62 held responsible as probe uncovers cause of deadly Baotou steel plant blast

An official investigation into a January explosion at a steel plant in Baotou, Inner Mongolia autonomous region, that killed 10 people and injured 84 has found that long-term corrosion severely damaged a spherical tank and that no effective action was taken after a leak was detected. A total of 62 people were held accountable.

The report, released on Sunday by Inner Mongolia's emergency management department, classified the incident as a major work safety accident and held those involved liable.

The explosion occurred at about 3:01 pm on Jan 18 at a plate plant operated by Baogang United Steel in Kundulun district.

Investigators found that the plant's No 1 spherical tank had sustained long-term damage caused by the combined effects of corrosion, localized stress and cyclic loading.

The report noted that the damage, identified as a combination of caustic stress corrosion cracking and corrosion fatigue, continued to accumulate until it penetrated the tank wall, causing saturated water to leak from the north side of the tank's lower circumferential weld.

No effective on-site measures were taken after the leak was detected. About 90 minutes later, the pressure exceeded the damaged tank's ultimate load-bearing capacity.

A weld near the leak then tore rapidly around its full circumference, causing the tank to rupture. A large volume of saturated water inside underwent instant flash vaporization, triggering the explosion.

The report identified problems at the plate plant, Baogang United Steel and its parent company, Baogang Group.

It also found deficiencies involving Beijing Jingcheng Kelin Environmental Protection Technology Co and Anshan Huaxin Heavy Industry Machinery Co, as well as relevant regulators and local Communist Party of China and government authorities.

Seven plant employees have been arrested on suspicion of criminal offenses, while the report recommended that six others be referred to judicial authorities for investigation.

The report said administrative penalties would be imposed on four entities: Baogang United Steel, Beijing Jingcheng Kelin Environmental Protection Technology Co, Anshan Huaxin Heavy Industry Machinery Co and the Baotou branch of the special equipment inspection institute.

In the wake of the explosion, more than 1,300 rescue personnel and over 70 emergency and medical vehicles were dispatched to the site. The Ministry of Emergency Management and the State Administration for Market Regulation also sent officials to guide rescue and emergency response efforts.