On July 4th, the Ministry of Emergency Management announced the historical July hazardous chemical accidents, including the major explosion of a 7.28 propylene pipeline leak in Nanjing, Jiangsu, the major explosion of a 7.28 chlorination tower in Sheyang, Yancheng, Jiangsu, and the major explosion of a 7.26 fine chemical plant in Wuxi, Jiangsu.

1、 Typical accidents that occurred in June 2024

Gansu Honghui Energy and Chemical Co., Ltd. "6.11" nitrogen gas major suffocation accident

On June 11, 2024, a nitrogen suffocation accident occurred on the mobile particle bed production line of Gansu Honghui Energy and Chemical Co., Ltd.'s dry distillation line 2, resulting in three deaths. The direct cause of the accident was that the maintenance personnel did not blow, replace, and inspect according to the operating procedures, and illegally opened the manhole for fault inspection without taking any protective measures or obtaining a confined space work permit. After one operator suffocated, two rescue personnel blindly rescued, leading to the expansion of the accident.

2、 Dangerous chemical accidents that occurred in July in history

（1） Domestic accidents in petrochemical industry

The "7.26" atmospheric pressure unit of China Petroleum Qingyang Petrochemical Branch experienced a major leakage and fire accident

On July 26, 2015, a leak and fire occurred in the residual oil/crude oil heat exchanger of the atmospheric unit of PetroChina Qingyang Petrochemical Company, resulting in 3 deaths and 4 injuries. The direct cause of the accident was that the drain pipe plug on the outer head cover of the residual oil/crude oil heat exchanger in the atmospheric pressure unit was assembled incorrectly during maintenance, resulting in the pipe plug falling off under high temperature and high pressure. High temperature residual oil (with a spontaneous ignition point of 240 ℃) of about 342 ℃ -346 ℃ was instantly sprayed out, and it ignited with air, causing a fire.

Shandong Shida Technology Petrochemical Co., Ltd.'s "7.16" major explosion accident

On July 16, 2015, a liquefied hydrocarbon spherical tank of Shandong Shida Technology Petrochemical Co., Ltd. leaked and caught fire during the pouring operation, causing an explosion. Two firefighters were lightly injured, resulting in a direct economic loss of 28.12 million yuan. The direct cause of the accident was that during the process of pouring the tank, the method of replacing the tank with water was used in violation of regulations, and there was no one on site during the water cutting process, resulting in the leakage of liquefied petroleum gas from the drainage outlet after the water was discharged. The static electricity generated during the leakage process or sparks caused by the violent movement of the fire hose, metal interfaces, and bundled iron wires colliding with equipment or pipelines, could cause explosions.

Leakage fire accident of heat exchanger "7.16" in atmospheric and vacuum distillation unit of Liaoning Dalian Petrochemical Company

On July 16, 2011, a leakage and fire accident occurred at the crude oil head flange of the E-1007D tube side heat exchanger of the 10 million ton/year atmospheric and vacuum distillation unit in the production area of Dalian Petrochemical Company in Liaoning Province. This caused some steel frames, heat exchangers, pipelines, valves, etc. of the unit to catch fire, and there were no casualties. The direct cause of the accident was that a large amount of leaked oil suddenly leaked from the flange of the E-1007D pipe box, flowing onto the three-layer platform. It flowed along the gap between the platform plates and onto the exposed flange of the heat exchanger (E-1011AD) on the second layer below it (flange temperature 350-360 ℃, flash point of crude oil is -6.7-32.2 ℃). After the oil leakage, combustible vapors were generated and burned at high temperatures.

Henan Luoyang Runfang Special Oil Co., Ltd.'s "7.14" major poisoning accident

On July 14, 2007, Runfang Special Oil Co., Ltd. in Luoyang, Henan Province, China, experienced a poisoning accident while cleaning up the residue at the bottom of a storage tank, resulting in 3 deaths and 1 serious injury. The direct cause of the accident was that the operators violated the operating procedures, failed to analyze and detect the gas inside the tank, and did not take safety measures, directly entering the storage tank for operation. Rescue personnel blindly attempted to rescue without taking any safety measures, leading to the escalation of the accident.

