It is designed to produce a well shaped evenly graded sand from surplus crusher dust, without the need for blending. It allows gradations to be manufactured to order, including a tight control over the minus 75 micron content.
This manufactured sand can be used as a complete replacement for natural sand, whether dredged or from a gravel pit.
A research program by Cardiff University?s Engineering Department has demonstrated that good quality sand can be manufactured from surplus crusher dust. The research was part-funded by the Aggregate Levy Fund for Wales (ALFW) and sponsored by Kayasand (UK) Limited, Kotobuki Engineering and Manufacturing Company, Aggregate Industries, Cemex, Hanson and Grace Construction Products.
The current program was sponsored to prove that new Japanese technology allows for crusher dust to be reprocessed and the resulting manufactured sand can completely replace natural sand.
Significant samples of crusher dust, in excess of five tonnes each, from four different rock sources (limestone, granite, basalt and gritstone) were sent to Japan for reprocessing, and the new sand returned to the UK.
Tests were undertaken on various gradations of this sand both by Cardiff University and the suppliers of the individual materials.
The results clearly demonstrated that the well shaped and evenly graded sand performed well from every rock type tested, leading to the conclusion that most rock sources will be suitable for this technology.
These results matched the findings in Japan where 40 per cent of all manufactured sands are already processed in this way, from eight different rock types.
Due to the lack of land based sand, this new technology may provide a real cost-effective alternative to dredged sand and may alleviate the need to stockpile more surplus crusher dust.
A second paper that will include the results of more recent tests will be presented by Martins Pilegis and Andi Lusty at the Construction Materials Industry Conference (CMIC 12) on 21 September in Melbourne.