Old tires
Used tires are tires that are no longer suitable or approved for the respective purpose. This includes car tires with a tread depth of less than 1.6 mm (legal limit) and damaged tires.
It is estimated that around 13.5 million tons are dismantled worldwide every year. This includes all types of tires. The quantities are: United States 4.4 million tons, Europe 3.4 million tons, rest of the world 5.7 million tons.
The quantities of used tires are also increased by premature tire replacement. In practice, European motorists are encouraged by some players in the industry to replace their tires before they reach the legal limit. The same influence on unnecessary tire replacement can be observed when tires are more than six years old.
Waste tires are mainly in cement plants in shredded (maximum 30 cm pieces) form a so-called secondary fuel and incinerated. The combustible parts are soot, rubber and polyester (high-tensile threads and fabrics). The iron in the tires (steel wire in the belt and bead, spikes) serves materially in the cement as a substitute for iron ore or blast furnace slag for the formation of iron silicates. There is also a technique for smoldering tires as a whole in an upstream unit ( pyrolysis ), adding the wire mixture and the fuel gases to the cement process at specific points in order to better control the process parameters.
Another method is the material recycling of used tires, in which the tires are separated into their components such as rubber (67%), steel (18%), textile (14%) and remainder / tread stones (1%). All components are used there individually and are not burned or outgassed.
Used tires are waste that requires monitoring, which means that the transport, sorting, storage and recycling must be reported to the responsible authorities and generally require official approval. Producers of waste requiring monitoring have a special duty of care with regard to the whereabouts of their waste. Among other things, they may only be given to recyclers who are authorized to treat this waste and who can document the acceptance with correctly completed acceptance forms. These receipts must include the amount of waste, the producer number of the waste producer and the disposal number of the waste recipient.
If a used tire is still functional except for a worn tread, it can be replaced ( retreading ). For this purpose, the tread is peeled off and then a new covering tread is vulcanized onto the carcass . This process is very complex and not suitable for all tires, for example for higher speed classes. It is common practice for truck tires.
Situation in Germany
In Germany, around 650,000 tons of old tires are produced every year. More than half of this is burned as substitute fuel in the cement industry , while some are exported abroad.
In recycling, over 30% of all old tires are broken down into the main components, as there are: rubber 67%, steel 19% and textile 14%. The rubber is used in numerous applications, the most important currently being the modification of asphalt and bitumen , fillings in artificial turf and industrial rubber applications. The steel is melted down in steel works. The textiles have so far been burned to generate energy, but are currently undergoing extensive product developments that will lead to end products in the field of noise and heat insulation. The world market leader in this area is, for example, the company Genan . In Germany alone you recycle 30% of all old tires (195,000 t).
Situation in Switzerland
Almost half of all used tires in Switzerland are burned as substitute fuel in the cement industry.
Situation in other countries
In countries where there is no recycling loop for tires, they are deposited in landfills . In some cases, landfills of considerable size are created. For example, the tire dumps in the desert of the Kuwaiti region of al-Jahra are already so large that they can be clearly seen on satellite images . The "tire graveyards" pose a danger to people and the environment if they catch fire. The extinguishing work is difficult due to the high porosity of the material to be fired and the enormous amount of heat generated.
Fires
- In April / May 2005 tires burn on 10,000 m² of the Berliner Runderneuerungswerke GmbH at the Adlergestell in Berlin- Schmoeckwitz. It had already burned there in August 2004.
- June 2010 - in Komotau , North Bohemia , Czech Republic, a waste tire store burns for 4 days.
- 2012 - Al-Jahra Governorate , Kuwait , has 5 million tires burning.
- May 2016 - in Seseña , Spain , a warehouse that had been piled up for years burns for days - 100,000 tons of used tires on twelve hectares. The operator disappears before a planned recycling plant is set up. Shortly after the authorities decided to recondition the tires by the public sector, the fire occurred. - There are another 15 such tire cemeteries in Spain.
- October 9, 2016 - In the tire recycling KIAS, a subsidiary of the Asamer Group , a warehouse of shredded tire parts is on fire in Ohlsdorf , Upper Austria .
- In July 2018, a waste tire store near Senftenberg , Brandenburg , D starts to burn in two places and covers the entire 5000 m² store. The wind carries the smoke away from the settlement area.
When tire rubber and polyester burn, poisonous combustion gases are generated, which can cause acute irritation and damage to the respiratory tract and also pose a cancer risk.
Individual evidence
- ↑ Ernst & Young study “Planned obsolescence that can be avoided”, May 2017, download at http://michelin.de/vorzeitiger-Reifenwechsel
- ^ Retreading of old tires , accessed on November 3, 2013.
- ↑ Augsburger Allgemeine : Genan: The world's largest tire recycler comes to Kammlach on September 24, 2010.
- ↑ Erich Aschwanden: Cement: Federal Council wants to know how big reserves are. In: nzz.ch . January 18, 2020, accessed January 20, 2020 .
- ↑ Tire dump in Kuwait can be seen on photos from space , Spiegel-Online, June 11, 2013.
- ^ Accidents: Berlin tire warehouse in flames faz.net, updated May 1, 2005, accessed June 24, 2019.
- ↑ Major fire in North Bohemian tire warehouse cleared after four days radio.cz, June 20, 2010, accessed June 24, 2019.
- ↑ Hans-Günter Kellner: Spain: major tire fire reveals failure of the authorities deutschlandfunk.de, May 20, 2016, accessed June 24, 2019.
- ↑ Senftenberg - major fire in old tire warehouse LausitzNews, youtube.com, published July 27, 2018, accessed June 24, 2019, video (10:33).