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Project Manager : June July 2011
23 www.aipm.com.au Project Manager PROBLEM WASTER Allied & Coal takes almost 20 million tonnes of coal out of the ground at its Mount Thorley Warkworth and Hunter Valley Operations annually. But it’s what is being put back in the ground that is turning heads. Ten thousand tonnes of mixed source compost will be used to boost nutrient levels as part of the rehabilitation of more than 100 hectares of land across the two mining operations. The use of organic waste, which would usually end up in landfill, will be trialled for 12 months. Bill Baxter, Environmental Specialist Rehabilitation at Coal & Allied, said compost – manufactured to specification by SITA Environmental Solutions – will improve the soil productivity and ultimately the local biodiversity of the rehabilitation areas. “Compost has long been a gardener’s secret weapon to improve soil structure and provide added nutrients,” he said. “The addition of compost is aimed at building long- term soil health by ‘feeding’ the soil rather than using chemical fertilisers to ‘feed’ the plant.” This innovative solution to the challenge of rehabilitating mined land has the added benefit of reducing the amount of organic waste that ends up in landfill, he said. “ Many people throw organic waste, like garden trimmings and food scraps, into their rubbish bins, even though it can be composted. This organic waste makes up to 40 per cent of all rubbish in council garbage collections. “Mixed source compost is also easier to handle and spread over large areas than biosolids, which Coal & Allied has previously trialled on rehabilitation projects,” Baxter said. He added that the trial’s biggest costs come from the delivery of the compost, rather than buying the material itself, making it a cost- effective solution to an age-old problem for miners. site just in case they were needed. All the equipment used was brand new to cut down on maintenance issues given the project’s remote location, the salt in the air and the cyclones that occasionally hit the island and frustratingly add water to the pit. “There’s no land access so all the materials usually come in by barge, which is a 24-hour journey from Derby, and it’s a two or three-day drive from Perth to the port at Derby. Everybody’s flown in by plane and it’s two flights to get to the island. So logistically it’s a massive challenge. It’s not the sort of place where you can call up and get something from around the corner. It requires a lot of pre-planning.” Choosing partners When Moore joined the project four years ago, all that had been assumed was that some of the work would have to be conducted from floating barges. He spent the first 12 months developing the methodology, creating a budget, producing a document for the Mines Department and choosing the right partners. “We didn’t have expertise in absolutely every area , but we sought partners who did,” Moore said. “ You’ve really got to surround yourself with experts in their field who are also positive and proactive people who share the same beliefs.” ROCK augmented its experience in drilling and ground support with specialist providers of marine vessels and personnel, and rope access technicians through Vertech. “Rope access was crucial to delivering the project. The mining industry has a lot of reservations about using rope access technicians in an open pit mining environment, but there was really no other solution.” The right tools Perhaps the most important challenge was sourcing a drill rig capable of operating from a floating base. The DX800R drill rig was chosen, and its remote operation capabilities were critical whenever the condition of the wall, with its potential for rock falls, posed a direct threat to the operator. Other critical innovations have included the use of a mine radar that monitors movement of the pit walls to warn of likely dangers, and the development of marine-based agitators that sit on the barges to spray the concrete onto the pit wall, given the wall’s inaccessibility. “We took a piece of equipment that you’d normally find in an underground mining environment and used it in an open pit mine,” Moore said. After four years Moore’s cautious, safety-conscious approach is working, with 25 metres of water already drained and the initial stage of the project due to be completed by year’s end. There has been no lost time to injuries, and now that the GFC (which stalled the project for eight months) has abated, it seems like nothing can stop Moore’s quest to turn back the Indian Ocean ... not even those tiger sharks. ( COVER STORY • Miners abseil down one of the walls of the Mount Koolan mine, WA Drills operating on floating barges extract iron ore from the mine walls
April May 2011
Project Manager Aug Sep 2011