Mobile phones allow users to communicate in speech or writing on the move. Mobile phones are part of evolving electronic products. Thanks to the miniaturization of electronic components, these products have become more compact and now include an increasing number of features.
Mobile phones are differentiated by their size, there are generally three different form factors. Bar, flip (or clamshell) or slider. There are also several types of interface, keyboard, touch screen or mixed. However there are mostly four to five subsets that are the screen, the battery, the shell, an electronic card and a keyboard.
The functions offered by a average second generation mobile phone that will be considered thereafter are:
- Income and outcome voice call
- Incoming and outgoing SMS
- Alarm clock
Third generation mobile almost systematically include internet access.
Composition of a second-generation mobile phone
Figure 1: Composition of a mobile phone (ADEME study)
The category “Other” consists of all materials and substances in small quantities. Among these materials are plastics (PMMA, PP, PA), graphite, glass, silver, nickel, gold (66mg in ADEME’s study) or rare earth elements.
Figure 2: Changes in the number of mobile lines in France (Source ARCEP)
Regarding to number of mobile lines, it is estimated the current fleet of mobile phones in circulation to over 60 million. Nevertheless, according to a study conducted in July 2008 by a mobile phone maker, only 3% of users would recycle their old phones. In addition, 44% of unused mobile phones would be stored in a drawer. This suggests a potential source of products to recycle much more important.
Depollution and recycling of the product
Depollution / pre-treatment
During the depollution phase, only the battery is removed from cell phones, the rest is then ground for further recycling. Batteries are sent in treatment facilities suitable for the treatment of heavy metals such as cadmium, which can be present in these components.
Treatment / Recycling
After depollution, mobile phones are treated as all SHA, namely crushed to sort recyclable materials. Mobile phones have printed circuit boards with a significant amount of metals with high economic value. The metal reached include:
Proposed improvement plan
The table below provides some ideas to improve the recycling of WEEE. These ideas are from studies on the recycling of some products and difficulties encountered by treatment operators responsible for the treatment of WEEE. These areas for improvement can initiate a deeper reflection from producers. However, each product has its specificities and a number of other constraints to fulfill.
|Encountered difficulties||Impact for recycling||Eco design opportunities|
|Batteries are sometimes glued, screwed to the product or it is not possible to access the battery (back cover not removable)||Removing the battery requires more time.||Facilitate access to the battery, ensuring its removal without tools.|
|Presence of PVC, or plastics containing brominated flame retardants.||These substances must be removed according to the WEEE Directive.||Substitute these substances with low concern chemicals / materials.|
|Presence of precious metals rare earth elements.||Requires an advanced separation materials.||Facilitate recovery and recycling of these materials with high economic value.|
|Joining materials (plastics) are not compatible.||Recycling impossible if mixture is too important.||Promote the assembly of compatible materials for recycling or facilitate the separation of incompatible materials.|
|The chargers are not compatible from a brand or product to another.||- In case of failure of the charger, it is necessary to acquire a new charger whose value may exceed the value of the phone.|
- In case of failure of the phone, the charger can still be functional and it is not possible to reuse it.
|Standardize chargers to allow their use with different products(1)|
|Batteries are sometimes fixed to the back cover of the product.||The replacement is difficult or impossible without damaging the device.||Facilitate access and replacement of batteries that is often the component having the shortest lifespan.
Improve the lifespan of batteries to match with those of products.
|A number of unused or unusable products are not collected.||The affected phones can not be recycled or reused.||Promote the collection (for recycling purposes, but also reuse).
Propose an alternative economic model (e.g. leasing like DSL box), to capture more easily products at end of life.
|The disposing of a device is sometimes conditioned by the failure of a single component in the product (broken screen, battery, etc..).||The device can not be restored because the unavailability of spare parts or their prices sometimes higher than the value of the product to be repaired.||Ensure the availability of spare parts for a sufficient time, if the lifetime of the product exceeds its trade life.
Protect the weakest parts, or with the shortest lifespan, if not, facilitate their replacement.
(1) To solve the problem of chargers, in 2009, the European Commission has prompted manufacturers to think about and agree on a common charger format. Fourteen manufacturers have agreed to ensure compatibility of their products with a micro-USB type charger:
Figure 3: Micro USB connector
Since 2011, European consumers can buy these universal chargers.