www . refrigerationandaircon . co . za RACA Journal I November 2024 33
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ABS ( acrylonitrile butadiene styrene ) and sometimes PVC ( polyvinyl chloride . The dominating plastics of refrigerators are PS , which are used for the interior cladding . Fruit and vegetable trays are made of PP , less often ABS . Sometimes PVC is found on the top of refrigerators ( part of enclosure ), but this is rare . ABS and PP used for domestic refrigerators nowadays do not contain flame-retardants anymore and are thus valuable components for further use . The plastics of old refrigerators may still contain flame-retardants ( e . g . brominated substances ), but this is rare . Plastic parts found in commercial refrigerators mainly contain PS , sometimes with additional aluminium coating . Air conditioners consist predominantly of PP , but can also contain ABS . In air conditioners , it is more common to find flame-retardants . Apart from flame-retardants , inorganic compounds such as antimony trioxide and halogen-free organic phosphorus compounds might be found . Other possible critical compounds are : inorganic pigments ( titanium oxide , iron oxide , chrome yellow ), organic pigments ( phtalocyanine , chinacridone ), heavy metal additives ( Cr , Cd , Pb ), plasticiser ( e . g . phthalate ).
4 . Refrigerants . The refrigerant circuit contains refrigerant and oil . The dominant refrigerants are HCFC-22 , HFC- 134a , R410a and R32 . Ammonia is found in absorption refrigerators , This refrigerant requires special processes that differ from all other refrigerants . This is not only due to the properties of ammonia but also because of the hexavalent chromium found in the refrigerant . These refrigerators must be processed in specialised facilities .
5 . Printed circuit boards : The United Nations Environment Programme ( UNEP ) has calculated that printed circuit boards make up to approximately 0.3 % of the weight of units . Printed circuit boards contain minor quantities of metals and substances such as antimony , beryllium , cadmium , and chlorine in electronic components . Brominated flame-retardants and lead in solder can also be present . Refrigerators and air conditioners contain one or more printed circuit boards , in particular new domestic refrigerators and commercial refrigerators . Apart from the hazardous substances associated with printed circuits , the circuit boards are of high value on the recycling market .
6 . Mercury can be found in the thermostats , sensors , relays , switches and lighting . Mercury is rarely present in domestic refrigerators and air conditioners , but often present close to the lamp in the top cover of chest freezers . Mercury is a hazardous substance , thus a complete removal of parts containing mercury is of high priority .
7 . Capacitors : As it can be difficult to differentiate the capacitors based on the labelling codes , the recommendation is handling all capacitors as hazardous waste with treatment in specialised plants .
8 . The compressors of refrigerators and air conditioners need oil . About 200-300ml are found in hermetic-refrigeration compressors and up to 1kg in air conditioning equipment , depending on the size . A certain part of the refrigerant is dissolved in the oil , which is then also classified as hazardous waste . To remove the refrigerant from the system and oil a recovery machine should be used .
9 . Fridges contain glass . The glass is used within the refrigerators as shelves and can easily be extracted before the dismantling process . Air conditioners generally do not have a glass fraction .
10 . Non-iron fraction from enclosure . Non-iron fractions are brass , copper and aluminium . The condenser of air conditioners generally consists of copper and aluminium . These are materials with a high thermal conductivity . Brass is used for connections in air conditioners but less in refrigerators
In all cases we would first recover the refrigerants and lubricants followed by the main components and then once all separated , they would undergo a further recycling process .
www . refrigerationandaircon . co . za RACA Journal I November 2024 33