I've now had the following response to the FOI request I put forward.
"Environmental Information Regulations Response 14588
Request:
1. What process does council general waste undertake?
2. Does any of it go to landfill?
3. Is it pre- sorted for recyables before being incinerated?
Response:
1. Suffolks residual (black bin) waste is sent to an energy from waste facility where energy is recovered from the waste enough electric to power a town the size of Lowestoft. More information on the treatment of Suffolks waste is available on our website -
http://www.greensuffolk.org/recycling/where-it-goes/
2. A very small amount may go to landfill each year, this would occur when the energy from waste facility undergoes planned downtime to maintain the plant.
3. There are separate kerbside collections for all households for paper, card, cans, and a wide range of plastics. More details on kerbside recycling in Suffolk can be found at
http://www.greensuffolk.org/recycling/how-to-recycle/kerbside-recycling/
Less than half of Suffolks waste is residual waste. There is no further pre sort on the waste sent to the energy from waste facility, however, metals are recovered for recycling after residual waste has been incinerated in 2016 around 7,500 tonnes of metals was recycled this way."