Using a Belgian driving licence in the UK
The Belgian driving license (both the paper model and the bank card model) is still recognized in the United Kingdom. You can drive in the UK with your Belgian driving license while it is valid or until you turn 70.
When residing in the UK, you have the choice whether to use your Belgian driving licence or exchange it for a UK licence (https://www.gov.uk/exchange-foreign-driving-licence).
If you lose your Belgian driving licence you need to apply for a replacement in the UK, not in Belgium (https://www.gov.uk/apply-online-to-replace-a-driving-licence#before-you-start). Before applying, however, you will need to obtain a certificate stating details of your driving licence from the Belgian commune where you last resided.