Tarmac - Shireoak

Tarmac is a leading supplier of aggregates, mortar, concrete blocks, asphalt and ready mixed concrete.

The Tarmac Shireoak site north of Birmingham is a bunter sand deposit.

Raw Material Analysis
The material is spilt 50/50 between sand and gravel but the sand is very fine- typically 30% passes the 300mm sieve, 7% of the raw material is silt.


Tonnage: 200,000 TPY, 100 TPH + recirculated material from the crusher

Equipment on Site:

  • Commander 1400 10x5 2 deck full rinser
  • Powerscrub 120R
  • Finesmaster 120
  • Commander 1400 10x5 2 deck part rinser
  • 6 T5032 conveyors
  • Pegson cone crusher
  • Caterpillar genset


Materials Produced:

  • Building sand to BS1200
  • Concrete sand to BS882
  • 10mm stone
  • 5-20mm stone

Method Statement:

The material is loaded via the hopper on the primary Commander

On the first screen the material is washed producing the following materials, 0-3mm sand, 0-6mm sand (the bottom deck is split), a midsize 6-20mm and an oversize (+20mm)

The sand slurries are piped to the Fines master to be dewatered and recover the fines, these are stockpiled using 2 T5032 conveyors.

The oversize product goes to the in line crusher and the crushed material is then fed back on to the conveyor on the primary Commander.

The midsize material from the Primary screen is scrubbed to remove any remaining clay in the Powerscrub 120R, any wood material will float off via the sieve bends at the backend.

The stone from the Powerscrub is fed to the secondary screen where it is rinsed and graded to the required 10 and 20mm products.

NB: The 20-5mm is the most important gravel product the customer needs this for there concrete plant, but they need to take out some of the 10mm to get the material within specification.

On the second screen they are producing 2 products from a 2 deck box- the material from both the top and middle decks goes to the 20-5mm product. The 10mm product is through the bottom deck. A variety of modular mats are used on both decks to ensure some overrun and bring the 20-5 within the required spec.

Summary:

The Powerscreen wash plant is producing 4 grades of high quality clean aggregate. The Finesmaster 120 with its combination of bucket wheel and twin hydro cyclone sand recover systems means that fine sand losses to the ponds are minimised thus maximising production of saleable product.