Aggregates Manager Digital Magazine
Issue link: http://read.dmtmag.com/i/891178
AGGREGATES MANAGER / November 2017 11 screen that pulls out all the sand and sends it to a classifying tank. The rock drops into a log washer that breaks up the clay balls and takes out the mud. The classifying tank separates out the concrete sand; everything else is considered fi ll sand. The concrete sand drops into a dewatering screw, and then goes to the radial stacker and on to a stockpile. In the meantime, the rock passes through the log washer and goes to a vibrating screen that divides it into three different sizes — 2-inch septic gravel, 3/4-inch gravel, and pea gravel — which are then stockpiled for sale. "We have to keep our asphalt and concrete gradation in spec for roadwork," says Mark Nicoson, area production manager, adding that they use one product for both because they are so similar. Everything is shipped out of the plant by truck. A loader fi lls all the customer trucks that come in and is also responsible for moving the material around within the plant itself. "Sand is our main product. We sell it for asphalt and concrete sand. It goes out faster than we can make it," Nicoson says. "The septic gravel, we can't make enough of. The size is hard to get. They use it in their leach fi elds." "The customer trucks are here at 3:30 in the morning, waiting for us to open the gate at 7 a.m.," Chambers adds. "It's that way all over Iowa. Gravel is a really scarce commodity. The bigger it is, the bigger the cavities, and the more water that can drain through it." During the summer months, the operation runs 24 hours a day to try to keep up with customer demand for both sand and gravel, but the current plant is barely abot to do that, so there are plans to put in a new portable plant in 2018. "They didn't have this kind of demand for sand 30 years ago, so this plant is running at 110 percent of its capacity," Chambers says. "The new portable plant will be capable of doing in four months what this plant does pretty much all year, while eliminating the need to run two shifts as well." "And we can put the portable plant closer to where we're dredging and increase our effi ciency," Nicoson adds. "It'll save on fuel." Caring for the environment When the area around the processing Martin Marietta Materials' New Harvey Sand is a sand and gravel dredging operation located near the Des Moines River in southern Iowa.