Oh wow - that's made me all nostalgic. I used to go around lots of the old woollen mills in that area as a kid. My mum used to buy sacks of sweepings and sort them to crochet into granny square blankets and shawls and headscarves and things. I can still smell the air in those mills if I try hard enough, and hear the noise...
I imagine all that yarn was no longer worth anything because it was on spindles that worked with the old machinery but couldn't be sold off to work in the newer machines. Pretty emblematic of the kind of thinking that turns a resource into a waste.
If it's cotton, the spools could be unwound and the outer threads used for paper or some other waste selvedge. The inner threads should be okay so long as the bugs haven't chewed through it.