Stadler adds plants in Italy to its resume

G.A.I.A. SpA and Iren Ambiente SpA, which owns 45 percent of G.A.I.A. and provides environmental services to more than 3 million people, selected Altshausen, Germany-based Stadler to design and build new recycling plants in Asti and Parma, Italy.

Inaugurated last October, the Asti plant plays an important role in waste management in northern Italy, Stadler says in a news release about the installations. The result of a 10 million-euro investment, it can process 50,000 tons per year of material from separate waste collection.

Flaviano Fracaro, CEO of G.A.I.A. and technical manager of Iren Ambiente, says, "The sorting plant is like an open-air mine, but instead of extracting raw materials from the planet, it recovers them, avoiding the dispersion of plastics in the environment or the saturation of landfills that no longer need to receive recoverable materials."

The G.A.I.A. plant processes materials coming from the Asti basin, the Iren Group (from Turin, Genoa, Piacenza and Reggio Emilia, Italy), Val d'Aosta and others that request its services.

Once processed and cleaned, the materials are delivered to the National Consortia for the recovery of packaging, which will transform them into secondary raw materials and reintroduce them into the production cycles.

"We chose Stadler after an extensive technical and economical evaluation process," Fracaro says. "Stadler was able to design plants capable of treating different types of materials with great efficiency, and in terms of the support we received, their engineers and technicians were at our side in every phase of the project."

The plant consists of a feeding and presorting section, a mechanical and optical sorting line, a sorting cabin for manual selection of the bulky products and a storage and baling line.

A drum screen performs the first selection according to size, separating the materials into three streams. The main material stream, with sizes ranging from roughly 2 inches to  roughly 14 inches (50 to 350 millimeters), is sent to the main sorting line, which is comprised of

• 10 optical separators to sort out plastic products;
• one wind shifter system to improve the 3D and 2D separation;
• two magnetic separators to remove ferrous metals;
• one eddy current separator to remove nonferrous metals;
• one fine screen to sift fine residue;
• one STT5000 ballistic separator and 1 STT2000 ballistic separator to increase the quality of plastic recirculation inside the plant; and
• one bottle piercer to recover bottles even if they are filled with liquids.

All the sorted plastics are stored in reversible bunkers. This material then feeds two independent baling lines with balers designed for plastics.

At the end of the process, the output materials are clear polyethylene terephthalate (PET), colored PET, light blue PET, high-density polyethylene (HDPE), polypropylene (PP), mixed PE and PP, low-density polyethylene (LDPE) and PP film, bulky plastics (four different products), residue, fine residue, nonferrous metals and ferrous metals.

The project presented multiple challenges. Pietro Navarotto, director of Stadler Italy, explains, " In Asti we had to design a plant with many machines and conveyors in a small existing building, taking into account also the space for maintenance. We also considered the possibility of extending the line in the future. Also, since the plant sorts multiple types of materials, we had to perform many tests to check the purity of the recycled material and the recovery rates.”

The Parma plant, soon to be completed and inaugurated, is designed to treat two different streams of material from the separate collection of paper and plastic. Stadler says it designed and built two integrated sorting lines that achieve spatial efficiency by sharing the baling system.

“We appreciated the professional approach of Stadler’s engineers and the quick response in implementing a last-minute request on the paper sorting line,” Fracaro says. “We asked for the inclusion of four NIR (near-infrared) optical sorters, and Stadler was able to do this within the tight deadline."

The plastic sorting line, which has a capacity of 9 tons per hour, processes PET, HDPE and PP bottles, PE and PP film, bulky plastics, mixed plastic packaging and nonferrous and ferrous metals, while the paper sorting line, with a capacity of 20 tons per hour, processes cardboard, mixed paper and deinking grades.

The two lines have different input areas but share the same output section and baling line. Each line consists of a feed section, a section for mechanical and optical sorting, a sorting cabin for manual sorting of bulky material and a storage and baling line.

In the plastic sorting line, once the bulky waste in the presorting cabin has been removed, the industrial waste can be sent to a shredder. A big drum screen performs the first selection based on the size of the material (bulky, medium and fine), according to Stadler.

The bulky fraction is sent directly to the sorting cabin, where operators sort it into three fractions. The main medium-sized material stream is fed to an STT5000 ballistic separator, which divides the products according to their ballistic and weight characteristics into fine, 3D (heavy and/or rolling objects) and 2D (flat and light objects) fractions.

All fractions then pass through the plant, which is equipped with:

• three optical separators to sort the different types of plastics;
• one wind shifter system to improve 2D and 3D separation;
• one magnetic separator to remove ferrous metals; and
• one eddy current separator for the removal of nonferrous metals.

A movable conveyor under the first NIR optical unit of the paper line offers flexibility in the sorting process, while the second optical separator can work with either the positive or negative selection from the first NIR unit, optimizing paper recovery, the manufacturer says.

The paper sorting line starts with a PPK2000_6_3H ballistic separator, which is specially designed to separate bulkier cardboard from lighter paper. The cardboard is sent to the picking cabin, while the main stream is sent to two parallel sorting lines. Each line consists of a PPK2000_6_1 ballistic separator that removes fine fractions and two 110-inch, or 2,800 millimeters, NIR optical sorters that separate mixed and deinking paper from the main stream. The sorted material is then sent to the picking cabin for manual sorting.

"In addition to the change requested by the customer during the project’s implementation, the other difficulty was installing the paper line once the plastic line was in place,” Navarotto says.

"So far, the performance of the two plants in Parma and Asti has lived up to our expectations," Fracaro says. “We hope that in the future they will even exceed them!"