Tilcon’s Mount Hope Quarry achieves significant savings through air classification.

In this era of outrageous oil prices, any time a producer can create a saleable product from waste material and reduce fuel costs at the same time — without sacrificing production or quality in any stage of the process — it’s like putting money in the bank.

By changing the way it processes asphalt sand, Tilcon New York, Inc.’s Mount Hope Quarry, located in Wharton, N.J., found that it has significantly reduced downstream fuel costs associated with its on-site asphalt plants from 10 to 20 percent, depending on product and type of fuel used.

The Mount Hope facility has enjoyed a mining history that dates back to the mid-1700s. The 560-acre quarry site surrounds the historic Mount Hope Mine, which was the last iron mine to operate in New Jersey — mining iron ore until the mid-1970s, when it turned to producing crushed stone. Located about 40 miles west of New York City, Mount Hope became part of the Tilcon New York family of operations, a division of Washington, D.C.-based Oldcastle Materials Inc., in 2001.

The Mount Hope Quarry has become legendary over the years as one of the nation’s largest producers of quality crushed granite and the highest-volume, single-location producer of hot-mix asphalt. With more than 300 million tons of permitted reserves, the site operates 24 hours a day and produces more than 4 million tons per year. Many of its crushed stone products are used in the facility’s three on-site asphalt plants — including manufactured sand that meets Superpave specifications.

Until two years ago, the Mount Hope facility could only produce an asphalt sand via a wet process — pulling out the minus-200 material in order to use the remaining manufactured sand product as specification sand for asphalt mixes. But the company had excess screenings that it could not efficiently process with the washing plant.

Then in 2006, Tilcon New York acquired the nearby Bedrock Quarry Materials location, which was in the process of installing an air classification system manufactured by the Lebanon, Pa.-based Buell Division of Fisher-Klosterman, Inc. The company quickly decided that the system, made up of two 75-ton-per-hour Buell GI-108 gravitational inertial classifiers, would find a better fit at the Mount Hope facility.

Clif Morris, quarry manager at the Mount Hope facility, says the team decided to move the classifiers based on several factors. “One was the foreseeable life of the Bedrock quarry; it didn’t have a long-term plan. Also, Mount Hope is a much larger operation, with asphalt plants on site and a bigger need for the manufactured sand that would feed the plant. Bedrock was using it to make a clean grit product, for which there wasn’t a real need in the area. And we had to do something with the excess screenings at Mount Hope. We knew the Buell system could answer that need.”