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 MOBILE HOPPER CHALLENGE OUT WEST - Nov 11

An Australasian manufacturer of quarrying and mining equipment takes on an unusual mobile plant challenge: constructing rail-mounted hoppers for an integrated conveying system out west.

Rocktec, which specialises in the manufacture of quarrying and mining equipment in Australia and New Zealand, has gained the reputation of “thinking outside the box” with its innovative approach to unconventional challenges, but none more so than with the mobile shiploading system that was designed and built for the Port Hedland Utah Point Berth project, commissioned by PINC Group Pty Ltd on behalf of the Port Hedland Port Authority. Rocktec does not manufacture off-the-shelf mobile crushing equipment.

As CEO Rick Johnson confirmed: “The market for stock type mobile crushing plant is well served by a plethora of existing suppliers. Our expertise is targeted towards providing custom solutions for more project-specific applications.” However, following this policy of bespoken configurations, Rocktec has, in recent years, built and supplied a variety of wheeled mobiles, incorporating jaw and cone crushers, screen/HSI combinations, specialised screening and washing outfits, as well as the largest tracked impact crusher in Australasia. When it was appointed for the Utah Point Berth shiploading scheme in September 2009, Rocktec had to design rail-mounted hoppers, each capable of delivering a maximum of 2500 tph to an integrated 1500mm wide conveying system, and with the capability of being loaded from large front-end loaders.

The trains were designed to operate over a central load-out conveyor, with trailing power cables and water pipes for dust suppression. The six hoppers and two motor control centres required for this solution have achieved considerable capital and operating cost savings. The contract imposed strict time schedules on Rocktec to meet and, with manufacture commencing in October 2009, these deadlines were met, and shipment from New Zealand to Australia completed in April 2010 – a challenge in itself with a total supply exceeding 700 tonnes in weight, mostly of over gauge items (no disassembly for shipment was undertaken).

A special vessel was chartered to ship the equipment direct from Tauranga, New Zealand to Port Hedland. This substantially reduced the transit time as it enabled shipment of complete units (avoiding part dismantling). Trans-shipment via Perth, followed by a road train to the site and reassembly in Port Hedland, would have required substantially higher labour costs. Installation commenced immediately upon arrival of the equipment on-site, and commissioning and acceptance taking place by late May 2010.

Technically, Rocktec faced a wide array of challenges to comply with the performance requirements of the contract, as well as strict environmental, safety and standards compliance issues. The complete scope of supply complied with and surpassed all applicable Australian Standards. Provisions were made to ensure that all lifting points were properly designed to suit the physically large and open hoppers, whilst corrosion protection was also a prerequisite in the design. Conditions were imposed on time to manufacture, supply and install, as well as performance guarantees to a maximum of 7500 megatonnes per hour of iron ore.

A design life of 25 years was also built into the design criteria and there had to be a 95 to 98 per cent operational availability on a 358 days per year operation (2575 hours per year), with an annual throughput in excess of nine million tonnes per annum (9MTPA). An automated water spray/dust suppression system with additional sprinklers at transfer points was incorporated into each of the six hoppers, together with hoods to minimize dust emissions. The water supply, using fixed tension hose reelers on each unit, also comprised a wash-down function. Removable enclosures/covers were included to reduce noise levels to below 85 decibels at a one metre distance.

Other operational conditions which had to be met included:
• A standard hopper design to permit hopper interchangeability in case of damage.
• Hopper and transfer points design to cope with extremely abrasive material, with the potential for handling high percentages of fines in some products.
• An interface with prescribed definitions of feeder types, and the inclusion of a facility for access to skid steer loaders for spillage clean-up from the loading process. This condition dictated the maximum height of hoppers to avoid building ramps. The slope angle of the hoppers had to enable complete self-emptying to avoid any contamination between changes of material being handled.
• The conveyor system was designed to handle high impact loads, maintain high capacity at high levels of availability, and the inclusion of effective skirting, ensuring low levels of maintenance.
• Each feeder (a Rocktec XHD apron feeder for each of the six hoppers) is capable of 2500 tph sustained capacity at 100 per cent speed and each incorporated 20 to 100 per cent speed variability. Provision was made for each hopper to be discharged even in theevent of a feeder failure. Dribble conveyors were supplied with each feeder to collect any fines spillage between the pans.
• Redundancy of key components was built into the design in all areas ito allow for operation in the event of a component failure.

