Moving Ahead
New York quarry completes upgrades to meet production growth
As the closest quarry to New York City, Tilcon New York’s West Nyack facility is in a privileged position due to steady construction growth and expansion in the greater New York area. But Tilcon New York are well aware that with such privilege comes responsibility. ‘We are responsible for providing quality aggregate at a reasonable price for the market,’ commented Bernardo Bulnes, plant manager at West Nyack Quarry.
That said, business has been good for West Nyack and its two sister sites — Tomkins Cove and Haverstraw quarries — located in Rockland County, NY, just north of and across the Hudson river from Yonkers. While aggregate producers in some parts of the US have had to cut back production goals, West Nyack Quarry has slowly been working towards a projected increase in production of more than 35%.
‘There have been a lot of big infrastructure projects going on in New York City, as well as work on the Freedom Tower and the building of sports complexes for the Yankees and the Mets, and work on high-rises, said Mr Bulnes. ‘Having a source of aggregate nearby is a great benefit for these contracts. And at this location we produce trap rock, which is very abrasive, so it’s also excellent for high-friction applications and speciality paving projects, such as airport tarmacs and SuperPave.’
The West Nyack site was originally owned by the Trap Rock Company, which commenced operations in 1911, although the quarry can actually trace its roots back as far as the mid-1800s as a source of stone for the surrounding area. The site received its first major upgrade in 1958, and was upgraded again in 1999 to produce 2.5 million tons per year. By mid-2008 the quarry was in the process of another upgrade with the eventual goal of producing 3.2 million tons a year.
A vast venture
West Nyack Quarry has several working benches, but in order to increase production Tilcon New York have been working to open new areas for extraction as well as switching other areas from extraction to processing as they move their crushing and screening stages to make best use of the 150-acre property for future production. As part of these changes, the company has also invested in various equipment upgrades.
At the end of 2007, the facility’s crushing process included an Allis Chalmers 42in x 65in primary gyratory, a 7ft Symons secondary crusher, a 51/2ft Symons tertiary crusher, a Raptor XL400 quaternary cone crusher from FLSmidth and a Svedala H4000 quaternary cone crusher.
‘In January 2008 we replaced the H4000 with another Raptor XL400 for our quaternary stage, and right now we’re setting up new sites to locate the primary and secondary crushers,’ said Mr Bulnes. ‘We’re getting a new H7800 cone and we’re also making room to move our tertiary. In addition, we will install a new primary that will be the first of its kind in operation — a 54-series (55in x 83in) heavy-duty, top-service gyratory crusher from FLSmidth.’
Mr Bulnes explained how the design of this gyratory crusher allows service to be performed on the unit by pulling necessary parts from the top, which eliminates the need to send personnel down into the crusher unit. ‘This feature will be a great advantage from a safety standpoint,’ he said.
According to Mr Bulnes, in all of Tilcon New York’s early preparations, it was the addition of the second Raptor cone crusher that helped West Nyack Quarry turn a corner, as it began to increase production in 2008. ‘We bought the first Raptor cone in 2005. It was actually an emergency purchase, which can be harder to justify than a planned purchase, but we needed a new cone to replace a failed H4000,’ he explained. ‘We wanted a cone that was comparable to the old machine, but could provide better throughput and production for future goals. We also needed a manufacturer that was reliable and could support the machine, so we looked at customer response and parts availability. When we looked at the Raptor cone crusher, we knew it was the first XL400 cone the company had produced – serial number 001 – but we had used their rebuild services in the past and we trusted their capabilities. The price and warranty were attractive, and as we’re not afraid to experiment with new products, we decided to give them a shot. With it being serial number 001, we probably were going out on a limb, but it turned out to be a good decision.’
The XL400 ran alongside a second H4000 for a couple of years, during which it began to prove that its production capabilities provided improvement over the older cone. According to John DeAngelis, maintenance supervisor at West Nyack, the older cone had about two-thirds the capacity of the Raptor cone crusher, so more material had to be sent to the Raptor than the H4000. ‘If the Raptor cone was shut down for maintenance it would cause production issues, because the older cone could not produce fast enough,’ he said. ‘Also, the H4000 was not as automated, so we replaced it with a second Raptor cone at the beginning of the year as a step in our upgrade to increase production, match our goals and automate the process as we completed our crushing circuit.’
The design of the Raptor XL400 cone crusher features a high pivot point and large crushing stroke that is said to offer better crushing action throughout the crushing chamber than many competitive models. An active feed opening creates a desirable end-product shape for high production of salable material, while a large head diameter of 52in (1.3m) allows the XL400 to accept feed sizes up to 25% larger than those accepted by crushers with less throw or head diameter.
Automated features include advanced overload-sensing technology that detects crushing force overloads. Should this occur, a simple alarm is activated or, alternatively, the system can be configured to automatically take corrective action. This same advanced automation system can be used to optimize crusher performance, with feed control, setting adjustment and monitoring of all critical lubrication and hydraulic parameters.
