"Tim Watts" wrote

I must admit - I don't know if British Gypsum do recycling at the
Mountfield/Robertsbridge plant. Though if they can take crap out the
ground and turn it into plaster (they do all that here) I would have
thought they would have added a preprocessing feed for doing whatever you
need to old PB and sticking the result of it in with the raw materials
from the mine.

British Gypsum make cat litter too, Nature Cat Gold, so that is probably
also gypsum and it's in granules too. Should be available at any good pet
place or could be ordered, but check the price first. Worth ringing BG first
to find out if it is pure gypsum.

--
Regards
Bob Hobden
W.of London. UK