Operations

Recent operations at Durnford Quarry

With less than three million tonnes of stone remaining, and with demand falling, the decision was made in 2007 to decommission the large aggregate processing plant and replace it with modern mobile crushing and screening equipment. Planning permission was granted to allow more time for the remaining stone to be removed and also for the amount of aggregate recycling to increase.

The photograph (left) shows the old fixed processing plant.

The photograph (below) shows the mobile crushing and screening equipment sited in the base of the quarry previously occupied by the large primary crusher and transfer house buildings.

An advantage of mobile crushers and screens is that they're much smaller and hence visually less intrusive. Operationally, they are more energy efficient than the old static plant that used to be at the quarry and they are also cheaper to maintain, repair and operate. In addition, it is much easier to change the processing arrangements so that the size of the aggregates produced is consistent with the market demand. This means that the stock piles of aggregates  are generally much smaller.

The photograph (left) shows the old secondary processing plant, being the large structures toward the top left of the image.

The more recent photograph (below) shows the current layout of the Recycling processing site, with the aggregates recycling operations being undertaken in the area previously occupied by the large secondary plant house.

In 2008, the production of stone at the quarry (known as primary aggregate) was 250,000 tonnes, together with 70,000 tonnes of recycled aggregates. All of the products from Durnford quarry, some of which are listed below, are manufactured in accordance with British Standards.  All our BSi certification can be seen on Tarmac's website.

Dry stone

A variety of different sized aggregates are produced, depending upon market demand.

Recycled aggregates

These are produced from the inert waste materials which mainly come from construction and demolition sites, and include material from utility trenches, concrete, blocks, brick, tiles etc. They are crushed using the mobile crusher (left) and then screened using the mobile screen (below).

In addition, road planings, produced when old road surfaces are replaced, are also processed on site to produce a secondary aggregate.

Some of our recycled products are then blended with the dry stone to form special products.

The Durnford stone was also used for the manufacture of asphalt and concrete on site, however, in 2009/10 these plants were decommissioned and removed from site.