Sierra County RHRF

STEPS

Recycling Process

Once the materials arrive at the RHRF, the route trucks offload them onto the tipping floor. Then the materials are moved onto the conveyor belts using a metering drum. With this drum, the recyclables are distributed evenly on the belt. Recyclables then pass through a pre-sort line where manual sorters are stationed to remove any bulky items or materials that cannot be processed in the system. Some of these materials are large, rigid plastics, hazardous items, textless, etc. These sorters are particularly skilled and specialized in tagout protocols; for instance, if something jams the machine, it’s their job to prevent equipment from being damaged and clear the blockage.

The first screen is the star screen (also known as the OCC screen). As OCC is lighter and larger in size, it glides over the screen, whereas the heavier materials, such as glass, fall to the lower deck. The gaps between the shafts are less than 2 inches, which allows for a 2-inch minus segregation, which helps in improving the sorting process. Then the materials pass through another screen, which helps in segregating fiber. Another prominent piece of equipment at this RHRF is the Eddy current separation unit, which creates a magnetic force that helps in extracting non-ferrous materials such as aluminum from the materials flow. Further down the line, there are magnets that help in segregating ferrous materials, such as steel items.

Once the mechanical separation is completed, recyclables are directed towards the containers belt. The RHRF has five optical sorters that includes 3 CIRRUS Optical sorters that help in identifying and segregating plastics as per their resin type using NIR spectroscopy. The facility also uses AI-powered robots for post-sort backup. They were introduced during the pandemic when maintaining a safe distance was required. The CIRRUS 1 Optical sorter separates (#2) HDPE, including both colored (detergent containers) and natural (milk jugs), whereas CIRRUS 2 segregates PET (#1) plastics and CIRRUS 3 is for mixed plastics grades #3 to #7. All the segregated materials are then sent to a bunker from where they are conveyed to balers. The facility has three balers and all of them are automated. One of the balers is dedicated only to fiber, while the other two balers are for containers. The baled materials are then ready for shipment. Plastics are usually processed and repurposed within the country, whereas fiber materials such as mixed paper and OCC are often sent overseas with India serving as a major destination. At the end, most of the residual waste is primarily plastic films and trash bags.