Hebei Cangzhou Refinery's "7.31" Condensate Oil Leakage and Suffocation Accident

On July 31, 1998, the engineering company of Cangzhou Refinery in Hebei Province experienced a suffocation accident while repairing the condensate pump of the catalytic unit, resulting in four deaths. The direct cause of the accident was that the catalytic unit was temporarily shut down for maintenance, and the construction workers did not check and verify the valve closure status as required before maintenance. Due to the fact that the inlet and outlet valves of the condensate pump were not closed, the material was not emptied and discharged completely, and the condensate oil sprayed out, forming a white dense mist in the closed pump room, resulting in a suffocation accident.

coal chemical industry

Large fire accident of the "7.12" storage tank in Heilongjiang Chemical Plant

On July 12, 1994, the top of the tar tank in the tar workshop of Heilongjiang Chemical Plant was torn, and the stored materials sprayed out and caught fire, resulting in three deaths. The direct cause of the accident was that the temperature of the tar and anthracene oil mixture injected into the storage tank was not strictly controlled. The high temperature of the tar and anthracene oil mixture injected into the storage tank resulted in an increase in gasification volume, tearing the top of the tank and causing hot oil to spray out and catch fire.

The "7.22" major explosion accident at the carbide factory in Hanzhong City, Shaanxi Province

On July 22, 1989, a molten carbide explosion occurred at the carbide factory in Hanzhong City, Shaanxi Province, resulting in 4 deaths and 2 serious injuries. The direct cause of the accident was that there was a large area of water accumulation on site, and there was no command in front of the calcium carbide pot car when it was overturned. The knot of the steel wire rope at a distance of 1.8m from the rope distributor automatically fell off when it met the guide wheel, causing the direction of traction to shift, causing one of the calcium carbide pot cars to derail and overturn. After the overturning, the molten red calcium carbide exploded in water.

Sichuan Suining Chemical Plant "7-8" Major Gas Poisoning Accident

On July 8, 1984, a gas poisoning accident occurred at a chemical plant in Suining County, Sichuan Province, resulting in 3 deaths and 1 injury. The direct cause of the accident was that four employees entered the conversion furnace to scrape old catalysts, but did not use blind plates to cut off the gas source, causing the gas to flow back into the conversion furnace from the washing tower, resulting in poisoning of the operators. The operators did not apply for a work permit to enter the confined space, did not implement relevant safety measures, did not have enough time to blow harmful gases from the conversion furnace, did not wear gas masks, and entered the toxic and harmful confined space for work. In addition, the on-site operators lacked emergency knowledge and blindly carried out rescue operations, resulting in the death of rescue personnel and the expansion of the accident.

Fine chemical industry

Jiangsu Sheyang Yancheng Fluorine Source Chemical Company Linhai Branch's "7.28" Chlorination Tower Major Explosion Accident

On July 28, 2006, an explosion occurred in the chlorination reaction tower of the Linhai Branch of Yancheng Fluorine Source Chemical Co., Ltd. in Sheyang County, Yancheng City, Jiangsu Province, resulting in 22 deaths, 3 serious injuries, and 26 minor injuries. The direct cause of the accident was that, without cooling water in the condenser of the chlorination reaction tower and no product flowing out at the top of the tower, the equipment was not immediately stopped. Instead, it mistakenly continued to heat up, causing the material (2,4-dinitrofluorobenzene) to remain in a high temperature state for a long time, ultimately leading to its decomposition and explosion.

Jiangsu Wuxi Hudai Fine Chemical Plant "7.26" Major Explosion Accident

On July 26, 2005, during the trial production of hexachlorocyclopentadiene at Hudai Fine Chemical Plant in Wuxi City, Jiangsu Province, an explosion occurred in the cracking kettle of dicyclopentadiene, resulting in 9 deaths and 3 injuries. The direct cause of the accident was that during the cracking reaction stage of the hexachlorocyclopentadiene production process, due to serious defects in the manufacturing quality of the dicyclopentadiene cracking reactor, the fillet weld connecting the lower tube plate and the shell flange cracked, causing the heating carrier - molten salt of the cracking reactor to flow into the dicyclopentadiene cracking reactor. Molten salt contains 55% strong oxidizing agent potassium nitrate, which reacts violently with organic compounds such as dicyclopentadiene in the cracking kettle, causing the cracking kettle to explode.

