Canada’s “Rock to Road” Magazine

July/August 2005 Issue

• Record attendance at Hillhead 2005
• Aggregate owner bucks trend, begins own production
• New crushing plant fits application, pays dividends
• New screen plant capitalizes on aggregate deposit
  

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Record attendance at hillhead 2005

By Robert L. Consedine, Editor

Sunshine and success was how one exhibitor summed up Hillead 2005 – The International Quarry and Recycling Show –which took place from June 21-23 at Tarmac Central’s Hillhead Quarry near Buxton, 50 km south east of Manchester, England. For three hot, sunny days, a record 19,500 visitors were on hand at the world’s largest working exhibition of quarrying, road building and recycling equipment. The show featured 430 exhibitors who used a total of 140 000 m2 of space, including 105 000 m2 of outdoor display area, 3 500 m2 of covered pavilions and 35 000 m2 of working demo areas, to showcase their latest products and services for an international audience of industry professionals.
    The quarry face at the north end of the showgrounds was used by large wheel loaders and excavators to load rock trucks from a 10 000-tonne stockpile. The main participants included Terex, Liebherr, Komatsu and Caterpillar who demonstrated new earthmoving models in a real working environment that gives the show its unique appeal. Other manufacturers participating in the live action at the quarry face were Volvo, Case, Hyundai and Daewoo.
    Also at the quarry face was a Liebherr Mobilmix modular concrete batching plant complete with feed hoppers and a specially-built loading ramp. According to show organizers, Hillhead 2005 was first appearance at a British exhibition for the Mobilmix.
    In the rock processing area a large array of portable crushers and screens was kept busy throughout the show with a near continuous processing of material into single-size and multiple graded products. Among the manufacturers taking part this year were Powerscreen who put its new Warrior H3S dry screen and the Chieftain 2100 triple-deck screen plant to work, Terex Pegson who demonstrated its new 1412 Trakpactor primary impactor and Extec who unveiled its new E-7 screening and stocking system. A spokesperson for Terex Pegson reported that the eight crushers brought to Hillhead 2005 were sold during the show.
    The south end of the exhibition site was reserved for demonstrating C&D recycling systems and associated machinery. More than a dozen manufacturers carried out demonstrations including Terex Finlay, McCloskey, Rubble Master and Red Rhino.
Prominent exhibitors with major stands in the static display area included Atlas Copco that was another firm that sold all four drill rigs on the stand, including the company’s new ROC D7 RRC remote-controlled unit, as well as three large hydraulic breakers.
Summing up this year’s show, exhibition director Jack Berridge stated that Hillhead 2005 had not only enjoyed the best weather since 1989, but thanks to the efforts of the exhibitors, the presentation of the exhibition as a whole had now reached a very high standard.
    “It is this level of commitment, combined with the range and scale of equipment on display – all set against the dynamic backdrop of Hillhead Quarry, that ensures the enduring appeal of the show, which yet again attracted a record attendance,” he said.
The International Quarrying and Recycling Show was established in 1982 and has become widely recognized as one of the top construction shows in the world. The biennial event is organized by Nottingham-based QMJ Publishing Ltd.

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Aggregate owner bucks trend, begins own production

