A mobile laser scanning system can be mounted on the back of a standard SUV, allowing data points to be collected as the vehicle drives around the stockpile.

Performing physical inventories of material stockpiles is a task that most aggregate companies see as a necessary evil — it is something that has to be done for accounting purposes, but it takes up valuable resources and can slow down production. At the same time, the accuracy and traceability of the methods are important from the accounting side and need to be consistent from inventory to inventory so that the results can be relied upon. After all, these are valuable corporate assets that are being characterized.

Steve Brooks, plant manager for Tilcon in Poughkeepsie, N.Y., wanted to use the most accurate method available to inventory his company’s stockpiles. Tilcon, an Oldcastle Materials Group company, is an integrated materials company with multiple New York and New Jersey operations that include quarries, asphalt plants, recycling plants, water terminals, and a heavy highway construction division.

“About three years ago, we began to investigate the use of 3D laser scanning,” Brooks says. Instead of collecting 10 to 20 shots on a typical 20,000-cubic-yard stockpile using a total station measurement system, with laser scanning on the order of 100,000, 3D points are typically collected for that same pile. The spacing of the laser scanned points on the pile surface is typically on the order of 3 to 6 inches.

Manual surveys cannot begin to match this level of surface detail. In fact, the laser scanning field crew has to be careful not to collect too much data because this can bog down the post processing and data analysis without improving the end result.

“We were using a different laser scanning contractor when we became aware of the mobile laser scanning-based methodology that H2H offers,” Brooks says. “We made the decision to give it a try and have been very impressed with the results.” H2H Associates is a geo-consulting firm based in Troy, N.Y., with expertise in mining, engineering, geology, survey, regulatory, and environmental services.

Its mobile laser scanning system is mounted on the back of a standard SUV. The 3D point data is collected by driving around the stockpile, typically at a speed of 5 to 10 miles per hour, with the scanner rotating at 1,800 revolutions per minute. The mobile laser scanning system includes a global positioning system (GPS) receiver and inertial measurement unit (IMU) that allow the data to be geo-referenced to the exact location on the earth. This ensures that each inventory operation will be referenced to the same coordinate system and pile limits each time the inventory is performed.

Faster data collection and processing

Speed was the key factor in Vic Coleman’s decision to use a mobile laser scanning system. He is the CFO at Braen Stone, a New Jersey firm with more than 100 years of involvement with the aggregates industry. Braen uses the physical inventory surveys for both internal and external financial audits.

When Coleman first started doing quantity surveys, his crews were averaging two sites per week, but the mobile laser scanning system has allowed crews to assess three sites in two days. “The speed is remarkable, and we have a high degree of confidence in the results,” Coleman notes. He has seen three or four generations of technology, and says he is continually amazed at the pace of change. “I remember when the field crews had to keep the batteries warm with their hands,” he recalls.

Mobile laser scanning not only speeds up the data collection portion of the workflow, but, as compared to the use of aerial photogrammetry, it has led to much faster turnaround of the actual physical quantities. Using point cloud software supplied by the sensor manufacturer, the 3D data for a 20,000-cubic-yard stockpile can be reduced and computed into volumes within a matter of hours.

Gary Wall, operations manager for Tilcon Connecticut, a leading supplier of quality crushed stone, hot-mix asphalt, and ready-mix concrete throughout the state, notes that stockpile quantities are typically available within a couple of days of the survey.

Safety and standards

Site safety is another factor that leads companies to choose mobile laser scanning over other inventory methods. Wall notes, “The use of laser scanning, in general, is a safer and more accurate method for inventorying stockpiles.”

Once collected, stockpile data can be reduced and computed into volumes within a matter of hours.

Safety can be either prescribed, in the form of government regulations, or desired, in the form of company policies that reduce liability, property damage, and costly injuries. The U.S. Mine Safety and Health Administration has issued a number of regulations that apply to stockpiles and other related facilities such as drawholes, bins, hoppers, and surge piles. These regulations prohibit a worker from standing or walking on a pile when it may expose the person to a hazard. Other regulations require the construction of platforms, staging, or safety lines.

Laser scanning eliminates the need for anyone to walk on a storage pile and can, in the case of mobile scanning, keep the survey crew safely inside a vehicle. When the project requires the use of a tripod-mounted scanner, the survey crew generally has the flexibility to select locations that are not in harm’s way.

The use of mobile laser scanning as a standard method for inventorying aggregate stockpiles in the United States is being addressed by the American Society of Testing Materials International (ASTM). Originally formed in 1904, ASTM Committee D05 on Coal and Coke is responsible for a variety of standards for this industry that have application to aggregate and mineral mining and storage as well.

ASTM D6172 was originally developed to standardize photogrammetric measurement procedures for inventorying coal and coke stock piles. Recognizing the importance of laser scanning techniques, as well as GPS, this standard is now in the process of being updated to include these game-changing technologies.

Investing in the future

During a downturn in the economy, forward-looking companies may see the use of new technology as an opportunity to position themselves for future growth. Having up-to-date, accurate inventory information and confidence that it is being obtained in a cost-effective, safe, and defendable manner is critical to overall business operations and a potential source of competitive advantage for aggregate companies.

3D laser scanning is a powerful technology that, from a technical point of view, is well suited to the physical inventory of aggregates and minerals. Safety agencies, standards organizations, and owners are beginning to recognize the multiple benefits that this methodology offers. In this rapidly emerging world of 3D technology, it is not a question of if the use of laser scanning will become the preferred method of developing physical inventories of construction materials, it is just a question of when.

Richard A. Hisert Ph.D., principal, and Trevor R. Thomas, P.E. are with H2H Associates, LLC. Based in Troy, N.Y. H2H is a consulting firm that provides geologic, hydrogeologic, construction, regulatory, and environmental services.

A mobile laser scanning system can be mounted on the back of a standard SUV and allows data points to be collected as the vehicle drives around the stockpile.

Performing physical inventories of material stockpiles is a task that most aggregate companies see as a necessary evil — it is something that has to be done for accounting purposes, but it takes up valuable resources and can slow down production. At the same time, the accuracy and traceability of the methods are important from the accounting side and need to be consistent from inventory to inventory so that the results can be relied upon. After all, these are valuable corporate assets that are being characterized.

Steve Brooks, plant manager for Tilcon in Poughkeepsie, N.Y., wanted to use the most accurate method available to inventory his company’s stockpiles. Tilcon, an Oldcastle Materials Group company, is an integrated materials company with multiple New York and New Jersey operations that include quarries, asphalt plants, recycling plants, water terminals, and a heavy highway construction division.

“About three years ago, we began to investigate the use of 3D laser scanning,” Brooks says. Instead of collecting 10 to 20 shots on a typical 20,000-cubic-yard stockpile using a total station measurement system, with laser scanning on the order of 100,000, 3D points are typically collected for that same pile. The spacing of the laser scanned points on the pile surface is typically on the order of 3 to 6 inches.