Sichuan Yibin Hengda Technology Co., Ltd.'s "7.12" major explosion accident

On July 12, 2018, a major explosion occurred at Yibin Hengda Technology Co., Ltd. in Sichuan Province, resulting in 19 deaths and 12 injuries, with a direct economic loss of over 41.42 million yuan. The original production scale was designed to produce 2000 tons of 5-nitroisophthalic acid and 300 tons of 2- (3-sulfonyl-4-chlorobenzoyl) benzoic acid per year, but in reality, it produced imidacloprid (herbicide) and 1,2,3-triazole (pharmaceutical intermediate). The direct cause of the accident was that during the production process of Micao smoke, the operator added sodium chlorate without packaging label as butylamine and added it to R301 kettle for dehydration operation. In the stirring state, the mixture of butylamide and sodium chlorate forms an explosive system with rapid deflagration ability. After steam heating is turned on, it causes a chemical explosion of the butylamide sodium chlorate mixture in the reactor, which leads to the disintegration of the reactor body; The high-temperature toluene vapor ejected during the dismantling process of the reactor quickly forms an explosive mixture with the external air and produces a secondary explosion. At the same time, it causes the explosion and combustion of materials such as sodium chlorate, toluene, and methanol stored on site in the workshop, as well as the ignition and combustion of the second and third workshops, further expanding the consequences of the accident, causing significant casualties and property damage.

Jiangxi Jiujiang Zhijiang Chemical Company's "7.2" major explosion accident

On July 2, 2017, an explosion occurred in a high-pressure reactor of Zhijiang Chemical Company in Jishan Industrial Park, Pengze County, Jiujiang City, Jiangxi Province, resulting in three deaths and three injuries. The direct cause of the accident is that the amination reaction material has a risk of combustion and explosion. When the accident occurs, the cooling fails, and the safety interlock device is shut down in violation of regulations. A large amount of reaction heat cannot be removed through the cooling medium, and the system temperature continues to rise; The reaction product decomposes nitroaniline at high temperatures, leading to a rapid increase in system temperature and pressure, resulting in an explosion.

The "7.13" major poisoning and suffocation accident at an illegal chemical plant in Heze, Shandong

On July 13, 2016, a major poisoning and suffocation accident occurred at an illegal chemical plant located in Jigai Village, Huangji Township, Yuncheng County, Shandong Province, resulting in three deaths and a direct economic loss of 2.79 million yuan. The direct cause of the accident was that during the cleaning process of residual wet materials from rubber accelerator (TETD, tetraethylthioperoxydicarbonamide), one operator entered the reactor without ventilation, replacement, testing, and approval, and engaged in unauthorized operations; Other personnel on site risked entering the reaction vessel for rescue without taking protective measures, resulting in three people suffocating and dying due to carbon disulfide poisoning.

A major explosion accident occurred in the "7.7" chlorobenzene recovery tower of Yunnan Qujing Zhongyi Synthetic Chemical Co., Ltd

On July 7, 2014, a detonation accident occurred in the chlorobenzene recovery system of the first workshop of Qujing Zhongyi Synthetic Chemical Co., Ltd. in Yunnan Province, resulting in 3 deaths and 4 injuries, and a direct economic loss of 5.6 million yuan. The direct cause of the accident was: internal leakage in the AO thermal oil heat exchanger at the bottom of the chlorobenzene recovery tower, and high-temperature thermal oil leakage from the tube side entering the shell side mixed with residual chlorobenzene, causing an increase in temperature inside the chlorobenzene recovery tower and a sharp increase in residual gasification pressure, resulting in the explosion and combustion of the chlorobenzene recovery tower; The temperature control regulating valve was not installed according to the design requirements, and only the on-site operated "cut-off valve" was installed. When the temperature and pressure at the bottom of the recovery tower are abnormal and exceed the normal range of process parameters, the "cut-off valve" cannot automatically adjust and adjust in a timely manner.

