Increased Production from Metso Minerals Crushing Plant in Oman

With Sharjah the latest Gulf State to ban crushing operations on environmental grounds and others restricting wadi or riverbed gravel operations – Tarmac is set to almost double its designed production capacity to meet the resulting increased demand for highway and construction projects in Abu Dhabi.

Tarmac Middle East’s Al Dhahira quarry in Oman saw production increase by more than 35% at the end of its first 12 months to 4.8 million t and, according to General Manager, Julian James, it will increase to seven million t by the end of 2004.

At the heart of the operation is a crushing and screening installation from Metso Minerals comprising a primary Nordberg C100 jaw crusher, three NP1110 impactors, A Nordberg HP200 cone crusher, five 12 m2 screens and in excess of 40 conveyors.

In a turnkey project, Metso Minerals designed, built and installed the plant for a production output of 650 t/h. By the end of its first year’s operation, the installation was producing almost 800 t/h; achieved according to Julian James, by producing the best mix of aggregate for the plant configuration, and improved efficiency resulting from experience of operating the Metso units.

The quarry started production in May 2002 and is Tarmac’s largest wadi gravel deposits occupying a site of almost 40 km2 close to the Omani-United Arab Emirates border.

Due to environmental concerns, the Gulf States of Kuwait, Bahrain and Qatar, and the Emirate of Sharjah, have closed down crushing and screening operations. Consequently quarries such as Al Dhahira are poised not just to supply Oman and the UAE, but the entire Gulf region.

For the moment, however, increased production is predominantly geared towards highways and construction projects in Abu Dhabi and Al Ain.

The quarry, with a recent 40 million t plus extension, has a potential for at least 16 years with the increased production. The rock extracted is a very hard gabbro – considered to be the region’s toughest rock with a density of up to 3 t/m3 and a crushing value of 13.1 t. It is also highly abrasive and has a 44 – 50% silica content.

“This gabbro product represents at least 60% of our production for asphalt plant in Abu Dhabi,” said Julian James, continuing, “It provides us with the highest investment return.” The remaining 40% is used for concrete production throughout the region.

Metso installation

The Metso Minerals plant comprises primary, secondary and tertiary crushing and screening equipment.

The primary circuit is a single Nordberg C100 single toggle jaw crusher with a feed opening of 760mm x 1000mm. The material is then fed to the three Nordberg NP1110 horizontal impactors to produce three different products, asphalt, ready mix and sand. Material is fed to the primary crushers via a push feeder and a two-deck primary screen, with undersized material passing through one of the site’s CVB2060 2m x 6m triple deck screens.

Each of the impactors feeds onto a dedicated Nordberg CVB2060 triple deck screen to classify and check for the correct product size and cubicity. The site’s processing plant also includes one HP200 cone crusher for sand production.

To meet stringent pollution regulations, the plant also incorporates a dust suppression system which includes infrared-triggered spray systems at the feed points.

The area is also close to the water table, with nearby water bottling plants supplying Oman and the UAE. Any pollution or dust from the site is strictly controlled.“To meet recent tightened environmental controls we will shortly be completely enclosing the sand conveyors to further restrict dust,” said Julian James. He also confirmed that the installation is environmentally friendly with dust suppression and extraction meeting the strictest Omani regulations.

The Al Dhahira operation is producing a wide range of aggregates to standard sizes including, 40/25 mm; 25/20 mm; 20/10 mm; 10/5 mm; 5/3 mm; and 0/3 mm. Three sizes of natural sand are also produced – 20/10 mm; 10/5 mm; and 0/5 mm.

In order to meet the continuing increase in production to meet local demand, Tarmac is transferring a 700 t/h crusher from a nearby quarry which is closing down. The company has also placed an order for screens for the relocated plant with Metso Minerals for two four deck CVB2060 IV screens. “We opted for the Metso screens to give a synergy with spare parts plus of course they are very good screens,” said Julian James.

Delivery of the new screens is expected to be mid-2004 by the Muscat office of local distributor Arabian Car Marketing Co. which also provides regular back-up and spare parts support for the Al Dhahira operation.

The quarry is located approximately 40 km from the nearest town with Tarmac constructing a 12 km long asphalt access road to connect to the nearby main highway to the UAE border and the city of Al Ain.

For more information, please visit:

https://edir.bulk-online.com/profile...o-minerals.htm

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