Manual surveys cannot begin to match this level of surface detail. In fact, the laser scanning field crew has to be careful not to collect too much data because this can bog down the post processing and data analysis without improving the end result.

“We were using a different laser scanning contractor when we became aware of the mobile laser scanning-based methodology that H2H offers,” Brooks says. “We made the decision to give it a try and have been very impressed with the results.” H2H Associates is a geo-consulting firm based in Troy, N.Y., with expertise in mining, engineering, geology, survey, regulatory, and environmental services.

Once collected, stockpile data can be reduced and computed into volumes within a matter of hours.

Its mobile laser scanning system is mounted on the back of a standard SUV. The 3D point data is collected by driving around the stockpile, typically at a speed of 5 to 10 miles per hour, with the scanner rotating at 1,800 revolutions per minute. The mobile laser scanning system includes a global positioning system (GPS) receiver and inertial measurement unit (IMU) that allow the data to be geo-referenced to the exact location on the earth. This ensures that each inventory operation will be referenced to the same coordinate system and pile limits each time the inventory is performed.

Faster data collection and processing

Speed was the key factor in Vic Coleman’s decision to use a mobile laser scanning system. He is the CFO at Braen Stone, a New Jersey firm with more than 100 years of involvement with the aggregates industry. Braen uses the physical inventory surveys for both internal and external financial audits.

When Coleman first started doing quantity surveys, his crews were averaging two sites per week, but the mobile laser scanning system has allowed crews to assess three sites in two days. “The speed is remarkable, and we have a high degree of confidence in the results,” Coleman notes. He has seen three or four generations of technology, and says he is continually amazed at the pace of change. “I remember when the field crews had to keep the batteries warm with their hands,” he recalls.

Mobile laser scanning not only speeds up the data collection portion of the workflow, but as compared to the use of aerial photogrammetry, it has led to much faster turnaround of the actual physical quantities. Using point cloud software supplied by the sensor manufacturer, the 3D data for a 20,000-cubic-yard stockpile can be reduced and computed into volumes within a matter of hours.

Gary Wall, operations manager for Tilcon Connecticut, a leading supplier of quality crushed stone, hot-mix asphalt, and ready-mix concrete throughout the state, notes that stockpile quantities are typically available within a couple of days of the survey.

Safety and standards

Site safety is another factor that leads companies to choose mobile laser scanning over other inventory methods. Wall notes, “The use of laser scanning, in general, is a safer and more accurate method for inventorying stockpiles.”

Safety can be either prescribed, in the form of government regulations, or desired, in the form of company policies that reduce liability, property damage, and costly injuries. The U.S. Mine Safety and Health Administration has issued a number of regulations that apply to stockpiles and other related facilities such as drawholes, bins, hoppers, and surge piles. These regulations prohibit a worker from standing or walking on a pile when it may expose the person to a hazard. Other regulations require the construction of platforms, staging, or safety lines.

Laser scanning eliminates the need for anyone to walk on a storage pile and can, in the case of mobile scanning, keep the survey crew safely inside a vehicle. When the project requires the use of a tripod-mounted scanner, the survey crew generally has the flexibility to select locations that are not in harm’s way.

The use of mobile laser scanning as a standard method for inventorying aggregate stockpiles in the United States is being addressed by the American Society of Testing Materials International (ASTM). Originally formed in 1904, ASTM Committee D05 on Coal and Coke is responsible for a variety of standards for this industry that have application to aggregate and mineral mining and storage as well.

ASTM D6172 was originally developed to standardize photogrammetric measurement procedures for inventorying coal and coke stock piles. Recognizing the importance of laser scanning techniques, as well as GPS, this standard is now in the process of being updated to include these game changing technologies.

Investing in the future

During a downturn in the economy, forward-looking companies may see the use of new technology as an opportunity to position themselves for future growth. Having up-to-date, accurate inventory information and confidence that it is being obtained in a cost-effective, safe, and defendable manner is critical to overall business operations and a potential source of competitive advantage for aggregate companies.

3D laser scanning is a powerful technology that, from a technical point of view, is ideally suited to the physical inventory of aggregates and minerals. Safety agencies, standards organizations, and owners are beginning to recognize the multiple benefits that this methodology offers. In this rapidly emerging world of 3D technology, it is not a question of if the use of laser scanning will become the preferred method of developing physical inventories of construction materials, it is just a question of when.

Richard A. Hisert Ph.D., principal, and Trevor R. Thomas, P.E. are with H2H Associates, LLC. Based in Troy, N.Y. H2H is a consulting firm that provides geologic, hydrogeologic, construction, regulatory, and environmental services.

When boulders continued to bust up its barges, an Ohio sand and gravel operator turned to a custom solution to keep its water transportation moving smoothly.

By Carl Emigh

For more than 80 years, Oscar Brugmann Sand & Gravel, Inc., located in Mantua, Ohio, near Akron and Cleveland, has been a thriving family business. “We’ve always been a family-owned and operated company,” says President Alan Brugmann. “The company was founded in 1929 by my grandparents, Oscar and Sally Brugmann.” Their children, including Roy Brugmann, Joan Martin, and Olga Van Auken — along with her husband Don — comprised the second generation of owners and operators. Third generation owners include Alan, his brother Todd, and two cousins, Jeff and Tom Van Auken. Brugmann serves as president while his brother and cousins serve as vice presidents, and the four form the current management team.

A heavy-duty, all-steel barge with an outboard motor-powered pusher launch is moored alongside a clamshell dredge to accept oversize rocks down the chute from the hopper. A higher outside wall on the barge keeps rocks from overshooting.

“Nobody works as hard as the owners to please the customers and provide them with the products and service they want. Our livelihood and good name are on the line with every transaction,” Brugmann says. “If any of our customers have a problem, we always take care of it. We take great pride in the fact that we have so many long-term customers who give us repeat business year after year after year. We aren’t always the cheapest, but we give our customers the kind of quality and value that they want and need in this highly competitive business world.”

The company produces 40 different products. These include everything from concrete and asphalt sand to sand for horserace tracks and golf greens, as well as grit for icy winter roads. Large rocks and boulders are sold mainly as decorative products, but that oversized rock can cause headaches during dredging.

Meeting the materials challenge

To provide the right mix of materials for its customers, the company operates two wash plants, two floating clamshell dredges, and produces about 600,000 tons of material in an average year. Extracted sand and gravel includes rocks and boulders too large for the water-borne and connecting land-based conveyor system. Rocks more than 8 inches in diameter are separated out in the dredge-vessel’s hopper and deposited down a steep 20-foot chute into a barge moored alongside each floating dredge.

