A crane dumps 50 tons of dolomitic limestone into a super-sized dump truck at Carmeuse Lime and Stone in Cedarville Wednesday, April 22. The truck can hold 150 tons of limestone.

A story in The St. Ignace News' ongoing series bringing our readers fresh perspectives on the top issues facing the Straits area and the Eastern Upper Peninsula.

 

Over the past two years, the Carmeuse Lime and Stone quarry in Cedarville completed a major rebuild of its entire facility to introduce new technology and replace aging equipment. The project cost more than $14 million.

When the quarry began its seasonal operations about a month ago, it was, essentially, a whole new plant.

Operations at the facility are split into two sections: quarry operations, where dolomitic limestone is mined, and mill operations, where the limestone is sorted and stockpiled for shipping. All of the screening, crushing, and conveyor equipment at the mining site was replaced, and much of the screening and conveyor equipment in the mill area, five miles south of the quarry, was also replaced.

A double-trailer semi-truck from Maverick Construction in St. Ignace is loaded with limestone at the Carmeuse Lime and Stone quarry in Cedarville Wednesday, April 22. The two trailers can hold about 50 tons of stone. Most of the stone is shipped out of the quarry by lake freighter, one of which can hold up to 69,600 tons.

Electrical systems throughout the operation were upgraded and most electrical processes are now trackable on a custom-made computer program. The program allows operations manager Ray LeClair to track every process at the facility, including conveyors, motors, and sensors.

 

"We have much better control of the process, which gives us more consistency for our customers and what they need at the other end," he said. "I can see the whole process; the flow, how many tons per hour running through. I can follow the whole process through here."

From his office, he can track how much and how fast stone is being processed. The new machinery is targeted to run at about 1,200 tons per hour.

A train car dumps 100 tons of limestone at the Carmeuse Lime and Stone quarry in Cedarville Wednesday, April 22. The 14-car train moves 1,400 tons of limestone five miles south from the quarry to the mill operations, where the rocks are sorted and prepared for shipping.

Over the past 10 years, he said, limestone production ranged between 2 million and 4 million tons a year.

 

The quarry, which has about 60 employees, began operations in Cedarville in 1955 and has had almost no equipment upgrades outside of regular maintenance. What's more, much of the equipment was already 20 years old when the quarry opened in Cedarville. It was disassembled and moved in 1953 and 1954 from a quarry site in Alpena that opened in the 1930s.

"The equipment has seen a fair amount of age, thus the reason why we went through and did this big rebuilding project," Mr. LeClair said. "The age of some of the equipment was very questionable. We had numerous breakdowns with it and needed to make that transition."

The quarry produces dolomitic limestone, a mineral essential in making steel, chemicals, and cement. It is also used as a flux to remove impurities when smelting iron and steel. Most of the limestone produced at the quarry is shipped to steel and concrete plants along the Great Lakes, Mr. LeClair said.

Total crude steel production in 66 countries around the globe is down by more than 23% in March 2009 compared to March 2008, from 132.25 million tons to 101.5 million tons, according to the World Steel Association. Steel production has steadily decreased since June 2008.

The slowing trend in the steel industry didn't affect his plant until last fall, right before the quarry shut down for the winter, Mr. LeClair said. Its production is based on how much demand it gets from customers, and he will only slow production if he has to.

"Right now the steel industry is down; just watch the news," he said. "It's somewhat slowing, but it really hit the brakes in the latter part of last year, in October and November. It just seems like the whole industry dropped right down. It's a demand thing. If they don't need it, then we're kind of stuck."

The quarry currently operates two eight-hour shifts Monday through Friday.

The rebuild process was briefly slowed when Cleveland-based Oglebay Norton Minerals sold the facility to Carmeuse North America of Pittsburgh. Oglebay Norton owned the Cedarville quarry, as well as quarries in Rogers City and Gulliver, for nine years before selling to Carmeuse, a subsidiary of the Belgium-based Carmeuse Group. Carmeuse North America is the largest producer of limestone in North America, with 35 manufacturing facilities in the U.S. and Canada.

How is limestone harvested?

When more limestone is needed, the quarry is cleared of all staff as a demolition crew prepares to blast the quarry wall. Holes drilled at specific points are filled with a twogel chemical compound, which is not volatile until the gels are mixed together, and connected to a detonator placed a safe distance away.

