Yes, the box is still there, and it's recorded as continuously open in the Compendium of Signal Box Opening Times.
Presumably it links to the new Rochdale West box, and to the Manchester North Signalling Centre, and possibly Bagueley Fold on the Ashton line from Miles Platting. Maybe someone better informed can confirm or deny this....
Apparently the manufacture of sulphuric acid nearby had ceased quite a bit before 1898, according to an article in the Manchester Evening News some years ago:
THE Middleton Guardian of 13 August 1898 contains the following report. "The Works, which at one time were a flourishing industry at Middleton Junction, known for miles around as the 'Vitriol Works' owned by messrs Hannibal Becker and Co, are at present in a crumbling condition and are occupied by a caretaker.
The box is more modern, I would guess a BR 1950's type.