Left to right: A third generation of management includes (left to right) Vice President Todd Brugmann, President Alan Brugmann, Vice President Jeff Van Auken, and Vice President Tom Van Auken.

“Years ago, when we first started using clamshell dredges, we bought some metal barges with wooden sides because they were relatively inexpensive and easy to build,” Brugmann says. “But we soon learned that was a mistake. The rocks — some of them larger than 36 inches in diameter and weighing up to 5,000 pounds — made short work of the wooden sides.” Suddenly, an inexpensive capital investment yielded significant operating expenses, and the company turned to all-steel barges from various manufacturers as it sought a solution to the heavy wear of its oversize material.

“Even then, the big rocks were battering the barge sides and bottom so much that we were constantly having to repair them,” Brugmann says. The result was considerable expense in manpower, repair materials, and lost production time. “We absolutely needed a custom-built rock barge that could take a real beating and have a long, trouble-free service life.”

The open ends of the barge allow unloading with an excavator.

The challenge was finding a barge maker who would design a unit to fit the company’s exacting requirements. Brugmann says that the company considered the low maintenance operation of its Grasan wash plants and custom engineering abilities and approached the manufacturer to see if it would design and build a custom unit.

“We talked to Grasan Vice President Ed Eilenfeld, and he said — somewhat to our surprise — that they could and would do it, even though they had never built a barge before,” Brugmann says. The operator and manufacturer’s engineering staff worked out the design options, and the equipment was ordered.

“They built the barge in a surprisingly short time, trucked it to our site, put it in the water, and guess what — it didn’t sink,” Brugmann says with a chuckle. “What’s more, it’s exactly what we need. Barge problem solved!”

Brugmann owns and operates two wash plants.

The barge has now been in use for the better part of a year and has shown no signs of damage. “When the barge we’ve been using with our other dredge needs to be replaced, we know what to do about it,” Brugmann says.

The all-steel barge measures 35 feet long, 18 feet wide, 8 feet, 4 inches high, and weighs about 77,000 pounds. It has a load capacity of about 53,000 pounds. The deck is constructed of heavily reinforced 1-inch thick plate. When full, the barge is pushed ashore with a flat-nosed, outboard-motor-powered launch. The open-ended design facilitates easy unloading with an excavator, and the barge design is adaptable to other sizes.

Brugmann’s two clamshell dredges include a 7-yard, 250-ton-per-hour luffing jib type and a 10-yard, 350-ton-per-hour gantry type, which is used with the all-steel barge. The company operates two wash plants, as well as a 5- x 10-foot screen and screen tower with 30-ton hopper and belt feeder; a screen feed conveyor and 20-inch x 80-foot wash screen conveyor; a 5- x 14-foot, triple-deck wash sizing and rinsing screen; a 6- x 12-foot, double-deck de-watering screen with 24-inch x 70-foot stockpiling conveyor; a sand plant with 6- x 16-foot, triple-deck wet screen with hopper and belt feeder; a screen-feed conveyor; and a 30-inch x 80-foot, pit-portable conveyor.

Leaving its mark

In addition to the continuity of its family-based management team, Oscar Brugmann Sand & Gravel, Inc. boasts an excellent employee retention record. “Almost all our employees have stayed with us, too, for many years. And the company has hired a lot of people since 1929,” Brugmann says. “We’ve always tried to be fair with them, and they’ve been fair with us. Currently, we have 18 employees.”

Brugmann converts mined-out pits to scenic parks and home site areas and has received awards for reclamation achievements.

The work environment puts a high priority on its workers, including miner safety. “Safety is very, very important, of course,” Brugmann adds. “I’m proud to say that we have had no serious injuries in the entire 82 years we’ve been in business. That’s pretty amazing.”

The company also is an active corporate citizen in its local community. “Civic responsibility is another hallmark of our company. We try to be good citizens and give back to the community,” Brugmann says. “For example, we donate our loaders and operators for snow removal on roads and township properties each winter. And we have donated materials for making asphalt when no funds were available for paving township roads. We worked with an asphalt manufacturer nearby that also donated its time and materials.”

That same attitude of being a good corporate neighbor can be seen in the company’s sustainability goals. “Down through the years, we have made a concentrated effort to responsibly reclaim the land and water-filled pits, which are now being used for recreation and picturesque home sites,” Brugmann says. “In fact, the company has received awards for reclamation achievements. We’re very proud of that.”

By paying attention to customers and the community, Oscar Brugmann Sand & Gravel, Inc. is creating a legacy of family-owned excellence in operations and safety. AM

This article is courtesy of Grasan.

California producer eliminates the need for settling ponds and captures water for reuse.

Any time an aggregates producer can provide sound environmental practices while improving its own profitability, it is on the winning side of the production equation. Sustainability in the aggregates industry is a business approach that has gained considerable attention in the past several years. The BoDean Co., Inc., of Santa Rosa, Calif., however, has applied a sustainable approach to its business practices almost from day one.

Dean and Belinda (Bo) Soiland opened BoDean Co. in 1989 with the purchase of the Mark West Quarry in the northern Napa Valley. The quarry has been in operation since 1910, and the Soilands put plans in place not only to reclaim mined-out land, but also to begin using a benching method as they continued to mine. Over the past 20 years, this system of benches has improved safety and operational costs, remediated stormwater runoff, and helped to better manage the mine plan in general. BoDean Co. has since applied the same practice to its newer Blue Rock Quarry in Forestville, Calif.

Filter cakes are being sold to Napa Valley wineries for use as pond liners.

Both the Mark West Quarry and the Blue Rock Quarry supply aggregate material for customers in the surrounding area, as well as to BoDean Co.’s vertical asphalt operation in Santa Rosa. In 2006, in order to combat the cost of purchasing sand for its asphalt plant, BoDean installed a washing plant at the Mark West Quarry and began to produce its own sand. The wash plant includes a blademill, washing screen, cyclone, and dewatering screen. At the same time, BoDean opted to install a Phoenix HiFlo circular thickening plant and an overhead beam Diemme GHT 1500 P13 recessed-plate-frame filter press at the end of the washing stage to capture and reclaim as much water as possible.

Fresh water circulates to its own tank for use in the plant while the underflow thickens to about 50-percent solids and is sent to the filter press.

According to Robb Folmar, site manager for the Mark West Quarry, “We don’t have space for settling ponds, and water is hard to come by here with just a pond above the plant and a creek below.” In addition, the footprint shared by the processing plant and loadout area within the quarry is very tight. Because of this, he says, the wash plant operates in a closed circuit with fresh water coming off the thickener over a weir through gravity overflow to a fresh water tank, pumping back to the wash circuit. The underflow thickens from about 4-percent solids by weight to about 50-percent solids. This mud slurry feeds the filter press, which removes the remainder of the water and produces hard cakes of filtered fines that are up to 90-percent dry.

