Search for efficiency

In a business with tight margins, quarry operators have to look for cost-effective ways to move the rocks.

Conveying the right idea: David Matyus of Quarry & Mining looks for cost efficient ways to move stone through plant in the heart of a quarry
Conveying the right idea: David Matyus of Quarry & Mining looks for cost efficient ways to move stone through plant in the heart of a quarry

The quarry industry in the UAE has grown hand-in-hand with the construction industry, which has driven demand for aggregates, as well as high-quality finished limestone.

As with all process driven operations, having the right tools and techniques at your disposal is essential for optimising production and making the most of the opportunities for profitability. When it comes to high-volume, low-cost end products such as stone, this optimisation is all the more important.

"Quarrying is a very difficult business, many people think it is easy, but it is capital intensive," said David Matyus, general manager, Quarry & Mining, a quarry machinery company based in Ras Al Kaimah.

"To set up a reasonable size operation, which will work at a reasonable return, you've got to think of spending AED 60-70 million. When you think about investing, if someone puts in a brand new plant they need to be looking at something like AED 12-15 million per annum profit to get a decent pay back."

Downtime is the killer. If you invest, you've got to aim to be working that plant 24 hours a day at a minimum 85% availability - David Matyus.

Matyus also notes pressure put on the market by demand from other Gulf countries.

"The boom in the UAE demand is increasing," said Matyus. "Maybe ten years ago Kuwait closed its operating crushers, suddenly switching its demand to somewhere else. You can almost say the same for Bahrain and Qatar. Materials there are very poor quality and not suitable for the high quality requirements of construction materials seen in Dubai. You've got to have good quality material to satisfy the standards. Fujairah was an ideal place and Ras Al Kaimah was well down the road of producing materials being used locally."

Achieving a good return means working efficiently, especially in a market where there is plenty of competition and tight margins.

"Quarries have proliferated in places in Fujairah, where there can be up to 15 quarries in a line on one ridge of stone," said Matyus. "But the selling price of aggregates has generally not risen."

"When a client is looking at a quarry operation there are three things to consider: location compared to market, quality of the stone, and how easy is it to quarry. There are two sorts of basic rock in the emirates, limestone found as far up as up as Mussandam on the Gulf side, and on the east coast, mainly gabbro rock.

"They are very different in nature and characteristic physical properties. The gabbro is a very abrasive rock, about 10% more dense than limestone, but usually a cleaner material. How easy is it to get out is important, limestone is often beautifully located for a plant. There are flat wadis alongside cliffs of limestone rising straight up, so you can put plant right next to the limestone."

With efficiency a key to profitability in this tight market, each stage of the operation has to be as efficient as possible and that means fine-tuning the way the rock is handled on site, through both plant supply and operational design. One of the most important parts of this process is moving the quarried stone from the rock face to the point where it is processed.

A well-known and almost iconic method is to use huge off-highway dump trucks, such as those manufactured by Caterpillar. Caterpillar's specialist agent in the UAE, Mohammed Abdulrahman Al-Bahar group recently announced the introduction of the latest 775F dump truck.

"The 775F is our new dump truck," said Sudhir Tripathi, Caterpillar, general construction industry manager. "This series of off highway trucks are very popular in the quarries, and make up the majority of our buyers. These trucks are huge and have the ability to move more material at one time than they have ever done so in the past.

"The 775F machines are especially designed for the off-road, for mining as well as quarries, so you wouldn't see them at the general construction sites in the city."


With a 63.5 tonne payload capacity the 775F offers huge scope for moving rock in the right environment, but according to Matyus, trucks like this aren't the only option.

"The typical way of getting material from the quarry face to the plant is by dump truck," said Matyus. "Everybody does it that way, but that doesn't meant it's the right way, it depends on the operation. We try to utilise the experience we have within the business to offer alternative solutions to our clients. We try to talk to customers to suggest other opportunities, such as using a mobile crusher, or trying to get them to look at using conveyors instead of dump trucks. It can be a much more technical industry than many give it credit for."

"Much of our principle focus for business is quarrying and extraction and a major component is the conveying side of things. If you are looking to move material over a long distance, conveyors can offer a cost-effective solution and an alternative to using dump trucks, where you have to engineer the quarry.

Quarry and Mining offer feasibility studies to assess a quarry's potential reserves in volume terms, looking at the different ways things can be set up.

"When they get offered a reserve or a license many operators don't look at the basic costs of how they're going to make that operation work profitably for them," said Matyus. "So many quarries in the country operating on a marginal basis. There are many reasons for it, but if you just look at the coastal quarries they have an immediate advantage over any inland type quarries and that's basically because the transport costs have escalated quite dramatically over the last two years."

Regardless of whether vehicles or static plant are used, getting the right quality is essential for long-term success.

"A general rule is that you pay for quality plant when you invest at the beginning of the business operation, or pay later in increased cost or extended downtime if you invest in second-rate stuff," said Matyus. "Downtime is the killer. If you invest, you've got to aim to be working that plant 24 hours a day at a minimum 85% availability."

775F

Each of the F-series trucks was given a new engine and radiator, replacing those used in the previous E-Series. The trucks also include enhanced transmission and brake systems and a new cab and operator station.

Caterpillar has said the new trucks offer better access for operators and service personnel, while the Cat Messenger information system helps maintenance technicians and operators.

The F-Series trucks use Cat engines with ACERT technology for fuel-efficient operation and emissions compliance. With the cost of fuel a considerable portion of current operating costs, any gains in fuel efficiency are likely to be welcomed by quarry operators.

Caterpillar claims the efficient combustion technology has extended the engine service interval for each of the trucks to 500 hours: twice that of the previous truck models. In addition, QuickEvac, the Caterpillar on-board engine oil evacuation and pre-lube system, is standard on F-Series trucks and reduces oil change labour time by up to 50%. The company says a new modular radiator provides 3.5 times more fin spacing, which makes it easier to clean and service, and the single-pass flow cools more efficiently compared to the old dual-pass system.

All F-Series brakes are hydraulic, rather than air-over-hydraulic and automatic retarder control (ARC) is standard on F-Series trucks and automatically controls braking on grade and keeps engine speed at around 1900 rpm. Caterpillar says ARC protects the engine from over-speeding, further improves fuel efficiency, provides better control of the truck, increases productivity and eases the burden on the operator.

The company says a new ergonomic design and layout of controls promotes operator efficiency and reduces operator fatigue, a key factor in overall operational efficiency.

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