WCYCLE, waste treatment in the circular economy for the City of Maribor
The Center for the preparation of secondary raw materials (the Center) is the most modern sorting plant in this part of Europe and the only one in the region providing purely real recycling. Construction began at the end of August 2017 and the machines were tested for the first time in the middle of May 2018. The Center will be fully operational by the end of June this year.
The Center consists of more than 150 elements, each of which plays an important role in the separation of mixed municipal waste. The surface of the device extends to an area of more than 5,000 square metres. Within one year, the Center will be able to process almost 40,000 tons of mixed municipal waste in one shift.
When a truck delivers waste to the Center, the waste route begins with the tearing up of all the bags in which the waste was deposited. Waste then travels to the drum, which sorts the waste into four sizes. This is very important since large sections could cause disturbances and clogging or could also cover small material and therefore make sorting more difficult. The efficient and technologically advanced seal drum provides the basic conditions so that the output fractions are cleaner and of better quality.
Now waste is ready for the real action. Two optical machines eliminate all plastics. This moves forward to two ballistic separators, which classify plastics in size and shape in three fractions: rolling materials or so-called 3D material, for example bottles, separated from flat materials or so-called 2D materials, such as various foils, the fine fraction is sieved. This is extremely important for the efficient operation of the optical devices called the NIRs which sort different types of materials, there are six of them at the Center. NIRs separate waste by means of infrared light. In addition, three iron magnets, two air separators and two turbine circuits sort colored metals, predominantly aluminum.
The extremely precisely sorted mixed municipal waste is divided into three main groups after completing the journey at the Center: fractions suitable for recycling, the light and the heavy fractions. While the bulk of the mixed municipal waste that is brought to the Center goes further into the recycling process, the light fraction is used in the heating plant and the heavy fraction is disposed of. In the Wcycle model, ways and technologies to further process the heavy fraction are being considered which would completely avoid waste disposal.
The ratio of waste to recycling, which is passed on as light or heavy fractions, makes the Center so unique in this part of Europe: 77% of collected waste is used for real recycling, 9% of the light fraction is dedicated to energy use; and only 14% of the heavy fraction is disposed of. Such results are not achievable at any other centre in Slovenia, which is why the only 'pure' recycling in Slovenia is from the Center for the preparation of secondary raw materials in Maribor.