Feature: Crushing & screening equipment

There are many areas of quarrying and aggregates production where stationary equipment still dominates. If the throughput of material is high, it can be difficult to design a mobile plant which is big enough to cope and still remain mobile. In any case, it may still be more efficient and convenient to have a fixed crushing and screening plant.

But in many small and medium-sized operations, mobile equipment can have a lot of advantages, and these have become all the more persuasive over the years, as set-up has become quicker and easier, and machines have been designed to be easy to transport.

One advantage is that mobile crushers and screens can be positioned next to freshly blasted materials. This saves on quarry haulage equipment and the associated staff, fuel and consumables costs.

Another argument in favour of mobile plants is that they can be transported between sites. This could mean that a company which owns several quarries running at low capacity might keep them operational with one set of crushing and screening equipment which can be moved between the different facilities.

And at the light end of the market, compact crushers can fulfil a need on urban demolition sites, allowing concrete, masonry and other materials to be crushed and re-used in-situ, without the cost and disruption of trucking them off site.

These arguments and others have driven growth in the mobile crushing and screening sector for years in many parts of the world. But at the same time, there have been countries where the traditions of fixed processing plants have continued.

China is one of the countries, where historically there had only been suppliers of fixed equipment. However, the last few years have seen some interesting changes.

In 2010, Terex signed a joint venture agreement with Chinese batching plant manufacturer NFLG to build mobile crushing and screening equipment in China for sale domestically.

In 2011 Sandvik acquired a controlling interest in Chinese crusher manufacturer Shanbao, and this has subsequently seen Shanbao start to sell mobile equipment in China, having gained access to the technology through Sandvik.

Meanwhile, 2012 saw Metso and Liugong announce a joint venture to build an adapted version of Metso’s Lokotrack mobile units for the Chinese market. The first of these machines were exhibited by Liugong at November’s Bauma China exhibition.

And most recently of all, XCMG, China’s largest construction equipment maker, has developed and launched its own mobile units, albeit with input from its German concrete equipment subsidiary, Schwing, and the Beijing University of Technology. The result is the 38 tonne tracked two deck MSP1561that is claimed to offer a throughput of 600 tonnes per hour. According to the company, the new screen should find application in recycling, mining and general construction.

Although the long-term trend seems to be towards mobile plants, with new entrants to the market and new countries adopting the concept, conditions look tough at the moment for manufacturers.

Sandvik has now closed the former Extec factory in Swadlincote, UK, and moved all its mobile crushing and screening production to Ballygawley in the UK province of Northern Ireland.

Anders Kjellberg, Sandvik’s vice president for crushing & screening said, “Ultimately it’s about creating a centre of excellence, but we will also have satellites around the world. It has also improved our cost base and made it leaner.”

Similarly, Atlas Copco has exited the mobile crusher business just five years after getting into it through its acquisition of Austria’s Hartl Anlagenbau.

On the other hand, there are still those keen to get into the sector. October saw UK-based engineering company Weir Group announce its acquisition of Trio Engineered Products for
US$ 220 million.

Trio is based in Shanghai, China, where it has two manufacturing plants, and the company also has facilities in the US. According to Weir, 31% of Trio’s revenues last year were generated in the US, primarily in the aggregates sector. A further 25% came from China, predominantly the mining segment.

The deal came after Weir had twice seen offers to acquire Metso rejected earlier in 2014.

Latest products

One of the latest fruits of Sandvik’s operation in Ballygawley is the QA335 Doublescreen – the ‘Doublescreen’ was a patented feature of the Extec range, with two independent screens in the same box, effectively performing two processes on one plant. Sandvik says this system still outperforms a similarly sized single screen by about 30%.

It features a 75 kW Cat engine, and has a simple to use sequential start-up system on-board, which allows it to be set up and put into operation at the push of five numbered and colour-coded buttons. The standard machine weighs in at just over 27 tonnes, and the transport dimensions are 15.3 m long x 3.4 m wide x 3.0 m wide.

Also new is the QE441 scalping screen, which replaces the QE440 at the top of the range. Changes include updates to the screen box, screen drive and screen media, as well as improvements to the apron plate feeder, wear resistant hopper and radio remote controls, all of which are fitted as standard.

It has a maximum capacity of 900 tonnes per hour, and the maximum feed size is 800 mm. Power comes from a 96 kW Cat engine and the weight of the standard model is just over 37 tonnes.

Terex’s Powerscreen meanwhile used last month’s Intermat exhibition to launch the Warrior 600 compact mobile screen, which it describes as its most compact heavy-duty screen.

Stephen McCartney, international sales director, said, “With extremely positive customer and distributor feedback at a recent preview event in Florida, US, and from the experiences of operators during the test phase of this machine, we were, and are, very excited about the launch of our new Warrior 600 screen.”

Key features include simple conversion from 3-way split mode to 2-way split mode, which the company says takes just minutes. Powerscreen said versatility, manoeuvrability and transportation, along with a fast set-up time were key design considerations. Hydraulically folding side conveyors are one feature which help this.

Meanwhile, sister brand Terex Mineral Processing Systems has expanded its CR Series of mobile screens with the addition of the Cedarapids CRS620S, which offers increased productivity with greater capacity, according to the company.