Henan Luoyang Luoyang Dyeing Co., Ltd.'s "7.15" major explosion accident

On July 15, 2009, an explosion occurred in a workshop of Henan Luoran Co., Ltd., resulting in 8 deaths and 8 injuries. The direct cause of the accident was that the chlorobenzene vapor emitted from the chlorobenzene metering tank in the neutralization and extraction workplace collided with a nearby power line fire source due to aging and short circuit, causing the chlorobenzene vapor to explode. The chlorobenzene metering tank was ignited, and then an explosion occurred, causing the first explosion of the finished product 2,4-dinitrochlorobenzene in the water washing kettle, which in turn caused the second explosion of 2,4-dinitrochlorobenzene in the nitration kettle.

Inorganic chemical industry

Gansu Jinshi Chemical Co., Ltd.'s "7.21" major poisoning accident

On July 21, 2013, a carbon monoxide poisoning accident occurred in the sulfide alkali workshop of Gansu Jinshi Chemical Co., Ltd., resulting in 4 deaths and 4 injuries, and a direct economic loss of about 3.67 million yuan. The direct cause of the accident was that during the operation of the dryer, the frequency converter of the induced draft fan tripped, the induced air volume was insufficient, and the coal powder in the dryer was not fully burned. Toxic and harmful gases such as carbon monoxide were generated in the furnace, which flowed back into the maintenance pit on the negative floor through the elevator casing, resulting in a high concentration of toxic and harmful gases such as carbon monoxide in the pit. The operator entered the pit without any protective measures to clean the ash and caused poisoning.

Gansu Baiyin Tianxiang Building Materials and Chemical Co., Ltd. experienced a major poisoning accident on July 4th

On July 4, 2010, a poisoning accident occurred at the Zinc Carbonate Plant of Tianxiang Building Materials and Chemical Co., Ltd. in Baiyin District, Baiyin City, Gansu Province, resulting in 3 deaths and 3 injuries. The direct cause of the accident was the reaction between ammonium bicarbonate and zinc oxide in the reaction tank, which produced ammonia gas. The operators illegally entered the reaction tank to work, causing poisoning and coma. The emergency response capabilities of rescue personnel were insufficient, resulting in the expansion of the accident.

chemical fertilizer

Guizhou Xingyi Yihua Chemical Industry "7.22" Pipeline Leakage and Major Explosion Accident

On July 22, 2010, an explosion occurred in the transformation section of Guizhou Yihua Chemical Co., Ltd., resulting in 8 deaths and 3 injuries. The direct cause of the accident was a leakage in the auxiliary pipeline of the 1 # transformation system, which generated static electricity due to gas erosion and ignited combustible gases (mainly carbon monoxide, hydrogen, etc.) on site, leading to a space explosion.

Shandong Deqilong Chemical Group Co., Ltd.'s "7.11" major explosion accident

On July 11, 2007, an explosion occurred at the first branch of Shandong Deqilong Chemical Group Co., Ltd. during the trial operation of the renovation and expansion project, resulting in 9 deaths and 1 injury. The direct cause of the accident was insufficient strength of the compressor outlet pipeline, poor welding quality, and failure to conduct pressure testing before use, resulting in the rapid expansion of small cracks caused by vibration in the area where residual stress was concentrated in the pressure pipeline. As a result, the entire pipeline in the accident section failed, leading to a physical explosion.

pesticides

Ningxia Ruitai Technology Co., Ltd.'s "7.1" methylamine storage tank major explosion accident

On July 1, 2014, an explosion occurred in the N - (6-chloro-3-pyridinomethyl) methylamine storage tank in the imidacloprid production workshop of Ningxia Ruitai Technology Co., Ltd., resulting in 4 deaths and 1 injury, with a direct economic loss of about 5 million yuan. The direct cause of the accident was that N - (6-chloro-3-pyridylmethyl) methylamine in the storage tank was kept in a thermal insulation state for a long time, and a condensation reaction occurred. The large amount of heat and gas generated could not be discharged in time, leading to overpressure explosion of the container.

other

A major explosion accident caused by the 7.28 propylene pipeline leakage in Nanjing, Jiangsu Province

On July 28, 2010, a propylene explosion accident occurred in Qixia District, Nanjing City, Jiangsu Province, resulting in 22 deaths and 120 injuries. The direct cause of the accident was that during the process of leveling and demolishing land on the original plastic factory site, an excavator dug through an underground propylene pipeline, causing liquid propylene in the pipeline to leak. After the leaked propylene evaporated and spread, it ignited when encountering an open flame.

