OSHA Accident Investigation · Summary #170048037
MAGMA COPPER CO.
SAN MANUEL, AZ·
Event description
One Employee dies, others injured in steam explosion
Investigation abstract
Employees were removing a hot buildup of smelted concentrate inside the waste he were drilled or burned with oxygen lances to accept the explosive charges for b lasting. Some pockets of molten material were found near the furnace end of the mass when the oxygen lances burned into it. As the blasting process continued, c racks developed in portions of the mass and the face of the mass fell to the bot tom of the boiler. A water lance with a valve was used for cooling the holes. Th e valve handle for the water lance was broken. Rather than fix the valve, or go outside the boiler to turn off another valve, employees at times allowed water t o flow onto the top of the mass. Also, some boiler tube leaks had been spraying onto the bottom of the mass. Apparently, some of the water entered a crack and c irculated into the hot mass, probably to a pocket of molten material. A steam ex at boiler of an Outokumpu flash furnace at a copper smelter. The partly smelted plosion occurred within the surrounding mass, breaking a large section (estimate d to be at least 2 tons) off the left part of the face. The blast struck Employe e #1, who was standing on the upper platform in line with the explosion, causing him to fall about 4 1/2 ft to the lower platform, where he apparently struck an d broke a 2 by 4 brace below the upper platform. Employee #2, who was sitting cl osest to the explosion, was severely burned and sustained a depressed skull frac ture and puncture wounds from explosion fragments. Employee #3, who was standing behind Employee #2, sustained minor burns. Employee #4 was on the lower level p latform and sustained a temporary hearing loss. Employee #1, who was unconscious , died about an hour after the explosion, at about the same time that rescuers w concentrate was composed of extremely fine particles that had passed through the ere able to cut a large enough opening in the boiler to remove him on a stretche r. The entry door was 18 in. by 18 in. before the accident. flash furnace at temperatures of up to 2,300 degrees F. As the partly smelted c oncentrate passed into the waste heat boiler, it stuck on the sides of the boile r, eventually forming a mass that bridged across the walls of the boiler from th e throat to a water-cooled 16 ft high baffle wall. When the boiler was taken dow n for repairs, the mass was about 800 to 1,000 tons and had retained much of the heat. Blasting with explosives was used to break up the face of the mass; holes
Victims (5)
-
#1 Fatality Age 47 M
- Nature of injury
- 6
- Part of body
- 4
- Event type
- 1
- Source
- 43
- Occupation code
- 999
- Human factor
- 1
- Environmental factor
- 15
- Task assigned
- 1
-
#2 Hospitalized Age 34 M
- Nature of injury
- 5
- Part of body
- 19
- Event type
- 1
- Source
- 43
- Occupation code
- 999
- Human factor
- 1
- Environmental factor
- 15
- Task assigned
- 1
-
#3 Non-hospitalized injury Age 40 M
- Nature of injury
- 5
- Part of body
- 13
- Event type
- 1
- Source
- 43
- Occupation code
- 999
- Human factor
- 1
- Environmental factor
- 15
- Task assigned
- 1
-
#4 Non-hospitalized injury Age 40 M
- Nature of injury
- 14
- Part of body
- 6
- Event type
- 1
- Source
- 43
- Occupation code
- 999
- Human factor
- 1
- Environmental factor
- 15
- Task assigned
- 1
-
#981 Degree 0 Age 0
- Nature of injury
- 0
- Part of body
- 0
- Event type
- 0
- Source
- 0
- Occupation code
- 0
- Human factor
- 0
- Environmental factor
- 0
- Task assigned
- 0
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