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Sand, gravel, rip rap: what is the best screen media for each?

Rip rap, gravel and sand are processed similarly, although there are subtle differences in the procedures. This article assesses each material’s handling requirements and which type of screening media is best suited.

1. Rip rap.

Typically used to combat erosion along coastlines, rip rap is rough-edged rocks that are relatively similar in dimension.

At times, screening isn’t necessary, as the material can be quite large (up to 121cm). When choosing specific media, consider the size of the material.

For quarries processing smaller class rip rap (eg 15cm), a heavy woven wire screen is the best option. Polyurethane screens encounter damage when handling heavy stone.

Depending on certain dimensions (eg thickness), rubber media may also be useful.

2. Gravel.

When handling gravel, the key is to separate sand or other debris from the crushed stone, so it can be used for roads, foundations and other purposes. This process typically necessitates water, so it’s important to assess how wet material will impact the effectiveness of certain screens.

As far as creating a slick surface goes, polyurethane and water are a match made in quarrying heaven. Combining the two creates a lubricant that enables gravel to move more quickly down the media.

In regard to the actual design, a polyurethane ripple screen is the best choice. This will allow sand to easily slip through the apertures, and will probably reduce the number of times you’ll have to clean it.

3. Sand.

More often than not, a conversation about gravel typically involves a discussion about sand. In regards to water-based processing, sticking with polyurethane ripple screens is probably best.

In other instances, fine wire screens are often better for drier conditions. The vibrations combined with thin metal screening can create just the right amount of flexibility needed to shake sand to carrier belts located beneath the media.

It should be noted that fine wire may create minor frustrations in regards to pegging and blinding, depending on the size of the stone mixed in with the sand. If larger stones are involved, then this will probably be less of an issue.

Be aware that choosing between polyurethane, wire and rubber depends on numerous factors. The recommendations above are for very specific situations, and may not be applicable to your protocols. 

Source: The Locker Group

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