Terex MPS goes on to say that the new unit can be used in applications where traditional horizontal screens cannot because of the combination of its EL-Jay high g-force stroke motion combined with adjustable slope operation, which allow it to handle larger deck loads and larger screen openings.

Hartl Crusher has launched its new HSP 3300 compact two deck screening plant, which has a maximum throughput of
90 m3/hour. According to the company, it will find use in natural stone processing and recycling among other applications.

“The main advantage lies in the screen box’s electro-hydraulic drive which provides more power than comparable pure electric drives and is also much more robust and durable. At the same time, with this drive system the speed of the screen’s rotation is continuously variable and a reversal of rotation direction is also possible.”

“The screen box is spring mounted and thus provides the best power transfer for both screen decks,” said the company.
Maskin Mekano’s new 1200 mobile screening range comes in several variants, including the choice of various feeders, two or three screening decks, and with the option of an on-board generator.

“The 1200 range is designed to provide maximum screening output in Scandinavian conditions. The combination of an aggressive stroke and low inclination provides an unequalled screening capacity and screening accuracy even when the weather is challenging. Qualities that will boost the production of fines for any aggregate or quarry producer,” said the company.

New crushers

On the crushing side new from Terex Finlay is the J-1170AS primary mobile jaw crusher built around the Terex 1100 mm x 700 mm jaw crusher. A key new feature of this model is the on-board detachable sizing screen

The jaw chamber is also available with optional hydraulic release which has an automatic overload protection system to prevent damage by un-crushable items in the feed material – a useful feature when handling demolition waste.

In addition, hydrostatic transmission of the jaw chamber offers reversible operation in the event of a blockage. The hydrostatic system also provides variable chamber speed to suit different applications and the crusher features hydraulic adjustment of the chamber’s closed side setting (CSS), which allows adjustments to be made in a matter of minutes, according to Terex.

Kleemann’s latest model meanwhile, is the 30 tonne MCO-9 mobile cone crusher, which the company says has been designed for easy transport and rapid and simple set-up. According to Kleemann, the new cone can achieve a throughput of up to 250 tonnes/hour, and also achieves a higher crushing ratio to produce an end product with a higher fines content in comparison to other cones in its class.

It can also be equipped with an anti-spin system that prevents intrinsic spinning, and therefore noticeably reduces wear. A magnet and metal detector are also available as an option to increase operational reliability.

The MCO-9 makes use of the same touch screen panel control system already proven on the company’s other EVO machines. When operated together with the Mobicat MC 110 Z-EVO jaw unit, the two machines’ material conveying elements can be adapted to ensure that the MCO-9 always maintains the optimum filling level, and that a high quality end product is produced.

Sandvik also has a new mobile cone crusher unit out in the shape of the QS331. It features one of the company’s S-type gyratory cones, which are well-proven in stationary plants. They are able to accept a feed size up to +90% larger than standard cones, which means the upstream primary crusher can be run at a coarser, higher throughput setting for greater productivity. Sandvik added that in applications such as gravel crushing, the S-type cones can be used as primary crushers.

The 36 tonne QS331 also features sensors above the crusher chamber to control the feed rate, a metal detector and an automatic system to control the closed side setting, among other features.

New from Metso is the Nordberg HP5 cone crusher unit, which follows on from the previously released HP3, HP4 and HP6.
Metso says more than 9,000 of its cone crushers are in operation around the world today, and that this latest model draws on that experience.

The company says it can take +5% larger feed sizes than the old HP400 unit and the offers higher capacity than the HP500 in tertiary applications.

On the maintenance side, the HP5 features a new fastening system for the mantle and bowl, which is designed to make liner changes fast, while thicker liners can be used for longer life.

The unit also features Metso’s IC70C crusher automation system, which controls feed and discharge conveyors, wear compensation, setting adjustments and offers remote control.

Aggregates washing

Another growth area in the aggregates business is aggregates washing. Indeed, Terex has set up a specialised division, Terex Washing Systems, to address this need.

The company has introduced two new washing modules for its including one suited to the demands of recycling construction and demolition waste. This is the Aggrescrub 150, with a maximum throughput of 150 tonnes per hour. According to Terex, it features improved wear characteristics, reduced costs and the ability to scrub aggregate and float out clays, silts, wood and plastic on a single chassis.

The other new system is the Aggresand 206 wash plant, the larger model of the recently launched 165, with a throughput of 400 tonnes per hour. It offers modular design features, increased productivity and all the features of the smaller 165 platform.

Meanwhile Haver & Boecker has introduced its Tyler Hydro-Clean, which is available in three sizes covering the 18 to 360 tonnes per hour range.

Material as large as 150 mm is fed into a rotating vertical drum, where it is cleaned with high-pressure water jets at pressures of up to 2,000 psi (140 bar). The system can use as much as 90% recycled water from previous washes and removes clay particles as small as 63 microns.

The system is very compact compared to traditional washing systems, and Haver & Boecker says it uses significantly less water and energy than traditional systems.

The company says the ideal application is clay-heavy material deposits, and the combination of rotation, high pressure water and the aggregates rubbing against each other provides a superior clean because clay particles are more easily dislodged from hard-to-reach parts of the stone.

This all goes to show that both the mobile and stationary segments of the crushing & screening market are seeing increased technology and sophistication, which can translate into better efficiency and productivity.