Most ducting is galvanised steel, though that's not usually shiny.
http://www.letsrecycle.com/prices/metals/ suggests a scrap value of a
bit over £100 per ton for steel (galvanised or not) so may not be
worthwhile if there's less than 100 kg.
TL
I think it's normally galvanised steel - problem is, it's not very heavy,
so probably wouldn't fetch much as scrap. Personally I use offcuts for
all sorts of DIY projects - it's easy stuff to cut and shape. Maybe
freecycle it?
cheers
Jules
My description was misleading; it's shiny in a dull sort of
way... The ducting though bulky is not heavy as the material
is thin, so I don't think I would make my fortune from scrap
value so probably freecycle is the best option unless these chaps
http://www.cambridge-news.co.uk/Home/Metal-recovered-after-lab-raid.htm
want it after their first unsuccessful attempt.