Archie Anderson suffers from Cerebral Palsy and has difficulties walking. But a £50,000 operation in St Louis Hospital, Missouri, could give him a chance.
The workers, who are being made redundant, have donated their entire social fund to three charities - one of which is Archie's charity.
The donation from the Rio Tinto workers brings his total to more than £45,000.
Marie Anderson, Archie's mother, has tweeted: "Thank you so much to the workers at Alcan for your wonderful donation to Archies Dream."
More top news
She was presented with a pastoral staff, the traditional bishop’s 'crozier' symbolising a shepherd’s care for a flock, at York Minster
The Middlesbrough boss has warned over-confidence could be the greatest threat in the Capital One Cup quarter-finals on Tuesday night.
Mike Barton of Durham Police is the national policing lead for the programme, which aims to turn around thousands of lives.