After the blast, the site is checked to make sure all of the explosives ignited and it is safe to return to work. The "all-clear" signal is given and production resumes.

A giant shovel-crane then scoops up 25 tons of the blasted dolomite and dumps it into the bed of a super-sized dump truck, which carries it off to the crusher. Each of the quarry's two trucks stands about 25 feet tall and can hold 150 tons of rock.

"They can crush a car and not even know it," Mr. LeClair said of the trucks.

Once the truck is full, it's driven up a small hill at the bottom of the quarry to drop its load into a separator. Rocks smaller than three inches are sent up a conveyor belt to a stockpile area, while the larger rocks are dropped into a crusher before going to the stockpile.

A hatch under the stockpile feeds a 3,700-foot-long conveyor belt that carries the stones nearly out of the quarry to a staging area at the quarry's edge. Before the new equipment was installed, the dump trucks carried the dolomite almost out of the quarry to a separator and crusher, where the staging area is now.

"We're processing it down there and conveying it up here. That'll save us on truck costs and fuel," Mr. LeClair said. "These trucks burn a fair amount of fuel. Here it's gallons per hour, as opposed to miles per gallon."

A hatch under the staging area feeds a second conveyor that carries the stones the rest of the way out of the quarry and drops them on top of a 50-foot pile of stones. Housed under the pile is a 14-car train on a set of tracks that carries the stones five miles south to the dock area. It takes about one minute to gravity-feed 100 tons of stone into each of the waiting open-top cars.

At the dock area, the open-top cars are dumped onto another pile with a conveyor system under it. These conveyors carry the stones up to a series of screens that separate the stones into six different sizes, ranging between threeeighths of an inch and 2.25 inches. The stones are then sorted into piles, ready to be loaded onto a lake freighter or semi-truck.

From Cedarville, most of the stones are shipped out on freighters headed for numerous ports in every Great Lake except Lake Ontario, Mr. LeClair said.

The dock can accommodate all sizes of freighters, which hold between 5,000 and 69,600 tons of dolomitic limestone. A semi-truck with two trailers can hold only about 50 tons, he said. It's more economical to ship the stones by water.

"We're loading [freighters] at 2,600 tons per hour, so there's a fair amount of truckloads that can go into one boat every hour," he said.

Fractional freighters Although some freighters on the Great Lakes can carry almost 70,000 tons of rock, many are not being filled to their capacity. Freighters traveling to some of the many ports on the lakes are struggling with low water levels and channels in need of dredging. The boats are not filled to capacity for fear of running aground.

Businesses are responsible for dredging waterways leading to their docks from navigational channels, however, the U.S. Army Corps of Engineers is responsible for any necessary dredging of federally authorized channels.

The Great Lakes Maritime Taskforce, an Ohio-based labor coalition that represents shipping in the Great Lakes, said the Corps of Engineers would need more than $200 million to properly dredge the shipping channels in the Great Lakes and rivers.

The Corps needs about $60 million to "dredge 3.9 million cubic yards of material on an annual basis, just to maintain the status quo," said Wayne Schloop, chief of operations for the Army Corps of Engineers Detroit District.

He estimates more than 17 million cubic yards of material must be dredged in the navigation channels. If the Corps receives adequate congressional appropriations, he said, the process would take about five to seven years.

"We're dependent on an annual appropriation from Congress," he said. "We're competing for infrastructure dollars."

This year, he anticipates the Corps will dredge about five million cubic yards of material in the various channels.

The 25-foot-deep waters at the dock in Cedarville don't give freighters any problems, Mr. LeClair said. He's more concerned with the docks where the limestone is being shipped.

"There are some harbors we ship to, that we can't load the boats up fully because they don't have the depth in certain points. There's a lot of lost cargo capacity just because of that," he said. "It does make a difference on what you can put in a boat."

Two to four freighters a week are loaded at the Cedarville quarry. It takes about 24 hours to fill the largest boats at a rate of 2,600 tons per hour.

The number of ships being loaded at the quarry depends on the volume of orders with customers and freighter availability, he said.

"What this rebuild will do for us is allow us to be able to run more efficiently. The more critical thing is, we needed to upgrade it to run more consistently to keep our customers happy. Because if we won't do it, somebody else will," he said. "This plant is probably as modernized as you can find. Everything we put in is, I won't say cutting edge, but is the most up-to-date of what anybody's got on the market for this type of plant."