Capital Equipment News January 2022

wear parts to deplete more quickly. No matter the crusher type – impact, cone or jaw – material recirculation causes the wear parts to be replaced more often, and without benefit of adding revenue to the business. One of the biggest issues of recirculation is lost revenue. This pattern reduces the amount of near-size material – the most valuable to an operation – being produced. The producer winds up taking a double hit – one from the expense of crushing the material a second time, and another from the loss in revenue and reputation from producing less near- size material. Preventing the problem Screen media choice is often the single biggest factor in improving screening efficiency. Where most media falls short is in delivering efficient stratification. Some producers use high-vibration wire screens, which are strategically designed to promote material stratification and offer exceptional screening performance. High-vibration screen media magnifies the screen box’s own vibration. Independently vibrating wires run along strokes per minute, with high-frequency machines reaching in excess of 4 000. Because high-vibration screens vibrate independently of the screen box, the wires can reach frequencies of 6 000 to 10 000 cycles per minute — up to 13 times greater than that of a standard vibrating screen with traditional media. This high vibration accelerates material stratification, causing coarse material to rise to the top of the material bed faster. Fines and near-size material comes in contact with the screen much faster. This combined with a wide material spread – again, thanks to the extreme vibration – puts fines and near-size material in contact with the screen for a much longer time period, drastically improving the screen’s effectiveness and reducing the amount of material sent back to the crusher unnecessarily. High-vibration screen media can be a game-changing solution for operations struggling with productivity. Recirculation is a frustrating drain on efficiency, racking up crushing costs and diminishing the quality of the final product. Reducing or eliminating recirculation with more efficient screening is a relatively low- investment solution for a potentially high- dollar problem. b the full length of the screen media, increasing the vibration frequency. Consider that a typical screen box vibrates between 600 and 1 200

Efficient crushing is a critical factor in a screening plant’s profitability.

To truly maximise a processing plant’s efficiency, unnecessary crushing must be minimised or eliminated

To do this, plant operators must understand how recirculation could be hurting their profitability, and what they can do to minimise it

If the screen box is not doing its job well, material that should have fallen through the screen media ends up circulating back to the crusher to be crushed again

Screen media choice is often the single biggest factor in improving screening efficiency

QUICK TAKE

CAPITAL EQUIPMENT NEWS JANUARY 2022 27