An official investigation into the fatal explosion at Baogang United Steel’s plate plant in Baotou, Inner Mongolia, found that long-term corrosion damage to a pressure tank and inadequate action after a leak was detected led to the accident, according to local media reports.
The explosion occurred on January 18, killing 10 people and injuring 84. The investigation classified the incident as a major work safety accident, with 62 people held accountable, the reports said.
According to the investigation findings, a spherical tank at the plate plant had suffered prolonged damage caused by corrosion, localized stress and cyclic loading. The deterioration eventually penetrated the tank wall, resulting in a leak of saturated water.
Investigators found that no effective measures were taken after the leak was detected. Around 90 minutes later, pressure exceeded the damaged tank’s load-bearing capacity, causing a weld to rupture and the tank to fail. The sudden vaporization of saturated water subsequently triggered the explosion.
The investigation identified deficiencies involving the plate plant, Baogang United Steel and its parent company Baogang Group, as well as equipment and service providers and relevant regulatory authorities.
Seven plant employees have been arrested on suspicion of criminal offences, while six others were recommended for referral to judicial authorities for further investigation. Administrative penalties were also recommended against Baogang United Steel and three other entities.
Baogang United Steel is the largest steel producer in Inner Mongolia and a major global supplier of rare earth-integrated steel products. The state-controlled company is majority owned by Baotou Steel (Group) Co., Ltd., and produces a wide range of products including seamless pipes, heavy rails, pipeline steel, flat steel products, and specialized mineral materials.