How Recipe Sand Plants Work
Recipe Sand Plants allow a producer to supply many construction aggregates and specialty markets while maximizing the use of every particle mined. With customized blending, Recipe Sand Plants can easily produce Department of Transportation concrete sand, plaster sand, and glass, sports, filter and foundry sand.
Hydrosizers™ producing the discrete sand fractions are at the core of Recipe Plants. Cyclones are used to deslime and concentrate feed to the Hydrosizers™. Cyclones and Dewatering Screens are combined to dewater the sand fractions, which are typically placed in storage bins. Based on the desired end product, feeders at the bottom of these bins, controlled by a combination of mass flow and moisture measurement, dispense the exact quantity of each fraction to meet the most stringent gradations.
In the most sophisticated of the plants, four individual fractions are monitored for storage volume and replenishment rate. The operator is alerted when replenishment is not keeping up with demand due to the natural variations in the deposit, and several options are offered, including making a different recipe. Additionally, the dredge operator is kept informed of critical mass balances within the plant by way of an radio frequency signal.
Plant integration allows the operator to start and stop all motors in the plant; control flows of materials; trend any number of process values, such as line pressures, flow rates, amperage draw and slurry density; and design and produce products by size distribution.
Vertically integrated companies can take immediate advantage of lower ready-mix concrete costs due to the consistent and highly accurate sand gradation, leading to less (over)addition of cement. Where a contractor-guaranteed project is in place, peace of mind is provided by this extreme consistency, offsetting risk associated with variable product gradations typical of other plant designs.