5 types of accidents, 3 types of risks, the metallurgical industry should pay attention to the prevention of →

Metallurgical products are important basic raw materials in the development of the national economy of the mainland

The metallurgical industry represents the level of industrialization development of the country

It is an important support for the realization of a manufacturing power

It has made important contributions to the economic and social development of the mainland

However, there are also certain risks and hidden dangers in the metallurgical industry

2023

A total of 83 production safety accidents and 94 deaths occurred in the metallurgical industry (excluding fire, special equipment, and construction engineering accidents)

There were 3 major accidents and 13 deaths

According to the analysis

Falls from heights, mechanical injuries, object strikes, poisoning and suffocation, burning, etc

It is the five types of frequent accidents in the metallurgical industry

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Accident cases

At about 7:55 on June 22, 2023, the No. 1 blast furnace of the ironmaking plant of Yingkou Iron and Steel Co., Ltd., Yingkou City, Liaoning Province, burned through the furnace cylinder during the production process, and the liquid iron slag exploded when it encountered cooling water, causing a scalding accident, resulting in 5 deaths, 4 injuries, and a direct economic loss of about 28.2527 million yuan. The accident investigation team determined that the "6.22" large scalding accident of the No. 1 blast furnace of Liaoning Yingkou Iron and Steel Co., Ltd. was a production safety liability accident caused by serious erosion and burn-through of the furnace cylinder caused by super-strength smelting.

After investigation, it was determined that the direct cause of the accident was that Yingkou Iron and Steel leaked iron in the main ditch of the west tap port of the blast furnace of the accident, and the leaked molten iron burned the thermocouple signal parameter cable used to monitor the temperature of the furnace cylinder in real time. After comprehensive analysis, it is found that the refractory erosion of the blast furnace cylinder in the accident is serious, and the furnace is not stopped for overhaul in time according to the actual furnace condition, and high-strength smelting is still used; the long-term management of the safety monitoring parameters of the blast furnace body is missing; the refractory material in the weak place is eroded, resulting in the burning of the high-temperature molten iron and the leakage of the cooling wall, and the cooling water and the molten iron contact are rapidly vaporized and detonated, which further erodes the grouting layer and the furnace shell, and induces the furnace cylinder to burn through; the high-temperature liquid slag iron sprayed from the furnace cylinder burns the cooling water pipe in the furnace base area, and the leaked cooling water is in contact with the covered liquid slag iron and explodes violently。

01 Security risk warning

In general, there are major safety risk factors such as high-temperature molten metal and gas that are easy to cause mass deaths and injuries in the metallurgical industry.

No.1 Significant Risks

1. In the process of molten metal lifting, the tank (bag) falls, overturns, and the molten metal leaks, and the emergency storage facilities for the steelmaking continuous casting process and die casting process are not in place, resulting in the leakage of molten metal in accidents, and there is a risk of burning and fire accidents.

2. Leakage and slag overflow during molten metal smelting and transportation, damage to the water-cooling equipment of the steelmaking furnace, leakage of cooling water into the furnace, and the risk of molten metal explosion accident when exposed to water.

3. During the production of the blast furnace, there are abnormal furnace conditions such as material collapse, and the pressure on the top of the furnace is overpressurized, and if the pressure is not relieved in time, there is a risk of burning, fire and explosion accidents.

4. If there is a gas leak in gas production, recovery and purification, pressurized mixing, storage and other equipment and facilities, there is a risk of gas poisoning accident.

No.2 Higher risk

1. A large amount of water vapor is generated when the molten iron and slag meet water or moisture, and the energy release leads to explosion and splashing;

2. Water or humidity in dry slag pools, molten iron tanks, iron ditches, slag ditches, etc., and damp tools that come into contact with high temperature molten iron and slag may lead to explosion.

3. The failure or water leakage of the blast furnace water cooling system may lead to the burning of the tuyere, the splashing of the high-temperature charge, and the damage of the water cooling wall can lead to the redness and burn-through of the furnace wall, and the flue gas of the high-temperature charge will penetrate out, causing fire, burning and other accidents.

4. The accumulation of pulverized coal in the pulverizing system, the outlet temperature of the coal mill exceeds the standard or the oxygen content exceeds the standard, and the failure of the dust removal system may lead to fire and explosion accidents in case of ignition sources.

5. Scrap steel is wet or mixed with explosives, closed containers, radioactive sources, etc., and accidents such as molten steel splashing and explosion may occur in the process of adding scrap steel, and explosion in the furnace, lining erosion and leakage, radioactive hazards, etc. may occur during the smelting process.

6. The slag in the converter furnace is not poured out, and the water accumulation of scrap steel in rainy days may lead to explosion and scalding accidents; if the blowing oxygen pressure is low, there may be tempering explosion and burning accidents, the blowing oxygen pressure is high, the oxygen rate is too large, the molten steel pool may boil and cause splashing, and even the furnace bottom burns through and leaks the steel; if the oxygen contains particle impurities, it may be rubbed at high speed in the pipeline, resulting in fire and explosion accidents; the water leakage of the vaporization flue or water cooling furnace mouth is serious, which may lead to explosion accidents.