A make-down system mixes dry batch polymer flocculants with water and injects the polymer into the slurry upstream of the thickener.

The use of belt presses to claim moisture from fines is not unusual in North American aggregate operations. The application of plate presses for aggregates dewatering, however, is new in the United States. BoDean Co.’s plate press, manufactured by Diemme S.p.A. of Italy (now represented in the United States by Louisville, Ky.-based Phoenix Process Equipment Co.), operates by compacting mud slurry between 140 vertical plates that are each about 5-foot square, until the end product is a dry cake that drops beneath the press for loadout.

“Dean had seen Diemme presses used in mining in Europe, and he thought the method would work well for us,” says Folmar. “He is really good at looking forward to the bigger picture and applying his ideas to the company.”

Pumps fill the spaces between the plates with the thickened slurry mixture. The plates work like a mold as they tighten to 225 pounds per square inch of pressure to filter water and create 300-pound filter cakes.

The washing and dewatering plants were installed and running by mid 2006. Folmar explains that fines-laden water slurry captured from the wash plant is pumped to the circular thickener. A dry polymer make-down system mixes dry batch polymer flocculants with water and injects the polymer into the slurry upstream of the thickener. The flocculants attach and help the fines to settle more quickly to the bottom of the tank. The clarified water at the top of the thickener tank flows over weirs and uses gravity to run into the fresh-water tank, where it is pumped back to the wash plant for reuse. BoDean Co. owner Dean Soiland explains that, while a system of totes can be installed to premix the flocculants, he prefers having his crew mix each 250-gallon batch individually for better control. This is because plate presses typically require significantly reduced polymer usage.

From the bottom of the thickener, the slurry of 50-percent solids pumps to holding tanks adjacent to the filter press. A nuclear densometer calculates mud density as it enters the press.

“The press works over pressure and time,” says Ian Scroggins, wash plant operator for the thickening/filter press system at the Mark West Quarry. Scroggins explains that each press plate is covered by its own filtering cloth. The plates hang vertically in a row. At the beginning of a cycle, pumps fill the spaces between the plates (called chambers) with the thickened slurry mixture. The plates work like a mold as they slowly tighten to 225 pounds per square inch, compacting the fines between them and filtering the water first through the outer layer of mud, through the cloths, and finally through holes in the plates to be captured beneath, where it is sent back to the fresh-water system.

At the end of the cycle, when the maximum amount of water has been pressed from the fines, the press opens at one end and the plates move aside one by one at a speed of 30 plates per minute, allowing the caked fines to drop to a stockpile below. The filter cakes weigh 300 pounds each, for a total of 21 tons processed per cycle.

Family member Will Soiland gets an early start in the business as he inspects a filter cake.

“We pump a slurry that’s 45- to 50-percent mud. If we pumped more often, we would have more water in the slurry and a wetter cake at the end of the process,” Scroggins says. “We can make the cakes as dense as we want.” The caked fines that drop from the filter press are so dry and compact they have a consistency of hard clay. “For the reclamation of water, you will never get anything as dry as these cakes from a (traditional) belt press,” Scroggins adds.

Scroggins says that a full press cycle takes about an hour. Because the thickener makes more mud than Mark West Quarry can process through the filter press in one shift, the press is programmed to run automatically after personnel leave the quarry at the end of the day.

“The press could run 24 hours a day if we wanted,” he says, “but, typically, we set up the thickener to fill the mud tanks to capacity before we leave for the day.” The filter press processes it automatically, running 16 to 18 hours per day and shutting off when the tanks hit a certain level. In the morning, when a shift begins, the fines are all in cakes at the bottom of the press, and there is no mud left in the tanks.

Within two months of the press’ startup, BoDean built a second mud tank to hold more fines slurry for processing through the filter press, according to Folmar. “The initial cost to purchase this press was more than if we had bought a belt press,” he says. “But over time, if you don’t have storage for additional drying of fines or room for settling ponds, it pays for itself. In fact, with this technology, settling ponds may just go the way of the past.” Additionally, BoDean Co. has found a local use for the filter cakes that carries its sustainable practices even further — selling the material for use as pond liners in Napa Valley’s wineries.

Folmar says that because BoDean was the first aggregate operation to install a plate filter press in the United States, and the manufacturer wasn’t represented in the U.S. aggregate market when the press was purchased, making the learning curve tougher for the operation than it might be today. Having a domestic distributor has been helpful, he says.

Scroggins agrees, noting that it bridges a gap with parts availability. “We can’t have downtime with the press because that bottlenecks everything. If the machine went down, and we had to wait for parts to ship from Italy, we could be completely down for more than a week,” he says. “So it’s nice to have a U.S. distributor in the industry.” Phoenix has also been working with BoDean to test cloths for the plates on the press, working to find an optimal weave to tweak the system and further raise efficiency.

In keeping with its spirit of self-reliance, BoDean handles its own drilling and blasting, shooting once or twice a week as needed to meet demand. At the end of the mining cycle, BoDean also handles reclamation internally, planting native grasses and vegetation, and moving trees, including redwoods, on site to preserve them as the mine expands.

The Mark West Quarry employs a primary jaw, a secondary cone, a tertiary vertical shaft impact (VSI) crusher, and a tertiary screen that recirculates materials to the secondary crushers as needed. From the secondary stage, a surge tunnel feeds the wash plant, which consists of a scalping screen, blade mill, triple-deck wet screen, and a cyclone and dewatering screen. The quarry produces material from 1-inch down to sand; washed material includes 1-inch by #4 and 3/8-inch. The wash plant also has a VSI crusher as part of the circuit. This allows the company to make all sand material, if necessary, by running coarse material back through the wash plant and reducing it through the VSI.

“We’ve seen a lot of wash plants with water just sitting around the equipment,” says Soiland. “We want to drain and recapture as much water as possible, so the wash plant is sitting on asphalt. Even water that’s dripping off the plant is caught in basins and sent back for reuse.”

“This operation ultimately hinges on the press. Without this press, we wouldn’t be able to have the wash plant,” Folmar says. “When we had to purchase sand for the asphalt plant, it was really expensive. By manufacturing our own sand, the wet plant has slowly, but surely, paid for itself.” AM

Article courtesy of Phoenix Process Equipment Co.

Fifty-ton haul trucks scurry about the new quarry being established by Grace Pacific Corp. on the Hawaiian island of Oahu. Like ants from a pile of honey, they scurry from the loading excavator, one every minute and 20 seconds, their beds heaped high.

Bob Singlehurst, project manager of this huge venture, looks down on the activity from his lofty vantage point with a knowing smile. “We have 6 million cubic yards of material to move to get this site ready,” Singlehurst says. “The production we’re getting from the EX1200 is keeping us on schedule.”

