Editor's Desk

Modern crushing, screening technology showcased at PNG quarry

Papua New Guinea is the host nation of the 2018 Asia-Pacific Economic Co-operation (APEC) leaders’ summit. This is a great honour and provides the country with the opportunity to boost investor confidence by demonstrating it has the fundamentals and capabilities to drive sustainable economic growth. Fifty-five per cent of PNG’s population is younger than 24, and 35 per cent of this group is younger than 14. This age distribution is a key indicator of PNG’s high potential for growth and highlights the urgency of attracting investment to enable the rapid development of the country’s infrastructure.

Monier is PNG’s single largest producer of construction materials and building products. When the company upgraded its Nebiri Quarry to increase annual output capacity from 300,000 to one million tonnes, PNG’s government publicly commended Monier for its contribution to the country’s ability to deliver significant infrastructure improvements.

Established in 1958, Monier was purchased by its current owner Sir Theophilus (George) Constantinou in 2005. Since then, the company has invested in its capability to meet the complexities and growth of PNG’s construction industry. Currently employing 350 people, Monier supplies readymix concrete, quarry products, pre-stressed/pre-cast concrete products, masonry products and reinforced concrete pipes.

Monier’s Nebiri Quarry, in PNG’s National Capital District, supplies the key ingredients required for developing infrastructure, including aggregates, roadbase, armour rock, sand and select fill. The upgrade will serve as a standout example at the 2018 APEC summit of PNG’s ability to harness the latest technology.

Investing in technology

{{image8-a:c-w:300}}The decision to invest in upgrading the Nebiri Quarry was made in 2012, so Monier could be well positioned to take full advantage of the growth in infrastructure that would be generated during preparations for the APEC summit, as well as the ongoing opportunities the summit might bring. Monier wanted to be seen as a supplier of choice for future infrastructure projects, so it was important for the company to make a good impression on PNG’s government and infrastructure developers. With this in mind, Monier focused on a new plant design that would feature a high degree of sophistication, combining record efficiency and high operational standards.

The company aspired to build a highly advanced plant that would be seen by the country’s construction industry as “the plant of the future”. Importantly, this approach would also allow Monier to become a shining example of PNG’s ability to deploy advanced technologies. Therefore, it was vital that the plant featured leading edge technology that would create new benchmarks in safety, automation, ease of maintenance, production efficiency and versatility.

Operational needs, constraints

Campbell Johnston, Metso’s director of systems sales and support systems, explained the company’s approach to the project.

“The plant configuration requested by Monier was not typical,” he said. “Before attempting any design work for our tender submission, we needed to clearly understand Monier’s space constraints and its operational requirements. We decided that the best way to achieve that was for our engineers to visit the site.

“While sending our engineers over to PNG was a costly exercise, it proved to be a very good move. Based on our team’s first hand appreciation of site conditions and an exchange of ideas with Monier’s management, they were able to propose an optimised solution.”

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Locating the new plant close to existing plants was a logistical necessity. Land adjacent to the existing plants was allocated, but it did not offer the ideal amount of space for a plant that matched Monier’s production requirements. Metso’s proposal was based on an innovative design that ensured the new plant would be compact enough to fit into  the allocated area.

Following a rigorous review of submissions from a significant number of potential suppliers, in July 2013 Monier chose Metso as a strategic partner, awarding the company a 10.5 million Euro ($AUD15.5 million) contract for the upgrade. The contract included design, fabrication, installation and commissioning of the new plant.

“When our final bid was ready, we returned to site with our France-based project manager Jean-Marc Tonneau to present the proposal in person,” Metso’s Australasian systems business manager Glenn Oldfield said. “We were the only company that took the approach of visiting the site to understand Monier’s requirements and then returning to present a proposal. We wanted to show Monier our commitment to a partnership that could successfully deliver an outstanding solution. Combined with our deep knowledge of Monier’s requirements, this helped us to win the order. It set a really good tone for the entire project.”

Project execution

Delivering the project involved teamwork across three countries: PNG, Australia and France. A Metso team based in the French town of Mâcon undertook the design and supply of equipment. Plant safety had to be in line with Australian occupational health and safety (OHS) regulations, and all electrical work was to comply with Australian electrical standards. To best cater to these requirements, Metso Australia took the lead on OHS as well as the plant’s electrical design, installation and commissioning.

