Efficiently separating aggregate is an essential step in many production processes. There are many types of aggregate that require screening, including:
- crushed stone
- minerals
- coal
- gravel
- topsoil
- sand
- construction waste
To effectively separate different sizes of aggregate with a high rate of efficiency, high-quality and well cared for screening equipment is necessary.
We’ll share several tips to help you ensure you’re getting the most from your aggregate screening equipment. Let’s start with a brief overview of common screening equipment.
An Overview of Aggregate Screening Equipment
There are several components of a screening system, including the following:
Engine: Controls the vibration that allows finer aggregate to fall through the coarser pieces and through the screens.
Screens: Separates larger, coarser aggregate from the smaller, finer aggregate. Wet screens use water and spray nozzles to sort while dry screens use vibration. Screens sort aggregate through woven wire cloth, also known as wire mesh, or polyurethane, sometimes referred to as rubber or elastic mesh screens.
Feeders: Transports and loads aggregate to the screens.
Some mine screening systems also attach to a crusher for a full-circuit system. The crusher is not part of the screening process but can crush coarser aggregate into finer pieces for further screening.
Understanding Screening Efficiency
Screening efficiency measures how much of the desired aggregate is accurately separated during the screening process. For example, if your screens are operating at 80% efficiency, that means 80% of the desired aggregate size passes through the screens while 20% does not.
Efficiency should be as close to 100% as possible, but keep in mind that it’s unlikely you’ll ever achieve perfection. Hitting 90-95% is excellent for most operations.
How to Maximize Your Screening Efficiency
It’s possible to maximize aggregate screening efficiency if you proactively audit your machinery’s performance. Here are a few ways to increase efficiency right away:
Use the correct equipment and screen media
Always ensure your equipment is optimal for the sizing specifications of your desired aggregate. Regularly check to make sure your machine and its media are operating within these sizing parameters. Additionally, this should include checking that the feedbox is not overloaded and that your screen mesh is large enough to let the right-sized particles through.
Adjust vibration frequency and direction
If your operation uses a vibratory screen, always ensure that the screens are not vibrating too fast or too slow, making it more difficult for finer particles to pass through the openings.
In addition, changing the direction of the vibration may allow for certain aggregate to dislodge from coarser pieces in order to more easily pass through the screens.
Apply appropriate screen inclination
The angle of your screens can complement the vibration frequency and direction. For some aggregate, properly angling the screen will increase its efficiency.
Select the right media for your aggregate
To cut down on wear and tear and the potential for plugging or blinding of the screens, use correctly sized mesh made of wire cloth or polyurethane, whichever best serves your aggregate material.
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Ongoing Screen Feed Evaluation and Maintenance
Once you’ve established an efficient operation, follow these tips to maintain efficiency:
- Clean the equipment frequently. This helps prevent plugging and blinding, which can block aggregate from passing through the openings.
- Audit your machinery’s performance on a regular schedule. Look for issues like deflections, displacement, and abnormal acceleration.
- Change one thing at a time when identifying a problem. While it may seem slow, it will help you isolate where the real problem is with your machinery.
Efficiency is an ongoing process. Prioritize regular audits and routine maintenance to maximize your machine’s screening efficiency.
AEI’s Aggregate Screening Solutions
AEI Screens offers high-quality screening solutions for the aggregate and mining industries. The BIVITEC dual vibratory screen is an excellent option for screening challenging materials without plugging and blinding the screen. Meanwhile, the Ortner is a high efficiency solution for washing and dewatering fines like manufactured sand. Get a quote for your equipment needs today or give our sales team a call at 717-656-2131 for more information.
