What are Material Recovery Facilities?
Economically recovering waste materials for recycling is an immense problem. In order to deliver clean and pure products to be reused, any waste stream must be sorted. Although industrial automation of this process has improved, much of the separation must be done by hand in material recovery facilities, also known as material recycling facilities, or MRFs.
Each facility is a large building where a mixed waste stream enters on a conveyor belt, and as the waste is carried forward various methods are used to separate it into its components. The easiest removal is accomplished by magnets, which pull out any ferrous metal. Air sorters can remove heavy materials, such as glass and other metals, by suspending lighter plastics and paper, while the heavier products fall out of the stream.
These technologies are relatively inexpensive. To sort various non-ferrous metals, infra-red, and even x-way scanning has been developed. However, only recovery facilities which handle a huge amount of waste can afford these types of sensors.
It remains problematic to sort numbered plastics. So far, human beings are more efficient at this than industrial automation. Naturally, the manual sorting of waste is a dirty, odorous task, which does not command high pay.
There are two basic types of material recovery facilities. Clean MRFs accept only materials which are considered recyclable. Typically these would come from curbside or collection point recycling programs. This reduces the amount of unusable materials which enter the stream. However, consumers often do a poor job of pre-sorting their waste, particularly when it comes to plastics. All of these contaminants must be removed, in addition to the sorting process.
Dirty MRFs accept mixed consumer trash. All sorting is done at the facility. The “dirty” process actually recovers more recyclables than the “clean” process. This is because 100% of the waste is subjected to sorting. Of course, the recovery is more labor-intensive than dealing with a somewhat pre-sorted stream.
Recently, some dirty MRFs have experimented with adding water to the mixed waste. This adds the capability of sorting material by density, it cleans the waste, and begins the decomposition process on organic waste.
Recovery of recyclable materials will only become cost-efficient when industrial automation can be used to complete their separation. The reclaimed raw materials must be pure enough to be of value to manufacturers, and the cost of accomplishing this task must be lower than the price the material commands.