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Diary of a Powerscreen Washplant
Every site is unique and has its own challenges when setting up and running a washing or crushing and screening plant. Powerscreen meet these challenges by bringing in-depth industry knowledge and experience to understand the different material and site specifications. This enables Powerscreen to create a comprehensive package of the right machines for the job - and install them correctly.
Powerscreen have installed a wash plant with feeders, conveyors and a Powerscreen® Finesmaster at the heart of the plant to clean and process aggregates for a construction project in North Spain. Powerscreen are a truly global supplier of washing equipment with an extensive dealer network to advise, install and provide customer support, parts and finance, from the Americas and Europe to Asia.
Working in so many markets gives Powerscreen vast experience in designing and installing wash plants for many applications: sand, gravel, iron ore, magnesium ore, railway ballast, construction demolition waste, dredged sea sand, quarry over burden, scalpings, slag,
crushed material, crushed fines, and silica sand.
Powerscreen are experts in advising on and handling all aspects of set-up and design to give customers what they need to produce the right materials. For example:
- Local planning issues
- Transportation / logistics
- Site planning / preparation
- Local Health & Safety regulations
- Climate conditions
Powerscreen have recently installed a large static installation in the North of Spain with the dealer of the region - Terex Espana. The plant is for processing natural fine sand from a lakebed and includes: Powerscreen® 40 Ton Hopper, Powerscreen® M80 Feed Conveyor, Powerscreen® 20 x 6 2 Deck Rinser, Powerscreen® Finesmaster 200, Powerscreen® 2 x T6532 Sand Conveyors, Overflow waste water sump, and Fresh Water pumps. The 0-2mm end product is sold as building sand and the 0-4mm product as concrete sand.
Installation
The plant arrived on site in December 2007, was installed in January & February 2008 with full commissioning taking place in March 2008. The plant is now fully operational, processing 180 tph of sand material
Stage 1:
The first step in this process is preparing the site, for this particular installation Powerscreen recommended that a concrete plinth was installed as a foundation for stability and easy cleaning It had to be at least 200mm deep with hardcore fill underneath. Water inlet pipes, water return pipes, electric conduit pipes and any other additional equipment need to be in place before the concrete is poured.
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Due to the nature of concrete the plinth is laid at least 7 to 10 days before the installation begins so the full curing process can take place.
Stage 2:
An experienced installation team, supported by the Powerscreen engineers installed the plant including electrics in 7 days.
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Stage 3:
Commissioning of the plant was carried out over a 5 day period where production targets and end productquality was reached.
The raw material at the site is natural fine sand with approximately 90% below 4mm. Due to this very high percentage of fine material careful consideration had to be given to the size of screenbox and sand plant required.
Operational Process:
Material is fed to a Powerscreen® 40 ton hopper via a 40 tonne dump truck. A large capacity hopper was essential for the customer who was transporting large volumes of raw material from the lakebed source 1.5km away.
A Powerscreen® M80 conveyor complete with walkway, transfers the material to the Powerscreen® 20 x 6 2 Deck washing screen.
The Powerscreen® 20 x 6 (6m x 1.8m) 2 deck washing screen was selected because of its ability to process high volumes of sand, producing two grades of quality sand in a single unit. Fresh water is pumped to the plant using a 55kw electric water pump. Approximately 300m³/hr (1100 gpm) of water is pumped to the plant.
As the material passes along the screen it is blasted with high pressure water to wash the material and create slurry of the sandy material and water.
The small amount of 4-12mm and 12mm+ is discharged from the end of the Powerscreen® 20 x 6 into a bay. The 20 x 6 has a split bottom deck which separates the sand into two products – 0-2mm and 0-4mm sands. These products are transferred to the Powerscreen® Finesmaster 200 where the sand is recovered and the silt is flushed out with the waste water.
The Powerscreen® Finesmaster 200 uses a 3 step dewatering process to remove the maximum amount of water. The Powerscreen® Finesmaster 200 sand classification system is the largest in its field. An on-board high frequency dewatering screen ensures the finished sand has a moisture content of 10 – 12 %. On-board hydro cyclones recover the fine sand particles to ensure no saleable product is lost to the pond. Waste water and silt from the Powerscreen® Finesmaster 200 are discharged into a sump tank where it is pumped to a water management system.
Sand recovered and dewatered by the Finesmaster is discharged onto two Powerscreen® T6532 stockpiling conveyors. These conveyors have radial, powered wheels which give maximum stockpiling capacity. The 0-2mm and 0-4mm materials are now ready for sale as building and concrete sand.
Terex Pegson and Powerscreen are global leaders in mobile crushing and screening with sales of almost 3,000 machines a year and a global dealer network of more than 100 dealers.
Wash Plant Summary Equipment: - Powerscreen® 40 Tonne Hopper -Powerscreen® M80 Feed Conveyor -Powerscreen® 20 x 6 2 Deck Rinser -Powerscreen® Finesmaster 200 -Powerscreen® 2 x T6532 Sand Conveyors -Overflow waste water sump -Fresh Water pumps Dealer - Terex Espana Plant Installed - Jan & Feb 2008 Material - Very fine natural sand from a dried lake bed -Raw material approx 90% below 4mm -Silt content in raw = 8-12% - depending on area of lake bed taken from -Silt content in finished = 2.7% Products Produced: -0 – 2 building sand -0 – 4 concrete sand -4 – 12 aggregate -+12mm oversize Throughput - 180 tph |