Wash plants have traditionally been static or modular, with limited mobility around the quarry. Jim Hankins explains how recent iterations of the wash plant have evolved to become more portable and flexible – and may one day be capable of covering all facets of operation.
Portable plants have been utilised in the quarrying industry for decades. In the US, portable wash plants became popular in the 1960s and generally consisted of a vibrating screen mounted over a sand screw. The various configurations were typically used for projects with short to medium term contracts, requiring screening and washing on-site, and the ultimate removal of equipment at the end of the project. With developments leading to more flexibility, portable plants are now found in a broad range of applications.
In the past decade, Superior Industries acquired washing, crushing and screening, as well as portable equipment, manufacturing firms. With these acquisitions, its range of portable processing plants – dry or wet, crushing, screening and integrated washing plants – has grown immensely.
The first Superior Industries Aggredry portable wash plant was imported into Australia in late 2017. This was a standard configuration, with Australian requested modifications to suit local conditions, described as a 2m x 6m (6’ x 20’) Aggredry. It combines a Guardian horizontal triple-deck 6m x 2m (20’ x 6’) screen, with a pan feeding a 91cm (36”) twin Aggredry dewatering washer makes a powerful and flexible plant. Two reversing and roll-out cross conveyors, made from the Superior Industries product range, accommodate the product of the screen decks on either side of the plant, with the third screen discharge to a chute at the end. An arrangement of stackers, appropriate to the site requirements, will stockpile the various products.
This unit has been in operation for close to two years, processing a sand with minimal bottom end with some organics. The washing process is cleaning the organics out, while producing sand in grade at a high production rate.
The second portable Aggredry wash plant to come to Australia had considerable Aussie input to modifications to make the plant more versatile. Both technical and operational modifications were involved. For the first time, Superior Industries built a twin 112cm (44”) Aggredry with removal flared sides, for travel, again making use of the Guardian 6m x 2m horizontal triple deck screen. The water manifold was reconfigured, valve changes, electrical components were altered for road travel within Australia.
With the changes, what can the newly configured portable plant do? The Guardian screen can process in excess of 500 tonnes, depending on feed and aperture sizes. The twin 112cm Aggredry can produce a nominal 275 tonnes per hour, depending on the raw feed grading of the –4.75 mm material.1
Based on river rock (or pebble) and sand in a typical alluvial deposit, the Aussie Aggredry wash plant could take a 45:55 ratio of rock to sand, of the material fed to this plant.1 If a feed hopper is used with a grizzly, the plant can produce one oversize, three-screen washed rock or pebble size ranges, depending on preferred screening apertures, in addition to a washed sand.
Washing pebbles for the landscaping market is an art or science in itself. Removal of difficult surface coatings may require further processing. If the river rocks are crushed to make aggregates, and require washing after crushing, the same processes could be followed, while the crusher dust could be blended with the natural sand, if blending ratios were acceptable.2 If a hard rock site was looking at washing aggregates, three washed aggregate ranges could be produced, while washing crusher dust to make a local manufactured sand. The versatility of this plant is only limited by the site-specific products and required feed rates.
While portable and easy to move within a site and from location to location, the plant can be set up in position for permanent operation. With regards to modularity, plants can be set up to operate in tandem, once a second one is added (or more, as required). Is it possible for one plant to cover all facets of portable, mobile, modular and fixed operations? Within reason, yes. With experience in operation and expertise in sizing plants it is possible to base an initial operation around the use of the Aggredry wash plant, with expansion in multiples of these added to the process, with some materials handling additions or modifications, as well as inputs such as water and power.
With level assist technology, to efficiently utilise hydraulic levelling of the plant, the Superior Industries portable range can be brought on site and set up in a matter of days, with supply of electricity and water (if required). With Superior Industries’ foundation in conveying and stacking, needless to say, there is a vast range of options for conveyors and stackers, ranging from fixed, to radials, to the Telestacker telescopic radial with automated controls.
Superior Industries continues to innovate in the portable field, recently unveiling the latest development in portable washing – the Portable Spirit Wash Plant, which was on show at CONEXPO-CON/AGG Las Vegas in March 2020. •
Jim Hankins is the principal of Rivergum Industries.
Portable captures STATIC cousin’s ‘spirit’
Superior Industries, the US-based manufacturer and global supplier of bulk material processing and handling systems, showcased its newly configured portable wash plant at CONEXPO-CON/AGG 2020 in Las Vegas in March.
Based on the company’s successful
brand of static Spirit sand plants, the Portable Spirit Wash Plant is capable of producing as many as five products. It carries a 6m x 2m (20’ x 6’) Guardian Horizontal Screen, plus a sand production module and ultrafines recovery module.
As part of the sand washing process, material is fed to a slurry box, which liquifies it to improve the screening and stratification processes. The three-deck horizontal screen washes and sizes three products from a top, middle or bottom deck. Leftover sand is then processed through one of two Spirit wash modules, which comprise of one or more Helix cyclones followed by a dewatering screen.
The first wash module uses a cyclone to size and separate material for a traditional sand product. A dewatering screen ensures it is instantly saleable off the discharge chute. Depending on the deposit, an optional ultra-fines recovery module washes out -100 to -400 fines for microfine material, which is saved from being lost to a waste pond.
“It’s the first time such a configuration has been created for the portable market in North America,” Matt Voigt, Superior’s manager of portable plants, said. “We incorporated our low profile dewatering screens and a series of hydraulically-powered components to ensure the plant is road permissible and quick to deploy.”
Applications for the new portable plant include operations with settling ponds, crushed aggregate, sand and
gravel, dredging and frac sand.
The Portable Spirit Wash Plant was one of a dozen new products for crushing, screening, washing and conveying applications that Superior Industries launched at CONEXPO-CON/AGG 2020. The new equipment included the brand new Sentry Horizontal Shaft Impact (HSI) crusher, the Fusion Modular Platform, the Valor Vertical Shaft Impact (VSI) crusher, the bolted model Liberty Jaw Crusher, and the Alliance Low Water Washer. Additional equipment with new features included the Anthem Inclined Screen, the Valor Vertical Shaft Impact (VSI) crusher, the P500 Patriot Cone Crusher, the Aggredry Dewatering Washer and the TeleStacker conveyor.
Superior also displayed aftermarket solutions for new conveyor idlers, pulleys and accessories, plus crushing rotors, cone bushings, cone heads and jaw dies, alongside a multimedia experience showcasing several turnkey projects completed by the company’s construction management division.
Source: Superior Industries
1. The basic operation of an Aggredry washer is determined by the water requirements and the speed of the shafts, which are directly related to the raw material feed grading. The throughput will depend on site-specific parameters.
2. Ratios for blending of natural sand and manufactured sand are dependent on a number of issues related to the ultimate end product.