Each train is equipped with a dedicated Motor Control Centre (MCC), with electrical supply provided through a trailing cable for power, and fibre optic cable for communications. Each MCC, being airconditioned, dust proof, insulated and sound proof, provides a safe, comfortable working environment, and is positioned clear of the hopper area to avoid damage from falling ore. Each MCC incorporates an on-board PLC, with a control philosophy providing interlocked operational and safety functions, remote emergency stops and lock-out facilities for maintenance.

Visual operational devices, such as beacons, have been included, as well as external lighting aimed at the hopper area. Full instrumentation, with visual and audible alarms, has been incorporated into the controls. As summarised by Neil Parker, managing director of the PINC Group and project manager of the Utah Point Berth Project: “We required infrastructure to facilitate loading out at 7500 tph a wide range of ores in an environmentally challenging application. Under a fixed lump sum design, fabrication and supply contract, Rocktec delivered on time two unique rail mounted hopper trains that were assembled and commissioned with relative simplicity and performed to expectation. It was a breath of fresh air to work with a vendor that got on with the job without fuss and delivered above expectation on a part of the project that presentedpotentially significant risks.”

 

SEEKING A TOTAL PLANT CONCEPT - May 11

Today’s plant and equipment are being developed to “design out” the usual wear, tear and maintenance of the quarrying environment.

Rocktec, a reputable industry leader in New Zealand for over 20 years, expanded operations into Australia by setting up a facility near Brisbane in 2009 to provide contract maintenance support in major aggregate processing plants. Since then, it has evolved its operation to provide a complete design and build capability. It has recently overseen a major plant extension for Southern Quarries in South Australia and has almost completed a turnkey crushing and screening plant for Boral in Victoria.

Rocktec’s philosophy includes a thorough evaluation of process and development of flow. It uses the best independent simulation programme, in conjunction with ongoing client input, to ensure that the concept proposed is 100 per cent suited to the required duty and will meet the client’s required performance parameters.

The plant design is executed with 3D modelling by a team of trained, experienced engineers who use their expertise to design out maintenance and wear. A 15 per cent or more reduction in maintenance can be achieved by attention to, for example, transfer points and chutes, where trajectory points and velocity are analysed in order to prevent wear by repositioning conveyors, introduction of rockboxes/dead pockets, and the use of the optimum type of liner to resist abrasion, impact, or a combination thereof. Reduction of maintenance is reflected by a significant increase of availability and is complemented by the provision of ample and free access for maintenance, etc, all of which increase operational profit.

Careful selection of manufacturing sources internationally enables Rocktec to provide significant cost reductions of cost per tonne, with no consideration of any compromise on weight or quality. All manufacturing is carried out under Rocktec supervision and to its own onerous standards, surpassing those imposed for Australia and New Zealand. The design of the conveyor system, often regarded as ancillary to the process, is carefully sized and designed. All components are selected to be reliable/ durable in operation. Rocktec believes that operational efficiencies achieved by adhering to the supply of quality components will yield ongoing, long term economies in the form of reduced running costs, long into the future. Another example is that all Rocktec conveyor drives are adequately sized to enable, at a minimum, full load starts at any time. Rocktec’s policy on structural steel and selective sourcing enables it to maintain competitive prices yet supply the high standards demanded by its clients.

 

ADVANCED CONTROL SYSTEMS
No strategy for high quality plant and simplified operation is complete without a reliable, advanced control system. Rocktec incorporates well recognized control and switchgear into its plant control panels, which are based on the PC/PLC Scada control system of the whole plant. This includes the full technical integration of all quarry plant and associated equipment, as agreed with clients. Rocktec is now equipped to provide complete plant solutions to all quarrying applications, incorporating optimised process equipment, computer-assisted design and manufacture, robust and well designed and built machines, and state of the art controls.

 

AUSTRALIAN SERVICE CONTRACT SUCCESS

On July 1st, 2009 Rocktec Australia began a 2 year contract at Hanson’s Wolffdene Quarry, Qld, to undertake preventative and breakdown maintenance. The contract has recently been re-signed by both parties for a further 2 years. The Wolffdene plant is one Hanson’s largest in Australia, and is a focus of local Hanson management and its parent group, Heidelberg Cement, in Germany.

