Tonnage
100tph
Material
Sand & Gravel
Output
0-2mm, 0-4mm, 4-8mm, 8-16mm and 16-32mm
THE CHALLENGE
The raw material processed by Kieswerk Kohler contains a large proportion of material smaller than 250 microns, and with the crushing and screening processes previously employed on the material, the sand was often out of specification for use in concrete. In addition to the problems caused by the excess fines content in the feed material, Kieswerk Kohler were also faced with clays and silts which the dry processing system was notable to effectively remove.
THE SOLUTION
The solution offered by CDE includes an M2500 E4 mobile washing plant and an AggMax 83 portable log-washer.
The consultation between Thomas Kohler, site owner, and CDE revealed that by introducing the AggMax, the quality of aggregates produced would also be improved. “This solution also helps to maximize sand production from the washing plant,” explained CDE’s representative. ‘The attrition process within the AggMax plant’s log-washer liberates a lot of valuable fines that would previously have been destined for the aggregate fraction. By aggressively scrubbing the material and returning the liberated fines to the sand washing plant, we are ensuring that Kieswerk Kohler recover the maximum amount of sand from the material while also enhancing the quality of the washed aggregate products by removing these fines.”
The sand and gravel feed are delivered to the M2500 washing plant by loading shovel. Operating at a rate of 100 tonnes/h, the plant accepts 0–100mm material while a grid on the feed hopper rejects any oversize. The feed material is delivered to the M2500 unit’s integrated ProGrade P2-75 rinsing screen, the top deck of which separates at +32mm; this material is sent to stockpile via one of the integrated wing conveyors. Material from the bottom deck, which separates 4-32mm, is sent to the AggMax for scrubbing, via the integrated RotoMax RX80 log-washer.
Once material has been processed by the RotoMax it is discharged onto a triple-deck horizontal sizing screen which classifies the aggregates into 16-32mm 8-16mm and 4-8mm. Meanwhile, any –4mm material collects in the ProGrade screen sump and is pumped to the integrated EvoWash sand washing plant. The EvoWash screen is split to allow the production of two sand grades: a 0–4mm concrete sand and a 0–2mm product.
THE RESULTS
Following the installation of a M2500 mobile washing plant, Kieswerk Kohler GmbH have addressed the issues caused by excess fines in the material at their quarry in Engen/Welschingen, Germany. Moreover, the solution offered by recently formed CDE GmbH has also allowed the production of an additional sand product which the company is now able to offer to its customers.
“The creation of the additional 0–2mm sand product was necessary as there was too much of this material in the 0–4mm range,” explained CDE’s expert. “The sand washing phase is configured to remove up to 25% of the 0–2mm material from the 0–4mm product to allow for the production of concrete sand.”
Nevertheless, the creation of this extra 0–2mm sand product has provided an additional benefit for Kieswerk Kohler, as they have found a ready market for it as cable sand. “This is a bonus for us as our initial focus was very much about getting the concrete sand right,” said Thomas Kohler. “Having a new sand product as a result of the investment is final confirmation that we made the right decision in purchasing the new CDE plant.”