7. If the smelting charge of the electric furnace is too high, the water cooling plate may break down and leak, resulting in explosion; the electric furnace using natural gas as a supplementary heat source may not follow the principle of ignition first and then gas supply, or the pipeline valve leakage may be improperly handled, which may lead to explosion; improper baking of new refractory materials of the electric furnace may cause steel leakage and cause fire. Burning accident: the water-cooled electrode holder is not regularly cleaned and the conductivity is poor, which may cause the arc with the graphite electrode after power-on, and the water-cooled copper block leaks into the molten steel and causes an explosion; the tap car is not set up with interlock conditions, and the steel is discharged to half of the steel position, which may cause the molten steel to leak to the furnace and cause a fire.

8. The ladle is prone to splashing or spilling in the process of lifting, argon blowing and wire feeding, LF furnace heating, vacuum treatment, temperature measurement and sampling, slag making agent and alloy addition, which may lead to burning accidents; equipment cooling water enters the ladle furnace or alloy material and slag agent are wet, which is prone to molten steel discharge; maintenance of argon blowing at the bottom of the ladle may cause suffocation accidents due to argon leakage and poor ventilation.

9. Ferroalloy powders such as ferrosilicon and calcium silicon produce flammable and explosive hydrogen when wet, and ferroalloys and carbon dust are mixed with air, which may lead to explosion accidents.

10. In the process of continuous casting and crystallization, the temperature of molten steel is too high, the oxidation is too strong, the quality of refractory materials is not good, the ladle and tundish are overused, and the leakage accident may occur; the mold defects, uneven cooling and stirring, uncoordinated vibration, and too fast pulling speed, etc., may cause the mold leakage accident; the use of coal gas or natural gas to bake the tundish and nozzle in the continuous casting area may cause poisoning, suffocation, fire and explosion accidents.

11. The safety control system of various heating furnaces and annealing furnaces in the rolling process fails, and the gas leakage may cause fire and explosion accidents when exposed to open flames; the leakage of flammable toxic gases may cause poisoning and fire accidents; the leakage of nitrogen gas may cause suffocation accidents; and the cleaning of iron oxide scale slag ditches, whirlpool pools and oil-water separation tanks and other facilities may cause drowning accidents.

No.3

New risks

1. Green and low-carbon transformation is the future development trend of the metallurgical industry, and the rapid development of low-carbon smelting technologies such as direct reduction and melt reduction non-blast furnace ironmaking and hydrogen metallurgy has promoted the green transformation of the metallurgical industry, but also brought new safety risks.

2. In recent years, there have been many specialized subcontracting of inspection and maintenance operations, resulting in an increase in regional multi-party collaborative operations and a complex operating environment.

3. Metallurgical enterprises accelerate the promotion of ultra-low emissions and environmental protection performance to create a work, intensive construction or transformation of environmental protection facilities, resulting in cross-synchronization of production and construction, and superposition of safety risks. At the same time, the emergence of a new management contracting model is prone to security vulnerabilities in contracting management.

02 Suggestions for next steps

(1) Improve the quality of safety production standardization. Give full play to the role of the enterprise safety production standardization management system in consolidating the foundation, and take it as a long-term and basic work measure for safety production. Actively promote metallurgical enterprises to improve the quality of safety production standardization construction, strictly control the quality of review, implement the "one-vote veto" of major hidden dangers, and implement the incentive policy for enterprises that meet the standards.

(2) Strengthen the research and judgment of safety risks of new process equipment. Supervise and urge enterprises to organize professional and technical teams such as equipment, instruments, and safety, accurately identify the safety risks of new processes and new equipment, and discuss and formulate targeted safety control measures and emergency response measures. Organize technical experts from scientific research institutes and metallurgical enterprises to accelerate the research and formulation of safety technical guidelines or standards to guide the safe development of new process equipment.

(3) Strengthen the dynamic clearance of hidden dangers of major accidents. Urge enterprises to establish a normalized mechanism for self-inspection and self-improvement of major accident hazards, and carry out comprehensive investigation and rectification in strict accordance with the "Judgment Standards for Major Accident Hazards in Industry and Trade Enterprises". We will continue to strengthen the special rectification of potential accidents such as molten metal and coal gas, which are prone to mass deaths and injuries, and achieve dynamic clearance of major accident hazards.

(4) Plugging loopholes in the safety management of contracted operations. Systematically study the deep-seated problems exposed by contracted operation accidents, promote the implementation of safety production management responsibilities of all parties with strong supervision and strict law enforcement, and build a safety community. Urge enterprises to strengthen safety inspections of contracted operations.

(5) Improve the level of digital intelligence of enterprises. Promote the construction and application of safety production risk monitoring and early warning systems, and realize real-time monitoring and alarm of key safety data of enterprises and dynamic early warning of safety risks. Combined with the application of artificial intelligence, big data, Internet of Things and other technologies, promote the informatization of safety management, and improve the efficiency and quality of safety management. Promote robot inspection in the gas area, reduce human-machine contact, and improve the intrinsic safety level of the industry.