Choosing the right sorting and separating equipment

From eddy currents to optical sorting machines, we look at a range of applications to consider when choosing high-tech sorting and separating systems. 

Materials recovery facilities and recyclers require a range of sophisticated technologies to help sort and separate materials such as paper, plastic, metal, glass and wood.

Sorting equipment can in itself be a broad term, referring to simple products such as picking stations, to the more complex magnet and infrared-controlled processors. 

While the range of technologies will differ in their componentry and can be more suited to a specific application, Waste Management Review breaks down the mix of the more complex sorting and separating technologies and how they can be used for a variety of waste streams and sizes. 

Whether you’re processing municipal solid, commercial and industrial or construction and demolition waste, the equipment required will depend on the waste stream, blend of materials, size of operation or level of contaminants. 

If you’re working with metal, organics or plastic, optical and near-infrared sensors can help sort and separate contaminants. Near-infrared spectroscopy with colour sensors can detect materials and provide colour recognition. As such, they are ideal for distinguishing a number of materials by discovering how they reflect light and can be used to detect the often undetectable.

Magnetic separators, such as eddy currents, can also remove aluminium caps in the glass industry, brass rivets and hinges in wood recycling, scrap and electronics processing and a range of other uses.

Eddy currents are generally used to sort non-ferrous metals and other materials. The varying physical properties of materials will mean some non-ferrous metals are easier to separate than others. Ultimately, the ability to separate materials will largely come down to whether the materials are low enough in density and the electrical conductivity of the machine. 

Induction sorting may also complement magnetic sorting and eddy current separation by recovering residuals. The induction sorting can detect materials in accordance with processing requirements, using sensors to locate materials such as metals like stainless steel.

X-ray technology is another option for facilities hoping to separate materials by density and is suitable for glass, metal, stone and other solid particles. X-rays are able to detect material density and particle size in order to separate materials such as plastics and steel mixed in together. It can also be used for e-waste when you’re working with a variety of component materials and heavier metals found within. 

Ballistic separators are used for sorting materials such as paper mixed with bottles and cans. The materials are fed onto a series of paddles to screen the materials down into small fractions, including from municipal solid waste, single stream recycling and commercial and industrial waste. These can then be fed onto other machines such as near-infrared sorters to detect contaminants. 

Ultimately, when deciding on the right piece of equipment, it’s essential to speak with a distributor as they may be able to provide a custom solution to suit your individual requirements. Depending on the input material and desired output, they will be able to advise you on an efficient process flow and the most suitable equipment required to achieve your desired results.