To comply with PNG’s laws, Metso had to set up a local subsidiary. The company’s employees and contractors from outside PNG all needed to have work permits and visas. Setting things up for effective project execution was complex. The process was delayed due to new business and visa procedures that had just been introduced by authorities.

Robert Palmer, Metso’s Australian project manager, explained how Monier helped Metso work through these issues.

“Customers are not obliged to get involved in a supplier’s logistical problems,” Palmer said, “but Monier closely partnered with us to get the necessary authorisations. Good collaboration between our two teams is what made all the difference in delivering this complex contract.”

Metso engaged its Australian electrical partner Peak Industrial Electrical, plus PNG companies, including electrical subcontractor SBS Electrical and Workforce, for the construction work.

Vincent Gibert, the installation project manager from Metso in France, said: “The key to the success of this project was the excellent co-operation between our multinational team that included representatives from Monier, Metso and our contractors. From the outset and throughout the project we performed well together. We shared competencies, information and best practices in each phase, from bid to installation.

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“From a Metso point of view, our teams in Australia and France collaborated to engineer a proposal that led to detailed budget estimates and split responsibilities. This is what ultimately delivered the most cost-effective solution for Monier.”

Construction challenges

With the new plant designed to fit into the allocated space, one problem still remained – there was not enough room for a construction area. Thinking “outside of the box”, Metso gained permission to convert a nearby rugby field into a construction zone.

Equipment was transported from the construction zone to the new site as complete and semi-complete assemblies. Access to the new plant is shared with existing plants, so an extraordinary level of project management was required to ensure the movement of equipment and personnel to the new site would in no way hinder production at the existing plants. This required careful planning and strict scheduling by the project team. Good communication between Monier, Metso and all the contractors was essential.

Plant configuration

The new plant includes four stages of aggregate crushing and screening (see Table 1, page 15). The first three stages consist of three crushers in series, each followed by a triple-deck screen. In the final stage, there is the option to send all or part of the product for shaping through a vertical shaft impact crusher. A bonus from this stage is a fine aggregate by-product that can be used as an additive in roadbase.

The plant simultaneously produces up to nine different products at a rate of 350 tonnes per hour. “Made to order” products have no impact on production rates or quality. To achieve this result, Metso worked closely with Monier’s management to develop a design that offers a unique level of flexibility. Metso’s design allowed for extra capacity, so Monier was delighted when final tests showed the plant is capable of delivering the nine different products at a rate of 450 tonnes per hour, 100 tonnes per hour more than the contractual requirement.

Power considerations

During pre-contract discussions, Monier’s management expressed concerns about intermittent power cuts that they experienced, mostly without warning. These were caused by unexpected demands on Port Moresby’s electricity grid. Metso addressed these concerns with an electrical design that enabled the plant to be run on either mains power or by diesel generator sets (gen-sets). When power is lost, the gen-sets provide power to the plant without the need for connection to the electricity grid.

The system incorporates an uninterruptible power supply, which provides back-up power for the PLC and SCADA system. A signal appears on the SCADA screen to let the operator know when mains power is lost. The system also lets the operator know when the gen-sets are “run up” and in operation.

Monier wanted to be assured its new plant would operate reliably for the next 20 years. To address this, Metso included a five-year equipment protection plan in the contract. Shaun Fanning, Metso’s Australasian head of aggregates said, “In the unlikely event of component failure, we cover all costs, which demonstrates our faith in the reliability of our equipment. This has given Monier a high degree of confidence in the plant’s endurance and performance.”

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Plant of the future

“The new plant is very advanced in terms of technology, ease of operation and maintenance,” Stanley Correa, Monier’s electrical services manager, said. “On the electrical side, the PLC system design is a real standout for me. From the maintenance diagnostic tools and monitoring equipment that can pinpoint a problem at its source, right down to the compartmentalised layout and the reporting software.”

In operation the plant has proven highly efficient, using 40 per cent less power per tonne than the older plants and delivering three times the output of both existing plants put together. This has been achieved through the combination of the plant’s high production capacity and a unique design that allows production to continue while sections of the plant are offline for maintenance.

Anthony Grimmer, Monier’s quarry manager, is pleased with the new plant.

“In my 35-plus years of mining and quarrying experience in Australia and PNG, I have not yet come across the level of sophistication as provided by Metso in the total crushing package at the Nebiri Quarry,” he said.

“In my opinion we can easily claim to have a true ‘plant of the future’. It puts us in a strong position to be selected as a preferred material supplier for PNG’s current and future infrastructure projects.” 

Source: Metso

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