Quarrying: Cost-effective investments
By Helen Wright17 July 2012
Modernising quarry machinery can have a real impact on margins, from fitting machines with the most sophisticated and efficient engines available to simply making basic, but effective changes to processes.
An obvious driver behind new machinery launches has been the US Interim Tier 4 regulations on exhaust emissions, and the equivalent European legislation, Stage IIIB - which now apply to diesel engines from 56 kW to 560 kW.
Manufacturers have responded by launching new generations of quarry machinery fitted with emissions-compliant and often more fuel efficient engines. JCB's new Interim Tier 4/Stage IIIB-compliant 457 wheeled loader, for instance, has a new eco mode that is said to produce fuel savings of up to 6%.
The 3.5 m3 bucket capacity machine also boasts a +16% increase in power and +18% more torque. Other technology on-board includes automatic differential locking and an intelligent clutch cut-off system that allows maximum hydraulic power at low travel speeds.
Similarly, Liebherr's new Interim Tier 4/Stage IIIB wheeled loaders - the 2.6 m³ to 14 m³ bucket capacity L 550, L 576 and L 580 - also feature a host of new technology in combination with their new, low emissions engines.
The Liebherr-Power-Efficiency system (LPE) enhances the loader's engine management in proportion with the hydraulics during operation and is said to provide up to 8% additional fuel savings, while Liebherr's data transfer and locating system LiDAT comes as standard.
Caterpillar has also introduced new wheeled loaders which all meet the Interim Tier 4/Stage IIIB emissions requirements - the five-model K-series. The 950K, 962K, 966K, 972K and 980K cover the 157 kW to 275 kW power bands and bucket capacities from 3.3 m3 to 5.3 m3.
The 966K CVT wheeled loader was showcased at Intermat - the 'CVT' stands for Constant Velocity Transmission, which the company says provides better fuel economy and performance compared to a traditional torque converter.
The K series machines replace the H-series models in the US and Europe, while in less regulated markets, the H series will be retained.
This is significant as new machines targeting the more developed markets such as the US and Europe, where the strict regulations apply, are only half the story.
Quarrying is a global industry, and there is also huge demand in resource rich, developing countries where equipment requirements are very different. For a start, such strict emissions regulations are not necessarily in place, and even if they were, the latest engines would have a big problem running on anything but ultra-low sulphur diesel - fuel that is not widely available outside North America, Europe or Japan.
And it's not just a question of the engine - demand in many developing markets also calls for simpler machines that are robust and reliable, with fewer electronic bells and whistles than their North American, Japanese or European counterparts.
This two-tiered global demand is putting pressure on equipment manufacturers to develop dual equipment lines, with one set of models designed for use in mature markets, and another for developing countries.
As Doosan has demonstrated with its latest wheeled loader and excavator launches, this pressure is resulting in the production two separate machines that essentially perform the same task in different parts of the world.
For instance, the manufacturer has introduced two new ranges of wheeled loaders this year - there is the Mega range, which targets the Middle East and African markets, and then the Dash-3 range, which have Tier 4 Interim/ Stage IIIB-compliant engines and are targeted at North America and Europe.
The new Dash-3 machines - the DL300-3, DL350-3, DL420-3,
DL450-3 and DL550-3, with bucket capacities from 3.0 m3 to 5.5 m3 - are powered by Scania diesel engines that use selective catalytic reduction (SCR) to meet the strict emissions rules. The machines also feature technology including three engine working modes (Eco, Normal and Power), a torque-converter-cut-off system and a new ZF five-gear transmission.
In contrast, the three model Mega range, with bucket capacities ranging from 2.5 to 4.5m³, are powered by Doosan Tier 1 (the DL250A) and Tier 2 diesel engines (the larger DL300A and DL420A models), which are less sensitive to fuel quality than Tier 3 engines, whilst still offering reduced fuel consumption and emissions.
A key focus on the Mega range has also been ease of serviceability - the radiator grille on the DL250A opens wider for better access, while the swing-out fan on the DL300A and DL420A simplifies maintenance, for instance.
This two-tiered approach is also reflected in the latest excavator launches from both Doosan as well as JCB. Doosan's new 22
to 35 tonne DX225LCA, DX300LCA and DX340LCA excavators for the Middle Eastern and African markets have Doosan Tier 2 compliant engines and feature very few electronics on board, while the company's latest Stage IIIB/Tier 4 Interim launches (DX180LC-3, DX300LC-3, DX340LC-3, DX140W-3) sport features such as new control consoles, in addition to their more advanced engines.
And for larger machines in regulated markets, JCB is using Stage IIIB/Tier 4 Interim Isuzu engines, but for the 20 to
24 tonne excavators that it sells in lesser regulated markets, it will use its own Stage 2/Tier 2 Dieselmax engines.
But while the global appeal of excavators and wheeled loaders has resulted in the launch of two or more machines or machine options in order to meet the requirements of different markets around the world, the target market for articulated dump trucks (ADTs) is more-clear cut.
Since these machines are aimed at the North American and European markets in which they are traditionally most popular, manufacturers have had fewer concerns about making two ranges of equipment.
To stand out from the crowd, manufacturers have added new technology to their latest ADTs in addition to the newest low emissions engines. Volvo, for instance, won gold at the Intermat 2012 innovation awards for the on-board weighing system it designed as an option for its new F-Series ADTs.
The system monitors the input of weight on the machine from its full suspension pressure sensors, and relays this information to load software integrated into the machine's electronics. All transport loads are logged and displayed to the operator, as well as remotely through Volvo's CareTrack telematics system, allowing data such as tonnes transported per litre of fuel to be recorded.
