Wear of Screening Surfaces
Wear is a naturally occurring process in all aggregate producing plants. Wear begins the moment that aggregate comes into contact with any and all processes in aggregate producing facilities. Abrasion or friction of the aggregate coming into contact with steel or other synthetic surfaces manifests the wearing situation, and this wear occurs on all surfaces "where the steel meets stone." Loader buckets, crushers, bins, chutes, conveyor belts, transfer points and screen media are most subject to rapid wear caused by the aggregate. These are the primary high-wear areas involved in aggregate production. Specifically, however, we would like to address screen wear.
Remove the "Fine Material" First
removing the "fine material" before crushing, screening and/or washing, dramatically reduces wear of all major processing components downstream. Removing the fines first not only reduces downstream wear but also increases processing capacity. The removed fines can then be processed in a secondary or tertiary circuit where further crushing, screening and/or washing can be performed more effectively. Fine removal will also increase production and wear-life of all components involved in primary crushing and screening operations.
Install a "Rock on Rock Feed Box"
This is especially beneficial when scalping screens are utilized in the primary circuit. Larger aggregate impacts other aggregate material instead of causing localized and, quite often, severe wear of the feed box and screen media. Additionally, the material discharge from the feed box onto the feed screen panel should not exceed >8 inches. This will effectively increase the wear-life of the screen media by "laying" material onto the screen surface versus "throwing" it on.
Use custom made moulded pads/ wear Scalping Bars
For scalping decks where this severe wear occurs, Nepean recommends the use of moulded High-Impact absorption rider bars to effectively transfer the larger aggregate down the screen deck. The rider bars are positioned on the feed panel, under the impact area and parallel to the material flow.
Rider bars essentially act as an impact pad in addition to offering increased screening area and no loss of open area.