Why McLanahan Recipe Sand Plants
McLanahan is the expert in designing and engineering Recipe Sand Plants. We were the first to introduce them to the United States and were the first to install these plants in the United States. We continue to remain the major resource for all things related to Recipe Sand Plants.
McLanahan Recipe Sand Plants are automated, which benefits producers and their customers through improved service and product quality. Product variability and the deflated value of misplaced sand causes significant waste. Each particle represents potential profit, so any grain wasted or misclassified into a lower-valued product results in lost revenue. McLanahan's Recipe Sand Plant design ensures each particle goes to its highest and most profitable use.
Our process engineering group will work with you to define the number of fractions and their size ranges required for re-blending to hit the target specifications. Most commonly, three or four fractions are created. For example, a four-fraction plant might produce 4 x 16, 16 x 30, 30 x 70 and 70 x 140 sand fractions (5mm x 1.19mm; 1.19 x 600µm, 300 x 150 and 150 x 75).
How Recipe Sand Plants Work
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.
Popular Applications for Recipe Sand Plants
Recipe Sand Plants are specified for their ability to produce very tight gradations, multiple products and improving the yield of the deposit. With customised blending, Recipe Sand Plants can easily produce Department of Transportation concrete sand, plaster sand, and glass, sports, filter and foundry sand.
Benefits of McLanahan Recipe Sand Plants
- Improved yield from your deposit
- Every sand fraction is sold at the highest value
- Extreme consistency in final products
- Multiple recipes for standard and speciality products
- The facility short runs of speciality materials
- Eliminate product returns due to out-of-spec materials
- Reduce the risk associated with contractor guarantees
Frequently Asked Questions
Should everyone have a recipe concept plant?
No. First, the higher investment in a plant like this would not fit every market. Demands for high-quality speciality materials, a deposit that has challenges in its gradations and vertical integration will influence the decision on whether this design of plant will work for you.
Can I feed the plant with a dredge?
Yes, provided you have the appropriate up-front equipment and communication between the plant and the dredge operator. There are a couple of ways of looking at this, depending on the style of dredge, nature of the deposit and quantities of oversize materials. You certainly need to screen before the sand sized material is fed to the plant — this requires some automation to provide plant feedback to the dredge operator. In some cases, stockpiling on land and dry feeding can work better than feeding direct.
Being a large plant, I assume I will need more personnel to run it?
Quite the opposite. The levels of automation, self-monitoring equipment with simple loop controller, simplifies the plant and requires less supervision.
My deposit is variable. Is this a problem for this type of plant?
One of the Recipe Sand Plant’s benefits is its ability to automatically cater for the variations. The Hydrosizers™ place the sand fractions into the appropriate bins. From there, you are only limited by the availability of the fractions needed.
Does such a large plant require a lot of maintenance?
With the appropriate equipment and correct application of wear materials installed at the beginning, the operational costs are no higher than a conventional plant. Consider one valve on a Hydrosizer™ versus 27 on a Sand Classifying Tank. Use of rubber hoses, rubber lined pipe and collection vessels all contribute to long life in a plant. As in any design of plant, an ounce of prevention is worth a ton of cure. If there is any corrosive fluid involved, such as naturally occurring tannic acid, then this needs to be taken in to consideration.