By Andy Bateman, Engineering Editor

     Wayne M Schwartz Construction is a family-owned business based near Chesley, Ont., 35 km southwest of Owen Sound. The company’s main operation on Grey Road 25, one of three currently active sites, extends over 160 ha and contains some five million tonnes of sand and gravel reserves. Although Schwartz has sold aggregates for nearly 20 years, 2005 marks the first year that the company has produced its own crushed granular aggregates. Owner Wayne Schwartz explains that the new portable spread has been acquired to provide greater control over aggregate production and meet growing customer demand, most notably from a pit-based hot mix asphalt plant that is also a new arrival here.
    The new spread combines a Pegson Trakpactor 428 track-mounted impact crusher with a Powerscreen Turbo Chieftain screening plant and produces crushed granular and clear sized aggregates. From a production perspective its working conditions are almost ideal and include a uniform deposit with over 50 per cent coarse material, negligible clay or silt and no standing water. In normal operation, a Caterpillar 962G loader hauls pit run to the spread where it is first separated into 76 mm plus oversize, 25 mm drainage stone and Granular A base by a 5x10 screen.
    The oversize is directed to the impact crusher where it is reduced and stockpiled as 76 mm minus crusher run. This crusher run is picked up by loader and carried to a Powerscreen Mk II screening unit where crushed stone dust is separated by a 4x8 screen and any larger material is conveyed back to the primary screen.
    Subsequent to Aggregates & Roadbuilding’s visit in mid-June, an additional conveyor was incorporated into this plant layout, allowing the stone dust leg to be conveyor fed rather than loader fed.
The 2004 Pegson crusher was acquired in Louisville, Kentucky with about 1000 recorded hours of use and, since its arrival at Chesley, has been operating at some 125 tonnes/h or about a third of its maximum rated capacity of 360 tonnes/h. Schwartz recognizes that plant output can be significantly increased, preferring to ramp production up steadily given the significant investment for a business of this size.
    According to its UK manufacturers, the Terex Pegson Trakpactor 428 is suitable for processing soft to medium strength quarried rock, demolition materials and recyclable materials. It has a feed opening of 1067 x 711 mm while the diameter and width of the four hammer rotor are both 1066 mm. The 4.0 m long x 2.1 m wide hopper has a capacity of up to 3.8 m3 gross, depending on the method of feed. The unit is mounted on heavy-duty tracks as standard, with pitch of 160 mm, longitudinal centres of 3.3 m and track width of 400 mm.
The 428 has a maximum climbing grade of 30 degrees and has high and low travel speeds of 1.4 km/h and 0.322 km/h respectively. Transport dimensions for the unit include 14.9 m length, 2.8 m width, 3.44 m height and weight of 33.5 tonnes. The unit is powered by a Caterpillar C-9 engine producing 224kW at 1800 rpm, drawing on a 426 litre capacity fuel tank. The optional overband magnet provides 570 Gauss at 200 mm.
   A separate wash plant at the Schwartz operation consists of a rinsing screen and dewatering screw mounted on a Mormak Equipment chassis. Granular A feed from the crushing spread is separated on a 5x6 ElJay triple-deck screen with the sand fraction subsequently dewatered by a 914 mm x 8.54 m LB screw. Asphalt aggregates produced by this plant include HL3, HL4, HL8, 6.3 mm, 7.9 mm, 11 mm and asphalt sand, together with natural round sizes for roofing applications. Most of its asphalt aggregates travel only as far as the E.C. King Contracting’s hot mix asphalt plant that went into production here in November 2004. E.C. King Contracting is part of the Markham, Ont.-based Miller Group.
    The Barber-Greene 2.5-tonne batch hot mix plant has been reconditioned to the Miller Group’s exacting standards and features four cold feed bins, oil fired burner and a new baghouse. A 1220 hp Caterpillar engine driving a 1025kVA generator provides the necessary power.
   Additional equipment on site included a John Deere 544H loader hauling aggregates to the hot mix plant, while a Caterpillar 972G loader maintains a supply of feed to the wash plant and loads customer trucks.

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New crushing plant fits application, pays dividends

By Andy Bateman, Engineering Editor

A new aggregate crushing spread demonstrates how a good fit between equipment and application can pay dividends in productivity and quality.