The excavator’s 6.9-cubic-yard bucket fills quickly as 115,081 pounds of digging force rips through the volcanic material, cycle after cycle.

So what’s the hurry?

Time is money. The owners want the prep work done before the necessary operating permits arrive. Overburden must be removed, haul roads cut into the walls of the quarry, and berms built to shield the 35-acre project from view. Once in operation, more than a million cubic yards of rock a year will be mined for the next 25 years. It’s a big job, one of the largest this 69-year-old veteran of the quarry business has had in his storied career.

“The company has an enormous investment here,” Singlehurst says. “We need to be ready to produce as soon as those permits arrive.” He has never had a non-American-made machine in one of his quarries until now. His regular excavator manufacturer didn’t build a machine big enough for this job. “We tried the Hitachi and have liked it from the beginning,” Singlehurst says. “Now that it’s been on the job a while, I would honestly say the EX1200 has exceeded our expectations in every way.”

Dependable support

Singlehurst talks, too, of the importance a dealer plays in the selection of equipment: “A good dealer is particularly important when you’re dealing with a high-production machine. If it goes down, the job and all of the men and equipment working with it go down, too.” He notes that costs soar far higher than the repair bill itself. Dealers need to have competent technicians and well-stocked parts departments.

“We’ve had virtually no downtime… but when there’s an issue, the repair truck is here in an hour or less,” Singhurst says. “And there has been nothing that has stumped the technician. He’s been able to get us going fast.” The project manager does allude to one instance when the machine was down for a day. It seems a tooth ripped off the bucket, and to get it welded correctly just took time.

It’s important to have a competent dealer, particularly when working in a remote location like Hawaii can cause difficulties when parts are needed fast. Singlehurst says that this hasn’t been a problem. “American Machinery has had any part we’ve needed in stock.” He also points out that with today’s airfreight, parts can arrive in a couple of days.

Creature comforts

Operator comfort, particularly in a high-production machine, can help an operator work at peak efficiency for long shifts, and this machine stands tall on this measure, too. Large tinted-glass panels provide a clear view, 360 degrees around. A fully adjustable suspension seat molds to the operator’s body for total comfort, and the cab is heated, air conditioned, and fully pressurized to keep dust out.

“I’d have to fight to get that machine away from our operator,” Singlehurst says, “And, I’m not sure I would win.” He points to another area where a happy operator pays big dividends — the way the machine is operated and taken care of. He notes that pride can go a long way in increasing production and reducing abuse of the machine.

Back on the job

The seemingly unending stream of haul trucks continues to snake through the winding quarry roads as the 760-horsepower excavator swings smoothly, rock to truck, rock to truck, rock to truck. There’s quiet confidence that this huge project will be ready on time and on budget. “We couldn’t do it without the EX1200,” Singlehurst says.

 About Grace Pacific Corp.:

This 75-year-old company has constructed and maintained the roads and highways that are an integral part of Hawaii’s infrastructure. Besides being the state’s premier concrete, asphalt, and aggregate supplier, its 500 employess provide prestressed and precast concrete products, metal framing systems for construction, and traffic and highway safety products.

When it comes to plant safety, guidelines from the Mine Safety and Health Administration (MSHA) set the floor, not the ceiling, for Prairie Materials. “MSHA is a stickler when it comes to making sure that you keep your operation in top-notch condition at all times,” says Jim Purdy, plant manager of Prairie Material’s aggregate yard #95 in Manteno, Ill. “They physically inspect our operations at least twice a year and are very thorough. But even though they set the standards, when it comes to safety at Prairie, we use their standards as a baseline and improve on them from there.”

Safety is a mantra at Prairie, and nowhere is it more important than at their Manteno mine where Purdy oversees the operation. Over the years, it has consistently received awards for safe operation including Safety Achievement Awards from the Illinois Department of Natural Resources Office of Mines and Materials, and numerous Rock Solid Safety Awards from the Illinois Association of Aggregate Producers. 

Headquartered in Chicago, Prairie Materials, a Votorantim Cement Co., is one of the largest concrete and aggregates companies in the Midwest with facilities in Illinois, Indiana, Michigan, and Wisconsin. It operates 81 concrete locations and 17 aggregate mines, boasts more than 1,150 concrete mixer trucks, and employs nearly 1,800 people. Founded in 1948, it mines more than 6.5 million tons of aggregate each year.

The Manteno facility encompasses more than 250 acres and has been in operation since the 1970s. It features a working limestone quarry and three plants where the quarried limestone is crushed and screened to size for use in roadbeds, building and landscape construction, and cement production. Much of the finer ground limestone from the site is used by Prairie’s 39 ready-mix yards and 16 brick locations throughout Illinois.

Maintaining the three crushing and screening plants is a yearlong operation. Although most major maintenance work is done during the off-season when the quarrying operations are suspended, there are thousands of feet of overhead conveyors, as well as metal structures, drive motors, and other areas where ongoing maintenance is required. “Even though our newest plant went online in January 2008, we’re constantly doing preventive maintenance, splicing belts, or welding something on this or one of the other plants,” Purdy says, “and our boom lift makes it a whole lot easier for us to do it.”

The Prairie Manteno facility uses a JLG 600S telescopic boom lift rented from Illini HiReach of Lemont, Ill., that but also provides operator safety training to Prairie’s employees.

The boom lift features a 60-foot working height and almost 50 feet of horizontal outreach, so it not only reaches the overhead conveyors, but also provides access over ground-level obstacles to perform low-level maintenance that couldn’t be reached effectively from a ladder or other temporary structure. In addition, it has an 8-foot platform, 1,000-pound restricted platform capacity, and 360-degree continuous swing with 160-degree platform rotation so it can be positioned in almost any overhead location and can carry the men and materials necessary to perform any task. Because the platform is completely surrounded by guardrails with toeboards and has anchor points for fastening a safety harness, it meets the requirements set forth by all regulatory agencies, including MSHA.

The boom lift has proven so useful in performing a wide variety of tasks around the plant that Kort Alcorn, an aggregate division production manager responsible for six aggregate plants in Illinois, instructed all of the facilities he supervises to have a boom on site at all times.

“With the JLG on hand, whenever we have a problem involving an overhead area, we can slip a safety harness on one of our trained operators and go up and fix the problem,” Alcorn says. “We don’t have to wait for someone to bring in equipment or try to reach the area some other way. It’s faster, more productive, and a whole lot safer.”

 Purdy notes that the unit it rents has four-wheel drive and features 45-percent gradeability. “Coupled with a 65-horsepower motor, it’s powerful enough to go through mud, drive up inclines, and travel wherever we need it,” he adds. “It’s the ideal machine for use in an operation like ours, and I can’t imagine what we would do without it.”

