What can you do with a mountain of broken, woody debris that’s full of metal bolts? This pile of waste wood is what results from large construction projects that use wooden access mats for moving equipment over soft ground. The mats get a lot of hard use and don’t last forever, but they don’t need to end up in a landfill. Horizontal grinding is the answer.
Wooden access mats are a great tool for getting construction traffic across soft ground or protecting sensitive soil & underground utilities from damage, but they don’t last forever.
When they’re broken beyond re-use, they used to be piled up for burning or taken to the nearest landfill for disposal.
Landfill space is limited and expensive to use, plus dumping the used mat pieces is … a waste.
Mats used to be piled up and burned, but that impacts air quality and burning wood takes careful planning and risk management to perform safely. When the fire is finally out, there are scattered metal bolts, washers, and nuts left over from fastening the wooden mats boards together. Those metals also need to get gathered up and disposed of properly.
There is another way: Horizontal Grinding
Wooden access mats can be processed into wood fibre using a horizontal grinder. The wood fibre can be reused in several ways, but one favorite is to ship it off to the nearest bioenergy plant to have it turned into renewable electricity.
Wood fibre end users typically need clean product, so it’s important to have a way to separate the metal fasteners from the wood. To do this properly requires an electromagnet mounted on the discharge belt of the horizontal grinder. As the grinder breaks up the wood pieces, the metals break away from the wood. The electromagnet then gathers and separates the metals for collection in a recycling bin. Wooden access mats contain many metal fasteners, so this part of the process gathers up a lot of metal.
