Latest News - E-News

Cheap Media, Expensive Problems

Choosing screen media to improve production and solve screening problems By Lars Bräunling, MAJOR director of product technology

August 2022

Latest News - E-News

Cheap Media, Expensive Problems

Choosing screen media to improve production and solve screening problems By Lars Bräunling, MAJOR director of product technology

August 2022

With proposed infrastructure programs being discussed to offset the economic impacts of COVID-19, aggregate materials could see a spike in demand. This progression can lead to increased profits for mineral processing operations. However, maximizing efficiency to capitalize on this opportunity requires the right equipment. It is critical that operations evaluate their process flow and equipment selection routinely to ensure they are using the best tools for the job. Screen media selection, for example, is an often-overlooked factor that can have a significant impact on overall efficiency.

Though relatively cheap compared to the rest of the equipment in a quarry or mine, it could be argued that media has as much impact on productivity and material quality as the vibrating screen. And it is important that operations give screen media as much buying consideration as they do the vibrating screen itself. 

For this reason, a number of factors should influence the choice of screen media. Certainly, cost is a consideration, but it shouldn’t be reduced to purchasing price versus wear life. A full cost analysis needs to include labor cost for change-outs and cleaning, loss of production during downtime, media performance — tons produced, for example — and indirect factors like crusher relief. Thinking only in terms of dollar value can be shortsighted and end up costing an operation more in the long run. The operating environment — including material characteristics and recurring screening problems — should also be considered.

 

Look at the Application

Selecting the proper screen media for an application first involves examining the screening plant and any issues surrounding it. Start with taking a look at the material being processed to get an idea of what the media needs to stand up against. Consider the drop height, material size, abrasiveness, weight and volume. Naturally, the more impact the material will have on the screen media, the higher durability that media should have, at least at the impact point. Also, abrasive material — such as granite — calls for resistant screen media, such as polyurethane or high-vibration wire media. Likewise, top sizes of 10 inches or larger demand a more durable screen, including options like double wire screens, perforated plate or rubber.

Take a look at the flow of material. A visual check or belt cut of the crusher feed belt is an effective way to see if there is saleable rock being sent to the crusher. This could be the result of carryover or because the deck capacity is exceeded. The solution may be adjusting the cut, improving capacity or fixing screening problems like blinding or pegging with alternative screen media.

 

Finding Better Screen Media

Depending on the operation, an hour of downtime could cost hundreds of dollars in lost production. That makes choosing a screen media that maximizes uptime and efficiency even more critical.

Perforated steel plate and heavy rubber panels are, almost by definition, the most durable options. Rubber can be effective for screening material with a top size larger than 12 inches or for openings bigger than 4 inches, but tends to be more susceptible to pegging.  Perforated plate is an acceptable option for applications requiring a durable screen media with a lot of open area, but is often noisier and heavier, which can cause issues. Both also typically have less open area than wire alternatives.

Woven wire cloth has been the traditional option for a long time for a reason. It is relatively inexpensive and effective. But there are a number of advanced options available that offer more durability, throughput and versatility. And purchasing a traditional woven wire design based solely on price may end up costing more in terms of wear life and more frequent change-outs.

Synthetic modular media, such as polyurethane or rubber, is typically known for its long wear life and ability to reduce noise levels, but it isn’t without its own challenges. This type of media typically has less open area than wire screens, leading to decreased throughput. This, in turn, also reduces the capacity of bottom decks because the material takes longer to make its way down. Also, operations using synthetics must keep a close eye on the panel openings. Openings tend to wear by rounding out, making it necessary to regularly check that the panels are still the correct size and not letting out of spec material through.

Both synthetic screen media and traditional woven wire are very rigid and rely on the vibrating screen to do most of the heavy lifting. The static movement of the screens limits vibration to 800 or 900 cycles per minute. In most cases, this does not hinder the screen media from achieving adequate production and throughput, but it is not fully using screening equipment, either. And often it results in common issues, such as blinding and pegging.

 

About MAJOR

MAJOR is an innovative global manufacturer of wire screens for the aggregate, mining and recycling industries. FLEX-MAT®, the company’s renowned line of distinctive lime-green high vibration screens made with OPTIMUMWIRE® “The longest-lasting wire” sets the standard in lowering cost of production per ton by dramatically increasing throughput and wear life while eliminating blinding and pegging. MAJOR masters wire quality, screen manufacturing and the screening process, and provides on-site screening performance assessment and training seminars on screen maintenance and screening efficiency to help producers increase their screening performance and profitability.

Major Wire Industries Ltd.

A Haver & Boecker Company

225 North Montcalm Blvd

Candiac (Québec)

Canada J5R 3L6

T +1 450 659-7681

F +1 450 659-5570

www.majorflexmat.com