    The integrated new spread of Bertrand Construction L’Orignal Inc., achieves high production capacity and product quality in limestone quarry applications. Its primary and secondary crushing stages both utilise impact crushers, while product stockpiling is designed to minimise segregation.
   In addition to operating three quarries of its own, Bertrand has a thriving contract crushing division where continued growth signalled the need for a second full spread. Operation manager Alain Bernard explains the thinking behind the new equipment selection: “All of the quarries in Bertrand’s contract crushing area contain low silica limestone. Recognising that the spread would not be called upon to process hard or abrasive materials such as granite, limestone or sand and gravel with high silica contents, we opted for impactors at both crushing stages to obtain high output rates of cubical product.”
Aggregates & Roadbuilding recently visited the new ElRus Aggregate Systems spread in action on a custom crushing contract in the Braeside Quarry of Smith Construction near Arnprior, Ont. At the time, the plant circuit was designed to maximise the recovery of 23.8 mm x 6.3 mm clear stone. A Caterpillar 988G wheel loader carried well-fragmented shot rock up to 250 m from the active faces to the spread’s primary unit. Here, a variable speed vibratory feeder regulated material flow to a Sandvik primary P500 horizontal shaft impact crusher which reduced the feed to 150 mm minus. A surge feeder provided a steady flow of primary crusher run to the secondary system, where a 5x16 Cedarapids triple-deck scalping screen made an initial size cut at 16 mm. Material larger than 16 mm continued forward to a 7x20 ElRus triple-deck deck finishing screen while 16 mm minus granular product was conveyed to stockpile. The finishing screen separated HL8 (coarse asphalt aggregate) and screenings, while anything larger than 19 mm was directed to the spread’s Sandvik S300DC ImpactMaster secondary crusher operating in closed circuit with the screen. Granular product was stockpiled by a 914 mm x 42.7 m Thor programmable stacker, while the HL8 was loaded directly into a truck and stockpiled elsewhere.
   In this configuration, the plant was achieving an average production rate of 400 tonnes/h, consisting of about 165 tonnes/h 16 mm minus, 160 tonnes of clear stone and some 75 tonnes of screenings. When producing Granular A, Bernard reports output rates up to 500 tonnes/h versus a design rate of 425 tonnes/h, adding that the plant spread, primary loader and product stacker all play important roles in overall performance.
   On the familiar topic of fines production by impactors, Bernard recognises that impactors typically produce more fines than cone crushers of similar capacity. However, fines are in short supply in these area quarries and often reblended into granular products to meet specifications. Indeed, the fines generation characteristics of impactors can be used to advantage here, with the P500 primary impactor able to make specification Granular B on its own in a single pass, unlike a jaw crusher of similar capacity. Staying at the primary, Bernard notes that the P500’s large feed opening means that a hydraulic breaker is not required, although a boom may be fitted at some later date to dislodge bridged material. Refinements at the primary already include a detachable bulkhead to protect fenders and tires on the ramp side of the feeder, with hanging pins allowing the bulkhead to be attached to either side as required. Bernard has also added 1.2 m side wings to the feeder hopper, thereby improving the match with the loader bucket, increasing hopper capacity and reducing spillage.
   Manufacturer’s data puts the P500’s rated capacity at 280 tonnes/h to 520 tonnes/h, with the unit having a 1200 mm high x 1550 mm wide feed opening and a maximum feed size of 1000 mm. Equivalent numbers for the S300DC secondary crusher are rated capacity of 300 tonnes/h, 600 mm high x 1930 mm wide feed opening and maximum feed size of 300 mm. Power for the new spread is provided by a Caterpillar 3512 engine driving a 1259kW generator. The high generator capacity is a reflection of about 1000 total connected horsepower, including 350 hp and 400 hp for the primary and secondary crushers respectively.
   Further improvements in plant safety and efficiency have been achieved by using chrome steel instead of manganese hammers in both crushers. The switch has eliminated the need for frequent hard facing of wear surfaces and the attendant safety risks of a welder working alone. In terms of costs, Bernard estimates that the chrome hammers are saving about $1000 per week in labour and material costs or at least four cents/tonne in overall production cost.
Overall, Bernard is pleased with the performance of the spread so far. “The integrated set up is delivering the productivity and quality we are looking for, with the added bonus of improvements in both safety and costs.”
   Bertrand Construction L’Orignal Inc (www.bertrandconstruction.com) is based in L’Orignal, Ont. Established in 1936, the company’s services include portable crushing, garage repair services, truck transport, equipment rental and construction. In addition, an extensive product range includes aggregates from three eastern Ontario quarries, together with hot mix asphalt, ready mix concrete and agricultural lime, all from quarry based plants.

