McLanahan’s UltraSAND Plants (USPs) have been around for many years — they are a combination of a Sump, Pump, Hydrocyclone(s) and Dewatering Screen(s). They are typically fed <4 mesh (<5mm) material from the bottom deck of a wash screen. This discharge is nominally ≥35% solids by weight. Alternatively, they can be fed after a dry screen via a slurry box to hydrate the materials using high-pressure sprays.
Applications
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With the greater separation efficiency of Hydrocyclones/Separators™, UltraSAND Plants are proven to provide a higher product yield compared to Fine Material Screw Washers. Another advantage is a much lower moisture content from the Dewatering Screen, depending on the characteristics of the sand. The end result is almost immediate use of the product, steeper stacker angles for more stockpile capacity, reduced water loss, and better housekeeping. Sand equivalencies are also improved by the use of this design of plant.
The UltraSAND Plant is well-suited for a wide variety of applications from simple dewatering of sand to multistage wash systems. When a system is screen fed, it has the flexibility of receiving coarse material and making multiple products on a single screen. The most common use is to wash and dewater concrete, asphalt, and/or masonry sand, but can also be applied to different materials and industries. UltraSAND Plants are the industry standard to wash and dewater industrial sands (i.e. frac sand, foundry sand, glass sand, etc.) after classification of mid-size fractions.
UltraSAND Plants are mainly fed by two process scenarios: screen fed and sump fed.
With a screen-fed application, the material is directed onto the Dewatering Screen. Depending on the application, screen aperture sizes can range from 0.3mm to 2mm. In some cases, it is only necessary to dewater the sand and remove the fines to produce concrete sand; in other cases, it is required to make a dedicated cut on the screen for a secondary product such as a mason sand. The throughs from the Dewatering Screen are pumped to a Hydrocyclone or Separator™ to dewater and remove the deleterious ultrafine fractions, the underflow is then selectively discharged back to the DWS. Where a secondary product is being made, the DWS is often divided by a urethane deck-divider into two parallel coarse and fine streams (alternatively two screens are used). For greater flexibility in adjusting gradations, there is typically a facility to blend the fine materials into the coarse or vice versa at the discharge.
Sump-fed systems are used for dilute feeds or in cases of high concentrations of <200 mesh (-75µm). In these instances, the feed is directed to the collection sump first. The slurry is then pumped to a Hydrocyclone or Separator™ to remove the -200 mesh solids and dewater the product. The overflow containing water, fine silts and clays are transferred to the slurry pond or other downstream process. The underflow, being the deslimed and partially dewatered solids, is discharged onto the Dewatering Screen. The Dewatering Screen removes excess moisture from the sand and discharges a drip-free product. Water and fines that pass through the Dewatering Screen report to the sump and are recirculated through the system, minimizing the loss of sand-size product.
As every site has different needs, McLanahan is up to the challenge in designing a system to match a process instead of making the process match the equipment. Hydrocyclone-fed units with or without a scavenger cyclone, along with other types of designs, can be engineered to order to give the best possible solution.
McLanahan has been a leader in the industry for many years in the production of this style system. The experience from a wide range of applications given our sales and process teams the ability to provide the right solution for each application and the foresight to anticipate problems before they arise. McLanahan uses blending and multistage systems to make in-spec products in difficult applications.
McLanahan has the additional advantage of being a full equipment provider, being the sole supplier of the sump, Pump, Hydrocyclone, Dewatering Screen and structure. This allows McLanahan experts to customize and optimize the system to the process.
McLanahan Modular UltraSAND Plants are a quick and easy-to-set-up solution for washing and dewatering sand. These compact units are designed with McLanahan's field-proven equipment to fit in a small footprint. Modular UltraSAND Plants are skid-mounted for quick and easy setup, meaning you can be up and running faster than with a standard wash plant and move from site to site should deposits change. They can be combined with other modules in McLanahan's modular equipment range, including the UltraCRUSH, UltraWASH, UltraSCRUB and EcoCYCLE, to create an entire wet processing plant.
McLanahan Configurable UltraSAND Plants offer a tailored sand washing solution that is readily available. With three different Hydrocyclone clusters that are always in stock at McLanahan facilities, McLanahan's Configurable USP can fit many unique applications without the lead time associated with custom plants. Configurable USPs are comprised of all McLanahan designed and field-proven equipment, and they are quick and easy to set up and install on site.
Modular plants are measured in feed tons per hour. Producers are typically looking for a per annum output over a certain number of available hours. With a customized plant, we ask what is needed to feed the plant to get the desired output. Consider a modular plant with a feed tph of 250. The expected output may be 60% sand, or an output of 150. You need to feed 415 tph to get 250 tph of product to match the output of a custom plant. As long as this is understood between the parties, then it is okay. If not, it comes as an unwelcome shock. The end result is more hours worked or more equipment purchased. Even when the capacities are well understood, variations in the typical feed gradation and actual run of mine material can create bottlenecks in the system on either the coarse or fine side, which results in reduced capacity of the system. There are definite cases where a modular plant makes sense. In these cases, McLanahan offers a range of Modular Wash Plants that are close in design to the USPs we made 20-plus years ago but have now added a feed system, sizing screen and discharge conveyors, all provided in a compact, more complete offering.
If you are prepared to spend the necessary time to research the best options, then allow one to two weeks for sampling and getting results and two weeks for evaluation and preliminary quotation. After this, it is typical for one to two weeks for approval drawings (general arrangement by which to decide on configuration and orientations), then 10-12 weeks for a USP and 20-22 weeks for the more sophisticated options. Of course, some parts of the process may be able to be compressed; conversely, workload in engineering and fabrication will affect the final time frame. Starting early in the permitting process helps put a lot in place to give realistic expectations. Why spend hundreds of thousands of dollars, hundreds of hours, and the next 20 years only to regret not spending the necessary time in the beginning to get it right?
Listen closely to the claims and ask questions. When you do, these claims are qualified to 7-12% being the average. The thing is, 7-12% is not an average. The real answer is somewhat of a non-answer: It depends on the material being dewatered. It is all about surface moisture and how much surface you have. A very coarse concrete sand could well dewater to 7%; however, more typical is 12-15% by weight for C-33 sands. For very fine material being recovered with a UFR, this might be 23%, but it is drip-free as it comes off the end of the Dewatering Screen.
UltraSAND Plants are not designed for deposits that require mid-size adjustments. Operators will need to blend materials from different parts of the deposit to create a feed suitable for creating a concrete and or mason sand. Alternately, consideration should be given to the use of a Sand Classifying Tank Based Sand Plant.
UltraSAND Plants are proven to provide a higher product yield at a much lower moisture content.
