Why Mining Screens Experience Slurry Carryover — And How to Fix It

In mineral processing, vibrating screens play a crucial role in separating solids according to particle size. However, one common problem that operators frequently face is slurry carryover, often referred to as the screen “running pulp.” This issue not only affects screening efficiency but can also lead to equipment wear, production delays, and increased operational costs.

Slurry carryover typically occurs when the feed contains a high percentage of fine particles mixed with water. When the material becomes overly fluid, the slurry fails to stratify properly on the screen surface. Instead of passing through the openings or moving across the deck in a controlled manner, the mixture washes over the screen, reducing classification accuracy and causing valuable product losses.

Several factors contribute to this issue. Incorrect screen panel selection is one of the most common. If the aperture size does not match the material characteristics, even a small change in moisture or feed rate can cause flooding. Screen inclination and vibration parameters also play important roles. A screen angle that is too flat or a vibration intensity that is too low can slow material movement, increasing the chance of slurry buildup. Additionally, worn or partially blocked screen panels can restrict drainage, making the screen behave as if it has a smaller effective area.

To reduce slurry carryover, operators should regularly check panel wear, ensure proper aperture selection, adjust feed density, and optimize vibration settings. In many cases, upgrading to high-open-area polyurethane or wedge-wire panels can significantly improve dewatering performance.

Understanding the root causes of screen “running pulp” helps operations maintain stable efficiency and extend equipment life—ultimately improving overall plant productivity.