Gulf Construction Online - Sandvik’s hammers tackle virgin quarry

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The Rammers ... primary breakers.

Sandvik’s hammers tackle virgin quarry

01 January 2009

City Cement Company (CCC) of Saudi Arabia has built a new cement plant at a massive limestone deposit near Riyadh, and is using two new Sandvik Rammer hydraulic hammers to open up the virgin quarry.

Produce from the quarry, which is a major new resource of limestone, will be used to feed a newly-constructed cement plant nearby.
The two Rammer BR 3890 breakers have been supplied as secondary breaking equipment by Sandvik Rammer’s Saudi distributor, Zahid Tractor.
Saudi Arabia has, in very recent years, concentrated on the exploitation of its huge mineral reserves and, with a great domestic need for cement, has embarked on a programme to exploit its limestone deposits.
Surveys have revealed thick limestone deposits at various locations in the geological area known as the Arabian Shield, and the limestone now being worked by City Cement at the Marat region about 150 km from Riyadh is a particularly fine quality.
CCC, which is part of the giant Al Abdullatif Group, has constructed a 5,000 tonnes per day plant in Marat, working in conjunction with Holtec Consulting of India, which acted as the consultant for the project. The plant was built by Sinoma International of China.
CCC’s mining manager R Nagarajan says that the limestone deposit is found in shallow layers of between 40 and 150 cm, mixed in with granite deposits, and that the mine itself will be spread linearly.
Working with the hydraulic hammers, an impact rate of about 400 bpm is required to break the rock.
“This is why we decided to invest in the two Rammer BR 3890 units,” he says. “They are mounted on two new Cat 3300 hydraulic excavators, which were also supplied by Zahid Tractor, and we find that the combination works effectively.”
The hammers weigh 3,150 kg apiece, and work at an operating pressure of up to 150 bar.
“The quarry is a virgin one,” says Nagarajan. “Although the two Rammers are designed for secondary rock breaking, at this very early stage of the quarry, where we are only just below the surface of the desert floor, we have been using the breakers mainly as primary breaking production machines.
“Later, when we begin blasting on a regular basis, we shall use the Rammers to break the rock so that the pieces will pass through the 1,200 mm jaws of our crusher, which is a 1,000 tonnes per hour double-rotor hammer type of crusher.”
Using the Rammers as primary breakers, Nagarajan says that he is processing about 1,200 tonnes of rock per hour with each machine.
The quarry workers are working two 10-hour shifts per day, seven days a week. Once production is fully under way, with the drill-and-blast operation working regularly, the monthly output of limestone is predicted at between 250,000 and 300,000 tonnes. Total annual cement production is projected at 1.75 million tonnes.