Innovations in aggregates production will boost quarry efficiency
First publishedin World Highways
Improved stacking capabilities are claimed by Superior for its new conveyors
New innovations are underway that will help optimise rock crushing and screening operations and boost quarry efficiency overall - Mike Woof writes
Quarrying is a tough industry that provides enormous challenges to equipment providers as machines and technology have to be rugged, durable and productive. Cutting the cost of production while optimising output has been a major target for suppliers, with new technologies playing an increasingly important role.
Taking the long view with regard to increased quarrying efficiency, while improving sustainability, has been a particular focus for some firms in the field. And in this respect, Volvo CE’s partnership with the Swedish Energy Agency (SEA), construction giant Skanska Sweden and researchers at Sweden’s Linköping and Mälardalen universities to develop a quarry operation powered by electricity instead of diesel fuel is a major step forward.
The project is costing close to €22 million and is due for completion in 2018. The partners claim that it could deliver a great leap forwards in quarrying methodology, by pointing the way ahead for quarrying in terms of lowered running costs and improved output. A key issue is that it will allow producers to meet sustainability targets, while the project is also intended to reduce fuel consumption as well as emissions.
A government agency for national energy policy issues, the SEA is keen to increase the use of renewable energy, improved technologies and a smarter end-use of energy. The partners believe that by switching to electric power, the trial quarry site could reduce the amount of energy used by 71% and cut CO2 emissions from the current 0.7kg/tonne of material produced to 0.3kg/tonne.
“Collaboration is a key factor to achieving our environmental target,” said Martin Weissburg, president of Volvo CE.
Based on 2010 figures, the SEA estimates the energy consumption of construction equipment in Sweden at 14Terawatt–hours (TWh) compared to 19TWh for trucks, 3.7TWh for buses and 55TWh for private cars. The significance of these figures prompted the agency to ask Volvo CE what would happen if electrical power was used instead of diesel in a typical quarry. The subsequent discussions led to the electric quarry demonstration project.
“We estimated that if we could electrify a number of the functions in the quarry, we could reduce energy use by 71%. The intensity of the energy is much higher with electricity, which is why the potential savings are higher,” said SEA director general Erik Brandsma.
In many applications, excavators are sufficiently stationary to be powered with electricity through cables and this is common for many of the large excavators used in mining. Crushers in the demonstration quarry could also be powered through cables. Plug-in hybrid solutions could be developed for haulers. In the future, machines could be fully electrified with batteries, leading to the possibility of fully autonomous, driverless machines guided by computer, according to Brandsma.
Volvo CE has been working on the technologies that will be applied to the project for some time. The company will continue to develop the concepts in-house before Skanska incorporates the machines into its operations during the 2018 demonstration, proving the technology is viable for the industry.
Terex Finlay is offering a powerful new mobile cone crusher
This project involves creating new concepts which are part of our long-term future vision,” said Anders P Larsson, executive vice president of Volvo CE’s technology function. “The work that we’ll do over the next few years has the potential to change the entire construction industry.”
“We consider quarries to be a good place to start with electrification – many of them already have electricity installed and some electric equipment on site,” said Jenny Elfsberg, Volvo CE’s director of emerging technologies. “We have been working with general purpose and production equipment in quarries for a long time, so we know them,” she added. “We can analyse and find efficiency improvement and we can easily compare before and after performance.”
The technology could eventually be introduced to large construction projects and electric-powered construction equipment will offer benefits such as lower noise emissions, of particular concern in the urban environment. Experience with diesel electric machines shows that these tend to have low maintenance needs while the way power is applied means that tyre wear tends to be reduced, an important issue with regard to cutting running costs.
The electric machines also offer Volvo CE the chance to redesign certain aspects of the machines and boost performance, visibility and ease of maintenance. Volvo CE director of design Sidney Levy. “They create a great design opportunity by allowing us to remove conventional systems and components. This gives us the ability to explore different machine designs for better visibility and serviceability,” he claimed.
New machinesMeanwhile new equipment and systems for crushing and screening applications are coming to market, with major advances in machines from a number of firms. Machines are becoming more productive and reliable, while firms are devising ways to make equipment easier to service and more versatile and mobile.
IROCK is now offering its RDS-20 primary crushing plant, a versatile system designed for fast set-up times and ease of transport. The RDS20 (rapid deployment system) is said to be portable, easy to operate and highly mobile. The machine features a closed circuit design, with a high-performance four-bar impactor. It is equipped with heavy-duty components that maximise reliability, efficiency and help deliver a high quality, cubical product. The machine is also versatile as it can process a variety of materials, including quarry rock, demolition debris, recycled concrete and recycled asphalt.
Volvo CE is involved in a partnership to trial electric machines in a working quarry and will modify mobile equipment for the project
The machine features a 1.52m by 5.5m, double-deck screen. It has the ability to crush, screen and separate up to three different sizes of materials, two sized and one crusher run, at a rate of up to 450tonnes/hour.
The closed-circuit design allows both decks of oversized material to return to the feeder for another pass through the crusher after the initial round of screening. This is said to increase production by 20% over earlier generation machines. In addition, with onboard power supplying full plant operation, the entire process is self-contained. The crusher is powered by a 328kW Caterpillar C-13 ACERT Tier 3 engine. The RDS-20 can also be supplied with a Tier 4 engine.
