In a state where land, water and material hauling are at a premium and tough environmental regulation a fact of life, California’s Spragues’ Ready Mix has deployed the first closed-loop recycling equipment combination of its kind: a concrete reclaimer separating fine and coarse aggregate, coupled with a slurry-recycling filter that dewaters cement fines to yield nearly ASTM C 94-grade batch water (suspended solids < 60 ppm)
Sources: Alar Sales Inc., Mokena, Ill.; Liebherr Concrete Technology, Newport News, Va.; CP staff
In a state where land, water and material hauling are at a premium and tough environmental regulation a fact of life, California’s SpraguesÌ Ready Mix has deployed the first closed-loop recycling equipment combination of its kind: a concrete reclaimer separating fine and coarse aggregate, coupled with a slurry-recycling filter that dewaters cement fines to yield nearly ASTM C 94-grade batch water (suspended solids < 60 ppm).
A two-plant independent serving small and mid-sized contractors, SpraguesÌ has reclaimed aggregate with past equipment installations; however, when introducing gray water into batching, it encountered set-time and finishability variations. Vice President and COO Steve Toland, part of the founding family’s fourth generation, credits the new system with enabling reuse of clarified water in concrete orders and reducing the returned mix and drum washout residue waste stream by 90 percent. Yard staff plans to up that figure to 100 percent by year’s end.
Installed in late June at SpraguesÌ headquarters plant in Irwindale, east of Los Angeles, the system incorporates Liebherr Concrete Technology‘s LRS 708 concrete reclaimer, running _ yard/minute and configured for two trucks at a time; and, the Alar Auto-Vac AV640-C Wastewater/Water Recycling Filter. Processing 20 to 40 gallons/minute, the latter nets water with suspended solids of _ micron or smaller diameter. Dewatered slurry fines are captured on a drum with a porous media of diatomaceous earth. The chemically inert solids can be treated as nonhazardous waste or recycled as fine aggregate.
LCT and Alar staff piloted their equipment combination with a slurry-recycling-minded concrete cutting and sawing contractor last year. LCT has established a strong environmental component as part of its ready mixed and precast plant offerings. An established player in water/wastewater recycling equipment, Alar entered concrete through California operators Monier LifeTile (Irvine), Hanson Aggregates (San Diego) and Eldorado Stone (Rancho Cucamonga), plus Hanson Structural Midwest (Maple Grove, Minn.), High Concrete (Denver, Pa.), and Northfield Block/Oldcastle (Joliet, Ill.).