Hebei Huailai Great Wall Biochemical Engineering Co., Ltd.'s "7.22" major poisoning and suffocation accident

On July 22, 2019, a poisoning and suffocation accident occurred in the comprehensive sedimentation tank of the sewage treatment plant of Changcheng Biochemical Engineering Co., Ltd. in Huailai County, Zhangjiakou City, Hebei Province, resulting in 5 deaths and 4 injuries, with a direct economic loss of 6.9 million yuan. The direct cause of the accident was that the workers violated safety technical regulations and carried out dredging operations in violation of regulations. Toxic gases such as hydrogen sulfide in the sludge were released and escaped under pumping and drainage operations and external agitation. Due to the closure restrictions of the color steel room, toxic gases continued to accumulate, causing injuries and fatalities due to excessive inhalation by the human body. The on-site personnel blindly attempted to rescue the situation without emergency rescue equipment and facilities, causing the accident to escalate.

The "7.19" major explosion accident at the Yima Gasification Plant in Sanmenxia, Henan Province

On July 19, 2019, an explosion occurred in the C-set air separation device of the Yima Gasification Plant of Henan Gas Group in Sanmenxia City, Henan Province, resulting in 15 deaths and 16 serious injuries. The direct cause of the accident was that the air separation device's cold box leaked and was not dealt with in a timely manner, resulting in a "sand explosion" (when the air separation cold box leaked, a large amount of low-temperature liquid would be stored in the insulation layer's pearlescent sand. When the low-temperature liquid rapidly evaporated, the shell of the cold box would be cracked, and a large amount of gas carrying pearlescent sand would spray out), which led to the collapse of the cold box, causing the nearby 500m3 liquid oxygen storage tank to rupture, and a large amount of liquid oxygen would quickly leak out. The surrounding combustibles would explode and burn under liquid oxygen or oxygen rich conditions, causing a large number of casualties among surrounding personnel.

Dalian PetroChina International Storage and Transportation Co., Ltd. "7.16" Special Major Oil Pipeline Explosion and Fire Accident

On July 16, 2010, an explosion occurred in the crude oil pipeline of Dalian PetroChina International Storage and Transportation Co., Ltd. located in the bonded zone of Dalian City, Liaoning Province, resulting in a large amount of crude oil leakage and causing a fire. Causing partial burning of crude oil, pipelines, and equipment, as well as some leaked crude oil flowing into nearby waters causing pollution. The accident resulted in one worker being lightly injured and one missing; During the firefighting process, one firefighter died and one was seriously injured, resulting in a direct property loss of 220 million yuan. The direct cause of the accident was that, after the unloading operation of the oil tanker was completed and the unloading was stopped, the service provider Shanghai Xiangcheng Company continued to add a large amount of hydrogen sulfide remover (mainly hydrogen peroxide) to the unloading pipeline, causing the hydrogen sulfide remover to accumulate locally in the oil pipeline section near the dosing port and undergo an exothermic reaction, causing an explosion in the oil pipeline, crude oil leakage, and triggering a fire.

Taiwan Kaohsiung Huayun Warehousing Company's "7.31" pipeline leakage particularly serious explosion accident

On July 31, 2014, a propylene leak occurred in the pipeline of Huayun Storage Company in Kaohsiung, Taiwan. At midnight on August 1, a propylene gas explosion occurred in a trench, resulting in 30 deaths and 302 injuries. The direct cause of the accident is that the pipeline has been corroded and thinned for years, and under pressure, the pipeline ruptures, causing propylene leakage and explosion when exposed to a fire source.