Sandmaster™ enables a six month payback and a certified asphalt sand

Background

Located in Finnea, Co. Westmeath, Ireland, the site operated by Harton’s Sand & Gravel has been in operation since the early 1960’s. The incumbent crushing, screening and washing plant was installed in 1968.

Harton’s Sand & Gravel produces washed aggregates and two grades of washed sand for concrete and plastering applications.

Coarse and fine sands were being produced using an old Finlay bucket wheel. A large quantity of saleable fine sand was being lost to the settling ponds. This loss not only affected the specification of the fine plaster sand but also resulted in very high pond maintenance costs. On average, the plant had to be stopped and the ponds had to be dug out once every two weeks.

The challenge

A line of contact was established between Weir Minerals Europe and Harton’s Sand & Gravel following the Hillhead exhibition in June 2022, where a Sandmaster™ SP25 was featured on the Weir Minerals Stand. This interaction resulted in a site visit to determine the exact nature of the challenges being faced and to understand the longer-term investment and expansion plans for Harton’s Sand & Gravel.

The existing bucket wheel solution was producing two grades of sand – coarse for concrete and fine for plaster.

The bucket wheel sand washing technology was old and inefficient, resulting in an average loss of 10% of saleable sand to the settling ponds. Moreover, the fine sand specification was not sufficient for asphalt production due to excessive fine material loss.

Due to the inefficiencies of the technology, these sands were very wet, requiring extended drying time. Additionally, the specification for the fine sand was inaccurate. Fine sand production was approximately 10 tonnes per hour.

The loss of fine material from the sand to the ponds led to rapid filling of the settling pond, requiring biweekly excavation. This involved stopping production during this time and incurred a significant additional cost of around $46,000 (€43,000) per year.

Given the limited available space near the existing plant structures and the site boundary fence, a compact plant design was deemed optimal for Harton’s Sand & Gravel.

The solution

Samples of the sand were taken from the site and it was determined that a Sandmaster™ SP25 would be suitable for the application.

Flow sheet and budgetary offers were developed by the Weir Minerals team and presented to Harton’s Sand & Gravel.

The proposed solution was to bypass the fine sand processing on the bucket wheel and instead divert all this flow to the Sandmaster™ SP25 compact sand plant. This would allow the cyclone to recover the fine material being lost to the pond and, at the same time, deliver sand that was dry enough for immediate use.

After some minor adjustments of the cyclone configuration, the plant is now producing asphalt grade sand in accordance with EN 13108-1: 2006.

The Sandmaster™ SP25 solution included a Warman® WGR pump, Cavex® hydrocyclone, Enduron® dewatering screen and Linatex® hose and rubber lining. This particular SP25 also included our Gemex™ belt tensioning system, ensuring the best possible efficiency in the pump drive, saving energy and increasing the wear life of the belt transmission. The solution was fitted with the Gemex™ 160/180 belt tensioning system, delivering significant motor drive wear reduction and energy saving up to 7%.

The results

After a second opportunity to view the Sandmaster™ SP25 in April 2023 the customer placed an order for the solution. This marked the first sale of a Sandmaster™ machine on the island of Ireland. Having the machine available as stock for a quick delivery was a significant factor.

The recovery of the fine material, previously being lost to the settling pond, meant that instead of cleaning out the pond every two weeks, the pond has not needed excavation since the SP25 was commissioned at the end of June 2023.

This has resulted in two additional days of production at the plant and approximately 240 additional tonnes of fine sand produced every month. Fine sand sells for approximately $16 (€15) per tonne, translating to approximately $3,903 (€3,600) additional revenue per month, along with significant cost savings on pond maintenance in the region of $65,000 (€60,000) per year. This additional revenue of approximately $46,000 (€43,000) per year and cost savings of approximately $65,000 (€60,000) per year contribute to an ROI of around 6.5 months.

Bríain Harton - owner of Harton’s Sand & Gravel, said: “Brilliant machine, working even better than we expected.”