[Article from ScrapBook No 5 2014]
Ok Tedi Mining Limited (OTML), which operate a gold-copper mine in the Western Province of Papua New Guinea, is setting an example to the rest of the mining industry. The mining industry uses large tires on mining trucks, conveyor belting and drums and these have always presented a problem with disposal. They are usually disposed of in land-fills, but OTML decided that this material could be treated as a recyclable resource rather than a waste product.
Huge tires – a large scale problem
In the middle of Papua New Guinea, close to the town of Tabubil, the gold-copper mine company Ok Tedi Mining Limited (OTML) is setting an example for the mining industry globally. OTML has approximately 40,000 cubic meters of waste tires that have accumulated over the last 30 years of mining as well as a considerable quantity of conveyor belts, drums and other material which accumulates at the mining site. Recycling of waste car and truck tires is a successful business – what if it would be possible to recycle these old mine truck tyres and conveyor belts into a reusable commodity?
In order to find a solution, OTML got in contact with Eldan Recycling. South Pacific Manager for Eldan Recycling, Jim Hole, went to Papua New Guinea to meet with them in the middle of 2011. OTML wanted to process and dispose of the stockpiles of mining tires and conveyor belts in a socially responsible, as well as environmentally safe and sustainable manner.
“The most important thing for OTML was good citizenship and to clean up the countryside after 40 years of mining. They wanted to get the entire area as close as possible to its original state, including getting rid of scrap steel and old tires and conveyors. The fact that there is large money to be made is merely a pleasant bonus,” says Hole.
“Eldan is one of the leading manufacturers within tire recycling equipment, we have hundreds of reference plants within this recycling area world wide. This was however the first time that we had been asked to process a material as tough as this,” says Bjørn Laursen, Product Manager for tire recycling at Eldan. “We knew that there was a global problem with large mining tires piling up since no one had presented a solution to the problem. Basically all mining companies dispose of their used tires in the same way as OTML has done since 1984 – in landfills, or by using them as safety precautions for roads. Recycling of these tires is a huge business opportunity waiting to be dug up.”
Eldan had developed a complete solution to the problem, which had been partly delivered to a European company:
“The results from processing of mining tires at this customer were very positive. We had however not yet found a suitable customer for testing the complete solution until OTML got in touch with us. Naturally this project had highest priority,” continues Laursen.
Processing trials in Denmark
OTML was intrigued by the solution presented to them by Eldan, and in the end of 2011 OTML staff and Hole went to Europe to see the Eldan tire recycling equipment in production at two reference plants, and to be present at the test run for the mining tire recycling system in Denmark. A container load of the most difficult and oldest tires had been sent beforehand.
“The trials to produce a high quality rubber crumb from the large mining tires were very successful. The solution we had developed proved to be very efficient handling the kind of tough earth and ore moving truck tires used at the Ok Tedi mine. These tires have a diameter of up to 2.5 meters with a width of up to 1 meter, weighing as much as 3 ton,” says Larsen.
After the successful tests, and efficient negotiations OTML acquired an Eldan Tire Recycling Plant (type E4000T spec). in the beginning of 2012. This plant including one Tire Feeder (TF600), one Super Chopper (SC 2109T HD), one Multi Purpose Rasper (MPR200T), two Fine Granulators (FG1504), one Tumble Back Feeder, three Overband Magnets (DM1850/DM1450), one Drum Magnet, two Classifiers (PC10T/PC15), one Aspirator (UP1750) and a Separation table (C26). OTML also acquired a Complete Jet Air System and a Service Contact.
The mining tires are first handled and pre-cut by a heavy duty demolition shear into pieces which fit the in-feed of the Eldan Super Chopper HD, which is especially designed to process voluminous and tough waste. In the Super Chopper, the big pieces of mining tire are processed into tire shreds, and free steel wire is liberated and removed from the shreds by a powerful Overband Magnet. The tire shreds are then further processed in the standard Eldan granulation and separation plant. Depending on the customer specific requirements a high quality rubber granulate and clean steel wire can be produced.
The plant has a production capacity of approximately 3 ton rubber granulate/ production hour (corresponding to processing approximately 1-2 mining tires/production hour). The plant produces a 1-3 mm rubber granulate also separating and removing the steel reinforcement wires from the tires and conveyors for recycling. The rubber granulate is 99.9% free of liberated steel and textile.
