Metso had an opportunity to design and implement cutting-edge extraction technology with a large scale project at Nebiri Quarry in Papua New Guinea.
Monier, Papua New Guinea’s single largest producer of construction materials and building products, has upgraded its Nebiri Quarry to increase annual output capacity from 300,000 to one million tonnes.
The Papuan government is so pleased with the project that it will serve as a stand-out example of technology when the country hosts the 2018 Asia-Pacific Economic Cooperation (APEC) leaders’ summit.
Following a review of submissions from a number of potential suppliers Monier awarded Metso with the Є10.5 million upgrade contract in July 2013. This included design, fabrication, installation and commissioning of the new plant.
“The plant configuration requested by Monier was not typical,” says Campbell Johnston, Metso’s director of Systems Sales & Support Systems.
“Before attempting any design work for our tender submission, we needed to clearly understand Monier’s space constraints and their 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.”
Delivering the project involved teamwork across three countries, Papua New Guinea, Australia and France. The design and supply of equipment was undertaken by Metso’s team based in France, with plant safety and electrical work complying with Australian OHS regulations and standards. Under Papua New Guinea’s laws Metso also had to set up a local subsidiary in the country.
Says Vincent Gibert, the installation project manager from Metso in France: “The key to the success of this project was the excellent cooperation 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.”
With the new plant designed to fit into an allocated space near the old plant, the first challenge was making enough room for a construction area on site. Metso got permission to convert a close-by rugby field into a construction zone and equipment was transported from here to the site as completed. Access to the new plant was shared with the existing plants, which required a diligent level of project management, careful planning and strict scheduling by the project team.
The new plant includes four stages of aggregate crushing and screening. 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 road base.
The plant simultaneously produces up to nine different products at a rate of 350 tonnes per hour and the plant design allows for special orders and extra capacity. The finished plant is capable of delivering nine separate products at a rate of 450 tonnes per hour, which is 100 tonnes per hour more than the contractual requirement.
During pre-contract discussions Monier’s management had expressed concerns about intermittent power cuts caused by unexpected demands on Port Moresby’s electricity grid. This meant designing a plant that runs on electricity or diesel generator sets through a programmable logic controller (PLC) and SCADA system.
Monier also wanted to be assured that its new plant would operate reliably for the next two decades. To address this, Metso included a five-year equipment protection plan in the contract.
The plant of the future
“The new plant is very advanced in terms of technology, ease of operation and maintenance,” says Stanley Correa, Monier’s electrical services manager.
“On the electrical side, the PLC system design is a real stand out 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 to be highly efficient, says Metso, using 40 percent less power per tonne than the older plants and delivering three times the output of both the 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 says in his 35 plus years of mining and quarrying experience throughout Australia and PNG, he has not come across a level of sophistication as good as the new crushing package at the Nebiri Quarry.
“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.”