Aggregates Manager Digital Magazine
Issue link: http://read.dmtmag.com/i/945822
12 AGGREGATES MANAGER / March 2018 PLANT PROFILE where Native American relics have been found until the Arizona Historical Society has determined their significance. The quarry is currently working with an archaeological company to come up with a game plan to clear these areas in order to mine them. Another challenge the operation faces is the quality of the material con- tained in the Agua Fria Basin. According to Materials Manager David Beckel, the Peoria Pit presents challenges because of the "tough clay" that is a component of the soil makeup of the area. "The investment of Southwest Rock Products in the proper processing equip- ment, both in the crushing and washing of the product, as well as the stringent quality control testing, has allowed the company to produce high-quality aggre- gates at the Peoria Pit," Beckel explains. New homes seem to be popping up closer and closer to the Peoria Pit, which presents a challenge on the environmental side of things. Local planning and zoning departments don't help with this issue, as they sometimes allow the construction of homes right up to the property boundary of the mining operations. "We have a quarry in north Phoenix that has been there for years, and the city allowed homes to be built right next to the property," Palmer notes. "We share a common wall with a few houses. Situations like that make complaints from the residents a greater possibility. As long as we follow the rules and stay within our air permit limits, we have no issues." Currently, houses near the Peoria Pit are separated by the dry Agua Fria River, but the operation could suffer the same fate as the north Phoenix location in the future with the explosion of new home construction and the relative openness of the area. Upgrading the plant When Southwest Rock Products took possession of the property, it needed some cleanup and a bit of organization. The company determined that a wash plant was needed. Plans were drawn up, and Chris Reinesch, Sr., owner of the company, came out to determine where the wash plant should be located within the pit. Once that was decided, construction of the wash plant began in April 2015 and was completed by the end of July that same year. Of course, as with all new plants, it took a few months to iron out the wrinkles once it was up and running. "It didn't take long to construct, but we ran into some quality control issues with the materials, so we kept having to modify the plant," Palmer explains. "Now, it has been in for almost two years, and it's where it needs to be. So, we're just fine tuning it to get higher production and better-quality material." Production Manager Sean Clifford designed the wash plant and oversaw its construction. Clifford started in the aggregates business as an equipment operator in 1992 and joined Southwest Rock Products in 1999. He became a supervisor within two years and is now in charge of nine crushing and screening plants and three wash plants, including the units at the Peoria Pit. "It's quite the wash plant," Clifford says. "It has a tunnel feeder, log washer, screen, two attrition cells from Phoenix Processing, a sand screw, a concrete screw, and a coarse material washer. I don't know anybody in the valley that has two Phoenix Processing attrition cells of that size. They're like vertical log washers. They beat all the clay down out of the sand." Concrete sand goes into a tank, is pumped up into the cyclone, and then goes to the two attrition cells. After that, it goes through a sand screw and across the dewatering screen before being carried up the stackers to be stockpiled. The dirty water from the plant goes to the 40-foot thickener tank, where it mixes with a polymer to make the fines settle to the bottom. The fines, which look a lot like chocolate pudding by this time, are pumped through a hose to a fines pond in the bottom of the pit, and the clean water is recirculated back to the wash plant. The thickener tank allows the operation to reclaim and reuse up to 90 percent of the water from the wash plant. "When we first got the wash plant, The 40-foot thickener tank allows the operation to reclaim and reuse up to 90 percent of the water from the wash plant.