The contract is unique within Hanson and, we believe, within the Australian Quarry Industry. Rocktec supplies labour 5 nights per week for between 8 and 12 hours per night. We plan all the maintenance each night in conjunction with production requirements from Hanson. Rocktec is paid on a performance basis with an important part being to maintain availability of the plant at a minimum of 95%. An incentive bonus is paid above this level and, equally, a penalty applies if the plant doesn’t meet this - and the cause is directly attributable to Rocktec’s workmanship. In the last 22 months of the contract the plant has had 15 of those months at 95% or higher, with 3 of those months achieving 100%. An overall availability of 97% has been achieved in that time.

During the period the contact has been in force there have been many improvements made to the plant to make maintenance easier and reduce downtime. The plant today is in far better condition than when we started the contract in 2009 and is looked upon as a “role model” within Hanson. This is all due to the team of people we have put together in that time. They have taken on board the need to ensure our maintenance practices are sound so as to prevent plant breakdowns during production. The team identifies where improvements are required, what operating parameters Hanson require, and these are taken into account in future planning of maintenance tasks. They also propose minor capital improvements to further enhance the efficiency of the plant or to further reduce potential for down time.

Earlier in 2011 Rocktec was asked to extend its servive to provide 2 additional staff members to maintain the small road base plant also on the site. We currently employ 9 people between both plants and look forward to the challenge of keeping availability as close to 100% as possible.

 

 

ROCKTEC SOUTH AUSTRALIAN CONTRACT WIN

Rocktec has recently completed a contract with Southern Quarries to provide a tertiary screening plant at its Sellicks Quarry. Located between Aldinga and Myponga, just outside Adelaide, South Australia, the limestone quarry is mined to produce la large range of aggregate products for the South Australian market”.   

HOW THE CONTRACT WAS AWARDED
Southern Quarries undertook a competitive tender process, which included local suppliers, before selecting Rocktec. Southern Quarries CEO Brett Brown visited Matamata in New Zealand, where Rocktec is based, to personally check out the company’s manufacturing operations and capabilities. This evaluation also included Rocktec’s health and safety and quality values. Brett also had the opportunity to see the Stevensons Drury Quarry which Rocktec had previously supplied in 2003.

‘Viewing first-hand the quality of Rocktec’s manufacturing and processes, as well as taking into account their proven track record in delivering plant to a wide range of both local and international customers, helped to swing the decision in their favour,’ says Brett Brown. ‘It was crucial that we found a company that we could see as a project partner and not just a supplier of screens and conveyors when undertaking our evaluation of suppliers. The positive 'can-do-attitude' from all of the team at Rocktec gives us a lot of confidence that this would be and was a very successful project.’ 

 ‘We’re very pleased to have won the tender and now completed the work with a company of the calibre of Southern Quarries,’ says Rocktec CEO Rick Johnson. ‘They have demonstrated that they are forward thinking and open to new technology. It’s clear they were only interested in working with technology and suppliers with a good track record. This was a great outcome for us. It represents another vital step in our strategic penetration of the Australian market and our ongoing efforts to provide cost-effective solutions for its quarry industry.  ‘We’re pleased we have been able to provide Brett and his team with a solution that meets not only today’s needs but will also provide them with the flexibility to meet their future client requirements.’

Picture Below: Photo of the Quarry secondary and tertiary plant shown from the primary.

 

ABOUT THE TERTIARY SCREENING PLANT
Rocktec’s tertiary screening plant has been connected to the output of a second-hand Nordberg plant that Southern Quarries had purchased and relocated from Malaysia. This Nordberg plant crushes and screens through primary and secondary stages. The tertiary plant supplied by Rocktec takes the output from a Barmac crusher and provides multiple screening and stockpiling options (including radial stacking), which produces the various graded product splits required by Sellicks’ Quarry. The plant includes three new evolution Sandvik SC screens (two SC2463 20’ x 8’ and one SC1852 16’ x 8’units) which was commissioned with wire screen media sizing at the appropriate apertures. Rocktec completed the project in July 2010.