“The plant was successfully handed over to OTML in May 2013 and has been very interesting and developing for Eldan from a technical point of view as well as from a project management point of view,” says Michael Sønderby Andersen, Project Manager at Eldan Recycling. “Our gained experience and increased knowledge from our supply to the OTML plant will be very useful for Eldan in upcoming projects within the mining industry.”
Transporting a 23 ton MPR to an extremely remote location
Once the equipment set-up for the facility had been decided, the main issue was transportation. The location of the plant in the middle of Papua New Guinea is extremely remote and isolated situated at about 2500 m altitude about 15 km from the Indonesian border. The equipment was shipped by boat to Port Moresby, and then further shipped by barge several hundreds of kilometres up river. Finally the 21 containers where transported on 160 km of dirt road.
Adding a very high rainfall in the region – on average 339 days and 10,000 mm per annum at Mt Fubilan (location of the Ok Tedi mine) and Tabubil, where its township is located - logistics has always been a major challenge. Most of the equipment required by OTML for its mining operations as well as food supplies is ferried from barges up the Fly River, an 800 km river length between the town of Kiunga and its estuary. From Kiunga, mine supplies are transported in truck convoys to the mining township of Tabubil, a 137 km distance.
The logistics presented some logistical issues, but the plant was delivered early in 2013. As far as the Danish personnel was concerned they flew 27 hours (excluding transfer time) via Dubai, Singapore, Brisbane and Cairns in order to get there. “It has been a pleasure working together with OTML in all aspects in the project phases,” says Andersen.
Since OTML had no previous experience from the recycling industry, the contract for supply of equipment also included installation, commissioning and training of personnel at OTML. Also, a regular contract for maintenance was also instituted between OTML and Eldan.
“After past environmental misfortunes the plant is a reverse for better. OTML has chosen to address this environmental issue head-on with innovation and with a broader program of environmental initiatives which we believe will ensure a safe, sustainable environment for the people of Western Province and Papua New Guinea for years to come,” says Nigel Parker, OTML Managing Director & Chief Executive Officer, during the opening of the plant.
Reusing a mountain of waste tires
Today, production is running smoothly, producing rubber granulate to demand. “Today we process about 3 ton/production hour and production is running as expected with few maintenance. We have only one customer at the moment and will be finishing off their request. Unless we get in another request, we will focus on the environmental issues as a clean-up process to reduce environmental impact, meaning running the plant at our own phase,” says Hendrick Min, Superintendent Industrial Waste and Disposals, Ok Tedi Mining Limited.
The rubber granulate product has multiple uses including it being used in the bitumen component of road surfaces to make them more flexible and longer lasting, to create surfaced playing fields in children’s playgrounds, as underlays for carpets and tiles, as building blocks, various industrial uses and as an compound in explosives.
The steel content of the tire is approximately 20%. By reducing the steel in size in the Eldan Tire Recycling Plant, compared to merely stripping it from the tire, it is easier to containerise. The steel is, together with other residual steel, being shipped to Port Moresby in containers and is a high quality steel by-product.
“We would definitely recommend Eldan. In fact we already have industry and company representatives visiting our plant and we recommend them to use Eldan. Eldan are competitive and they can customise the plant set ups and even operation to customer requirement,” comments Min. “If they can install a completely new plant in the terrains of PNG only accessible via planes, they are there for you.”
Parker is proud to have brought the company’s environment footprint to a new level. “The use of recycling mine tires in this way is a world first, and the eyes of the mining world are fixed firmly on what we have achieved and the progress we will make over the coming months,” Parker said when the plant was commissioned in early 2013. “This plant will recycle used mining tyres, conveyor belts and other hard mining waste materials into sustainable environmentally friendly products”.
Parker also acknowledged the expertise of Eldan and its specialists together with personnel from OTML for their contributions and hard work from start to finish of the plant construction.
The recycling facility at OTML is used by Eldan as a reference plant, and OTML is looking to share its knowledge and experience on this project to other mines in PNG and elsewhere.
“The future of processing mining tires in Australia and other countries is enormous. It is estimated that there is 1-2 million ton of mining tires in dumps in Australia up to date. That number is increasing by up to 100,000 tonnes per year. This will have to be cleaned up eventually as all mine sites have in their agreement to restore the area to original condition” says Hole. “The only obstacle is the end use of the finished crumb. I know that there is an Australian company, which has developed an explosive where rubber powder is an ingredient. Research and development for end use of rubber granulate and rubber powder is awaited.”