New screen plant capitalizes on aggregate deposit

The April 2000 issue of Aggregates & Roadbuilding reported how an Ontario aggregate producer was maximising the use of raw materials in a new pit deposit. The same approach is still being applied there today, with a new portable screen plant facilitating the recovery of valuable aggregates while providing well graded rehabilitation material.

    Given the challenges of licensing new reserves close to southern Ontario markets, established producers such as Capital Materials Inc. are always looking for process improvements to help stretch existing reserves. John Theriault, Capital’s aggregate operations manager, points to the company’s recent portable screen purchase as an example of this focus on process efficiency. Now in its second season, the portable screen plant is being utilised to separate fines from pit run, thereby providing a supplementary source of aggregate feed and graded backfill material in a single process. Like virtually all natural sand and gravel deposits, there are some pockets in Capital’s Wellington pit where valuable aggregate feed is intermingled with excess fine material. Historically, producers would sometimes go around difficult areas such as these in favour of more accessible material, but modern screening technology now allows most of the deposit to be recovered and put to good use.
    The McCloskey 570 is a self contained track-mounted unit incorporating a feed hopper, double deck screen and three stockpile conveyors. Aggregates & Roadbuilding saw the unit processing pit run containing about 45 per cent coarse (6.3 mm and larger) material as well as a high percentage of 4 mm and smaller fine sizes. All screened material larger than 4 mm was loaded into articulated dump trucks and hauled to the operation’s main crushing plant for further processing, while 4 mm minus was separated for rehabilitation fill. The plant is generally fed by wheel loader, although on this occasion the plant was being fed by a John Deere 330 LC excavator due to some local soft spots. The screen itself has a 1.5 m x 5.4 m top deck, fitted for this application with regular side tensioned 25.4 mm wire mesh. Underneath the top deck, the heavy fine material load was separated by two Samscreen harp (also known as piano wire) end tension screens with 4 mm openings. The fine material was stockpiled by a 30.5 m long McCloskey stacker, set up to discharge the fill close to its final location and so minimize rehandling. In this configuration, the plant was processing feed material at reported average rate of 275-300 tonnes/h.
    Theriault adds that two custom design changes, one at each end of the process flow, were made to the plant in the company shop last winter. At the input end, the feed hopper was increased in size to match the bucket on the company’s Komatsu WA500 wheel loader. At the product end, chutes were added to allow material retained on the top and bottom decks to be recombined as crusher feed while still retaining the plant’s ability to stockpile three separate sizes when required. Additional duties for this plant include recycled asphalt pavement (RAP) screening, as well as top soil and sub soil screening where, once again, all available stone in the feed will be recovered and uniformly graded, workable rehabilitation material will be produced.
    Plant specifications indicate that the two-bearing, high-amplitude screen has hydraulic angle adjustment with the slope ranging from 22 degrees to 28 degrees in four working positions. Within the bolted screen box, the bottom deck is inclined an additional 5 degrees to provide increased screening efficiency. The top deck is fitted with quick release tension wedges in the high impact zone, while access to the screen box is facilitated by a wrap around walk way which folds for transport. The 570‘s feed hopper has a 3.6 m wide x 1.9 m target area which can be increased to 4.4 m x 1.9 m by the addition of two hinged wing plates. A crusher inlet chute is fitted as standard, allowing feed to bypass the hopper’s grizzly bars in those applications where the screening plant is working in tandem with downstream crushers.
    Standard equipment includes radio control to tip the grizzly bars for oversize removal. Capital’s hopper is also equipped with an optional second deck, allowing large sizes to be drawn off separately at the front end of the process if desired. Power for the 570 is provided by a Deutz four cylinder diesel engine producing 72 kW. The unit’s fuel tank has a capacity of 400 litres, with fuel consumption rated at 15 litres/h at 75 per cent load. All conveyors on the screen plant have hydraulic drives as well as hydraulic position adjustment and folding for transport.
   Capital Materials Inc. and Capital Paving Inc. provide asphalt, aggregates and construction services to the central and southwestern Ontario construction markets.

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July/August 2005 issue

Aggregates and Roadbuilding Magazine
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