SECONDARY PROCESSING PLANT
Following on from the successful completion and commissioning of the tertiary plant Southern Quarries commissioned Rocktec’s design staff to review the performance of the “second hand” secondary plant and to advise how to reconfigure this equipment into the best configuration for Southern Quarries needs and to better integrate it into the tertiary plant already provided. Rick noted “It is pleasing that Brett and his team were so pleased with our initial tertiary plant offering and were therefore prepared for us to help optimize the existing secondary plant process to better meet their needs”.

The secondary plant redesign and work became a project as large as the initial tertiary plant and Rocktec extended its time and personnel on site and worked closely with Southern’s operational staff to ensure that as minimal interruption to the plant’s operations could occur as possible when undertaking the corresponding changes to the plant. Rick says that Rocktec have enjoyed working with Southern Quarries and notes they have actively engaged with all of the Rocktec staff on site. “This engagement includes everyone from the Southern Owners/Directors, CEO and operational people and Rocktec have thoroughly enjoyed the positive working relationship that has developed between the parties. I believe that this has led to a true win/win outcome for both companies.”

 

ROCKTECS AUSSIE CONNECTION PAYS OFF - September 2009 - May 2010

Rocktec has gained the reputation of “thinking outside the box” with its innovative approach to unconventional challenges it has faced, but none more so than with the mobile ship-loading system designed and built for the Port Hedland Utah Point Berth project, commissioned by PINC Group Pty. Ltd. on behalf of the Port Hedland Port Authority.

ASSEMBLED AT THE ROCKTEC  FACTORY

PINC Group was a category winner at the 2011 WA Engineering Excellence Awards, as the project management team for the Utah Point Multi-User Bulk Export Facility, which won the Resource Development Category which includes mining and power industries, or any other engineering project or activity associated with the development and/or processing of any mineral or natural resource.

Rocktec does not manufacture off-the-shelf mobile crushing equipment –  as CEO Rick Johnson confirmed “The market for stock type mobile crushing plant is well served by a plethora of existing suppliers and our expertise is targeted towards providing custom solutions for the more project-specific applications”. However, following this policy of bespoke configurations, Rocktec has, in recent years, built and supplied a variety of wheeled mobiles, incorporating jaw and cone crushers, screen/HSI combinations, specialised screening and washing outfits, as well as the largest tracked impact crusher in Australasia.

When approached to offer for the Utah Point Berth shiploading scheme, Rocktec had a completely new set of circumstances to meet, namely rail-mounted hoppers, each capable of delivering a maximum of 2,500TPH to an integrated 1500mm wide conveying system, and with the capabilities of being loaded from large front-end-loaders. The trains were designed to operate over a central load-out conveyor, with trailing power cables and water pipes for dust suppression. The six hoppers and two motor control centres required for this solution have achieved considerable capital and operating cost savings.

Rocktec received the original enquiry in late 2007 and there followed a lengthy process of proposal and consultation, with PINC and Rocktec collaborating as partners, rather than as a traditional supplier/client relationship. Open communications and transparency at all stages were paramount in the successful execution of the project. Thus, by mid 2009, a final specification was issued, this being based on the results of the close co-operation between PINC and Rocktec, and a contract signed in September 2009.

The contract imposed strict time schedules for Rocktec to meet and, with manufacture commencing in October 2009, these deadlines were met, and shipment from New Zealand to Australia in April 2010 this in itself proving to be a further challenge, with a total supply exceeding 700 tonnes in weight, mostly of over gauge items (no disassembly for shipment was undertaken). A special vessel was chartered to ship the equipment directly from Tauranga port, in New Zealand, to the Port Hedland destination. This proposal by Rocktec substantially reduced transit time by enabling shipment as complete units and avoiding part dismantling, transshipment via Perth, followed by road train to site and reassembly in Port Hedland, that would have required substantially higher labour costs than could be achieved at Rocktec’s facility in New Zealand.

FINAL ASSEMBLY AT THE FACTORY               

LOADING FOR SHIPMENT

Unloading took place immediately after arrival at Port Hedland, with installation commencing immediately upon arrival of the equipment on site, and commissioning and acceptance taking place by late May 2010.