Komatsu's latest Stage IIIB/Tier 4 Interim ADTs - the HM300-3 and that HM400-3 - also feature new technology. The Komatsu Traction Control System (K-TCS) automatically provides optimum traction when operating in soft ground conditions. As ground conditions worsen and tyre slippage is detected by speed sensors located on four wheels, automatic application of the inter-axle differential lock occurs. If tyre slippage continues to be detected, then four independent brakes can be applied to slipping wheels to regain traction.
Both models also feature K-ATOMiCS - Komatsu Advanced Transmission with Optimum Modulation Control System - which offers a six speed, fully automatic transmission. Komatsu said it automatically selected the ideal gear based on vehicle speed, engine rpm and the shift position chosen. A large automatic retarder system allows the operator to select the optimum operating speed on downhill travel under full load.
Meanwhile, Bell says its new Mark 7 generation of ADTs are more powerful and fuel efficient. The company says the new 40 ton B40D Mark 7 outperforms rival models by as much as +6% in terms of production, while burning -13% less fuel. A more powerful Stage IIIB engine has improved the truck's power to weight ratio by +6.5% according to the company. This increased power translates to faster cycle times, while the introduction of a wet disc brake has helped reduce drag in the driveline.
The new generation features Stage IIIB engines, and Bell has taken the step of using an selective catalytic reduction (SCR) system to meet the new emission standards. Bell says these new SCR engines from Mercedez Benz are 15% more fuel-efficient than their Stage IIIA predecessors, and the use of this technology is being marketed as the 'Blu@advantage' in reference to the Adblu diesel exhaust fluid required for the SCR system.
On the rigid hauler side, machines with engines under 560 kW must also comply with EU and North American emissions regulations. Such haulers are in demand for large quarry operations around the world, unlike the more localised ADT market, and Caterpillar has dealt with the problem of different regulatory requirements in different regions by with different engine options.
Caterpillar's new 91 tonne class 777G rigid hauler, which replaces the 777F, can be fitted with a Tier 4 Final engine for more mature markets (two years in advance of the effective date of this next regulatory stage in the US), which it said provided customers an opportunity to advance their sustainability goals.
On the other hand, for other markets around the world, the 777G can be fitted with a US Tier 2 or EU Stage II equivalent engine.
Crushing and screening
Many of the latest crushing or screening machines have also been developed to offer very high productivity while lowering fuel consumption at the same time.
Metso claims to have produced up to 30% fuel consumption savings on its new Lokotrack LT106 crusher compared to its predecessor. This significant saving has been achieved thanks to combining a fuel-efficient Caterpillar 9.3 Tier 4-compliant engine with improved hydraulics and a larger flywheel mass.
Lokotrack LT106 product manager Jouni Hulttinen said, "Today, with rising energy prices, fuel economy is becoming more crucial for cost efficient crushing contracting. While designing the LT106, special attention was paid to the overall fuel economy. The field tests show that the targeted savings in fuel have been well reached."
The machine is built around the C106 jaw crusher, which boasts increased productivity thanks new features including a material sensor for continuous choked feed.
Meanwhile, Rubble Master concentrated on making transport easier when it designed its new RM100 GO crusher. This machine features a removable main discharge belt, a quick release crusher system and the new MS100 GO finishing screen. Rubble Master noted that it is becoming increasingly difficult to obtain special permits for the transport of large machines, adding, "flexibility is a must these days to survive in this lively market."
On the screening side, WS Tyler has developed an alternative to traditional screen media that combines polyurethane with woven wire cloth - the TY-Wire.
Characterised by its resilient, low-maintenance qualities, polyurethane is a common screen media choice, but can be very expensive and heavy. Woven wire is a lower-cost option but is more susceptible to blockages ('pegging') and is more easily broken. The Ty-Wire's hybrid design is said to be more affordable than polyurethane and last up to six times longer than wire mesh. It can withstand high temperatures and tonnage and deliver up to +80% more open area than modular polyurethane.
Ty-Wire is compatible with any vibrating screen and requires no deck conversion before installation - it is available in modular panels for a flat deck and can be hooked for a cambered deck.
Meanwhile, Sandvik has also developed new screening technology in the form of its WR Modular Screening Media, which has a wide surface area and screen cloths which can come in either a newly developed thin, fibre-reinforced rubber screen membrane for dry screening, or polyurethane for wet screening.
Danish gravel supplier Nymølle Stenindustrier replaced one of its existing polyurethane screens, which had become worn and damaged, with Sandvik's new WR Modular Screen and reported a +15% increase in production capacity as a result.
Site production manager Jens Rasmussen said, "The combination of the large, open screening area and cascade effect is enormously efficient. It provides greater capacity through the screen and we get sharper [material] separation. We are now able to deliver an even higher quality to our customers - Sandvik's new system is proving to be a highly cost-effective investment."
New technology is also being introduced to boost the performance of conveying systems. Superior Industries has unveiled a new track-mounted radial stacking conveyer, the Geotrek, which has been designed to be linked with portable crushing and screening equipment in stockpiling applications.
Equipped with independent hydraulic cylinders at both the head and tail ends of the conveyor, the unit can also be used as a mobile transfer or link conveyor. Other common applications include bulk material loading to ships, barges and trucks, and the unit's belt and tracks can also be operated by remote control.
While the latest products aimed at the quarrying sector demonstrate that the market is split at least along regulatory lines, international demand is united by the constant requirement to improve efficiency and make quarry operations as cost-effective as possible. Manufacturers of equipment for the quarrying sector are wise to focus on maximising value for money across all markets.