Capital Equipment News January 2021

Switching from the bucket wheel system to the Combo has resulted in production gains for Ground Breakers.

of these technologies means that control over the volumes of water required for accurate material classification is difficult,” says Du Plooy. “The inability to use sufficient volumes of water means that fines are not efficiently removed and 100 – 300 micron fractions are lost to ponds or to the water treatment phase, along with the overflow, making the sand product coarser.” He says the bucket wheel’s settings must be adjusted regularly to mitigate the risk of inaccurate material classification. As this method of classification depends on settling time, the cut point must often be chosen above the threshold to obtain a maximum amount of allowable silt in the final product. Diverting excess material to settling ponds requires considerably more space to accommodate them, and the classification inefficiencies increase as the proportion of fines in the feed material increases. Clearing out settling ponds to recover lost material requires plant downtime in addition to the operating costs incurred when reprocessing waste material. High maintenance and restricted throughput aside, the sand product typically discharged contains between 23% and 25% moisture, placing stockpiles at risk of contamination if located in proximity to one another. “As a consequence, stockpiling the final product requires double or even triple handling to move the material to separate

QUICK TAKE

Bucket wheel technology is fast becoming a much less attractive proposition when compared to new systems

The limited capacity at the feed point of bucket wheel technologies makes control over the required volumes of water difficult

Cyclone technology is now replacing bucket wheel technology as a 'natural evolution'

ROI is fast thanks to a reduced spares requirement, efficient water management and longer and running time

CAPITAL EQUIPMENT NEWS JANUARY 2021 17