This article was provided courtesy of JLG.

by Chip Winiarski

On most days, Hilltop Stone, located about 20 miles south of Cincinnati in Butler, Ky., produces 14,000 tons of crushed limestone in a 16-hour period. At this rate, Hilltop Stone easily generates nearly $100,000 in daily revenue when production is at full operating capacity.

Hilltop Stone realizes the value of equipment it uses to move limestone and the role it plays in keeping production running at full speed, so when its conveyor system continued to interrupt production by breaking down due to the harsh working environment, it turned to Flexco DRX impact beds for more reliable service and improved efficiency.

Founded in 1941, Hilltop Basic Resources, Inc. produces a variety of aggregates for commercial, industrial, and government projects from its seven plants in Ohio, Kentucky, and Indiana.

Identifying problems

Producing aggregates is a demanding job and can take a toll on equipment. This was the problem with Hilltop Stone’s previous conveyor system — it was simply unable to withstand rigorous quarry conditions. Depending on discharge point, limestone rocks as large as 18-inches in diameter fall onto the impact beds from a height of between 7 and 10 feet.

“The issue we were dealing with is that the impact beds would break right down the middle and, in some cases, the conveyor would break with them,” says Terry Figgins, quarry manager of Hilltop Stone’s Butler facility. “When they would break, we would have to fishplate the sides of the conveyor to keep them going. It was a very time-consuming repair.”

An average of five times a year, Figgins says the conveyor system could be down for maintenance for time periods ranging from just a few hours to an entire day or more. “When we’re producing 14,000 tons a day and the system is down completely, you can do the math on how much that’s costing us,” he adds.

Company officials ran the math and determined it was time to make a change, replacing its previous impact beds with three Flexco DRX3000 impact beds. Designed to meet the needs of impact areas requiring extreme energy absorption from large-size material or severe height, the impact beds can handle up to 3,000 pound-foot applications of impact energy.

The first unit was installed at Hilltop Stone in 2006. The belt it is installed on measures about 580 feet in length, with a width of 42 inches. A second impact bed, with a 300-foot-long by 48-inch-wide belt, was put into service nearly two years ago. Both impact beds are moving rock up to 18-inches in diameter on three-ply, 800 PIW-rated belts.    

Figgins says his crew installed both impact beds in about 6 hours. “The installation was pretty simple,” he notes. “We just slid them in and put on the two side pieces and that was it — a very painless process.”

The new impact beds are engineered not only to be strong, but also to deaden impact energy, reduce vibration, and extend belt life. To further protect the belt, impact energy absorbers along the base of the impact bed can compress up to 3 inches to minimize impact and vibrations on the bed and belt.  

“With our old impact beds, there wasn’t any give or release to them, which often damaged the belt,” Figgins says, adding that belts on his previous conveyor system generally lasted less than a year. “But these new impact beds do have give to them — and it saves the belts.”

Avoiding downtime

The material transfer system defines the process wherein material flows down through a chute onto a waiting conveyor, while the transfer point is the area of the conveyor where material impacts the belt. Since this part of the belt is taking the brute force of falling material, the transfer point is probably the biggest ongoing source of problems in a conveyor system.

Three common types of conveyor belt problems at the transfer point include top cover damage, tensile failure, and crushing of the belt carcass. Top cover damage is caused by the sharp, jagged edges of aggregate and the manner in which they land on the belt. Tensile failure of the carcass is usually indicated by a tear or hole in the belt which cuts the belt’s cord fibers and weakens the belt as a whole. Finally, crushing of the belt carcass can cause tracking problems, delamination of the top cover, or premature comb through — a condition where the mechanical fasteners spread apart due to added stress on the belt.

A slide-out feature allows the impact bed to separate in the middle and slide out for direct access to the bars. Figgins says he is able to quickly and easily inspect the beds, adding that he hasn’t had to perform any major service on the two impact beds. “The only thing we do is make sure they’re clean so they move up and down,” he says. 

Expanding solutions

Based on the performance of the first two impact beds, Hilltop Stone has added a third unit at its Butler, Ky., quarry. The new impact bed has been installed on a belt that stretches 260 feet in length and 42 inches in width. Much like the first two impact beds, Figgins says it only took 4 to 8 hours to install. It began moving rock up to 18-inches in diameter when the line became operational this past March.

“It’s the only type of impact bed that truly is an impact bed,” Figgins explains. “An impact bed to me is something that has some give to it. All the other ones are just flat beds, and the rock comes down and pierces the belt.”

In evaluating their overall effectiveness, Figgins says the company is pleased with the impact beds’ performance and return on investment. “They don’t break down and the belts last longer,” he adds. “We don’t have any more worries. It’s just a win-win situation for us.”

Chip Winiarski is Flexco’s market manager for heavy-duty applications. He serves customers, distributors, OEMs, design firms, and belting companies engaged in surface mining, quarry, aggregates, cement, and related industries.

by Carl Emigh

During the famous 1849 Gold Rush, miners panned for gold in California streams. Many years later, some enterprising companies took it to a new level by panning a number of river valleys in northern California with floating dredges.

One such dredging operation started circa 1936 and continued into the early days of World War II. A 100-yard-long, barge-mounted dredge was used to pan the Scott River Valley just south of the Oregon border near Yreka, Calif., in Siskiyou County. On the front end of the dredge was a 76-unit rotating bucket line that dug up dirt and rock. Gold was removed inside the hull, using a trommel screen apparatus with 1/4-inch and 1/2-inch holes. A 120-foot-long stacker at the back of the barge deposited the excavated rocks in giant windrows.

For Alturas, Calif.-based Eagle Peak Rock & Paving, the “gold” is in those windrows of large, smooth, very hard rocks still remaining from the dredging operation. “Our mining consists of crushing the rocks for use in our two asphalt plants,” says Eagle Peak President Tony Cruse. He says the company’s equipment includes three Terex Pegson crushers and two Powerscreen units, all in closed circuit. The current configuration has allowed the company to nearly double its production. “We produce what we call asphalt rock. This includes 3/8-inch clean, 1/2-inch clean, and #4- to 0-inch crusher dust,” Cruse says. “We blend all three in the asphalt production process. We reject all natural sand.”

The closed-circuit process consists of several steps. Material from the rock windrows is fed into a 26- by 44-inch jaw plant and crushed to 5-inch size. The 5-inch goes to a double-deck dry screen that rejects 1-inch minus stone. The 1-inch plus goes to a cone crusher that produces 2-inch minus which goes to a triple-deck producing 3/8-inch, 1/2-inch, and crusher dust. The oversize goes to a second cone, which also produces 3/8-inch, 1/2-inch, and crusher dust in closed circuit with the triple-deck screen.

