undersized feed reached the crusher, improving reduction ratio
- More consistent crusher product with finer size distribution
- Allowed a smaller closed side setting without risk of ring bounce
- Reduced wear on critical components and power consumption
- Plugging and tramp conditions were eliminated
- Maintenance became simpler and less labor-intensive
- Final mill feed became more uniform and stable
This wasn’t just a media swap—it was a crushing circuit upgrade.
Why It Worked: Smarter Screening Protects Downstream Equipment
By converting the screen support system and installing RUBBERDEX® XTREME modular media, Montana Resources gained precise control over the material entering the crusher. Reducing undersized feed minimized packing and allowed the machine to operate with less strain at a tighter setting. The upgraded screening circuit helped optimize throughput, protect equipment, and create a more stable process from screen to mill.
Frequently Asked Question
How does undersized material in crusher feed affect circuit performance?
Undersized material in the crusher feed can cause packing, ring bounce, and inconsistent reduction ratios. It increases power draw and accelerates wear on components like liners, socket heads, and bushings. Over time, this reduces crushing efficiency and leads to more frequent maintenance. Controlling the amount of undersized material entering the crusher helps stabilize performance and protect downstream equipment.
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