The crusher also employs ‘fail-safe’ hydraulics through an internal relief valve within the dual-acting tramp-release cylinders. This feature ensures that the machine is protected from mechanical overload in the event of an accumulator bladder failure. As an additional safety feature, a counter-clockwise rotation crushing action that protects the machine if adjustment ring movement is excessive or if the ring gear brake fails comes as standard on all Raptor cone crusher models.
Mr Bulnes pointed out that, between the installation of the first and second XL400 units at West Nyack, Tilcon New York placed another three Raptor XL400 cones in other locations. ‘This decision was based on the success we had with the first one,’ he said.
‘In addition to the new cone, our winter 2008 upgrade also included a surge bin upgrade. We replaced our belt feeders with vibratory electromagnetic feeders, which helped our throughput and performance,’ he explained. In addition, a new dry classifying system now cuts the –200 mesh material from all –1/4in manufactured sand product, and new conveyors have prepared the plant to fully handle added capacity. Additionally, the site has added new loaders to improve feed to the new gyratory primary crusher when it is in place.
Progress within the process
At West Nyack Quarry, the first three crushing stages are open circuit. The primary gyratory crushes the stone to –8in and sends it to a surge pile. At the secondary stage, the 7ft cone crusher further reduces the material which is then screened to – 11/4in and 11/4in x 1/2in. The 5ft cone crushes the oversize material and sends it to a three-deck screen that sizes it to 3/4in, 5/8in and 3/8in. The quaternary stage operates in a closed-circuit, with the two Raptor XL400s set at a 1/2in closed-side setting.
Each of the Raptor XL400 cones can produce at 750 tons/h, which allows the company to send stone to one or both crushers, depending on production needs. For anything over 750 tons/h, production is split between them.
‘The science of breaking rock hasn’t really changed in recent years,’ commented Mr Bulnes. ‘Mechanically, equipment is pretty much the same. It’s how you optimize and manage your equipment, make use of automation and interface with computers that helps to improve the equipment’s performance. For instance, we can control both Raptor crushers with one computer program and one screen, which is a big improvement over our other set-up where we had to go back and forth between two computer programs.’
John DeAngelis said he appreciates the cones’ ease of maintenance. ‘The controller tells us how much the liners have worn, so it’s easier to schedule liner changes, and there are very few moving parts, so they are easy to work on,’ he said. ‘We’ve enjoyed a lot longer uptime with these machines than with crushers we’ve used in the past. That makes it easier for us to produce the stone we need to match our sales.’
West Nyack’s production manager, Wayne Hardick, agreed: ‘The controller package allows us to adjust them automatically, and if we keep the [fluid] levels correct, and change the oil on schedule, they’re practically maintenance-free. We typically go 400,000 tons before we need to make a liner change,’ he said.
‘Until we get the FLSmidth gyratory into production, the bottleneck is now at the current primary,’ said Bernardo Bulnes. And according to his estimates, at the upgraded production rate, the West Nyack site will still have approximately 35–40 years of material reserves.
Extra efforts yield community benefits
West Nyack Quarry runs all year round, only shutting down for six weeks in January and February for maintenance, repairs and crusher rebuilds. According to Charlie Beers, the operation’s pit manager, blasting takes place just once or twice a week at noon. ‘We blast bigger shots this way, but we’ve found that, for neighbour relations, it’s better to shoot more material less often. Also, we have started to drill and blast in the west side of the pit, which is deeper in the hole, so it’s quieter,’ he said.
Mr Beers explained that another part of the operation’s current upgrade includes moving stockpiles to better accommodate the new primary, as well as organizing other stockpiles to help ensure leaner overall throughput. ‘Transportation costs more than the stone now,’ he noted, ‘which is why we are working to organize things better to eliminate such problems as returned product.’
These additional efforts to upgrade the operation emphasize Tilcon New York’s determination to improve more than just the quarry’s production figures. For example, one project that was completed in the summer of 2008 involved a US$300,000 restoration of the historic Storms Tavern, which forms part of the site. This helped improve opinions on Tilcon New York among the local residents.
Mr Bulnes also explained that while West Nyack Quarry is west of the Hudson river, it is located between Lake Deforest, which provides potable water to New York City, and the Palisades Mall, a popular three-storey indoor shopping center. ‘This is actually a very urban area and we have been working to address community concerns regarding noise, dust and traffic,’ he said. By the end of 2009, the quarry had closed the entrance by the lake and opened a new one off the interstate, which greatly reduced truck traffic. ‘We spray material at all crushing stages and on conveyors as a dust-control measure. And from an aesthetic point of view, the old buildings that had been here since 1958 are now gone.’
While some may see all these efforts as overkill, Mr Bulnes disagrees, because he firmly believes that with privilege comes responsibility. ‘We’re the closest quarry to New York City,’ he said. ‘All eyes are on this plant for a lot of reasons.’