The equipment features quick setup and tear down, as well as quality service from the dealer, Powerscreen of California. “They’re here anytime we need them, and sometimes they just show up on their own to check everything over on site wherever we are,” Cruse says.

A Paktronic control panel on the cone crushers helps ensure both product consistency and equipment durability. It sets the closed-side setting and shows the current setting. Further, the control senses anything uncrushable entering the crushing chamber and lifts up (dumps) to allow it through before automatically reverting to the current setting. The control also records and displays wear so the operator can gauge how much life is left in the liners.

The cone crushers include a feed hopper, product conveyor, crushing chamber, and power pack on a single chassis. The plants are engineered for high specification, flexibility, mobility, and low operating costs. The smaller cone can crush up to 220 tons per hour, while the larger unit can process up to 420 tons per hour, depending on the application. Typically, pre-screening is not required. The hydraulic system can be adjusted quickly, even while crushing. The entire feeder-hopper assembly can be hydraulically lowered into the feed ring for transport or raised for re-metaling.

The jaw crusher is designed for high-production quarrying, demolition, and mining operations. An aggressive crushing action with a single-toggle, high-swing jaw facilitates greater material entry into the crushing chamber. The design incorporates a hydraulic setting adjustment system that changes the jaw size at the press of a button for subsequent quick, product-sizing changes, thus reducing downtime. Throughput capacities range up to 400 tons per hour, depending on material and setting.

The two-deck 20- by 5-foot dry screen is designed and built for large-scale operations. The unit provides uniform sizing and can process up to 500 tons per hour, depending on mesh size and material type. The force in the screen provides optimum performance in wet, sticky applications. The plant is highly mobile. It sets up and is ready to run in 15 minutes.

Operators keep close tabs on the quality of the processed material to ensure it meets the needs of its asphalt plants. “We do gradation testing on samples every 500 tons. That’s six samples a day, and the product is very, very consistent,” Cruse says. “I couldn’t be happier with that.”

Working in tandem, the plant setup allows Eagle Peak to effectively turn a challenging by-product into a valuable revenue stream. “The rock feed material is very, very hard,” Cruse notes. “But our crushing and screening equipment handles it very well.”

Mining it old school

This artist’s concept of the dredge used in mining gold in the Scott River Valley is based on a 1930s postcard illustration. The hull and 120-foot stacker conveyor totaled about 100 yards in length. The hull had a 10-foot draft. At the front of the barge, a 76-unit rotating bucket line dug up the river bottom and as much of the shoreline as possible, sometimes re-routing the river in the process. Electric power was provided by a hydroelectric plant located 60 miles away. The dredge handled up to 9,000 cubic yards per day in three eight-hour shifts. Richard S. Moore of Callahan, Calif.-based Moores Gravel provided information about the gold dredging operations and equipment.

Carl Emigh is a freelance writer specializing in the construction materials market.

by Scott Ellenbecker

Conco Quarries Inc., a high calcium limestone quarry in Springfield, Mo., recently became the first U.S. operation to use a ROC F9C SmartRig. It put the drill into production to better manage its explosive scheduling and costs, but found additional benefits along the way.

A SmartRig is a rock drill with automation features, including a global positioning satellite (GPS) system used to direct hole placement. Other automation features include operator screens that indicate drilling functions and auto drilling that does everything from add steel to a pre-programmed depth to manage drilling speed so the bit doesn’t get stuck.

In Scandinavian countries, especially, the SmartRig concept has been working for years. In Norway, for example, all construction shots are laid out on computer and published on the Internet prior to doing a project. This is meant to elevate the level of safety because all blast material placements are planned in advance. In the United States, construction projects don’t currently require this level of design. Here, the advantage is saving costs and time associated with drilling, crushing, and moving rock.

When planning production schedules, Conco knows how much rock it needs and of what chemical composition. To lay out a shot well in advance gives management the time to plan ahead because the pattern isn’t painted on the ground, but rather electronically taken from a computer. That data is transferred to the computer in the drill. The rig can work with a foot of snow on the ground; it doesn’t matter to the computer.

“The goal is to lower our drilling costs and give us flexibility when laying out a pattern,” says Chris Upp, Conco’s director of quarry operations. In the months since introducing the rig, Upp says, “We have reduced drilling costs 10 to 12 percent, and we are continuing to see drilling and blasting costs go down.” He says he expects it will take six months to get a picture of the long-term savings associated with the rig.

When looking at costs, Upp looks for the optimum breakage on every shot. “If it isn’t perfect, you pay for it later,” he notes. He points out that Conco’s crusher can take a 60-inch cube, but that is not efficient. “You walk a fine line with your costs: oversized rock is bad for equipment and too much fines means you’re wasting money on explosives. With the GPS, you’re right on the money and you don’t miss,” he says.

In the next few months, Conco will continue to test burden and spacing to optimize its shot pattern. Currently, it drill 4-inch holes with T51 steel in a 9-foot by 13-foot by 27-foot pattern. Upp says the rig currently drills 2,200 to 2,800 feet per day, and the site blasts twice a week. Upp’s goal is to have 100,000 tons drilled and 80,000 tons on the ground all the time.

According to Upp, just a few inches make a difference. This is proven in the straightness of each hole as well. The high wall face shows clear evidence of the straight holes. “We don’t have a lot of back break on the high wall, and a smooth clean wall is left behind,” Upp says. This unplanned surprise also has reduced any safety issues and costs associated with removing hanging rock.

A driller’s perspective

Conco’s driller, Matt Cobb, has years of experience on a rock drill and says he was skeptical at first. “I think I’m like most experienced drillers when I say a person can do better than the computer because I can react to what is going on in the ground,” Cobb says. “And, for a time, I can drill as fast as the computer, but for how long is the question.” He said all drillers will drop a steel on occasion, but the computer never drops steel, shift after shift, day after day.

The automation function frees up the mind too. “When you’re drilling, your mind is always working, ready to react to the changing ground,” Cobb explains. “The computer on this rig allows me to think about other things and relax a bit.”

Cobb says the computer also allows him to multi-task while the drill is in operation. Once he starts the drill in auto-drill, he can leave the cab and check holes for blockage and place cones over open holes.

When the rig first arrived, Cobb ran two drills side-by-side to see if he could keep the same pace as the unit. Cobb would set up with the new rig, start auto drilling, and jump in the older Atlas Copco ROC 848 to drill a hole manually. When the new rig was finished, it would sit and wait for him to move it to the next location. He would then do the process again. “It’s not something I’d want to do for a long period of time, but it got me caught up,” Cobb says.

He says he especially likes the GPS system on the new rig. To set up the pattern, the first hole and last hole is set, and a computer extrapolates the rest. A memory stick transfers the information to the rig’s computer, and the operator just follows the screen.

“I match up the bull’s-eye on the screen with the transmitter on top of the feed, the computer tells me it’s straight or if I need to make adjustments,” Cobb says.

