Eriez Magnetics explains how modern separation equipment can increase ferrous and nonferrous recovery rates for material recovery facilities handling municipal solid waste.
Collecting, processing and recovering metals, both ferrous and nonferrous (NF), has spurred owners, operators and developers of material recovery facilities (MRFs) to install equipment to mine valuable resources from municipal solid waste (MSW).
Metals generally represent up to 9.6 percent of the total household waste stream and – until relatively recently – much of this material ended up in landfill.
However, according to Ezio Viti, Eriez Asia Pacific Regional Sales Director, councils are making enormous efforts to remedy the situation by sharing responsibilities, introducing separation at the source and initiating the recovery of commingled waste at MRFs.
“To recover metals and materials, many MRFs employ labour intensive processes such as hand sorting stations, which are essentially picking belts,” Viti says.
He explains that as target materials get smaller and workers become fatigued, picking belts become less effective.
“The expectation from a picking belt system is typically a maximum of 95 per cent. Once target sizes reduce, process rate demands increase, target is discoloured and absenteeism is factored in, the effectiveness drops below 65 per cent,” Viti says.
In contrast, he says the effectiveness of an automated total metal recovery system remains constant, and is typically designed to deliver a minimum of 95 per cent at each separation point.
“Today, municipalities are beginning to utilise some of the most innovative solutions when it comes to separation of ferrous and NF metals – including stainless steel, copper wire, aluminium, zinc and other valuable metals – from waste streams,” Viti says.
He adds that allocating capital for technology helps local waste recyclers become more efficient and lower-cost resource processors because newer equipment reduces energy consumption and recovers higher levels of marketable-grade metals and plastics.
Research and development teams from high-tech manufacturers like Eriez are behind many recycling industry breakthroughs.
“These innovations contribute to a decrease in the cost of sending metals and plastics to landfills because they recover valuable resources,” Viti says.
“Thereby offsetting operating costs and delivering increased profits for MRFs across many councils and municipalities.
“These systems not only maximise recovery but also occupy as small a footprint as possible, while offering high and sustainable process efficiencies and improving health and safety standards.”
Using Eriez technology, both mixed waste and single stream MRFs can recover nearly 95 per cent of all metals.
“By sending less to landfill, operations save money and enjoy a new revenue stream from metal reclamation,” Viti explains.
He adds that technological advancements in separation equipment can now recover valuable fine ferrous and NF metals smaller than 25 millimetres.
“By reducing the overall volume of waste sent to landfill, disposal costs go down and the recovered by-product becomes added revenue,” Viti says.
“The payback is realised at both ends of the business case. Of course, each situation must be analysed on its own merits.”
Eriez experts are always on-hand, Viti says, to assist operators in finding the ideal solution for their specific application needs.
Engineers and technicians at Eriez have collaborated with the scientific sector to produce separation equipment that is capable of meeting the challenges of modern resource recovery.
“The recovered metal, glass, paper and plastic fragments become commodities that can be recycled back into original products or re-purposed into new and different products and applications,” Viti says.
He explains that Eriez also works closely with other OEMs and engineering consultants to provide best practice metal separation and recovery processes to integrate with complete turnkey systems.
Chris Ramsdell, Eriez Product Manager-Recycling Equipment, says suspended electromagnets (SE), drum magnets and eddy current separators (ECS) are employed in many ways.
SE magnets, drum magnets and magnetic pulleys are used to recover steel and other iron-based derivatives.
Additionally, rare earth magnets may be incorporated to attract magnetic cutlery as well as deformed stainless steel syringes and other dangerous sharps.
Eriez ECS’ are used to separate aluminium cans or other NF metals from the waste stream.
“Recent tests at a Florida MRF demonstrated recovery rates in excess of 99 per cent for used beverage cans, while the Eriez Ultra High Frequency ECS can recover particles down to 2-3 millimetres,” Ramsdell says.
Eriez’s process equipment delivers optimum performance when the feed is constant and spread evenly to utilise the total width of the separator.
“Eriez produces a range of electromagnetic feeders to match process requirements of separation equipment,” Ramsdell says.
“These units are also used with OEM equipment and ideally suited to meter ground plastic material post separation.”
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