Performance and production are said to be further optimised by the four-bar impactor design. The design is said to maximise production while avoiding uneven wear on the impact bars. The heavy-duty, two-step tapered grizzly removes fines and allows only large materials into the crusher. The hydraulically adjustable aprons are easy to adjust and are said to allow better control over sizing. In addition, three optional auxiliary conveyors are available to sort and stack product.
The RDS-20 is available with IROCK’s patented Hydraset Hopper, which is designed to be fitted or removed as a single unit. This can be handled by one person and does not require the use of any outside lifting device. The system operates from an internal power pack, which allows the unit to be detached and placed on a trailer in a matter of minutes.
The mobile crusher also has IROCK’s novel ROCK BOX, which is said to cut down on maintenance needs and wear part costs. The ROCK BOX uses a shelf system with abrasion resistant wear bars that allow crushed material to build up and act as a wear liner. It also incorporates special AR-400 steel plate liners for each material transfer point, which boost durability over rubber liners used in other crushers.
To reduce cleaning and maintenance needs, the RDS-20 features a standard dust suppression system. Catwalks enable easier screen changeouts and provide convenient access to crucial maintenance and cleaning points. And operators can remove the machine’s control panel and operate the crusher from up to 9.14m away to remove it from the dust and vibration of normal operating conditions.
Meanwhile Metso is keen to improve safety for crusher maintenance personnel. The firm is offering a new maintenance platform for use when changing wear parts in its C Series jaw crushers.
The maintenance platforms consist of hand rails, sturdy work platforms and related control mechanisms. The firm says that using these platforms allows wear parts to be placed more easily, reducing the risk of accidents for service personnel.
The platforms are made of aluminium and are light enough for one person to move. The units are available to match with either single-piece or two-piece jaw dies.
"With a small investment, Metso's new maintenance platform offers a huge improvement in safety when making jaw changes. When the platform is installed correctly into the opening, it holds the jaw in place so that it cannot drop, even if the jaw's upper mounting hardware is loosened or even removed. The platform is lightweight and it is easy to handle and adjust to fit the desired level in the crusher cavity," explained Ilkka Somero, product manager of Metso's jaw crusher line.
"The textured aluminum platform is sturdy, slip resistant and covers the crusher cavity properly to prevent anyone from slipping or getting a leg wedged between the jaws. Due to its light weight, the platform is easy to lift into position and remove, speeding up the work of changing parts," said Somero.
The family of maintenance platforms is available for all Metso Nordberg C Series jaw crusher models from the C80 up to the C200 and the units weigh from 12-23kg, depending on specification.
Also intended to reduce output losses due to unplanned downtime is a new technology from Superior Industries. This allows the firm’s TeleStacker Conveyors to maintain level movement while in radial travel mode. This patent-pending technology allows the telescopic radial stacking conveyor to maintain a balanced structure. As a result, the belting for the TeleStacker Conveyors is less prone to mistracking, which can cause major production problems otherwise.
Auto level technology is standard on all FD Axle model TeleStacker Conveyors equipped with PilePro Automation. Superior manufactures FD Axle models in lengths of 33.5m, 39.6m, 41.5m, 45.7m and 48m.
Terex Finlay is widening its range of cone crushers with its new C-1545 and C-1554 models. The C-1545 is a 43.4tonne tracked mobile cone crusher and this mid-range unit is said to offer operators a high capacity suited to the aggregate production.
The Terex AggreStac Conveyors have been developed in response to market research which identified the need for new stockpile solutions
This productive machine incorporates the new Terex TC1150 cone crusher with direct variable speed clutch drive, automatic tramp relief and hydraulic adjustable closed side setting (CSS) adjustment. Its large hopper/feeder has an automated metal detection and a purge system to protect the cone and reduce downtime. Metal contaminants can be quickly removed, preventing damage and reducing production downtime. Additional benefits include rapid set-up time, ease of maintenance, high reduction ratio, advanced electronic control system, high-output capacity and high-quality product.
The machine benefits from a fuel-efficient direct drive transmission, a hydraulic tramp relief system with an automatic reset and a metal detection system on feed belt.
The C-1554 cone crusher is a 61tonne tracked mobile unit at the top end of the firm’s range. The C-1554 is said to be a high-output capacity machine that provides large reduction ratios and high-quality cubical shape.
The machine is equipped with the proven MVP450x cone crusher, which can accept an all-in feed and features direct variable speed clutch drive and hydraulic closed side setting (CSS) adjustment.
Other features include its patented Rollercone roller bearing design and a hydropneumatic tramp iron relief system. The firm says that the crusher offers efficient and aggressive operation, as well as high-performance and a low cost/tonne. Other advantages include, rapid set-up time, ease of maintenance, high reduction ratio, advanced plant electronic control system and a high-output capacity.
Meanwhile sister company Terex Washing Systems (TWS) has widened its portfolio with the introduction of the AggreStac Conveyor Range. The Terex AggreStac range currently consists of three options, 15.2, 19.8 and 24.4m. The TWS Design Engineering team considered a wide range of options and features in the new design to aid the customer, which included low transport costs. The conveyors can be transported in one 12.2m container, with track in, track out ability, eliminating crane costs and lowering set-up times. The Terex AggreStac Conveyor Range also comprises tried and tested components used in existing Terex equipment such as rollers, drums and drives.
The features include full under belt and head drum guarding, radio control movement and set-up where required. In addition the Terex AggreStac Conveyors are designed so they integrate with existing electrical and hydraulic control systems on TWS equipment.