MOBILE HOPPER TRAIN CONCEPT

Technically, Rocktec faced a wide array of challenges to comply with the performance requirements of the contract, as well as strict environmental, safety and standards compliance issues. The complete scope of supply complied with and surpassed all applicable Australian Standards (AS). Provisions were made to ensure that all lifting points were properly designed to suit the physically large and open hoppers, whilst corrosion protection was also a prerequisite in the design. Conditions were imposed on time to manufacture, supply and install, as well as performance guarantees to a maximum of 7,500MTPH of iron ore. Further to this, built in to the design criteria was a design life of 25 years, operational availability of 95-98% on a 358 days/year operation (2,575 hrs/year), with an annual throughput in excess of 9MTPA.

An automated water spray/dust suppression system with additional sprinklers at transfer points, was incorporated into each of the six hoppers, together with hoods to minimise adventitious dust emissions (with average ambient wind speeds of 17-21KPH this was a crucial consideration). The water supply, using fixed tension hose reelers on each unit, also comprised a wash down function. Removable enclosures/covers were included to reduce noise levels to below 85dBa at 1m distance.

3D SIMULATION OF STOCKYARD SHOWING CENTRALLY LOCATED MOBILE HOPPER TRAINS

Operational conditions which also had to be met included: 
- A common design of hoppers to permit hopper interchangeability as necessary in case of damage.
- Hopper and transfer points design to cope with an extremely abrasive material, with potential for handling high percentages of fines in some products.
- Interface with prescribed definitions of feeder types, and inclusion of facility for access to skid steer loaders for cleanup of spillage from the loading process. This condition dictated the maximum height of hoppers to avoid building ramps. The slope angle of the hoppers had to enable complete self-emptying to avoid any contamination between changes of material being handled.
- The conveyor system was designed to handle high impact loads, maintain high capacity at high levels of availability, and the inclusion of effective skirting, needing very low levels of maintenance.
- Each feeder (one Rocktec XHD Apron feeder for each of the six hoppers) is capable of 2,500TPH sustained capacity at 100% speed and each incorporated 20-100% speed variability. Provision was made to enable each hopper to be discharged even in the event of a feeder failure. Dribble conveyors have been supplied with each feeder to collect any fines spillage between the pans.
- Redundancy of key components/assembles was built into the design in all areas in order to allow for operation in the event of a component failure.

INBUILT COLLISION SENSORS

Each train is equipped with a dedicated Motor Control Centre (MCC), with electrical supply provided through a trailing cable for power, and fibre optic cable for communications. Each MCC, being airconditioned, dust proof (positive air pressure), insulated and sound proof, provides a safe and comfortable working environment, and positioned clear of the hopper area to avoid any damage from falling ore. Each MCC incorporates on board PLC, with a control philosophy providing interlocked operational and safety functions, remote emergency stops, lock-out facilities for maintenance. Visual operational devices, such as beacons, have been included, as well as external lighting aimed towards the hopper area. Full instrumentation, with visual and audible alarms, has been incorporated into the controls.

ONE LINE OF MOBILE HOPPERS IN OPERATION

As summarised by Mr. Neil Parker, MD of the PINC Group, who was the project manager at the time of execution of the Utah Point Berth Project - “In the Utah Point Stockyard (Port Hedland), PINC Group required infrastructure to facilitate loading out at 7,500 tonnes per hour a wide range of ores in an environmentally challenging application. Under a fixed lump sum Design, Fabrication and Supply contract, Rocktec delivered on time two unique rail mounted hopper trains that were assembled and commissioned with relative simplicity and performed to expectation. It was a breath of fresh air to work with a vendor that, despite a relatively tight performance specification, got on with the job without fuss and delivered above expectation on a part of the project that presented potentially significant risks”

The award reflected the purpose of the project, which was to address the need to expand the port facilities to meet global demand for mineral resources and provide resource companies to access the important export markets. It was considered that the Utah Facility introduced a range of innovative and new technologies to improve the port facilities and throughput capacity, and had mitigated a number of community concerns on noise, dust and traffic.

Within the first six months of operation, the system proved capable of exceeding design parameters, and delivering an expected export sales value in excess of A$1.5 billion annually. Both PINC and Rocktec are proud to have been part of this large project and are looking forward to executing projects together in the future, where they feel that their unique combination of skills, innovation and determination will give them a very competitive edge.

Source: Rocktec, Australia