Frimstone choose Finlay sand and gravel plant

Frimstone Ltd, part of the Cambridge-based Dickerson Group, recently selected Finlay Plant (Southern) to supply a new sand and gravel washing plant for their Mayton Wood Quarry near Coltishall in Norfolk.

The all-electric 120 tonnes/h plant features an advanced PLC plant-management system with Scada screen that facilitates single-man operation. The system allows operators to review process performance over time and to use this information to optimize the production process. The system, which includes a belt weigher, is available on all Finlay electric-powered plants, together with a range of belt cleaners and energy-efficient options.

At Mayton Wood material is fed by wheel loader into a Finlay 390 rinser that features a remote-controlled tipping grizzly over the feed hopper to reject any +100mm material.

Washing takes place on a 12ft x 5ft double-deck screen fitted with rubber mats to reject +40mm material on the top deck and a modular polyurethane bottom deck that screens at 5mm and 1.8mm. This material is flumed to a Finlay 150TP Hydrasander where coarse and fine sand products are recovered for stockpiling via Finlay 532 mobile stockpile conveyors. The 150TP requires only 11.5kW of power and is capable of producing one or two grades of sand at a rate of up to 110 tonnes/h. It can also be slaved to operate hydraulically from any of Finlay’s mobile rinsers if electrical power is not available.

There is independent variable-speed control of both bucket wheels and the fines recovery spiral. Final products can be blended on the discharge chute to vary the grades of sand produced as required.

All –40+5mm material is fed directly from the washing screen into a Finlay 206 Logwasher where a final rinse takes place prior to dewatering and transfer to a Finlay 683 Superscreen for grading. Effluents from the Logwasher flow back to the sand system, under gravity, where residual fines are recovered.

The Mayton Wood project was a turnkey operation where Finlay Plant undertook all the civils, plant supply, installation, and electrical works.