The man, not yet named, suffered burns in an explosion at Innovative Environmental Solutions on Union Road in Oldbury in the early hours of Monday (7 August).
He was taken to Queen Elizabeth Hospital but later died from his injuries.
Two other men also sustained burns in the incident, but remain in a stable condition, according to reports by Hereford Times.
The Health and Safety Executive said it is aware of an incident and is in contact with emergency services.
A West Midlands Police spokesman said: “A man has died following an industrial accident at industrial premises on Union Road, Oldbury on Monday, August 7.
“Police were called by the fire service just before 1.50am. Three men were taken to hospital where sadly a man in his 50s passed away. Two men in their 30s and 40s remain in a stable condition. The case has been passed to the Health and Safety Executive and the coroner to establish the cause of the incident.”
A West Midlands Ambulance Service spokesman said: “At 1.43am on Monday we were called to a recycling plant in Oldbury. We had three patients in total – including a male who had very serious burns.
“We sent three ambulances, a paramedic officer, the Hazardous Area Response Team, MERIT trauma doctor and critical care paramedic. They travelled to the Queen Elizabeth Hospital in Birmingham with that first patient.
“The second patient was another man who had burns, which were less serious. He was also conveyed to the same hospital. The third patient was a 32-year-old man with some fairly minor burns, who was taken to Sandwell General Hospital.”