There are many subtle benefits as well. Because of elevation changes in the quarry, Upp said the drill has allowed the operation to flatten out benches. And because the hammer adjusts with a split second to the ground conditions, it is more efficient and less stressed. The computer also monitors maintenance schedules to keep the rig running at peak performance.

Conco works with Atlas Copco distributor Victor L. Phillips for service and training. Since startup, Upp says they have had no downtime, but that comes with good training and regular preventive maintenance.

Dave Ferson, corporate sales manager with Victor L. Phillips, said that the drill’s advanced technology caused some apprehension for both the operator and the distributor, but their concerns were overcome by the simplicity of training and the unit’s strong design.

Jeremy Riley, Phillips’ field technician, says the drill is much easier to work on than conventional drill rigs due to its self diagnostics, as well as a 30-percent reduction in the use of hydraulic hoses and electrical wiring.

Because of an onboard GPS system, the manufacturer and distributor support the rig 24/7, monitoring pertinent drill information through data downloads to laptops. “The technology on this rig reduces the workload for the operator when drilling, but also helps everyone work smarter,” Ferson says.

Overall, it will take time to know the total financial benefit of the drill, but Upp says he can already see differences. “I had to sell the owners on this rig because it was more expensive,” he says, “but it’s clear that the savings we have seen in productivity are offsetting that difference.”

Scott Ellenbecker is editor-in-chief of two in-house publications for Atlas Copco: Deep Hole Driller and Mining & Construction USA. He has been involved in marketing construction and mining equipment since 1995.

by Carol Wasson

Cleaning out the settling pond and hauling away the muck was a labor-intensive, season-long drain on the bottom line for Wissota Sand & Gravel – one that owner Christopher Larson was no longer willing to settle for. As such, Larson ultimately settled on “sustainability” with the installation of a stationary water clarification system that he says “has already paid for itself” by eliminating costly pond cleanout and conserving valuable water and energy resources – capping the latter to a miniscule fraction of past levels. And the positive environmental impact is a plus he is proud of. “It proves that we are a good, proactive producer – and a good neighbor,” he says.

Previously, Larson had a four-man crew, a backhoe with a bucket, and a haul truck dedicated to daily pond cleanout throughout each summer at his Richfield, Wis.-based site. “Only the top 2 feet of the pond would dry out with everything under that being ‘soup.’ The muck was nearly 70-percent water and when we tried to haul it out, it would come out the back end of the truck. It was just a mess,” he says.

Prior to the installation of a new wash plant several years ago, Larson knew that it was time to eliminate the labor and fuel costs associated with settling pond management. “Our new plant produces up to 800 tons per hour, so we knew we needed to clarify and clean the water coming off the plant, so that we could use it more rapidly and manage our fines more effectively,” he says.

Customized clarification

Wissota Sand & Gravel installed a stationary water clarification system manufactured by Milwaukee-based Clearwater Industries, which provides turnkey solutions, site and water analysis, chemical selection, and complete systems that are custom-designed for each specific sand and gravel application.

Clearwater Industries engineers a clarification system that allows operations to take a dirty water stream and produce clean water immediately, while concentrating the fines or solids to a thick state. To obtain a greater compression of mud and a drier consistency, the system features two tall, cylindrical aging tanks with internal mud rakes combined with a dry polymer feed system, hydraulic package, control panel, and mud discharge pump.

“We adapted out equipment to accommodate their existing cyclones, which are mounted on top of the clarifier,” says Bob Gralton, president of Clearwater Industries. Regarding a basic overview of the system, Gralton explains that the cyclones spin out the sand, or plus-200-mesh material. Water, containing fines, overflows the cyclones and enters the clarifier where it is treated with flocculants, forming solids which settle to the bottom. Clean water continually overflows the top of the clarifier and is recirculated back to the clear water pond that supplies the plant. The solids are then pumped and discharged via a 10-inch pipeline to a pond where residual water weeps off the mud and runs into a low area. At the end of the season, the residual water is pumped back into the clean water pond, and the mud is used in reclamation.

Clarification payback

When Larson initially installed the system, he estimated an approximate 3.5 years for a complete return on investment. “But that was back when fuel was under $2 a gallon, so the payback on this has accelerated rapidly,” he says, adding that, “there are operations out there who shy away from clarification due to the cost of flocculants – but you can buy a lot of flocculants for the cost of fuel.”

Wissota is also realizing significant savings in water and electricity use. The plant is served by a 600-foot-deep, high-capacity well and a large industrial pump that had always been needed to replenish wash water used and the resulting water loss due to traditional settling pond management. “We used to run our well pump 24/7 all summer long to keep up with that water loss. Last season, with the use of the clarifier, we ran the well pump for a total of only 166 hours (approximately seven days), which is a tremendous reduction in water and power resources,” Larson says.

Then there is the issue of improved product quality. “Consistently clean water means that it’s easier to remain in spec,” Larson says. Before the clarifier was installed, he stresses that, even when constantly replenishing the water to the required levels, within a week the water would become cloudy, thus running the risk of fines contaminating the end product.

“Once you get past the learning curve, the system is very easy to operate. A computerized system handles flocculant injection, and all we have to do is keep an occasional eye on water levels, cleanliness, and flocculant percentages. It’s pretty seamless,” he adds.

Maintenance ease

Once part of the settling pond cleanout crew, Plant Manager Daryl Schmidt worked with the Clearwater team to fine tune the clarification system during its first few months of operation. “I call it ‘Wissota-sizing.’ There are things we always like to tweak to make things easier to live with over the long term. But it’s a relatively maintenance-free machine, and it’s the ultimate machine to eliminate the labor and fuel costs of hauling that mud around. Now, we just pump it where we want it to go, and we’re done with it,” he says.

Schmidt remembers ponds from the past “that sat for two years and still looked the same as the day they were filled up. That’s how runny it was,” he says. Today, Schmidt points to a recently filled pond that is already solid. “This new clarification system is the only way to go,” he says, adding that the system will streamline future reclamation plans when mud will be pumped directly to additional remote locations, and will be used as a base under the top soil.

A regional leader

Established in 1916, Wissota Sand & Gravel is a successful third-generation, family-owned company which serves home builders, road builders, landscapers, developers – and “anyone else who needs quality sand and gravel,” says the company.

“We can bring more value to our customers and to our community by using systems that save on labor, fuel, water, and power,” Larson says. “It’s funny, but when I first purchased the clarifier, the crew said ‘oh, no, what did you do now?’ But once we got it up and running, everybody said, ‘Why didn’t you put this in 10 years ago?’”

As a regional leader, Wissota Sand & Gravel has certainly settled on sustainability.

Author bio:

Carol Wasson is a freelance writer for the aggregate, mining, and construction industries.